Academic literature on the topic 'Cattle Embryos Transplantation'

Various methods of creating twin pregnancies in cattle have been investigated by other authors (see review by Sreenan and Diskin, 1987). However, virtually all of these methods have involved in vivoproduced embryos which, in separate studies, have employed either surgical or non-surgical transfer techniques, where embryos were transplanted either unilaterally or bilaterally in recipients which may or may not have been previously artificially inseminated. There have been no studies where all of these factors were examined collectively, and included with the transplantation of either frozen-thawed in vivoor in vitroproduced embryos. The objectives of the current study were, therefore, to compare pregnancy, twinning and embryo survival rates of recipients in which twin pregnancies were induced by various combinations of embryo source and transfer method to animals inseminated or not prior to embryo transfer, and the distribution of the embryos in the uterus.

Various methods of creating twin pregnancies in cattle have been investigated by other authors (see review by Sreenan and Diskin, 1987). However, virtually all of these methods have involved in vivoproduced embryos which, in separate studies, have employed either surgical or non-surgical transfer techniques, where embryos were transplanted either unilaterally or bilaterally in recipients which may or may not have been previously artificially inseminated. There have been no studies where all of these factors were examined collectively, and included with the transplantation of either frozen-thawed in vivoor in vitroproduced embryos. The objectives of the current study were, therefore, to compare pregnancy, twinning and embryo survival rates of recipients in which twin pregnancies were induced by various combinations of embryo source and transfer method to animals inseminated or not prior to embryo transfer, and the distribution of the embryos in the uterus.

Introduction. Now embryo transplantation technique widely used in breeding programs breeding centers in developed countries to accelerate genetic and technological progress. But in recent years have not observed significant progress in the success of engraftment of cryopreserved embryos, which for most households is 30 to 50 %, only the best breeding centers rises to 55 – 60 %. This suggests that, on the one hand, half of the outstanding animal genetic resources lost during the TE, and on the other that the successful spread of this method of reproduction in practice methodology for recipients in need of improvement. Purpose – to compare the effectiveness of two teaching approaches to prepare heifers recipient for transplantation of cryopreserved embryos. Materials and methods of research. The study was conducted at the point of transplantation of embryos JV "AF" Petrodolynske" (Odessa region.). The company has a breeding herd Ukrainian Red dairy cattle (600 cows) with an average productivity of 5.0 thousand kg. In March 2016 this sector the works transplant 64 embryos Angler breed German selection (firm «SPERMEX GmbH»). Embryos were obtained from 18 cows genetically valuable donor sperm using 12 producers. According to the technological requirements, two groups were formed heifers recipients that met accepted standards for the age and development. These groups were used two alternative methods of training recipients to TE. Control of clinical and morphological and functional parameters of reproduction heifers in preparation, synchronization, TE and definition of pregnancy carried out a comprehensive visual refleksolohichnym clinical palpation method of diagnosis. Heifers controls to synchronize induced hormonal cycle subjected to processing in accordance with the protocol Ovsynch, as used in the experimental group we developed probiotic-cyclic scheme (the drug "Multybakterin veterinary Bs + La», which includes strains of microorganisms Bacillus subtilis and Laktobacillus acidophilus). Results. Transplantation of thawed embryos Angler breed heifers was carried out only with the presence of morphologically typical of corpora lutea (positive recipients). Within 2 months spent visual refleksolohichnyy control animal behavior, and in 60 days - rectal examination pregnancy. The results of the studies found significantly higher (at 71,9 %) yield positive recipients daily routine TE than Ovsynch protocol, as well as the experimental group engraftment thawed embryos above 10 %. Consequently, the use of probiotic protection promoted regeneration and recovery of genital tract mucosal heifers. It is proved that the development of functional entities ovarian and endometrial status have a close physiological relationship thus resulted in the formation of normal microflora dysbiosis and elimination of the state was the harmonization of sexual recurrence of experimental animals. Consequently, effective TE in the economy in 3 – 3,5 years will be introduced in the heifers group herd milk production from 9 to 10 000 kg, which, in turn, become potential donors of embryos based economy. Conclusions. The results showed that in industrial dairy complex advanced probiotic-cycle method of preparation of heifers to the THAT (using probiotic protect mucous membranes and the use of prostaglandins in accordance with the functional state of the ovaries) was more effective than the conventional scheme of hormonal stimulation as during synchronization cycle, and the level of engraftment embryos.

Assisted reproductive technologies (ART) increasingly occupy the study of human reproduction. In addition, in developed countries they contribute to breeding of more than 50 % of cattle. In the management of collections of genetic lines of laboratory animals, these technologies are obligatory components of cryopreservation and rederivation. ART procedures include the development of early embryos outside the mother’s body and the high probability of incomplete synchronization of the physiological state of the surrogate mother and transplanted embryos. Since all this occurs at the stage of the highest susceptibility of embryos to epigenetic reprogramming, the full cycle of ART and its individual components can lead to stable phenotypic changes in the offspring. Their reality is confirmed by studies of the morphological and functional characteristics of sexually mature offspring of CD1 outbred mice, obtained using different variants of early embryo transplantation. Comparative studies of body mass and body composition, basal glucose level and response to glucose load (glucose-tolerance test – GTT) have been done on sexually mature males and females. Animals were separated in 4 groups according to the variant of embryo transplantation: group (control) – natural mating; group (2cl-bl) – incubation of 2-cell up to blastocysts; group (2cl-2cl) – removal and transplantation of the 2-cell embryo without incubation; group (Bl-bl) removal and transplantation of the blastocysts without incubation. All embryos were transplanted to recipient females of the same line. It was found that sexually mature offspring obtained with all variants of transplantations had a higher relative fat content and, correspondingly, lower lean mass compared to the control. This effect was more pronounced in females than in males. Unlike body compositions, embryo transplantations had a greater effect on basal glucose concentration and GTT in males than in females. In this case, the offspring of the 2cl-2cl and 2cl-bl groups were characterized by a higher tolerance to glucose load (GTT) compared with the control and the Bl-bl group. Stable deviations of body compositions and glucose homeostasis indices detected in experimental groups of progenies indicate the phenotypic significance of the embryo transplantations per se.

Producing embryos in vitro is an important technology used to improve the genetic potential of cattle and perfect the programs of their breeding. Regardless of the way they are produced, all embryos that had not been used for transplantation to recipients must be conserved. Because of significantly increased interest in the problem of cryoconservation of embryos, both coming from scientists and businesses, there are emerging new commercial environments that allow the facilitation of cryoconservation and the increase in the embryo survival. Oocyte-cumulus complexes obtained from the ovaries of slaughtered clinically healthy cows matured in 22–24 h in in vitro conditions. The oocytes were co-cultured with spermatozoids in Fertilization medium, and the obtained zygotes were cultured in Culture medium with Sodium-Pyruvate for 4 or 7 days up to the stage of morula or blastocyste, respectively. For the vitrification of cow embryos, we used a commercial kit for the vitrification of human embryos, having compared the duration of equilibration. According to the results of the studies, we observed high efficiency of cryoconservation of cow embryos using the commercial kit for vitrification of human embryos. The results revealed the significant effect of equilibration on survival and further development of embryos. In addition, we described the dependence of development stage of cattle embryo on the duration of the contact of embryo with equilibration solution. Therefore, optimal time of contact of cattle embryos at the morula stage with equilibration solution was 12 minutes. On the 24th h after thawing, 46.7 ± 3.3% of the embryos were observed to undergo blastulation, and on 48th h, this parameter increased to 96.7 ± 3.3%, which corresponded to the parameters in the group of embryos that had not been subjected to cryoconservation. In the conditions of further cultivation, the percentage of blastocystes that hatched in the experimental group was no different from that of the control. At the same time, the highest efficiency of vitrification of blastocystes of cows was seen after the contact with the equilibration solution for 15 min, since the percentage of hatched blastocystes was the same as in the control group. Therefore, using the commercial kit for vitrification of human embryos is beneficial, for it promotes the parameters of cow embryos after vitrification/thawing that are similar to such of intact embryos (without freezing). The data we analyzed and presented in the paper could help to increase the efficiency of cryoconservation of cattle embryos for both scientific and commercial purposes.

The purpose of this research was to evaluate three embryo biopsy techniques used for preimplantation genetic diagnosis (PGD) in cattle and to recommend the least invasive one for current use, especially when PGD is followed by embryo cryopreservation. Three hundred bovine embryos were biopsied by either one of the needle, aspiration or microblade method, and then checked for viability by freezing/thawing and transplantation to recipient cows. The number of pregnancies obtained after the transfer of biopsied frozen/thawed embryos was assessed 30 days later using ultrasounds. The results were significantly different between the three biopsy methods: the pregnancy rate was of 57% in cows that received embryos biopsied by needle, 43% in cows that received embryos biopsied by aspiration, and 31% in cows that received embryos biopsied by microblade. Choosing an adequate biopsy method is therefore of great importance in embryos that will undergo subsequent cryopreservation, as it significantly influences their viability after thawing.

Embryo transfer technique is one of the key in accelerated reproduction of cattle. One of the most important stages is the selection of donor cows that are most sensitive to the procedure of hormonal stimulation of ovulation. One of the promising genetic markers of the reproductive status of cattle is currently the gene encoding the luteinizing hormone / choriogonadotropin receptor (LHCGR). One of the SNP in the LHCGR gene of cattle has already been described in the literature as associated with the number of oocytes and the quality of embryos - rs41256848 (c.1401G> T, p.Trp467Cys). The purpose of this work was to estimate the frequencies of genotypes and alleles of this substitution in the population of Black-and-White holsteinized cattle (190 cows). Genotyping was performed by PCR-RFLP method. In the studied population of cattle, the frequency of the G allele associated with higher rates in the total number of oocytes and the number of embryos survived after transplantation, as well as with the least number of unfertilized oocytes, is 63.2%.

The purpose of the work was to analyze the situation regarding to the status and prospects for the use of reproductive biotechnology to increase productivity in cattle breeding. In the conditions of dynamic growth of the planet’s population, global climate changes and the russian-Ukrainian war, food security in the whole world and in Ukraine in particular has become a key issue. To increase food stocks of animal origin, it is necessary first of all to intensify dairy and meat cattle breeding with the involvement of the best world genetics. This becomes possible thanks to the application of modern biotechnological methods of reproduction, some of which (artificial insemination, embryo transplantation) are successfully used in the world and in Ukraine, the other part (in vitro fertilization, cloning, creation of transgenic animals) is constantly developing and improving in countries with developed cattle breeding. Technologies of artificial insemination and transplantation of cattle embryos have been improved in Ukraine. Artificial insemination has been introduced into the practice of cattle breeding, work on embryo transplantation is being resumed, and in recent years, dairy farms have used sperm of bulls separated by sex. Scientists of the institutions of the National Academy of Agrarian Sciences of Ukraine conduct sporadic experiments on in vitro fertilization and the creation of transgenic animals, which requires the expansion and deepening of these areas of research. To overcome modern challenges related to climate change and war, it is advisable to use biotechnological methods of reproduction in cattle breeding. For this, research on the development and implementation of the latest reproductive biotechnologies should be intensified: embryo transplantation, in vitro fertilization, creation of transgenic animals.

The results of experiments aimed at cloning of sheep and cattle embryos are described. Two experimental approaches were used to study the developmental potential of blastomeres from sheep and cow embryos: (i) blastomere separation followed by culture and (ii) fusion of isolated blastomeres with enucleated eggs followed by culture. Both approaches allow embryos to be cloned, but whereas blastomere separation allows only a relatively small number of genetically identical animals to be produced, nuclear transplantation will probably open the way for large-scale cloning of livestock.Key words: sheep, cow, cloning, blastomere separation, nuclear transplantation.

On September 29, 2021, Volodymyr Frankovych Stakhovskyi, a senior research fellow at the Laboratory of Biotechnology of Reproduction of the Institute of Animal Breeding and Genetics named after M.V.Zubets of the National Academy of Agrarian Sciences of Ukraine, turned 60 years old. He was born in the village Chupyra, Bila Tserkva district, Kyiv region. After studying at Ozeryansk Secondary School in 1978, Volodymyr Frankovych became a student of the veterinary faculty of the Bila Tserkva Agricultural Institute. In 1983, having obtained the specialty of veterinary medicine, he began working at the Lynovytsk Sugar Plant, working as a chief veterinarian. The first experience outlined the interests of the young specialist. Acting as a chief veterinarian, Volodymyr Frankovych, along with traditional biotechnological methods of increasing the level of reproduction of the cattle herds, has repeatedly been interested in the possibilities and prospects of introducing the method of embryo transplantation for accelerated reproduction of high-value animals. He began to master the latest technological developments and put them into production at the Pryluky Tribal Enterprise, where he worked since 1990 as Deputy Head of Embryo Transplantation. The main task of the project headed by him was to accelerate the creation of a herd of sires with a high genetic level of productivity for the Chernihiv RTE, which was successfully completed. As of 1998, 80% of the sires of this tribal association were transplants. Achieving high rates of obtaining and engraftment of embryos from record-breaking cows became possible due to perseverance and creative search for a specialist. This contributed to the further scientific path of the scientist, the practical implementation of which the future scientist began as a graduate student of the stationary form of education of the Institute of Animal Breeding and Genetics of UAAS in 1995. In 1998, Volodymyr Frankovych was hired as a researcher at the Laboratory of Farm Animal Breeding in the Northern Regions of Ukraine of the Institute of Animal Breeding and Genetics of UAAS. Within the walls of the Institute under the leadership of A.P.Krugliak, the scientist prepared and in 2004 successfully defended his dissertation "Biotechnological ways to increase the level of reproduction of cattle" in the specialty 06.02.01 – breeding and selection of animals (agricultural sciences). Since 2005 he has been working in the Laboratory of Cell Engineering (now the Laboratory of Biotechnology of Reproduction). Scientific research of Volodymyr Frankovych Stakhovskyi is aimed at the development and implementation of the modern methods of biotechnology of farm animal reproduction, in particular the in vivo production and non-surgical transplantation of cattle embryos. The main directions of scientific research are the development of ways to increase the level of reproduction of the cattle herd by improving the organization and technology of insemination of females and methods of embryo transplantation. Based on research, a method of effective use of bulls in production conditions was developed, which was approved by the Scientific and Technical Council of Ukrainian Tribal Enterprise (February 8, 1999) and included in the Instruction on the organization and technology of artificial insemination of cows and heifers (1999). Currently, scientific and practical activities of the scientist are aimed at assessing the level of reproduction of the herd, he constantly provides methodological and practical assistance in diagnosing gynecological diseases of cattle, insemination, infertility control to ensure productive and reproductive animal health in farms (TOV "AF Petrodolynske" of Odessa region, "Galax-Agro" of Zhytomyr region, TOV "Milk of the Fatherland" of Sumy region, TOV "Inter" and POSP "Zhatkivske" of Chernihiv region (http://iabg.org.ua/index.php?option=com_content&view=article&id=402: seminar03052018&catid=1&Itemid=30, http://iabg.org.ua/index.php?option=com_content&view =article&id=344:11042017&catid=1&Itemid=30)). Thus, in 2015 in the farm of TOV "AF Petrodolynske" together with scientists of the laboratory as a result of transplantation of 35 embryos of Angeln breed received pregnancy and birth of calves at the level of 23.0%. In 2015–2016, at the State Enterprise research farm "Khrystynivske" of the Institute of Animal Breeding and Genetics named after M.V. Zubets of National Academy of Agrarian Sciences of Ukraine they transplanted 25 cryopreserved embryos of Holstein breed (red-spotted coat) of German selection (SPERMEX GmbH), which were obtained from five donor cows using the semen of nine bulls. As a result of transplantation of 25 cryopreserved embryos of Holstein breed in SE RF "Khrystyniske of IABG named after M.V.Zubets NAAS" received a pregnancy rate of 20.0% and five transplant calves were born, among which four bulls (including two monozygotic twins) and one heifer. It was found that the highest genetic potential had embryos, the genetic parents of which were the donor cow Annabel 78492720 and the bull Paradox 297648, from which one bull № 4605 was obtained, which was a sire at PrAT "Uman Tribal Enterprise" for the selection process. Also, after the transplantation of embryos from the cow Dagmar 13341914 and the bull Avanti 297505, two monozygotic twin bulls were born (№№ 4606, 4607), which are currently also located and used at PrAT "Uman Tribal Enterprise". Over the past three years, with the scientific support of Volodymyr Frankovych, the laboratory for transplantation of embryos of cattle on the basis SE RF IRGT "Khrystyniske of IABG named after M.V.Zubets NAAS" was established (http://iabg.org.ua/index.php?option=com_content&view=article&id= 460:kovtun-060519&catid=1&Itemid=30, http://iabg.org.ua/index.php?option=com_content&view =article&id=564:14092021&catid=1&Itemid=30). The functioning of this laboratory as a training and demonstration site of NAAS for embryo transplantation has been ensured. They obtained 55 embryos, transplanted 27 ones to 19 recipient heifers, pregnancy and birth of calves - 50.0%. Also in 2019 on the basis of TOV "Milk of the Fatherland" (Sumy region) the creation of such a laboratory under the concluded economic contract was started (http://iabg.org.ua/index.php?option=com_content&view=article&id=481:kovtun-11019&catid= 1&Itemid=30). In the experimental farms of the system of National Academy of Agrarian Sciences of Ukraine V. F. Stakhovskyi performs a set of visual-clinical-reflexological methods of assessment and correction of sexual function of heifers to increase the efficiency of embryo transplantation and artificial insemination. He provides recommendations on ethological and morphological features of sexual arousal in cows and heifers unsuitable for embryo transplantation and the feasibility of their use for artificial insemination. Such approaches are part of the task of adjusting the breeding system, the use of breeds of foreign selection, obtaining purebred bulls (Resolution of the Presidium of NAAS from 30.06.15, protocol № 7). The main research results are used in the farms of various forms of ownership ("Breeder" of Pryluky district of Chernihiv region, Pryluky and Chernihiv regional tribal enterprises, PrAT "Agro-Soiuz", PAT "Poltavaplemservice"). The results of V. F. Stakhovsky's scientific research are presented in the 30 scientific works, including three methodical recommendations and a patent for a utility model.

Concentrations of trace minerals within the body are known to impact reproductive processes. Thus, the current study analyzed the effects of using an injectable trace mineral supplement containing selenium, zinc, copper, and manganese during a superovulation protocol on embryo outcomes in donor beef cows and further effects on pregnancy rate in recipient females. We hypothesized that an injectable trace mineral (TM) supplement provided to cows fed to meet known nutrient requirements would increase TM status and influence superovulation, embryo characteristics, and enhance pregnancy rates. Our findings indicate that the injectable TM increased concentration of Se within the liver. However, superovulatory response, embryo production, quality grade, and developmental stage were not influenced by TM status. In addition, embryo treatment did not influence pregnancy rate, gestation length, or calf body weight.

La sélection génomique, mise en place depuis 2009 en France, a drastiquement modifié les schémas de sélection dans les races bovines laitières françaises de grand effectif en augmentant le nombre de candidats à la sélection et en réduisant les intervalles de génération. L’essor de l’utilisation du transfert embryonnaire a également remanié les schémas de sélection, intensifiant la sélection des mères à taureaux et réduisant encore les intervalles de génération. Ces technologies permettent une augmentation du progrès génétique.Cependant, si leur utilisation n’est pas maîtrisée, elles mettent en danger la diversité génétique de ces races. Cette perte de diversité, caractérisée par une augmentation de la consanguinité, peut s’accompagner de dépression de consanguinité, d’une baisse de l’efficacité de la sélection et une perte de potentiel adaptatif. Il est donc primordial de comprendre et de prédire l’impact de ces changements sur la diversité génétique à l’ère de la génomique, afin de mieux la maintenir.Un bilan de la mise en place de la sélection génomique a montré que cette technologie a permis une augmentation du progrès génétique annuel chez la Montbéliarde, la Normande et la Prim’Holstein mais que la perte de diversité génétique s’est accélérée seulement chez la Prim’Holstein.Une étude par simulations a montré que, dans le cadre de la sélection génomique, l’utilisation intensive du transfert embryonnaire dans un schéma de sélection de type Montbéliarde présentait un risque pour la diversité génétique, et que la réduction du nombre de taureaux dans ces schémas causait à la fois une baisse du progrès génétique et une accélération de la perte de diversité génétique.Dans la race Montbéliarde, la dépression de consanguinité a fait baisser les performances pour cinq caractères de production et de santé sur les six caractères étudiés. Les effets de la consanguinité sur ces performances sont très hétérogènes le long du génome.Gérer la consanguinité et ses conséquences dans les races bovines laitières françaises nécessite la mise en œuvre de mesures efficaces, éthiques et applicables sur le terrain
Genomic selection, implemented in France since 2009, has drastically modified breeding schemes in large French dairy cattle breeds by increasing the number of candidates for selection and reducing generation intervals. The growing use of embryo transfer has also reshaped breeding schemes, intensifying the selection of dams of bulls and further reducing generation intervals. This resulted in an increased genetic gain.However, if their use is not controlled, they put the genetic diversity of these breeds at risk. This loss of diversity, characterized by an increased inbreeding, can be accompanied by inbreeding depression, a decrease in selection efficiency and a loss of adaptive potential. It is therefore essential to understand and predict the impact of these changes on genetic diversity. We studied the implementation of genomic selection and showed that this technology has led to an increase in annual genetic gain in Montbéliarde, Normande and Prim'Holstein while the loss of genetic diversity has only been accelerated in Prim'Holstein.We showed by simulations that, in the context of genomic selection, the intensive use of embryo transfer in a Montbéliarde-type breeding scheme presented a risk for genetic diversity, and that the reduction in the number of bulls in these schemes caused both a decrease in genetic gain and an acceleration of the loss of genetic diversity.In the Montbéliarde breed, inbreeding depression resulted in lower performance for five production and health traits out of six traits studied. The effects of inbreeding on these performances were very heterogeneous along the genome.Managing inbreeding and its consequences in French dairy cattle breeds requires the implementation of effective, ethical and feasible actions in the field

Au cours de la gestation précoce, la régulation de la physiologie endométriale est cruciale au bon déroulement de l’implantation. Chez les mammifères, une famille de facteurs de transcription est fortement impliquée dans la régulation de la physiologie endométriale, les facteurs STAT. Chez la vache, des analyses haut-débit ont révélé que l’expression endométriale de STAT1 est régulée au cours de la période préimplantatoire. Le but de cette thèse est donc d’apporter de nouvelles données sur l’expression et la régulation endométriales de STAT1 mais également sur ses fonctions biologiques au cours de la gestation précoce chez la vache.Grâce à différents modèles physiologiques et expérimentaux, l’impact de la progestérone, de l’IFNT (signal majeur de reconnaissance maternelle de la gestation chez les ruminants) et de la gestation sur l’expression et la régulation de STAT1 (y compris sa phosphorylation) a été analysé dans l’endomètre bovin et sur des cultures primaires de cellules endométriales. Ainsi, l’expression de STAT1 (transcrit et protéine) ainsi que sa phosphorylation sont augmentés en présence du conceptus et de l’IFNT, indépendamment du taux circulant de progestérone à l’implantation chez la vache. Pour avoir une meilleure connaissance des rôles de STAT1, l’identification de ses gènes cibles a été entreprise : d’abord avec une approche gènes candidats (avec la famille des gènes SOCS), puis par une approche exploratoire.Les facteurs SOCS sont connus pour être des régulateurs négatifs de la voie de signalisation des cytokines. L’utilisation des différents modèles physiologiques et expérimentaux évoqués plus haut a permis l’analyse de l’expression et de la régulation des huit membres de la famille des gènes SOCS au cours de la gestation précoce chez la vache. L’application d’un protocole d’immunoprécipitation de la chromatine sur des cultures primaires de cellules stromales bovines montre le recrutement rapide de STAT1 par l’IFNT sur les promoteurs des gènes SOCS IFNT-dépendants. D’autre part, l’identification systématique des gènes cibles de STAT1 a été entreprise via l’élaboration d’un protocole d’immunoprécipitation de la chromatine suivit de séquençage haut-débit, appliqué à des échantillons d’endomètre bovin. L’ensemble de ces travaux suggèrent l’implication de STAT1 dans la signalisation endométriale de l’IFNT, dans la régulation du système immunitaire maternel et également dans le contôle des phénomènes d’apposition et d’adhérence, fonctions cruciales à l’implantation chez la vache
During the early stage of the pregnancy, the regulation of the endometrial physiology is crucial to the right establishment of the implantation. In mammals, a transcription factor family is highly involved in the regulation of endometrial physiology, the STAT family. In cattle, high-throughput analyses light up the regulation of endometrial STAT1 expression during the pre-implantation period. Thus, the aim of this work is to bring new insights about endometrial STAT1 expression and regulation but also on its biological functions during the early pregnancy in cattle. Using physiological and experimental models, the impact of progesterone, IFNT (major signal of the maternal recognition of pregnancy in ruminants) and pregnancy on the expression and the regulation of STAT1 transcript and protein (including its phosphorylation status) have been analyzed in the bovine endometrium and endometrial cells. Thus, STAT1 (transcript, protein and phosphorylation) is up-regulated by the presence of the conceptus and by IFNT but independent of progesterone level at implantation in cattle. To better understand endometrial STAT1 functions, the identification of STAT1 target genes has been initiated: first, on a candidate genes family, SOCS genes, and secondly, with an explorative approach.The proteins SOCS are known to be negative regulator of cytokine signalling pathway. Using physiological and experimental models previously quoted, the eight members of SOCS genes expression and regulation were analyzed during the early pregnancy in cattle. Chromatin immunoprecipitation protocol applied on stromal cells show the recruitment of STAT1 on SOCS promoters by a rapid treatment of IFNT. Moreover, the exhaustive identification of STAT1 target gene has been initiated, using a chromatin immunoprecipitation followed by high-throughput sequencing on bovine endometrium samples. Collectively, this data suggests the involvement of STAT1 in IFNT signalling pathway but also in the regulation of maternal immune system and the apposition/adhesion process, all that being crucial for the implantation in cattle

In the technology of cattle embryo transplantation, the classic protocol for superovulation of embryo donor cows is used, based on 8-10-fold administration of follicle-stimulating hormone (FSH) every 12 hours for 4-5 days. For many decades of using this technology, the yield of high- quality embryos varies within 4-6 pcs. It is necessary to increase the effectiveness of FSH to increase the number of embryos. We conducted a study of the effectiveness of a pharmacological composition consisting of FSH combined with polyethylene glycol (PEG) with a molecular weight of 6000 Da, which increases the yield of the number of embryos obtained, suitable for transplantation into recipients, or their cryopreservation