Dissertations / Theses on the topic 'Sister'
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Kaplan, Liat. "Sister: Poems." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/cmc_theses/1646.
Full textDummit, Sandra Sharp. "The Boxer's Sister." ScholarWorks@UNO, 2008. http://scholarworks.uno.edu/td/674.
Full textMoifo, Hunadi Senkoane. "“She is my sister although she’s got factory faults”: a psychosocial study of Xhosa women’s sister-sister relationships." Thesis, Rhodes University, 2017. http://hdl.handle.net/10962/4443.
Full textCampbell, Kyle. "Sister Cities and Diaspora: From Diaspora to Potential Sister City Partnership." Thesis, Malmö högskola, Fakulteten för kultur och samhälle (KS), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-21219.
Full textRibner, Susan. "Sister stories and other tales." ScholarWorks@UNO, 2004. http://louisdl.louislibraries.org/u?/NOD,95.
Full textTitle from electronic submission form. "A thesis ... in partial fulfillment of the requirements for the degree of Master of Fine Arts in Drama and Communications."--Thesis t.p. Vita. Includes bibliographical references.
Ricklefs, Tonya Kay. "I am who I am because I am a sister: exploring sister relationships in middle adulthood." Diss., Kansas State University, 2015. http://hdl.handle.net/2097/20558.
Full textSchool of Family Studies and Human Services
Karen Myers-Bowman
Sibling relationships have often been studied with the goal of understanding the sibling influence on development of an individual. With the focus on development, research has often been limited to the time of life between the ages of birth to 18. Sibling research in adulthood has often been limited to examining siblings’ interactions in a particular context. Most of the research has examined siblings dealing with caregiving, family businesses, finances, or parental treatment. How siblings feel about their relationship, how the relationship has enhanced their lives, and what meaning individuals ascribe to that relationship through their lifetime has been understudied. This study focused on the meaning ascribed to a relationship between sisters by those in the relationship as well as the importance of sisterhood to the individual’s identity or perception of who they are because of the relationship. Participants responded to questions designed to gather information about what it means to them to be a sister in middle adulthood. The sisters indicated that the relationship held meaning for them though out their adult life. Parents were found to have influenced the relationship. In addition the sister relationship impacted the development of a sisters identity in multiple ways. For most sisters, they could not imagine who they would have become without the influence of their sisters.
Mauthner, Melanie Louise. "Kindred spirits : stories of sister relationships." Thesis, University College London (University of London), 1998. http://discovery.ucl.ac.uk/10020305/.
Full textClifford, Katrina. "Sisterly Subjects: Brother-sister relationships in female-authored domestic novels, 1750-1820." Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/10065.
Full textChou, Tau-San Weber David F. "Sister chromatid exchanges in Zea mays L." Normal, Ill. Illinois State University, 1985. http://wwwlib.umi.com/cr/ilstu/fullcit?p8514768.
Full textTitle from title page screen, viewed June 7, 2005. Dissertation Committee: David F. Weber (chair), Herman Brockman, Tsan Iang Chuang, Alan Katz, Derek McCracken. Includes bibliographical references (leaves 118-142) and abstract. Also available in print.
Warnock, Jeanie E. "Kind tyranny: Brother-sister relationships in Renaissance drama." Thesis, University of Ottawa (Canada), 2000. http://hdl.handle.net/10393/9116.
Full textWarnock, Jeanie. "Kind tyranny, brother-sister relationships in Renaissance drama." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ57078.pdf.
Full textFarcas, Ana-Maria. "Studies on sister chomated cohesion using minichromosomal DNA." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526774.
Full textGravells, Polly Laura. "Investigating spontaneous sister chromatid exchange in uveal melanoma." Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531106.
Full textBurner, Colleen. "Sister Golden Calf: Stories, Dissections, & A Novella." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/2081.
Full textLiu, Zhe. "Characterization of sister chromatid cohesins having overlapping function and the role of separase, AtESP1, in controlling sister chromatid cohesion in Arabidopsis." Connect to this document online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1134155133.
Full textTitle from second page of PDF document. Document formatted into pages; contains [3], vi, 124 p. : ill. Includes bibliographical references.
Chenier, Karen Marie. "Listening to the voices of the American Catholic sister." Pacifica Graduate Institute, 2013.
Find full textHebbeler, Michael H. "The Sister Karamazov: Dorothy Day's Encounter with Dostoevsky's Novel." Dayton, Ohio : University of Dayton, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1250126537.
Full textEssex, David John. "The Necessary Good: The "True Ethic" of "Sister Carrie"." W&M ScholarWorks, 1986. https://scholarworks.wm.edu/etd/1539625356.
Full textLewis, Kate G. "Mothers and sisters : instrument and idiom in the music of Maybelle Carter, Memphis Minnie and sister Rosetta Tharpe." Thesis, University of Surrey, 2018. http://epubs.surrey.ac.uk/848856/.
Full textAlmedawar, Seba. "A SUMO-dependent step during establishment of Sister Chromatid Cohesion." Doctoral thesis, Universitat de Lleida, 2013. http://hdl.handle.net/10803/123807.
Full textLos anillos de cohesina, formados por las proteínas Smc1, SMC3, Scc1 y Scc3, se unen topológicamente al DNA, manteniendo las parejas de cromátidas hermanas unidas desde la duplicación del DNA hasta el comienzo de la anafase. Esta función, conocida como Cohesión entre Cromátidas Hermanas, permite la biorientación de los cromosomas en el huso mitótico y, posteriormente, su correcta segregación. Se trata por lo tanto de una función fundamental para la vida. La cohesión entre cromátidas hermanas también tiene otras funciones, como favorecer la reparación del daño en el DNA a través de recombinación homóloga. Es por estos motivos que la cohesina está sometida a varios niveles de regulación a lo largo del ciclo celular, a través de diferentes factores reguladores y modificaciones post-traduccionales. Por ejemplo, la acetilación de la subunidad Smc3 es necesaria para que los anillos se mantengan establemente unidos a cromatina. Alteraciones en la molécula de cohesina y/o en su regulación pueden provocar el desarrollo de patologías y contribuir a la progresión tumoral. En este estudio, describimos la sumoilación de la cohesina como una nueva modificación post-traduccional necesaria para la cohesión en Saccharomyces cerevisiae. La sumoilación de la cohesina depende, en parte, de la SUMO ligasa Nse2 y de un complejo Smc5/6 plenamente funcional. Todas las subunidades del complejo cohesina se sumoilan in vivo durante la replicación del ADN, después de la formación de los anillos de cohesina y de su reclutamiento en cromatina, en un proceso dependiente de la unión de ATP a las subunidades SMC, e independiente de la acetilación de Smc3. Con el fin de alterar el estado de sumoilación de los anillos de cohesina e identificar la relevancia funcional de esta modificación, hemos diseñado una nueva aproximación experimental que permite eliminar SUMO de todas las proteínas del complejo, basado en la fusión del dominio SUMO peptidasa de Ulp1 (UD) a la proteína Scc1. Las fusiones Scc1-UD se incorporan a los anillos de cohesina, se cargan en la cromatina y se localizan adecuadamente sobre los cromosomas de levadura. Sin embargo, la desumoilación de los anillos de cohesina impide la cohesión entre las cromátidas hermanas, deteniendo el ciclo celular en G2/M y provocando la pérdida de viabilidad de las células. Estos efectos son debidos a la actividad del dominio SUMO peptidasa, y no a problemas estructurales en la proteína de fusión Scc1-UD, ya que la mutación puntual del centro catalítico de UD restaura la cohesión y la viabilidad celular. Experimentos en paralelo sugieren que la sumoilació de la cohesina podría tener funciones similares en células humanas. Sorprendentemente, los anillos de cohesina continúan acetilados en ausencia de sumoilación. Dado que los modelos actuales proponen que los anillos se cierran establemente al ser acetilados, es probable que en ausencia de sumoilación la cohesina se cierre en torno a una sola cromátida. En consecuencia, proponemos que la sumoilación de la cohesina sería necesaria durante la replicación del ADN para atrapar las dos cromátidas hermanas de forma estable en el interior del anillo.
Cohesin rings composed of the Smc1, Smc3, Scc1 and Scc3 proteins topologically bind to DNA, keeping pairs of sister chromatids together from the time of DNA replication until the onset of anaphase. This feature, known as Sister Chromatid Cohesion (SCC), allows the biorientation of chromosomes on the mitotic spindle, and their subsequent segregation. Sister Chromatid Cohesion also has other roles, such as enabling repair of DNA damage through homologous recombination. Thus, it is not surprising that cohesin is subjected to multiple levels of control during the cell cycle by different regulatory factors and post-translational modifications. For example, acetylation of the Smc3 subunit is required to prevent the opening of cohesin rings, keeping them stably bound to chromatin. Alterations in the cohesin molecule itself and/or its regulation may lead to the development of serious pathologies and can contribute to tumor progression. In this study, we describe the sumoylation of cohesin as a new post-translational modification required for Sister Chromatid Cohesion in Saccharomyces cerevisiae. Sumoylation of cohesin is partially dependent on the Nse2 SUMO ligase and the Smc5/6 complex. All subunits of the cohesin complex are sumoylated in vivo during DNA replication, after the formation of cohesin rings and their recruitment onto chromatin, in a process dependent on the binding of ATP to the SMC subunits, and independent of Smc3 acetylation. In order to alter the sumoylation status of cohesin rings and to identify its functional relevance, we designed a new approach to remove SUMO from all cohesin subunits, based on the fusion of the SUMO peptidase domain of Ulp1 (UD) to the Scc1 protein. Scc1-UD fusions are properly incorporated into cohesin rings, loaded onto chromatin and located along yeast chromosomes. However, desumoylation of cohesin rings prevents Sister Chromatid Cohesion, arresting cells in G2/M and causing the loss of cell viability. These effects are due to the activity of the SUMO peptidase domain rather than structural problems in the Scc1-UD fusion, since mutation of the catalytic site in the UD restores cohesion and cell viability. Parallel experiments suggest that sumoylation of cohesin might have similar functions in human cells. Surprisingly, cohesin rings remain acetylated in the absence of sumoylation. Current models propose that cohesin rings are stably locked once they are acetylated. Therefore, it is likely that in the absence of sumoylation cohesin encircles a single chromatid. Consequently, we propose that sumoylation of cohesin is required during DNA replication to entrap the two sister chromatids inside its ring structure.
Tang, Chi Kin. "Theodore Dreiser's Sister Carrie and the self in consumer society." Thesis, University of Macau, 2010. http://umaclib3.umac.mo/record=b2456357.
Full textHughes, Kathleen. "Becoming a Sister: The Socialization of Women into a Sorority." TopSCHOLAR®, 2003. http://digitalcommons.wku.edu/theses/600.
Full textIsaac, Nicholas John Bendall. "Continuous characters in macroevolution : hypothesis testing with sister-clade comparisons." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406085.
Full textMiyazaki, Wesley Y. "The drosophila ord gene, sister-chomatid cohesion, and chromosome segregation." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/32133.
Full textKelly, Elizabeth Jane. "Ecomorphological differences between sister species, Rhinolophus capensis and Rhinolophus swinnyi." Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/6109.
Full textIncludes bibliographical references (leaves 69-81).
Phenotypic analyses of sibling species provide the opportunity to examine divergence that is caused by adaptation rather than phylogenetic history. Rhinolophus capensis and Rhinolophus swinnyi diverged from a common ancestor between 15 and 20 million years ago. The Fynbos biome of the south-western Cape (South Africa) arose around the same time, and its distribution is coincident with that of R. capensis. Since this event probably influenced the speciation of these species, I examine differences in the ecomorphology of these bats in their current distributions. R. capensis is bigger than R. swinnyi, with corresponding differences in echolocation call signatures and wing morphology.
Gorman, Albert T. "Making the connection : transnational civilian-to-civilian partnerships." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Dec%5FGorman.pdf.
Full textThesis advisor(s): Robert Looney, Lois Roberts. Includes bibliographical references (p. 71-75). Also available online.
Titos, Vivancos Iris 1986. "Topoisomerase II and dynamic microtubules solve sister chromatid intertwinings in anaphase." Doctoral thesis, Universitat Pompeu Fabra, 2013. http://hdl.handle.net/10803/287225.
Full textA la transició entre metafase i anafase els microtúbuls del fus mitòtic transporten els cromosomes a les cèl·lules filles, tot i això la separació completa dels braços dels cromosomes no succeeix fins al final dʼanafase. Amb lʼobjectiu dʼentendre com es resolen els cromosomes llargs durant anafase, hem creat una sèrie al·lèlica de cromosomes artificalment llargs. Amb aquesta metodologia hem demostrat que les cèl·lules que contenen cromosomes llargs estan sensibilitzades a la pèrdua de gens involucrats en lʼestructura i la segregació de cromosomes. Hem descobert que la Topoisomerasa II es necesària durant anafase per resoldre les regions distals de cromosomes llargs i que lʼactivitat de la polimerasa de microtúbuls, Stu2, és essencial en la resolució de concatenacions entre cromàtides germanes. A més, hem pogut identificar lʼorganització nuclear com una nova font que contribueix a lʼestrés topològic acumulat als cromosomes. En conclusió, les restriccions topològiques que imposen tant la longitud dels cromosomes com lʼarquitectura nuclear determinen la quantitat de concatenacions entre cromàtides germanes que han de ser resoltes per la Topoisomerasa II i els microtúbuls dinàmics durant anafase.
Bevc, Irena. "The effects of early separation and intimacy on brother-sister incest." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0008/NQ39254.pdf.
Full textPage, Andrea Wilder. "The meiotic cell cycle and sister-chromatid cohesion in Drosophila oocytes." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9843.
Full textBorges, V. S. F. "Establishment of sister chromatid cohesion during DNA replication in Saccharomyces cerevisiae." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1370644/.
Full textCosta, Isaura Maria da. "Sister talk foundations and gleanings for a Black Brazilian woman's theology /." Theological Research Exchange Network (TREN), 1997. http://www.tren.com.
Full textAllan, Helen Therese. "'Sister will see you now' : managing emotions in a fertility clinic." Thesis, University of Manchester, 1999. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533443.
Full textGahlhoff, Debra Zoe. "Selling the Body: Representing the Prostitute in Maggie and Sister Carrie." PDXScholar, 1995. https://pdxscholar.library.pdx.edu/open_access_etds/4963.
Full textHenry, Amanda Ann (Shaffer). "Clarkia genetic basis of sister species divergence Clarkia concinna x Clarkia breweri /." Thesis, Montana State University, 2006. http://etd.lib.montana.edu/etd/2006/henry/HenryA0806.pdf.
Full textBlanning, Hannah Catherine. "Reanimating the image: Verbal triumphs in the battle of the sister arts." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1442953.
Full textKuo, Yeh Chen. "Caregiving identities of women with a brother or sister with cerebral palsy." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21967.
Full textL'identité d'aidante naturelle des taïwanaises avec frères ou sœurs atteints de paralysie cérébrale Résumé Cette étude a examiné l'identité d'aidante naturelle des taïwanaises qui prennent soin de leurs frères ou sœurs atteints de paralysie cérébrale. Elle est basée sur 12 interviews détaillées avec 6 femmes âgées d'au moins 20 ans. Ces dernières se sont identifiées soit comme les uniques sœurs des personnes atteintes de paralysie cérébrale ou encore comme les personnes les plus impliquées dans la provision de soins. Les résultats de cette étude suggèrent que la provision de soins présents et futurs aux frères ou sœurs atteints de paralysie cérébrale est un phénomène complexe qui contribue à la perception de soi de ces femmes. Ce phénomène est influencé par quatre processus associés à la provision des soins : (a) soins par interprétation (b) soins par transformation (c) soins par protection (d) soins par sacrifice. L'implication dans ces quatre processus a crée pour ces femmes des considérations uniques et des tensions dans d'autres domaines de leur vie. Plus précisément, ces tensions sont liées à la négociation des relations avec leurs mères, à leurs choix de conjoints, à la répudiation de leurs droits à la succession, ainsi qu'à leurs aspirations et attentes relatives à la provision de soins continus à leurs frères ou sœurs atteints de paralysie cérébrale après le mariage. Étant donné que les femmes ont assimilé la division du travail dans leurs familles et dans leur culture, et qu'elles continuent à vivre dans un système qui demande que les mères et les sœurs s'impliquent dans les soins familiaux, plus d'attention doit être accordée à la promotion d'un partage plus équitable des soins prodigués par les hommes et les femmes dans les familles. Plus d'attention doit aussi être portée au développement de politiques de soins à long terme adaptés à la société taïwanaise.
Gerster, Jean Louise. "A cytogenetic study of factors affecting sister chromatid exchange in Vicia faba /." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63936.
Full textSundaramoorthy, S. "Mediators of pre-mRNA splicing regulate sister chromatid cohesion in mammalian cells." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1418244/.
Full textLiu, Zhenhua, Raquel Tavares, Evan S. Forsythe, François André, Raphaël Lugan, Gabriella Jonasson, Stéphanie Boutet-Mercey, et al. "Evolutionary interplay between sister cytochrome P450 genes shapes plasticity in plant metabolism." NATURE PUBLISHING GROUP, 2016. http://hdl.handle.net/10150/621949.
Full textCooper, Amanda. "Ghanaian Siblings' Experiences of a Brother or Sister with a Mental Disability." Thesis, The Chicago School of Professional Psychology, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10260450.
Full textThe following study explored the experiences of Ghanaian adult siblings of a brother or sister with a mental disability in Accra, Ghana. The literature review included international and multidisciplinary research on culture, Ghana, Ghanaian culture, family caregiver experiences, and adult siblings of individuals with a mental disability. A descriptive phenomenological design was employed to capture and describe the essence of the experiences of the participants of this study. The primary research question explored through this design was: what is the experience of being an adult sibling of a brother or sister with a mental disability in Ghana? The secondary research question was: what are the factors that impact the adult caregiver in caring for the sibling with a mental disability in Ghana? A purposeful sampling method was used to recruit 15 adult siblings of an individual with a mental disability with the assistance of a school for individuals with special needs located in Accra, Ghana. Semi-structured interviews were used to collect the data for this study. Five themes were identified in relation to the primary research question: 1) impact on self, 2) sibling relationship, 3) family, 4) interactions with society, and 5) caregiver. In answer to the secondary research question, several factors were found to impact the adult siblings in caring for their brother or sister: level of care needed, total number of siblings, sibling rank order, age, gender, parents living or passed, parental status, and financial status. The results of the study were discussed in relation to the reviewed literature, implications for the findings, and recommendations for future research were included. This study added to existing body of international psychology literature, demonstrated the importance of attending to the influence of culture when seeking to understand the experiences and needs of adult siblings of a brother or sister with a mental disability, and has the potential to inform systems of support for Ghanaian siblings of individuals with mental disabilities.
Tolley, Rebecca. "Review of Tools of Her Ministry: The Art of Sister Gertrude Morgan." Digital Commons @ East Tennessee State University, 2004. https://dc.etsu.edu/etsu-works/5726.
Full textVickridge, Elise. "Management of E. coli sister chromatid cohesion in response to genotoxic stress." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS172/document.
Full textMaintaining genome integrity through replication is an essential process for the cell cycle. However, many factors can compromise this replication and thus the genome integrity. Mitomycin C is a genotoxic agent that creates a covalent link between the two DNA strands. When the replication fork encounters the DNA crosslink, it breaks and creates a DNA double strand break (DSB). Escherichia coli (E.coli) is a widely used model for studying complex DNA mechanisms. When facing a DNA DSB, E. coli activates the SOS response pathway. The SOS response comprises over 50 genes that are under the control of a LexA-repressed promoter. Upon a DSB induction, RecA, a central protein of the SOS response will trigger the degradation of LexA and all the SOS genes will be expressed.We have developed a novel molecular biology tool that reveals contacts between sister chromatids that are cohesive. It has been shown in the lab (Lesterlin et al. 2012) that during a regular cell cycle, the two newly replicated sister chromatids stay in close contact for 10 to 20 min before segregating to separate cell halves thanks to the action of Topoisomerase IV. This step is called sister chromatid cohesion. We have used this molecular biology tool to study sister chromatid cohesion upon a genotoxic stress induced by mitomycin C (MMC). We have shown that sister chromatid cohesion is maintained and prolonged when the cell is facing a DSB. Moreover, this sister chromatid cohesion is dependent on RecN, an SOS induced structural maintenance of chromosome-like (SMC-like) protein. In the absence of RecN, the proximity between both sister chromatids is lost and this has a deleterious effect on cell viability. By tagging the chromosome with fluorescent proteins, we have revealed that RecN can also mediated a progressive regression of two previously segregated sister chromatids and this is coordinated with a whole nucleoid compaction. Further studies showed that this genome compaction is orderly and is not the result of a random compaction in response to DNA damage.Interestingly, inhibiting TopoIV in a recN mutant fully restores viability and sister chromatid cohesion suggesting that RecN’s action is mainly structural. Preserving cohesion through precatenanes is sufficient to favor repair and cell viability even in the absence of RecN.An RNA-seq experiment in a WT strain and a recN mutant revealed that the whole SOS response is downregulated in a recN mutant. This suggests that RecN may have an effect on the induction of the SOS response and thus RecA filament formation. This is in good agreement with the change in RecA-mcherry foci formation we observed. In the WT strain, the RecA-mcherry foci are defined as described in previous work. However, in the recN, the RecA-mcherry foci seemed to form bundle like structures. These RecA bundles were previsously described by Lesterlin et al. in the particular case of a DSB occurring on a chromatid that has already been segregated from its homolog. This could mean that in the absence of recN, the sister chromatids segregate and RecA forms bundle like structures in order to perform a search for the intact homologous sister chromatid.Altogether, these results reveal that RecN is an essential protein for sister chromatid cohesion upon a genotoxic stress. RecN favors sister chromatid cohesion by preventing their segregation. Through a whole nucleoid rearrangement, RecN mediates sister chromatid regression, favoring DNA repair and cell viability
Vickridge, Elise. "Management of E. coli sister chromatid cohesion in response to genotoxic stress." Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS172.
Full textMaintaining genome integrity through replication is an essential process for the cell cycle. However, many factors can compromise this replication and thus the genome integrity. Mitomycin C is a genotoxic agent that creates a covalent link between the two DNA strands. When the replication fork encounters the DNA crosslink, it breaks and creates a DNA double strand break (DSB). Escherichia coli (E.coli) is a widely used model for studying complex DNA mechanisms. When facing a DNA DSB, E. coli activates the SOS response pathway. The SOS response comprises over 50 genes that are under the control of a LexA-repressed promoter. Upon a DSB induction, RecA, a central protein of the SOS response will trigger the degradation of LexA and all the SOS genes will be expressed.We have developed a novel molecular biology tool that reveals contacts between sister chromatids that are cohesive. It has been shown in the lab (Lesterlin et al. 2012) that during a regular cell cycle, the two newly replicated sister chromatids stay in close contact for 10 to 20 min before segregating to separate cell halves thanks to the action of Topoisomerase IV. This step is called sister chromatid cohesion. We have used this molecular biology tool to study sister chromatid cohesion upon a genotoxic stress induced by mitomycin C (MMC). We have shown that sister chromatid cohesion is maintained and prolonged when the cell is facing a DSB. Moreover, this sister chromatid cohesion is dependent on RecN, an SOS induced structural maintenance of chromosome-like (SMC-like) protein. In the absence of RecN, the proximity between both sister chromatids is lost and this has a deleterious effect on cell viability. By tagging the chromosome with fluorescent proteins, we have revealed that RecN can also mediated a progressive regression of two previously segregated sister chromatids and this is coordinated with a whole nucleoid compaction. Further studies showed that this genome compaction is orderly and is not the result of a random compaction in response to DNA damage.Interestingly, inhibiting TopoIV in a recN mutant fully restores viability and sister chromatid cohesion suggesting that RecN’s action is mainly structural. Preserving cohesion through precatenanes is sufficient to favor repair and cell viability even in the absence of RecN.An RNA-seq experiment in a WT strain and a recN mutant revealed that the whole SOS response is downregulated in a recN mutant. This suggests that RecN may have an effect on the induction of the SOS response and thus RecA filament formation. This is in good agreement with the change in RecA-mcherry foci formation we observed. In the WT strain, the RecA-mcherry foci are defined as described in previous work. However, in the recN, the RecA-mcherry foci seemed to form bundle like structures. These RecA bundles were previsously described by Lesterlin et al. in the particular case of a DSB occurring on a chromatid that has already been segregated from its homolog. This could mean that in the absence of recN, the sister chromatids segregate and RecA forms bundle like structures in order to perform a search for the intact homologous sister chromatid.Altogether, these results reveal that RecN is an essential protein for sister chromatid cohesion upon a genotoxic stress. RecN favors sister chromatid cohesion by preventing their segregation. Through a whole nucleoid rearrangement, RecN mediates sister chromatid regression, favoring DNA repair and cell viability
Conin, Brenna. "Genomic contacts reveal the control of sister chromosome decatenation in E. coli." Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS376.
Full textTopoisomerase IV, is responsible for the untangling of catenanes that are formed during the replication of the chromosome and has been shown to play an essential role in nucleoid segregation. Previous studies have shown that alterations in Topo IV result in a prolonged interaction between sister chromosomes leading to poor chromosome segregation and a loss in cell viability. Using chromosome conformation capture (Hi-C) and fluorescence microscopy, we have shown that the alteration of Topo IV affects the organisation of the entire chromosome. The most striking phenotype is the emergence of two distinct signals at 1.35Mb and 1.75Mb where loci in these regions are able to contact any loci of the origin-proximal part of the chromosome (butterfly wings). Furthermore, when compared to WT cells, the mutant cells showed a loss of contacts within the terminus domain, suggesting a change in the organisation of the ter domain. We also observed a general increase of short-range contacts along the diagonal. This phenotype was only observed in E. coli cells with a circular chromosome that was undergoing replication. Those observations suggest that in the absence of Topo IV, there is an accumulation of precatenanes throughout the chromosome, allowing loci on different siter chromosomes to interact (inter-chromosomal contacts). This hypothesis was further supported when we studied the interplay between Topo IV and Topo III, which showed that Topo III acts on precatenanes at a very short distances from the replication fork and cannot “reach” precatenanes responsible for the butterfly wing signals. We further showed that the butterfly wing positions are dependent on both matS and MatP. Interestingly, Hi-C of the matP parEts double mutant does not display the characteristic signals of the single parEts mutant at the border of the ter, but instead reveals that the ter domain itself is able to contact distant loci of the chromosome. This suggests that the precatenanes were unable to go passed the dif site probably because of the MatP-matS complex. In addition, previous NorFlIP experiments have showen that Topo IV is able to bind but not cleave at two sites positioned at 1.2Mb and 1.8Mb, which align with the centre of the butterfly wings. We thereby hypothesised that the matS-MatP complex and these Topo IV sites define a decatenation hub. Unresolved precatenanes would be “pulled” toward this hub, to be decatenated prior to cell division. In this hypothesis, the Ter linkage plays an essential role in the decatenation hub as it prevents precatenanes from passing through dif. The absence of a functional Topo IV will therefore disturb the decatenation hub, resulting in accumulation of precatenanes at the border of the crippled hub and this is turn would be represented as the butterfly wing signals seen on a Hi-C matrix. In regard to this hypothesis, we investigated the role of MukB that is able to condense the DNA, possibly by loop extrusion, and show that MukB defines the length and density of the butterfly wings
Goldman, Beryl D. "Adult-sister relationships the effect of childhood sibling experiences in the context of the family realm /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 0.88 Mb., 173 p, 2006. http://wwwlib.umi.com/dissertations/fullcit?3220800.
Full textTaylor, Priscilla Wilson. "The sister factor, the role of women in the emerging Assembly of God." Theological Research Exchange Network (TREN) Access this title online. Theological Research Exchange Network (TREN), 2004. http://www.tren.com.
Full textBourbeau, Denis 1971. "Characterization of S1eEF1A-2 function, a sister gene of elongation factor 1A-1." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36876.
Full textGillatt, Lucy Aimee Elizabeth. "Having a brother or sister with autism : children's experiences of the sibling relationship." Thesis, University of Leicester, 2007. http://hdl.handle.net/2381/7538.
Full textLee, Janice Ying 1974. "Localization studies of sister-chromatid cohesion proteins MEI-S332 and RAD21 in Drosophila." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32256.
Full textIncludes bibliographical references.
In cell division, the proper segregation of chromosomes requires sister-chromatid cohesion. This physical attachment between sister chromatids is established during DNA replication, maintained throughout mitosis and released at the metaphase-anaphase transition. In meiosis, sister-chromatid cohesion is released along the chromosome arms in the first meiotic division, but retained at the centromere until the second meiotic division. In this thesis, we have analyzed the localization of two cohesion proteins in Drosophila, MEI-S332 and RAD21. MEI-S332 localizes specifically to the centromere from prometaphase to the metaphase-anaphase transition in mitosis, and from prometaphase I to the metaphase II-anaphase II transition in meiosis. We find that the termini of MEI-S332 are required for its localization to chromosomes; these are also the regions that have homology to MEI-S332-like proteins in other organisms. The localization of MEI-S332 does not require the presence of cohesin, an evolutionarily conserved protein complex that is essential for the establishment and maintenance of cohesion, nor a replicated sister chromatid. However, MEI-S332 delocalization is dependent upon the activity of the separase pathway that regulates cohesin release. We have identified and characterized a key subunit of cohesin in Drosophila, DRAD21, and studied its localization in early stages of meiosis in spermatocytes.
(cont.) DRAD21 is nuclear in prophase I, but is not visibly localized on chromosomes in later stages. Although DRAD21 is concentrated in centromeric regions after prometaphase in mitosis, MEI- S332 and DRAD21 do not physically interact in a complex in whole embryo extracts. Immunostaining of spread metaphase chromosomes for MEI-S332 and DRAD21 reveals that the two proteins are not localized to the same domains.
by Janice Ying Lee.
Ph.D.
Challita, Jihane. "Study of the mechanisms reponsible for the cohesion of sister chromosomes in bacteria." Thesis, université Paris-Saclay, 2022. http://www.theses.fr/2022UPASL038.
Full textDuring cell proliferation, the maintenance of genetic information is essential. In bacteria, replication and segregation are concomitant. Replication starts at the single, bidirectional origin of replication of bacterial chromosomes. Two replication arms are then defined, and replication ends in a region diametrically opposite to the origin, the terminus. As replication progresses, the newly replicated sister chromosomes migrate to opposite cell compartments. However, microscopic observations suggest that there is a delay between replication and segregation, and that this delay varies along the length of chromosomes. The delay between replication and segregation of the sister copies of a genomic position is referred to as sister chromatid cohesion. During my PhD, I used the high-resolution tool that allows for a genome-wide analysis of Sister Chromatid Cohesion (High-SC2) and studied the cohesion profile of the model organism Vibrio cholerae. It has been shown in E. coli that the cohesion responsible for the variation of segregation speed is modulated by Topoisomerase IV, a major decatenating enzyme. One of the identified partners of this decatenase is an SMC complex, MukBEF. Cells carrying a mukB deletion show a production of anucleate cells, and a mispositioned origin of replication. Chromosome segregation is impaired, and therefore sister chromatid cohesion is increased overall. The Topo IV-MukBEF interaction is regulated by MatP, which seems to displace MukBEF from the terminus of replication, facilitating the association of the MukBEF complex with the origin of replication. I therefore decided to investigate the role of MukB, in the formation of the long-range patterns of cohesion in V. cholerae. Using genetic approaches coupled with the High-SC2 assay, I demonstrated that the deletion of mukB leads to an increase in cohesion on Chr1, especially on its left replication arm, far from the origin. These results suggested that MukB does not preferentially act on specific regions and that the differential effect of the mukB deletion on Chr1 and Chr2 is probably linked to differences in their origin of replication and/or partition systems. Previous observations in the lab have in fact shown that a double deletion of MukB and ParAB1 leads to a strong phenotype, thus I investigated its effect on the cohesion profile. My results show an additional increase of cohesion in Chr1 near the ori, suggesting that the partitioning system acts on the decohesion of the ori domain while MukB acts on the chromosomal arms. In addition, it has been shown that MatP kept the sister-copies of the ter domain of Chr1 together until cell division. I used the Hi-SC2 assay to study its role in the increased cohesion of this region. I showed that MatP was responsible for the cohesion of the ter1 domain at cell division not behind the replication fork, unlike MukB. My results have also shown that it is the density of the matS sites located on the ter domain of each chromosome that influence the level of cohesion of these domains