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Tennyson, Rachel B., Nathalie Ebran, Anissa E. Herrera i Janet E. Lindsley. "A Novel Selection System for Chromosome Translocations in Saccharomyces cerevisiae". Genetics 160, nr 4 (1.04.2002): 1363–73. http://dx.doi.org/10.1093/genetics/160.4.1363.
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Abstract Chromosomal translocations are common genetic abnormalities found in both leukemias and solid tumors. While much has been learned about the effects of specific translocations on cell proliferation, much less is known about what causes these chromosome rearrangements. This article describes the development and use of a system that genetically selects for rare translocation events using the yeast Saccharomyces cerevisiae. A translocation YAC was created that contains the breakpoint cluster region from the human MLL gene, a gene frequently involved in translocations in leukemia patients, flanked by positive and negative selection markers. A translocation between the YAC and a yeast chromosome, whose breakpoint falls within the MLL DNA, physically separates the markers and forms the basis for the selection. When RAD52 is deleted, essentially all of the selected and screened cells contain simple translocations. The detectable translocation rates are the same in haploids and diploids, although the mechanisms involved and true translocation rates may be distinct. A unique double-strand break induced within the MLL sequences increases the number of detectable translocation events 100- to 1000-fold. This novel system provides a tractable assay for answering basic mechanistic questions about the development of chromosomal translocations.
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Welker, D. L., i K. L. Williams. "TRANSLOCATIONS IN DICTYOSTELIUM DISCOIDEUM". Genetics 109, nr 2 (1.02.1985): 341–64. http://dx.doi.org/10.1093/genetics/109.2.341.
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ABSTRACT Fourteen translocations of independent origin were identified in Dictyostelium discoideum on the basis of segregation anomalies of diploids heterozygous for these chromosome rearrangements, all of which led to the cosegregation of unlinked markers. Many of these translocations were discovered in strains mutagenized with MNNG or in strains carrying mutations affecting DNA repair; however, spontaneous translocations were also obtained. Haploid mitotic recombinants of the rearranged linkage groups were produced from diploids heterozygous for the translocations at frequencies of up to 5% of viable haploid segregants; this is at least a ten-fold higher frequency than that seen with diploids not heterozygous for translocations (∼0.1%). These haploid recombinants included both translocated and nontranslocated strains. The T354(II,VII) translocation and possibly the T357(IV,VII) translocation reduce the chromosome number to n = 6; haploids carrying 11 other translocations all have karyotypes with n = 7. Genetic characterization of the T357(IV,VII) translocation showed that the bwnA and whiC loci normally found on linkage group IV were physically linked to the linkage group VII loci couA, phgA, bsgB and cobA.
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McKim, K. S., A. M. Howell i A. M. Rose. "The effects of translocations on recombination frequency in Caenorhabditis elegans." Genetics 120, nr 4 (1.12.1988): 987–1001. http://dx.doi.org/10.1093/genetics/120.4.987.
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Abstract In the nematode Caenorhabditis elegans, recombination suppression in translocation heterozygotes is severe and extensive. We have examined the meiotic properties of two translocations involving chromosome I, szT1(I;X) and hT1(I;V). No recombination was observed in either of these translocation heterozygotes along the left (let-362-unc-13) 17 map units of chromosome I. Using half-translocations as free duplications, we mapped the breakpoints of szT1 and hT1. The boundaries of crossover suppression coincided with the physical breakpoints. We propose that DNA sequences at the right end of chromosome I facilitate pairing and recombination. We use the data from translocations of other chromosomes to map the location of pairing sites on four other chromosomes. hT1 and szT1 differed markedly in their effect on recombination adjacent to the crossover suppressed region. hT1 had no effect on recombination in the adjacent interval. In contrast, the 0.8 map unit interval immediately adjacent to the szT1(I;X) breakpoint on chromosome I increased to 2.5 map units in translocation heterozygotes. This increase occurs in a chromosomal interval which can be expanded by treatment with radiation. These results are consistent with the suggestion that the szT1(I) breakpoint is in a region of DNA in which meiotic recombination is suppressed relative to the genomic average. We propose that DNA sequences disrupted by the szT1 translocation are responsible for determining the frequency of meiotic recombination in the vicinity of the breakpoint.
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Tulay, P., M. Gultomruk, N. Findikli i M. Bahceci. "Poor embryo development and preimplantation genetic diagnosis outcomes of translocations involving chromosome 10: Do we blame genetics?" Zygote 23, nr 5 (29.09.2014): 778–84. http://dx.doi.org/10.1017/s0967199414000422.
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SummaryBalanced reciprocal translocation carriers are usually phenotypically normal. Although the reproductive risk of these carriers varies, they generally have a lower chance to produce normal or balanced gametes. Preimplantation genetic diagnosis (PGD) is offered to these patients to increase their chances of becoming pregnant by selecting a balanced embryo for transfer. This study aimed to analyse the development and the PGD outcome of the embryos obtained from reciprocal translocation carriers focusing on ones with chromosome 10 rearrangements. In total, 27 reciprocal translocation carriers underwent 31 cycles of PGD. PGD was performed using multicolour fluorescence in situ hybridisation for 298 embryos and of these 136 were obtained from couples carrying translocations involving chromosome 10 rearrangements. Carriers of translocations involving chromosome 10 rearrangements have a lower chance of producing normal or balanced embryos compared with the carriers with other rearrangements. The development of embryos obtained from the patients with chromosome 10 rearrangements was impaired and only a limited number of embryos developed to the blastocyst stage.
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Leblon, G., D. Zickler i S. Lebilcot. "MOST UV-INDUCED RECIPROCAL TRANSLOCATIONS IN SORDARIA MACROSPORA OCCUR IN OR NEAR CENTROMERE REGIONS". Genetics 112, nr 2 (1.02.1986): 183–204. http://dx.doi.org/10.1093/genetics/112.2.183.
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ABSTRACT In fungi, translocations can be identified and classified by the patterns of ascospore abortion in asci from crosses of rearrangement x normal sequence. Previous studies of UV-induced rearrangements in Sordaria macrospora revealed that a major class (called type III) appeared to be reciprocal translocations that were anomalous in producing an unexpected class of asci with four aborted ascospores in bbbbaaaa linear sequence (b = black; a = abortive). The present study shows that the anomalous type III rearrangements are, in fact, reciprocal translocations having both breakpoints within or adjacent to centromeres and that bbbbaaaa asci result from 3:1 disjunction from the translocation quadrivalent.—Electron microscopic observations of synaptonemal complexes enable centromeres to be visualized. Lengths of synaptonemal complexes lateral elements in translocation quadrivalents accurately reflect chromosome arm lengths, enabling breakpoints to be located reliably in centromere regions. All genetic data are consistent with the behavior expected of translocations with breakpoints at centromeres.—Two-thirds of the UV-induced reciprocal translocations are of this type. Certain centromere regions are involved preferentially. Among 73 type-III translocations, there were but 13 of the 21 possible chromosome combinations and 20 of the 42 possible combinations of chromosome arms.
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Vasilevska, M., E. Ivanovska, K. Kubelka Sabit, E. Sukarova-Angelovska i G. Dimeska. "THE INCIDENCE AND TYPE OF CHROMOSOMAL TRANSLOCATIONS FROM PRENATAL DIAGNOSIS OF 3800 PATIENTS IN THE REPUBLIC OF MACEDONIA". Balkan Journal of Medical Genetics 16, nr 2 (1.12.2013): 23–28. http://dx.doi.org/10.2478/bjmg-2013-0027.
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ABSTRACT Robertsonian and reciprocal chromosomal translocations are the most frequent type of structural chromosomal aberrations in the human population. We report the frequency and type of detected translocations in 10 years of prenatal diagnosis of 3800 prenatal samples. The materials came from amniocentesis and chorionic villus samples (CVS). We detected seven Robertsonian translocations (0.18%), eight autosomal reciprocal translocations (0.21%) and one sex chromosome translocation (0.03%). The overall frequency of all translocations was 0.42%. Balanced state translocations were 0.29% and the frequency of translocations in an unbalanced state was 0.13%. There was one balanced de novo X-autosome translocation [46,X,t(X;10)(p11.23;q22.3)] and one balanced double translocation [46,XX,t(1;21);t(7;16)(1p21; 21q11) (7q31;16q23)] inherited from the mother. Most of the detected translocations were the result of unknown familial translocations, but some of them had been previously detected in one of the parents. In order to detect the recurrence risk for future pregnancies, we proposed genetic counseling in each of the cases and we established whether the parents were heterozygous for the same translocation. Histopatological findings for some unbalanced translocations correlated with phenotypes of detected unbalanced karyotypes
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Yu, Xin, i Abram Gabriel. "Reciprocal Translocations in Saccharomyces cerevisiae Formed by Nonhomologous End Joining". Genetics 166, nr 2 (1.02.2004): 741–51. http://dx.doi.org/10.1093/genetics/166.2.741.
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Abstract Reciprocal translocations are common in cancer cells, but their creation is poorly understood. We have developed an assay system in Saccharomyces cerevisiae to study reciprocal translocation formation in the absence of homology. We induce two specific double-strand breaks (DSBs) simultaneously on separate chromosomes with HO endonuclease and analyze the subsequent chromosomal rearrangements among surviving cells. Under these conditions, reciprocal translocations via nonhomologous end joining (NHEJ) occur at frequencies of ∼2-7 × 10-5/cell exposed to the DSBs. Yku80p is a component of the cell’s NHEJ machinery. In its absence, reciprocal translocations still occur, but the junctions are associated with deletions and extended overlapping sequences. After induction of a single DSB, translocations and inversions are recovered in wild-type and rad52 strains. In these rearrangements, a nonrandom assortment of sites have fused to the DSB, and their junctions show typical signs of NHEJ. The sites tend to be between open reading frames or within Ty1 LTRs. In some cases the translocation partner is formed by a break at a cryptic HO recognition site. Our results demonstrate that NHEJ-mediated reciprocal translocations can form in S. cerevisiae as a consequence of DSB repair.
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McKee, Bruce. "X-4 Translocations and Meiotic Drive in Drosophila melanogaster Males: Role of Sex Chromosome Pairing". Genetics 116, nr 3 (1.07.1987): 409–13. http://dx.doi.org/10.1093/genetics/116.3.409.
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ABSTRACT Males carrying certain X-4 translocations exhibit strongly skewed sperm recovery ratios. The XP4D half of the translocation disjoins regularly from the Y chromosome and the 4PXD half disjoins regularly from the normal 4. Yet the smaller member of each bivalent is recovered in excess of its pairing partner, apparently due to differential gametic lethality. Chromosome recovery probabilities are multiplicative; the viability of each genotype is the product of the recovery probability of its component chromosomes. Meiotic drive can also be caused by deficiency for X heterochromatin. In(1)sc4Lsc8R males show the same size dependent chromosome recoveries and multiplicative recovery probabilities found in T(1;4)BS males. Meiotic drive in In(1)sc4Lsc8R males has been shown to be due to X-Y pairing failure. Although pairing is regular in the T(X;4) males, the striking phenotypic parallels suggest a common explanation. The experiments described below show that the two phenomena are, in fact, one and the same. X-4 translocations are shown to have the same effect on recovery of independently assorting chromosomes as does In(1)sc4Lsc8R. Addition of pairing sites to the 4PXD half of the translocation eliminates drive. A common explanation—failure of the distal euchromatic portion of the X chromosome to participate in X:Y meiotic pairing—is suggested as the cause for drive. The effect of X chromosome breakpoint on X-4 translocation induced meiotic drive is investigated. It is found that translocations with breakpoints distal to 13C on the salivary map do not cause drive while translocations broken proximal to 13C cause drive. The level of drive is related to the position of the breakpoint—the more proximal the breakpoint the greater the drive.
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Liu, Hongfang, Bin Mao, Xiaojuan Xu, Lin Liu, Xiaoling Ma i Xuehong Zhang. "The Effectiveness of Next-Generation Sequencing-Based Preimplantation Genetic Testing for Balanced Translocation Couples". Cytogenetic and Genome Research 160, nr 11-12 (2020): 625–33. http://dx.doi.org/10.1159/000512847.
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The purpose of this study was to evaluate the effectiveness of next-generation sequencing (NGS)-based preimplantation genetic testing (PGT) for balanced translocation carriers to identify normal/balanced blastocysts and to measure pregnancy outcomes following euploid embryo transfer. We enrolled 75 couples with a balanced translocation who underwent 83 PGT cycles (58 cycles for carriers with reciprocal translocations and 25 cycles for carriers with Robertsonian translocations) and 388 blastocysts were diagnosed. Moreover, we transferred single euploid blastocysts through frozen embryo transfer and calculated the biochemical pregnancy, clinical pregnancy, miscarriage, and ongoing pregnancy rates per embryo transfer cycle. Despite a mean maternal age of 29.8 years and mean of 4.34 embryos biopsied, there was a 32.8% chance of recording no chromosomally normal/balanced embryos for reciprocal translocation carriers. The proportion of normal/balanced embryos was significantly higher (44.1 vs. 27.8%) in Robertsonian translocation carriers than in reciprocal translocation carriers. Female carriers had a significantly lower (23.3 vs. 42.4%, 34.7 vs. 54.7%, respectively) percentage of normal/balanced embryos than male carriers, regardless of the translocation. After transfering single blastocysts, we obtained a 64.4% clinical pregnancy rate per transfer, and the clinical miscarriage rate was 5.7%. Amniocentesis results showed that all karyotypes of the fetuses were consistent with PGT results. The clinical outcomes are probably not influenced by the type of translocation, maternal age, and blastocyst morphology following the transfer of euploid blastocysts. Therefore, we conclude that NGS-based PGT is an efficient method for analyzing balanced translocation carriers, and aneuploidy screening had good clinical outcomes.
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Schmid, Michael, Claus Steinlein i Heinz Winking. "Multicolor Spectral Analyses of Mitotic and Meiotic Mouse Chromosomes Involved in Multiple Robertsonian Translocations. I. The CD/Cremona Hybrid Strain". Cytogenetic and Genome Research 147, nr 4 (2015): 253–59. http://dx.doi.org/10.1159/000444597.
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Multicolor spectral analysis (spectral karyotyping) was applied to mitotic and male diakinetic chromosomes of hybrid mice carrying a unique system of 18 autosomal Robertsonian translocation chromosomes with alternating arm homologies. Only the autosomes 19 and the XY sex chromosomes are excluded from these Robertsonian translocations. The translocations, previously identified by conventional banding analyses, could be verified by spectral karyotyping. Besides the Robertsonian translocations, no other interchromosomal rearrangements were detected. In diakineses of male meiosis, the 18 metacentric Robertsonian translocation chromosomes form a very large meiotic ‘superring'. The predictable, specific order of the chromosomes along this ‘superring' was completely confirmed by multicolor spectral analysis. In the majority of diakineses analyzed, the free autosomal bivalent 19 and the XY sex bivalent form a conspicuous complex which tightly associates with the 12;14 Robertsonian translocation chromosome in the ‘superring'.
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Chand, Mahesh Kumar, Vanessa Carle, K. G. Anuvind i Kayarat Saikrishnan. "DNA-mediated coupling of ATPase, translocase and nuclease activities of a Type ISP restriction-modification enzyme". Nucleic Acids Research 48, nr 5 (24.01.2020): 2594–603. http://dx.doi.org/10.1093/nar/gkaa023.
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Abstract Enzymes involved in nucleic acid transactions often have a helicase-like ATPase coordinating and driving their functional activities, but our understanding of the mechanistic details of their coordination is limited. For example, DNA cleavage by the antiphage defense system Type ISP restriction-modification enzyme requires convergence of two such enzymes that are actively translocating on DNA powered by Superfamily 2 ATPases. The ATPase is activated when the enzyme recognizes a DNA target sequence. Here, we show that the activation is a two-stage process of partial ATPase stimulation upon recognition of the target sequence by the methyltransferase and the target recognition domains, and complete stimulation that additionally requires the DNA to interact with the ATPase domain. Mutagenesis revealed that a β-hairpin loop and motif V of the ATPase couples DNA translocation to ATP hydrolysis. Deletion of the loop inhibited translocation, while mutation of motif V slowed the rate of translocation. Both the mutations inhibited the double-strand (ds) DNA cleavage activity of the enzyme. However, a translocating motif V mutant cleaved dsDNA on encountering a translocating wild-type enzyme. Based on these results, we conclude that the ATPase-driven translocation not only brings two nucleases spatially close to catalyze dsDNA break, but that the rate of translocation influences dsDNA cleavage.
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Kindiger, B., i S. Hamann. "B–A chromosome mediated 3:1 disjunction in heterozygous reciprocal translocations of maize". Genome 35, nr 5 (1.10.1992): 714–18. http://dx.doi.org/10.1139/g92-110.
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In maize (Zea mays L.), meiotic segregation products of reciprocal translocations are well defined. The predictible meiotic behaviors and products generated by these interchanges allow them to be used as tools to gain basic information in cytogenetics, genetics, and plant breeding. In combining a classic reciprocal translocation with a single B–A chromosome from a tertiary trisomic B–A translocation stock, unique individuals with unusual chromosome karyotypes are generated. In cases where a B–A chromosome was present, the frequency of 3:1 disjunction within the ring of four was increased. In the case of T6–9(5454) + B–6Ld, cytological identification, via root-tip mitosis, was able to identify the specific tertiary trisomic products generated. These karyotypes are predictable and highly repeatable. Such karyotypes may have specific uses in chromosome mapping, chromosome dosage studies, or genetic or molecular investigations.Key words: reciprocal translocations, tertiary trisomes, interchange trisomes, B–A translocations, maize.
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Shilenkova, Yulia V., Anna A. Pendina, Irina D. Mekina, Olga A. Efimova, Evgeniia M. Komarova, Elena A. Lesik, Mariia A. Ishchuk i in. "Age and Serum AMH and FSH Levels as Predictors of the Number of Oocytes Retrieved from Chromosomal Translocation Carriers after Controlled Ovarian Hyperstimulation: Applicability and Limitations". Genes 12, nr 1 (25.12.2020): 18. http://dx.doi.org/10.3390/genes12010018.
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We studied the impact of age and the serum anti-Müllerian hormone (AMH)/follicle-stimulating hormone (FSH) levels on the number of cumulus–oocyte complexes (COCs) retrieved from female reciprocal and Robertsonian translocation carriers after controlled ovarian hyperstimulation (COH). The number of COCs retrieved after COH was retrospectively analyzed in female translocation carriers and 46,XX partners of male translocation carriers from 100 couples. The median number of COCs varied from nine to 16 and did not differ among subgroups of women categorized by age, presence and type of a translocation. The number of COCs correlated negatively with the woman’s age in both the reciprocal and the Robertsonian translocation carriers, while in 46,XX women no correlation was detected. The number of COCs did not differ between the reciprocal and the Robertsonian translocation carriers aged either <35 or ≥35 years. In translocation carriers, the number of COCs correlated with the serum AMH level only in the younger-age subgroups; the correlation was strong positive in reciprocal and moderate positive in Robertsonian translocation carriers. The 46,XX women aged both <35 and ≥35 years showed similar moderate positive correlations. Across all subgroups, the number of COCs correlated moderately negatively with the serum FSH level only in Robertsonian translocation carriers aged <35 years. Our results suggest that chromosomal translocations per se do not increase the risk of poor oocyte retrieval outcome after COH. In translocation carriers, oocyte retrieval outcome depends to a large extent on their age. The serum AMH level strongly predicts oocyte retrieval outcomes only in young reciprocal translocation carriers, while the serum FSH level has a moderate predictive value in young Robertsonian translocation carriers.
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Menges, Eric S. "Restoration demography and genetics of plants: when is a translocation successful?" Australian Journal of Botany 56, nr 3 (2008): 187. http://dx.doi.org/10.1071/bt07173.
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Restorations are complex, often involving restoring ecological processes, vegetation structure, and species’ populations. One component of restorations is translocation of key species. Translocations (introductions, reintroductions, augmentations) are often necessary to recover species diversity and install key species. In this review, I consider the ways translocations have been evaluated at various stages during the process of restoration. Vital rates (survival, growth, fecundity) of propagules (seeds, transplants) are commonly used to evaluate initial success. Transplants usually provide greater initial success than do sown seeds. Beyond initial rates, completion of the life cycle through flowering, fruiting, dispersal and subsequent seedling recruitment is a key benchmark. Modelling population viability of translocated populations is a logical next step and can bring in many powerful inferential tools. Of factors affecting the success of translocations, genetic issues are paramount, as restorationists need to consider inbreeding depression, reproductive viability, local adaptation, and evolutionary potential of translocated populations. The success of translocations is also clearly context-dependent, with herbivory, disturbance, competition and other ecological factors important. Future translocations need to make better use of comparisons with reference populations, a long-term perspective on success and an experimental framework that can provide both practical and basic knowledge. Demographic data collection and analysis in restorations has great potential to elucidate causes of translocation failure and improve the prognosis of future restorations.
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Pazarbasi, A., O. Demirhan, D. Alptekin, Ft Ozgunen, L. Ozpak, Mb Yilmaz, E. Nazlican, N. Tanriverdi, U. Luleyap i D. Gümürdülü. "INHERITANCE OF A CHROMOSOME 3 AND 21 TRANSLOCATION IN THE FETUSES, WITH ONE ALSO HAVING TRISOMY 21, IN THREE PREGNANCIES IN ONE FAMILY". Balkan Journal of Medical Genetics 16, nr 2 (1.12.2013): 91–96. http://dx.doi.org/10.2478/bjmg-2013-0039.
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ABSTRACT The majority of chromosome rearrangements are balanced reciprocal and Robertsonian translocations. It is now known that such abnormalities cause no phenotypic effect on the carrier but lead to increased risk of producing unbalanced gametes. Here, we report the inheritance of a translocation between chromosomes 3 and 21 in a family with one of two fetuses with Down Syndrome carrying the same translocation and the other also carrying the same translocation without the additional chromosome 21. Chromosomal analysis from fetal amniotic fluid and peripheral blood lymphocytes from the family were performed at the Çukurova University Hospital at Adana, Turkey. We assessed a family in which the translocation between chromosomes 3 and 21 segregates: one of the three progenies carried the 47,XX,+21,t(3;21)(q21;q22) karyotype and presented with Down Syndrome; another of the three progenies carried the 46,XX,t(3;21) (q21;q22) karyotype and the third had the 46,XY karyotype. Their mother is phenotypically normal. Apparently this rearrangement occurred due to an unbalanced chromosome segregation of the mother [t(3;21)(q21;q22)mat]. This family will enable us to explain the behavior of segregation patterns and the mechanism for each type of translocation from carrier to carrier and their effects on reproduction and numerical aberrations. These findings can be used in clinical genetics and may be used as an effective tool for reproductive guidance and genetic counseling
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Cook, Lola, James K. Hartsfield i Gail H. Vance. "Partners with reciprocal translocations: genetic counseling for the ‘double translocation’". Clinical Genetics 53, nr 5 (23.04.2008): 403–7. http://dx.doi.org/10.1111/j.1399-0004.1998.tb02754.x.
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Leach, R. C., I. S. Dundas i A. Houben. "Construction of comparative genetic maps of two 4Bs.4Bl-5Rl translocations in bread wheat (Triticum aestivum L.)". Genome 49, nr 7 (1.07.2006): 729–34. http://dx.doi.org/10.1139/g06-040.
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The physical length of the rye segment of a 4BS.4BL–5RL translocation derived from the Cornell Wheat Selection 82a1-2-4-7 in a Triticum aestivum 'Chinese Spring' background was measured using genomic in situ hybridization (GISH) and found to be 16% of the long arm. The size of this translocation was similar to previously published GISH measurements of another 4BS.4BL–5RL translocation in a Triticum aestivum 'Viking' wheat background. Molecular maps of both 4BS.4BL–5RL translocations for 2 different wheat backgrounds were developed using RFLP analysis. The locations of the translocation breakpoints of the 2 4BS.4BL–5RL translocations were similar even though they arose in different populations. This suggests a unique property of the region at or near the translocation breakpoint that could be associated with their similarity and spontaneous formation. These segments of rye chromosome 5 also contain a gene for copper efficiency that improves the wheat's ability to cope with low-copper soils. Genetic markers in these maps can also be used to screen for copper efficiency in bread wheat lines derived from the Cornell Wheat Selection 82a1 2-4-7.Key words: Triticum aestivum, wheat–rye translocation, homoeologous group 4, homoeologous group 5, GISH, comparative map, copper efficiency, hairy peduncle.
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Uysal, A., A. Uludağ, F. Sılan, N. Erçelen, C. Zafer i Ö. Özdemir. "Double Translocation: An Interesting Family History". Balkan Journal of Medical Genetics 16, nr 1 (1.06.2013): 77–80. http://dx.doi.org/10.2478/bjmg-2013-0022.
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Abstract Double balanced translocations are particularly rare and the risk of a fetus with an unbalanced chromosomal anomaly is greater than for single translocation carriers. In this present case, we describe an interesting family history which included three generations. A couple, married for 4 years, was referred to the genetic clinic due to infertility and family chromosome anomalies. A GTG-band chromosome analysis indicated that the male partner’s karyotype was 45,XY, t(3;18)(q11;ptel)t(13;14)(q10;q10). The same double balanced translocation was found in two others family members.
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P. Armstong, Doug, i Ian G. McLean. "New Zealand translocations: theory and practice". Pacific Conservation Biology 2, nr 1 (1995): 39. http://dx.doi.org/10.1071/pc950039.
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One of the most common tools in New Zealand conservation is to translocate species to new locations. There have now been over 400 translocations done for conservation reasons, mainly involving terrestrial birds. Most translocations have been done strictly as management exercises, with little or no reference to theory. Nevertheless, translocations always involve some underlying theory, given that people must inevitably choose among a range of potential translocation strategies. We review theory relevant to translocations in the following areas: habitat requirements, susceptibility to predation, behavioural adaptation, population dynamics, genetics, metapopulation dynamics, and community ecology. For each area we review and evaluate the models that seem to underpin translocation strategies used in New Zealand. We report experiments testing some of these models, but note that theory underlying translocation strategies is largely untested despite a long history of translocations. We conclude by suggesting key areas for research, both theoretical and empirical. We particularly recommend that translocations be designed as experimental tests of hypotheses whenever possible.
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McClellan, Amie J., i Jeffrey L. Brodsky. "Mutation of the ATP-Binding Pocket of SSA1 Indicates That a Functional Interaction Between Ssa1p and Ydj1p Is Required for Post-translational Translocation Into the Yeast Endoplasmic Reticulum". Genetics 156, nr 2 (1.10.2000): 501–12. http://dx.doi.org/10.1093/genetics/156.2.501.
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Abstract The translocation of proteins across the yeast ER membrane requires ATP hydrolysis and the action of DnaK (hsp70) and DnaJ homologues. In Saccharomyces cerevisiae the cytosolic hsp70s that promote post-translational translocation are the products of the Ssa gene family. Ssa1p maintains secretory precursors in a translocation-competent state and interacts with Ydj1p, a DnaJ homologue. Although it has been proposed that Ydj1p stimulates the ATPase activity of Ssa1p to release preproteins and engineer translocation, support for this model is incomplete. To this end, mutations in the ATP-binding pocket of SSA1 were constructed and examined both in vivo and in vitro. Expression of the mutant Ssa1p's slows wild-type cell growth, is insufficient to support life in the absence of functional Ssa1p, and results in a dominant effect on post-translational translocation. The ATPase activity of the purified mutant proteins was not enhanced by Ydj1p and the mutant proteins could not bind an unfolded polypeptide substrate. Our data suggest that a productive interaction between Ssa1p and Ydj1p is required to promote protein translocation.
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Badaeva, Ekatherina D., Jiming Jiang i Bikram S. Gill. "Detection of intergenomic translocations with centromeric and noncentromeric breakpoints in Triticum araraticum: mechanism of origin and adaptive significance". Genome 38, nr 5 (1.10.1995): 976–81. http://dx.doi.org/10.1139/g95-128.
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Triticum araraticum Jakubz. (2n = 4x = 28, AtAtGG), a wild progenitor of the polyploid cultivated wheat T. timopheevii, shows extensive chromosome translocation polymorphism in natural populations from the Middle East and Transcaucasia. From an extensive survey, eight intergenomic translocation types were observed and their breakpoints analyzed by genomic in situ hybridization. The previously reported species-specific 6At–1G–4G cyclic translocation was found in all accessions studied. In four translocation types, the breakpoints were in interstitial regions of chromosomes and the other four arose via centric–breakage–fusion. A model is presented on the mechanism of origin and the adaptive significance of translocations with centromeric and noncentromeric breakpoints.Key words: intraspecific diversity, intergenomic translocations, Triticum araraticum.
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Livingstone, Kevin D., Vincent K. Lackney, James R. Blauth, Rik van Wijk i Molly Kyle Jahn. "Genome Mapping in Capsicum and the Evolution of Genome Structure in the Solanaceae". Genetics 152, nr 3 (1.07.1999): 1183–202. http://dx.doi.org/10.1093/genetics/152.3.1183.
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Abstract We have created a genetic map of Capsicum (pepper) from an interspecific F2 population consisting of 11 large (76.2–192.3 cM) and 2 small (19.1 and 12.5 cM) linkage groups that cover a total of 1245.7 cM. Many of the markers are tomato probes that were chosen to cover the tomato genome, allowing comparison of this pepper map to the genetic map of tomato. Hybridization of all tomato-derived probes included in this study to positions throughout the pepper map suggests that no major losses have occurred during the divergence of these genomes. Comparison of the pepper and tomato genetic maps showed that 18 homeologous linkage blocks cover 98.1% of the tomato genome and 95.0% of the pepper genome. Through these maps and the potato map, we determined the number and types of rearrangements that differentiate these species and reconstructed a hypothetical progenitor genome. We conclude there have been 30 breaks as part of 5 translocations, 10 paracentric inversions, 2 pericentric inversions, and 4 disassociations or associations of genomic regions that differentiate tomato, potato, and pepper, as well as an additional reciprocal translocation, nonreciprocal translocation, and a duplication or deletion that differentiate the two pepper mapping parents.
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Ghosh, Sharmila, Candice F. Carden, Rytis Juras, Mayra N. Mendoza, Matthew J. Jevit, Caitlin Castaneda, Olivia Phelps i in. "Two Novel Cases of Autosomal Translocations in the Horse: Warmblood Family Segregating t(4;30) and a Cloned Arabian with a de novo t(12;25)". Cytogenetic and Genome Research 160, nr 11-12 (2020): 688–97. http://dx.doi.org/10.1159/000512206.
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We report 2 novel autosomal translocations in the horse. In Case 1, a breeding stallion with a balanced t(4p;30) had produced normal foals and those with congenital abnormalities. Of his 9 phenotypically normal offspring, 4 had normal karyotypes, 4 had balanced t(4p;30), and 1 carried an unbalanced translocation with tertiary trisomy of 4p. We argue that unbalanced forms of t(4p;30) are more tolerated and result in viable congenital abnormalities, without causing embryonic death like all other known equine autosomal translocations. In Case 2, two stallions produced by somatic cell nuclear transfer from the same donor were karyotyped because of fertility issues. A balanced translocation t(12q;25) was found in one, but not in the other clone. The findings underscore the importance of routine cytogenetic screening of breeding animals and animals produced by assisted reproductive technologies. These cases will contribute to molecular studies of translocation breakpoints and their genetic consequences in the horse.
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Weber, D., i T. Helentjaris. "Mapping RFLP loci in maize using B-A translocations." Genetics 121, nr 3 (1.03.1989): 583–90. http://dx.doi.org/10.1093/genetics/121.3.583.
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Abstract Plants hypoploid for specific segments of each of the maize (Zea mays L.) chromosomes were generated using 24 different B-A translocations. Plants carrying each of the B-A translocations were crossed as male parents to inbreds, and sibling progeny hypoploid or not hypoploid for specific chromosomal segments were recovered. Genomic DNAs from the parents, hypoploid progeny, and nonhypoploid (euploid or hyperploid) progeny for each of these B-A translocations were digested with restriction enzymes, electrophoresed in agarose gels, blotted onto reusable nylon membranes, and probed with nick-translated, cloned DNA fragments which had been mapped previously by restriction fragment length polymorphism (RFLP) analysis to the chromosome involved in the B-A translocation. The chromosomal segment on our RFLP map which was uncovered by each of the B-A translocations was determined. This work unequivocally identified the short and long arms of each chromosome on this map, and it also identified the region on each chromosome which contains the centromere. Because the breakpoints of the B-a translocations were previously known on the cytological and the conventional genetic maps, this study also allowed this RFLP map to be more highly correlated with these maps.
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Bernd, Karen K., i Bruce D. Kohorn. "Tip Loci: Six Chlamydomonas Nuclear Suppressors That Permit the Translocation of Proteins with Mutant Thylakoid Signal Sequences". Genetics 149, nr 3 (1.07.1998): 1293–301. http://dx.doi.org/10.1093/genetics/149.3.1293.
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Abstract Mutations within the signal sequence of cytochrome f (cytf) in Chlamydomonas inhibit thylakoid membrane protein translocation and render cells nonphotosynthetic. Twenty-seven suppressors of the mutant signal sequences were selected for their ability to restore photoautotrophic growth and these describe six nuclear loci named tip1 through 6 for thylakoid insertion protein. The tip mutations restore the translocation of cytf and are not allele specific, as they suppress a number of different cytf signal sequence mutations. Tip5 and 2 may act early in cytf translocation, while Tip1, 3, 4, and 6 are engaged later. The tip mutations have no phenotype in the absence of a signal sequence mutation and there is genetic interaction between tip4, and tip5 suggesting an interaction of their encoded proteins. As there is overlap in the energetic, biochemical and genetic requirements for the translocation of nuclear and chloroplast-encoded thylakoid proteins, the tip mutations likely identify components of a general thylakoid protein translocation apparatus.
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Ashraf, M., i M. J. Bassett. "Cytogenetic analysis of translocation heterozygosity in the common bean (Phaseolus vulgaris L.)". Canadian Journal of Genetics and Cytology 28, nr 4 (1.08.1986): 574–80. http://dx.doi.org/10.1139/g86-084.
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Twelve semisterile lines of Phaseolus vulgaris L. (2n = 22) were reported previously by this laboratory. Here we verify through cytological investigations that 5 of the 12 stocks are indeed chromosome translocations. Cytological analysis of a half diallel set of crosses indicates that these five stocks involve eight different chromosomes in reciprocal translocations. Pollen and ovule abortion rates increase with the increasing number of interchanges in a stock. Cytological behavior and morphological abnormalities with respect to pollen and ovule abortion produced by translocation heterozygosity in the common bean, as observed in this study, are similar to those reported in other crops.Key words: Phaseolus, chromosome translocation, translocation heterozygosity.
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Adames, K. A., Jocelyn Gawne, Chantal Wicky, Fritz Müller i Ann M. Rose. "Mapping a Telomere Using the Translocation eT1(III;V) in Caenorhabditis elegans". Genetics 150, nr 3 (1.11.1998): 1059–66. http://dx.doi.org/10.1093/genetics/150.3.1059.
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Abstract In Caenorhabditis elegans, individuals heterozygous for a reciprocal translocation produce reduced numbers of viable progeny. The proposed explanation is that the segregational pattern generates aneuploid progeny. In this article, we have examined the genotype of arrested embryonic classes. Using appropriate primers in PCR amplifications, we identified one class of arrested embryo, which could be readily recognized by its distinctive spot phenotype. The corresponding aneuploid genotype was expected to be lacking the left portion of chromosome V, from the eT1 breakpoint to the left (unc-60) end. The phenotype of the homozygotes lacking this DNA was a stage 2 embryonic arrest with a dark spot coinciding with the location in wild-type embryos of birefringent gut granules. Unlike induced events, this deletion results from meiotic segregation patterns, eliminating complexity associated with unknown material that may have been added to the end of a broken chromosome. We have used the arrested embryos, lacking chromosome V left sequences, to map a telomere probe. Unique sequences adjacent to the telomeric repeats in the clone cTel3 were missing in the arrested spot embryo. The result was confirmed by examining aneuploid segregants from a second translocation, hT1(I;V). Thus, we concluded that the telomere represented by clone cTel3 maps to the left end of chromosome V. In this analysis, we have shown that reciprocal translocations can be used to generate segregational aneuploids. These aneuploids are deleted for terminal sequences at the noncrossover ends of the C. elegans autosomes.
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Uehara, Erika, Atsushi Hattori, Hirohito Shima, Akira Ishiguro, Yu Abe, Tsutomu Ogata, Eishin Ogawa i Maki Fukami. "Unbalanced Y;7 Translocation between Two Low-Similarity Sequences Leading to SRY-Positive 45,X Testicular Disorders of Sex Development". Cytogenetic and Genome Research 158, nr 3 (2019): 115–20. http://dx.doi.org/10.1159/000501378.
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Unbalanced translocations of Y-chromosomal fragments harboring the sex-determining region Y gene (SRY) to the X chromosome or an autosome result in 46,XX and 45,X testicular disorders of sex development (DSD), respectively. Of these, Y;autosome translocation is an extremely rare condition. Here, we identified a 20-year-old man with a 45,X,t(Y;7)(q11.21;q35) karyotype, who exhibited unilateral cryptorchidism, small testis, intellectual disability, and various congenital anomalies. The fusion junction of the translocation was blunt, and the breakpoint-flanking regions shared only 50% similarity. These results indicate that Y;autosome translocations can occur between 2 low-similarity sequences, probably via nonhomologous end joining. Furthermore, translocations of a Ypterq11.21 fragment to 7q35 likely result in normal or only mildly impaired male-type sexual development, along with various clinical features of 7q deletion syndrome, although their effects on adult testicular function remain to be studied.
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Feldman, Andrew L., Ahmet Dogan, David I. Smith, Mark E. Law, Stephen M. Ansell, Sarah H. Johnson, Julie C. Porcher i in. "Discovery of recurrent t(6;7)(p25.3;q32.3) translocations in ALK-negative anaplastic large cell lymphomas by massively parallel genomic sequencing". Blood 117, nr 3 (20.01.2011): 915–19. http://dx.doi.org/10.1182/blood-2010-08-303305.
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Abstract The genetics of peripheral T-cell lymphomas are poorly understood. The most well-characterized abnormalities are translocations involving ALK, occurring in approximately half of anaplastic large cell lymphomas (ALCLs). To gain insight into the genetics of ALCLs lacking ALK translocations, we combined mate-pair DNA library construction, massively parallel (“Next Generation”) sequencing, and a novel bioinformatic algorithm. We identified a balanced translocation disrupting the DUSP22 phosphatase gene on 6p25.3 and adjoining the FRA7H fragile site on 7q32.3 in a systemic ALK-negative ALCL. Using fluorescence in situ hybridization, we demonstrated that the t(6;7)(p25.3;q32.3) was recurrent in ALK-negative ALCLs. Furthermore, t(6;7)(p25.3;q32.3) was associated with down-regulation of DUSP22 and up-regulation of MIR29 microRNAs on 7q32.3. These findings represent the first recurrent translocation reported in ALK-negative ALCL and highlight the utility of massively parallel genomic sequencing to discover novel translocations in lymphoma and other cancers.
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Crasta, O. R., M. G. Francki, D. B. Bucholtz, H. C. Sharma, J. Zhang, R. C. Wang, H. W. Ohm i J. M. Anderson. "Identification and characterization of wheat-wheatgrass translocation lines and localization of barley yellow dwarf virus resistance". Genome 43, nr 4 (1.08.2000): 698–706. http://dx.doi.org/10.1139/g00-023.
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Stable introgression of agronomically important traits into crop plants through wide crossing often requires the generation and identification of translocation lines. However, the low efficiency of identifying lines containing translocations is a significant limitation in utilizing valuable alien chromatin-derived traits. Selection of putative wheatgrass-wheat translocation lines based on segregation ratios of progeny from γ-irradiated seed using a standard phenotypic analysis resulted in a low 4% success rate of identifying barley yellow dwarf virus (BYDV) resistant and susceptible translocation lines. However, 58% of the susceptible progeny of this irradiated seed contained a Thinopyrum intermedium chromosome-specific repetitive sequence, which indicated that γ-irradiation-induced translocations occurred at high rate. Restriction fragment length polymorphism (RFLP) analysis of susceptible lines containing alien chromatin, their resistant sister lines and other resistant lines showed that more than one third of the progeny of γ-irradiated double monosomic seeds contained wheatgrass-wheat translocations. Genomic in situ hybridization (GISH) analysis of selected lines confirmed that these were wheatgrass-wheat translocation lines. This approach of initially identifying BYDV susceptible deletion lines using an alien chromosome-specific repetitive sequence followed by RFLP analysis of their resistant sister lines efficiently identified resistant translocation lines and localized the BYDV resistance to the distal end of the introgressed Th. intermedium chromosome.Key words: gene introgression, wide crosses, chromosome, repetitive elements, RFLP, Thinopyrum intermedium.
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Irvine, Robin. "Inositol phospholipids: Translocation, translocation, translocation …". Current Biology 8, nr 16 (lipiec 1998): R557—R559. http://dx.doi.org/10.1016/s0960-9822(07)00360-0.
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King, I. P., K. A. Purdie, C. J. Liu, S. M. Reader, T. S. Pittaway, S. E. Orford i T. E. Miller. "Detection of interchromosomal translocations within the Triticeae by RFLP analysis". Genome 37, nr 5 (1.10.1994): 882–87. http://dx.doi.org/10.1139/g94-125.
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Twenty-three wheat/alien addition or substitution lines were screened using restriction fragment length polymorphisms for the presence or absence of 4/5 and 4/7 reciprocal translocations in the alien chromosomes. Such translocations have previously been identified in wheat and rye. Group 4 and group 5 Aegilops umbellulata, Triticum urartu, and Thinopyrum bessarabicum chromosomes were found to carry 4/5 translocations. Evidence for a 4/7 translocation was also found in Secale montanum. The presence of the 4/5 translocations in T. urartu indicates that the translocation predates the polyploidization of wheat. The implications of these results are discussed.Key words: wheat/alien addition and substitution lines, RFLPs, translocations, wheat/alien introgression, Triticeae, evolution.
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Soster, Erica, Brittany Dyr, Samantha Caldwell, Amanda Sussman i Hany Magharyous. "Prenatal cfDNA Screening for Emanuel Syndrome and Other Unbalanced Products of Conception in Carriers of the Recurrent Balanced Translocation t(11;22): One Laboratory’s Retrospective Experience". Genes 14, nr 10 (10.10.2023): 1924. http://dx.doi.org/10.3390/genes14101924.
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Prenatal cell-free DNA screening (cfDNA) can identify fetal chromosome abnormalities beyond common trisomies. Emanuel syndrome (ES), caused by an unbalanced translocation between chromosomes 11 and 22, has lacked a reliable prenatal screening option for families with a carrier parent. A cohort of cases (n = 46) sent for cfDNA screening with indications and/or results related to ES was queried; diagnostic testing and pregnancy outcomes were requested and analyzed. No discordant results were reported or suspected; there were ten true positives with diagnostic confirmation, six likely concordant positives based on known translocations and consistent cfDNA data, and twenty-six true negatives, by diagnostic testing or birth outcomes. For cases with parental testing, all affected ES cases had maternal translocation carriers. Expanded cfDNA may provide reassurance for t(11;22) carriers with screen negative results, and screen positive results appear to reflect a likely affected fetus, especially with a known maternal translocation. Current society guidelines support the use of expanded cfDNA screening in specific circumstances, such as for translocation carriers, with appropriate counseling. Diagnostic testing is recommended for prenatal diagnosis of ES and other chromosome abnormalities in pregnancy. To our knowledge, this cohort is the largest published group of cases with prenatal screening for carriers of t(11;22).
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Nagy, E. D., M. Molnár-Láng, G. Linc i L. Láng. "Identification of wheat-barley translocations by sequential GISH and two-colour FISH in combination with the use of genetically mapped barley SSR markers". Genome 45, nr 6 (1.12.2002): 1238–47. http://dx.doi.org/10.1139/g02-068.
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Five wheatbarley translocations in a wheat background were characterized through the combination of cytogenetic and molecular genetic approaches. The wheat chromosome segments involved in the translocations were identified using sequential GISH and two-colour FISH with the probes pSc119.2 and pAs1. The barley chromatin in these lines was identified using SSR markers. A total of 45 markers distributed over the total barley genome were selected from a recently published linkage map of barley and tested on the translocation lines. The following translocations were identified: 2DS.2DL1HS, 3HS.3BL, 6BS.6BL4HL, 4D5HS, and 7DL.7DS5HS. Wheatbarley disomic and ditelosomic addition lines for the chromosomes 3HS, 4H, 4HL, 5H, 5HL, and 6HS were used to determine the correct location of 21 markers and the position of the centromere. An intragenomic translocation breakpoint was detected on the short arm of the barley chromosome 5H with the help of SSR marker analysis. Physical mapping of the SSR markers on chromosomes 1H and 5H was carried out using the intragenomic and the interspecific translocation breakpoints, as well as the centromere, as physical landmarks.Key words: wheat-barley translocations, sequential GISH and FISH, SSR markers, physical mapping.
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Li, Hong-Jie, Bei-Hai Guo, Yi-Wen Li, Li-Qun Du, Xu Jia i Chih-Ching Chu. "Molecular cytogenetic analysis of intergeneric chromosomal translocations between wheat (Triticum aestivum L.) and Dasypyrum villosum arising from tissue culture". Genome 43, nr 5 (1.10.2000): 756–62. http://dx.doi.org/10.1139/g00-020.
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Fluorescence in situ hybridization (FISH) was applied with total genomic DNA extracted from Dasypyrum villosum (L.) Candargy as a probe to characterize chromosome translocations arising from tissue culture in hybrids of Triticum aestivum × (T. durum - D. villosum, amphiploid). Chromosome translocations between wheat and D. villosum occurred in callus cells at an average frequency of 1.9%. Translocations existed not only in callus cells but also in regenerants. Three plants with translocation chromosomes were characterized among 66 regenerants of T. aestivum 'Chinese Spring' × 'TH1W' and 'NPFP' × 'TH1'. One of them proved to be a reciprocal translocation with an exchange of about one third of a wheat chromosome arm with about one half of a chromosome arm of D. villosum. The breakpoints of the other two translocations were located at, or near centromeres. The results are similar for both callus cells and regenerants and provide further evidence that translocations take place in tissue culture. Other structural chromosomal changes, for example, fragments, telocentrics, dicentromeres, and deletions, as well as numerical alterations including aneuploidy and polyploidy were recorded both in callus cells and regenerants.Key words: wheat, Dasypyrum villosum, translocation, genomic in situ hybridization, tissue culture.
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Ostevik, Kate L., Kieran Samuk i Loren H. Rieseberg. "Ancestral Reconstruction of Karyotypes Reveals an Exceptional Rate of Nonrandom Chromosomal Evolution in Sunflower". Genetics 214, nr 4 (7.02.2020): 1031–45. http://dx.doi.org/10.1534/genetics.120.303026.
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Mapping the chromosomal rearrangements between species can inform our understanding of genome evolution, reproductive isolation, and speciation. Here, we present a novel algorithm for identifying regions of synteny in pairs of genetic maps, which is implemented in the accompanying R package syntR. The syntR algorithm performs as well as previous ad hoc methods while being systematic, repeatable, and applicable to mapping chromosomal rearrangements in any group of species. In addition, we present a systematic survey of chromosomal rearrangements in the annual sunflowers, which is a group known for extreme karyotypic diversity. We build high-density genetic maps for two subspecies of the prairie sunflower, Helianthus petiolaris ssp. petiolaris and H. petiolaris ssp. fallax. Using syntR, we identify blocks of synteny between these two subspecies and previously published high-density genetic maps. We reconstruct ancestral karyotypes for annual sunflowers using those synteny blocks and conservatively estimate that there have been 7.9 chromosomal rearrangements per million years, a high rate of chromosomal evolution. Although the rate of inversion is even higher than the rate of translocation in this group, we further find that every extant karyotype is distinguished by between one and three translocations involving only 8 of the 17 chromosomes. This nonrandom exchange suggests that specific chromosomes are prone to translocation and may thus contribute disproportionately to widespread hybrid sterility in sunflowers. These data deepen our understanding of chromosome evolution and confirm that Helianthus has an exceptional rate of chromosomal rearrangement that may facilitate similarly rapid diversification.
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Denzel, Sabine, Tamara Alpermann, Wolfgang Kern, Susanne Schnittger, Torsten Haferlach i Claudia Haferlach. "MYC Translocations In Mature B-Cell Neoplasms: Single, Double, Triple and Quadruple Hit Lymphoma". Blood 122, nr 21 (15.11.2013): 2997. http://dx.doi.org/10.1182/blood.v122.21.2997.2997.
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Abstract Background According to the WHO classification from 2008 the subclassification of mature B-cell neoplasms is based mainly on cytomorphological features. So far entities are not defined by genetics, although some close associations between morphology and genetic abnormalities exist like MYC translocation and Burkitt lymphoma/leukemia, CCND1-translocation and mantle cell lymphoma, BCL6 translocation and diffuse large B-cell lymphoma and BCL2 translocation and follicular lymphoma. However, most of the mentioned genetic abnormalities are characteristic but not specific for the respective morphological subtype. Further, these genetic lesions can occur concomitantly. For lymphomas harboring MYC translocations as well as one, two or three additional translocations, respectively, involving BCL2, BCL6 and/or CCND1 the terms “double hit”, “triple hit” and “quadruple hit” lymphoma have been introduced. Aims To characterize a large cohort of patients with mature B-cell neoplasms and MYC translocation with respect to phenotypic presentation and additional cytogenetic abnormalities with a special focus on concomitantly occurring BCL2, BCL6 and CCND1 rearrangements. Patients and Methods 214 patients with mature B-cell neoplasms harboring a MYC translocation were included in this study. For all cases chromosome banding analysis and FISH data verifying the MYC rearrangements were available. Results 141 (65.9%) were male, 73 (34.1%) female, median age was 66.4 years (range: 5.5-88.2 years). Patients were diagnosed as ALL (n=38, 17.8%), Burkitt lymphoma (n=37, 17.3%), CLL (n=43, 20.1%), and other mature B-cell neoplasms including follicular lymphoma, mantle cell lymphoma and PLL (n=96, 44.9%). 134/214 (62.6%) patients showed a MYC translocation but no translocation involving BCL2, BCL6 or CCND1 (single hit), while 59 (27.6%), 19 (8.9%) and 2 (0.9%) patients had so-called double, triple and quadruple hits. Multiple hit lymphomas displayed more frequently a complex karyotype (defined as ≥5 abnormalities in addition to MYC, BCL2, BCL6 and/or CCND1 translocation) in comparison to single hit lymphomas (61.3% vs 28.4%, p<0.001). In mean 3.8 chromosome abnormalities in addition to the MYC translocation (ACA) were observed in single hit cases as compared to 9.2 in multiple hit cases (p<0.001). The most frequently translocated gene in addition to MYC in double hit lymphomas was BCL2 (n=41/59; 69.5%) and in triple hit lymphomas BCL2 together with BCL6 (n=18/19; 94.7%). While in ALL, Burkitt lymphoma and other mature B-cell neoplasms MYC was involved in a translocation with one of the immunoglobulin loci (IGH, IGK, IGL) in the majority of cases (86.8%, 94.6%, 83.3%, respectively), in CLL MYC was translocated to other loci/genes in 62.8% of cases. Additionally, patients presenting as CLL showed most frequently single hit lymphoma (93%) and only 4.1 ACA in mean compared to all others (6.2, p=0.035). Also the pattern of ACA differed between CLL and other entities. The most frequently observed ACA in CLL resemble the spectrum of abnormalities typically found in CLL such as del(13q) (n=16/43, 37.2%), del(11q) (n=11/43, 25.6%), del(17p) (n=12/43, 27.9%) and +12 (n=2/43, 4.7%). In contrast in ALL, Burkitt lymphoma and other mature B-cell neoplasms the most frequently observed ACA were gains of 1q (n=83/171, 48.5%), del(6q) (n=41/171, 24.0%), gains of chromosome 7 (n=49/171, 28.7%), del(17p) (n=31/171, 18.1%), gains of 18q (55/171, 32.2%) and +12 (n=29/171, 17.0%). MYC translocations occurred in Burkitt lymphoma and ALL always within the primary clone, while in mature B-cell neoplasms and in CLL it was also present within subclones exclusively. Conclusions 1. MYC translocations occured either as single hit or multiple hit lymphoma and presented as ALL or different mature B-cell neoplasms. 2. Multiple hit lymphomas more often harbored a complex karyotype in comparison to single hit lymphomas. 3. In double, triple and quadruple hit cases MYC translocations were most frequently accompanied by BCL2 rearrangements. 4. While in Burkitt lymphoma and ALL MYC translocations were always present in the primary clone, MYC translocations could also occur as secondary events in CLL and other mature B-cell neoplasms. 5. MYC translocations in CLL differed from those found in other lymphatic malignancies with respect to their translocation partners and their additional chromosome aberrations. Disclosures: Denzel: MLL Munich Leukemia Laboratory: Employment. Alpermann:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.
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Auger, Donald L., i William F. Sheridan. "Negative Crossover Interference in Maize Translocation Heterozygotes". Genetics 159, nr 4 (1.12.2001): 1717–26. http://dx.doi.org/10.1093/genetics/159.4.1717.
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Abstract Negative interference describes a situation where two genetic regions have more double crossovers than would be expected considering the crossover rate of each region. We detected negative crossover interference while attempting to genetically map translocation breakpoints in maize. In an attempt to find precedent examples we determined there was negative interference among previously published translocation breakpoint mapping data in maize. It appears that negative interference was greater when the combined map length of the adjacent regions was smaller. Even positive interference appears to have been reduced when the combined lengths of adjacent regions were below 40 cM. Both phenomena can be explained by a reduction in crossovers near the breakpoints or, more specifically, by a failure of regions near breakpoints to become competent for crossovers. A mathematical explanation is provided.
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Li, Wanlong, Ghana S. Challa, Huilan Zhu i Wenjie Wei. "Recurrence of Chromosome Rearrangements and Reuse of DNA Breakpoints in the Evolution of the Triticeae Genomes". G3 Genes|Genomes|Genetics 6, nr 12 (1.12.2016): 3837–47. http://dx.doi.org/10.1534/g3.116.035089.
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Abstract Chromosomal rearrangements (CRs) play important roles in karyotype diversity and speciation. While many CR breakpoints have been characterized at the sequence level in yeast, insects, and primates, little is known about the structure of evolutionary CR breakpoints in plant genomes, which are much more dynamic in genome size and sequence organization. Here, we report identification of breakpoints of a translocation between chromosome arms 4L and 5L of Triticeae, which is fixed in several species, including diploid wheat and rye, by comparative mapping and analysis of the draft genome and chromosome survey sequences of the Triticeae species. The wheat translocation joined the ends of breakpoints downstream of a WD40 gene on 4AL and a gene of the PMEI family on 5AL. A basic helix-loop-helix transcription factor gene in 5AL junction was significantly restructured. Rye and wheat share the same position for the 4L breakpoint, but the 5L breakpoint positions are not identical, although very close in these two species, indicating the recurrence of 4L/5L translocations in the Triticeae. Although barley does not carry the translocation, collinearity across the breakpoints was violated by putative inversions and/or transpositions. Alignment with model grass genomes indicated that the translocation breakpoints coincided with ancient inversion junctions in the Triticeae ancestor. Our results show that the 4L/5L translocation breakpoints represent two CR hotspots reused during Triticeae evolution, and support breakpoint reuse as a widespread mechanism in all eukaryotes. The mechanisms of the recurrent translocation and its role in Triticeae evolution are also discussed.
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Kodama, M., M. S. Rose, G. Yang, S. H. Yun, O. C. Yoder i B. G. Turgeon. "The Translocation-Associated Tox1 Locus of Cochliobolus heterostrophus Is Two Genetic Elements on Two Different Chromosomes". Genetics 151, nr 2 (1.02.1999): 585–96. http://dx.doi.org/10.1093/genetics/151.2.585.
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Abstract Previously, Tox1 was defined as a single genetic element controlling the difference between races of Cochliobolus heterostrophus: race T is highly virulent on T-cytoplasm corn and produces the polyketide T-toxin; race O is weakly virulent and does not produce T-toxin. Here we report that Tox1 is two loci, Tox1A and Tox1B, on two different chromosomes. Evidence for two loci derives from: (1) the appearance of 25% Tox+ progeny in crosses between induced Tox1– mutants, one defective at Tox1A, the other at Tox1B; (2) the ability of Tox1A– + Tox1B– heterokaryons to complement for T-toxin production; and (3) electrophoretic karyotypes proving that Tox1– mutations are physically located on two different chromosomes. Data showing Tox1 as a single genetic element are reconciled with those proving it is two loci by the fact that Tox1 is inseparably linked to the breakpoints of a reciprocal translocation; the translocation results in a four-armed linkage group. In crosses where the translocation is heterozygous (i.e., race T by race O), all markers linked to the four-armed intersection appear linked to each other; in crosses between induced Tox1– mutants, complications due to the translocation are eliminated and the two loci segregate independently.
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Coci, Emanuele G., Andrea Auhuber, Anna Langenbach, Kristin Mrasek, Joachim Riedel, Andreas Leenen, Thomas Lücke i Thomas Liehr. "Novel Unbalanced Translocations Affecting the Long Arms of Chromosomes 10 and 22 Cause Complex Syndromes with Very Severe Neurodevelopmental Delay, Speech Impairment, Autistic Behavior, and Epilepsy". Cytogenetic and Genome Research 151, nr 4 (2017): 171–78. http://dx.doi.org/10.1159/000471501.
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Isolated abnormalities in terminal regions of chromosomes 10q and 22q were formerly described in patients affected by neuropsychological impairment, abnormal facies, and heterogeneous structural abnormalities of the body. Chromosomes 10q and 22q harbor important genes that play a major role in CNS development, like DOCK1 and SHANK3, and in overall body growth, like FGFR2 and HTRA1. By using clinical, neuroradiological, neurophysiological, and genetic assessment, we studied 3 siblings affected by 2 different forms of very severe neuropsychological impairment with structural physical abnormalities, epilepsy, and body overgrowth. The genetic analysis revealed 2 different unbalanced translocations t(10;22)(q26.13;q13.32) of genetic material between the long arms of chromosomes 10 and 22, deriving from a maternal balanced translocation. Consequences of the unbalanced translocation were the simultaneous partial monosomy of 10q26.13 to 10qter and partial trisomy of 22q13.32 to 22qter in 2 patients and the simultaneous trisomy distal q10 and monosomy distal q22 in 1 patient, respectively. To the best of our knowledge, we here describe for the first time a causal association between an unbalanced translocation t(10;22) affecting the long arms of both chromosomes 10 and 22 and a very severe neurodevelopmental delay in 3 siblings.
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Figueiras, Ana M., Maria T. Gonzalez-Jaen, Julio Salinas i Cesar Benito. "ASSOCIATION OF ISOZYMES WITH A RECIPROCAL TRANSLOCATION IN CULTIVATED RYE (SECALE CEREALE L.)". Genetics 109, nr 1 (1.01.1985): 177–93. http://dx.doi.org/10.1093/genetics/109.1.177.
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ABSTRACT In rye (Secale cereale L. cv. "Ailés") the progeny of a cross between a structural heterozygote for a reciprocal translocation (involving the 1R chromosome) and a homozygote for the standard chromosome arrangement were analyzed for the electrophoretic patterns of eight different leaf isozymes and also for their meiotic configuration at metaphase I.—The Got-3 and Mdh-2b loci are linked to each other and also to the reciprocal translocation. The Mdh-2b locus is located in the interstitial segment of the 3Rq chromosome arm, with an estimated distance of 8 cM to the breakpoint. Therefore, the reciprocal translocation involves the 1R and 3R chromosomes.—Also, the Mdh-1 and 6-Pgd-2 loci are linked (16 ± 3 cM) and have been located on the 2Rq arm. Finally, the Per-3 and Per-4 loci are located on the 2Rp chromosome arm at an estimated distance of 26 ± 4 cM.
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Talbert, P. B., C. D. LeCiel i S. Henikoff. "Modification of the Drosophila heterochromatic mutation brownDominant by linkage alterations." Genetics 136, nr 2 (1.02.1994): 559–71. http://dx.doi.org/10.1093/genetics/136.2.559.
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Abstract The variegating mutation brownDominant (bwD) of Drosophila melanogaster is associated with an insertion of heterochromatin into chromosome arm 2R at 59E, the site of the bw gene. Mutagenesis produced 150 dominant suppressors of bwD variegation. These fall into two classes: unlinked suppressors, which also suppress other variegating mutations; and linked chromosome rearrangements, which suppress only bwD. Some rearrangements are broken at 59E, and so might directly interfere with variegation caused by the heterochromatic insertion at that site. However, most rearrangements are translocations broken proximal to bw within the 52D-57D region of 2R. Translocation breakpoints on the X chromosome are scattered throughout the X euchromatin, while those on chromosome 3 are confined to the tips. This suggests that a special property of the X chromosome suppresses bwD variegation, as does a distal autosomal location. Conversely, two enhancers of bwD are caused by translocations from the same part of 2R to proximal heterochromatin, bringing the bwD heterochromatic insertion close to the chromocenter with which it strongly associates. These results support the notion that heterochromatin formation at a genetic locus depends on its location within the nucleus.
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Menzel, Margaret Y., i Brian J. Dougherty. "Transmission of Duplication-Deficiencies from Cotton Translocations Is Unrelated to Map Lengths of the Unbalanced Segments". Genetics 116, nr 2 (1.06.1987): 321–30. http://dx.doi.org/10.1093/genetics/116.2.321.
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ABSTRACT Adjacent-1 duplication-deficiencies (dp-dfs) are readily recovered from most heterozygous translocations in Gossypium hirsutum L., but frequencies of specific cytotypes differ widely in progenies from heterozygote (♀) x standard crosses. Surprisingly, these frequencies seem to be unrelated to the primary (postmeiotic) frequencies predicted by metaphase I configurations or to the proportion of the chromosome arm that is duplicate or deficient. Deficiencies and duplications from different translocations involving the same arm, as well as the two complementary dp-dfs from the same translocation, seldom exhibit similar frequencies. We conclude that the frequency of each of 101 different adjacent-1 cytotypes is largely idiosyncratic and may depend in part on interactions between the specific chromosome regions that are respectively trisegmental and monosegmental. Few, if any, of these interactions can be between homoeologues of the Ah and Dh genomes. Adjacent-2 dp-dfs are seldom recovered, even if they involve chromosomes that are readily tolerated in monosomic condition. Comparison of monosomes and telosomes with deficiencies suggests that some chromosomes and chromosome regions may be more dosage-sensitive than others, but their identification is not strongly supported by these data.
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Voelker, Rodger, Janet Mendel-Hartvig i Alice Barkan. "Transposon-Disruption of a Maize Nuclear Gene, tha1, Encoding a Chloroplast SecA Homologue: In Vivo Role of cp-SecA in Thylakoid Protein Targeting". Genetics 145, nr 2 (1.02.1997): 467–78. http://dx.doi.org/10.1093/genetics/145.2.467.
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A nuclear mutant of maize, tha1, which exhibited defects in the translocation of proteins across the thylakoid membrane, was described previously. A transposon insertion at the tha1 locus facilitated the cloning of portions of the tha1 gene. Strong sequence similarity with secA genes from bacteria, pea and spinach indicates that tha1 encodes a SecA homologue (cp-SecA). The tha1-ref allele is either null or nearly so, in that tha1 mRNA is undetectable in mutant leaves and cp-SecA accumulation is reduced ≥40-fold. These results, in conjunction with the mutant phenotype described previously, demonstrate that cp-SecA functions in vivo to facilitate the translocation of OEC33, PSI-F and plastocyanin but does not function in the translocation of OEC23 and OEC16. Our results confirm predictions for cp-Sed function made from the results of in vitro experiments and establish several new functions for cp-SecA, including roles in the targeting of a chloroplast-encoded protein, cytochrome f, and in protein targeting in the etioplast, a nonphotosynthetic plastid type. Our finding that the accumulation of properly targeted plastocyanin and cytochrome f in tha1-ref thylakoid membranes is reduced only a few-fold despite the near or complete absence of cp-SecA suggests that cp-SecA facilitates but is not essential in vivo for their translocation across the membrane.
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Cruz-Coke, Ricardo. "Complex familial translocation". Clinical Genetics 37, nr 2 (28.06.2008): 158–59. http://dx.doi.org/10.1111/j.1399-0004.1990.tb03494.x.
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Lu, Benjamin C. "Karyotyping ofNeurospora crassausing synaptonemal complex spreads of translocation quadrivalents". Genome 49, nr 6 (1.06.2006): 612–18. http://dx.doi.org/10.1139/g06-008.
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The purposes of the present research are (i) to establish the karyotype of Neursopora crassa using visualization of kinetochores in the synaptonemal complex (SC) spreads, (ii) to assign each chromosome to a linkage group, and (iii) to examine chromosome pairing and recombination nodules in quadrivalents. Two strains containing reciprocal translocations were used: T(I;II)4637, which involves linkage groups I and II, and alcoy, which contains 3 independent translocations involving I and II, IV and V, and III and VI. Visualization of kinetochores in the spreads requires the use of freshly prepared fixatives. Kinetochore locations and arm ratios were documented in all 7 N. crassa chromosomes. This new information, based on kinetochore position, arm ratios, chromosome length, and quadrivalent analyses, enabled unequivocal confirmation of chromosome assignments to genetic linkage groups. Chromosome pairing in a translocation quadrivalent starts at the 4 terminal regions, and proceeds right up to the translocation break point. Recombination nodules are found in all 4 arms of quadrivalents. The ability to identify a specific chromosome to a genetic linkage group together with the ability to visualize recombination nodules and their locations will allow future cytological analysis of recombination events.Key words: Neurospora, synaptonemal complex, translocation, karyotype, kinetochore, linkage groups, recombination nodules.
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Perkins, David D., Robert L. Metzenberg, Namboori B. Raju, Eric U. Selker i Edward G. Barry. "REVERSAL OF A NEUROSPORA TRANSLOCATION BY CROSSING OVER INVOLVING DISPLACED rDNA, AND METHYLATION OF THE rDNA SEGMENTS THAT RESULT FROM RECOMBINATION". Genetics 114, nr 3 (1.11.1986): 791–817. http://dx.doi.org/10.1093/genetics/114.3.791.
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ABSTRACT In translocation OY321 of Neurospora crassa, the nucleolus organizer is divided into two segments, a proximal portion located interstitially in one interchange chromosome, and a distal portion now located terminally on another chromosome, linkage group I. In crosses of Translocation x Translocation, exceptional progeny are recovered nonselectively in which the chromosome sequence has apparently reverted to Normal. Genetic, cytological, and molecular evidence indicates that reversion is the result of meiotic crossing over between homologous displaced rDNA repeats. Marker linkages are wild type in these exceptional progeny. They differ from wild type, however, in retaining an interstitial block of rRNA genes which can be demonstrated cytologically by the presence of a second, small interstitial nucleolus and genetically by linkage of an rDNA restriction site polymorphism to the mating-type locus in linkage group I. The interstitial rDNA is more highly methylated than the terminal rDNA. The mechanism by which methylation enzymes distinguish between interstitial rDNA and terminal rDNA is unknown. Some hypotheses are considered.
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Robinson, David O., Yvonne Boyd, David Cockburn, Morag N. Collinson, Ian Craig i Patricia A. Jacobs. "The parental origin of de novo X-autosome translocations in females with Duchenne muscular dystrophy revealed by M27ß methylation analysis". Genetics Research 56, nr 2-3 (październik 1990): 135–40. http://dx.doi.org/10.1017/s0016672300035217.
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SummaryThe parental origin of 3 de novo X-autosome translocations in females with Duchenne Muscular Dystrophy (DMD) was studied by means of methylation analysis using the X-linked probe M27ß. In all three the translocation was found to be paternal in origin. The parental origin of X-autosome translocations in females with and without DMD is compared with other structural abnormalities of the X and with autosomal translocations.
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Lee, J. H., S. M. Kaeppler, R. A. Graybosch i R. G. Sears. "A PCR assay for detection of a 2RL.2BS wheat–rye chromosome translocation". Genome 39, nr 3 (1.06.1996): 605–8. http://dx.doi.org/10.1139/g96-076.
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A 2RL.2BS wheat–rye translocation, present in the wheat germplasm line Hamlet, carries a gene for resistance to Hessian fly biotype L, one of the most virulent biotypes presently encountered in wheat production environments. Unlike several other wheat–rye chromosome translocations common in wheat breeding programs, 2RL lacks genes encoding storage proteins or other easily selected markers. Oligonucleotide primers synthesized from published sequences derived from the R173 family of moderately repetitive rye DNA were used in the DNA polymerase chain reaction (PCR) to identify specific markers for 2RL. The same primers, when used with DNA extracted from additional wheat–rye translocation lines of importance to the wheat breeding community, gave distinctive PCR products for each genotype. The single primer pair, PAWS5 and PAWS6, may, therefore, have wide applicability for the identification of wheat–rye chromosomal translocations presently encountered in wheat breeding populations. Key words : 2RL.2BS wheat–rye chromosome translocation, polymerase chain reaction, detection.