scholarly journals Partenogenetic development of Bos taurus embryos from oocytes matured in different culture systems

2020 ◽  
Vol 197 (6) ◽  
pp. 66-72
Author(s):  
T. I. KUZMINA

Abstract. Identification of the factors determining of donor’s oocyte competence to parthenogenetic development will allow developing an effective method for obtaining parthenotes to solve fundamental problems of regulating gene activity in ontogenesis, creating homozygous embryonic stem cell lines, improving the stages of cloning technology, and modeling of in vitro oocyte maturation media. The purpose of study is to evaluate the potencies of Bos taurus oocytes matured in different culture systems to cold shock-induced parthenogenesis. Methods. For oocyte maturation, culture systems of the following composition were used: 1 – TC-199 with 10 % fetal bovine serum (FBS), 50 μg/ml estradiol, 10 μg/ml luteinizing hormone, 10 μg/ml follicle-stimulating hormone; 2 – TC-199 with 10 % estrous serum of cows; 3 – TC-199 with 50 % fluid from follicles (Ø 3–8 mm); 4 – TC-199 with 50 % protein of follicular fluid (molecular weight of 65 kDa); 5 – TC-199 with 10 % FBS, 1×106 granulosa cells/ml medium; 6 – TC-199 with 10 % FBS and walls of follicles (Ø 6–8 mm); 7 – TC-199 with 10 % FBS, 1×106 granulosa cells/ml medium and walls of follicles (Ø 6–8 mm). After 24 hours of cultivation, the oocytes were activated by cold shock (exposure time 20 minutes, temperature 0…–4 °C. Results. The proportion of embryos at the stages of late morula and blastocysts from oocytes matured in system 7 was 45 % (58/129), which was significantly higher than in other systems: 1 – 28 % (39/141), P < 0.05; 2 – 31 % (42/137), P < 0.05; 3 – 25 % (33/133), P < 0.01; 4 – 18 % (25/139), P < 0.001; 5 – 31 % (41/132), P < 0.05; 6 – 33 % (43/129). The introduction of estradiol or structural components of antral follicles into the oocytes maturation medium contributed to an increase in the proportion of parthenotes at the preimplantation stages of development, including blastocysts, and a decrease in the level of degenerated embryos. Scientific novelty. A comparative morphological analysis of the potentials for parthenogenesis of bovine oocytes matured in various culture systems and activated by cold shock was carried out for the first time. Optimal systems for in vitro maturation of female gametes were proposed. Based on the analysis of the results, we recommend before induction to parthenogenesis bovine oocytes culture in media supplemented with 50 ng/ml estradiol or structural components of antral follicles producing estradiol.

2019 ◽  
Vol 31 (2) ◽  
pp. 272 ◽  
Author(s):  
M. A. Abdel-Ghani ◽  
Y. Yanagawa ◽  
A. Z. Balboula ◽  
K. Sakaguchi ◽  
C. Kanno ◽  
...  

In this study we investigated the effect of astaxanthin (Ax), which exhibits strong antioxidant activity, during invitro growth (IVG) on the developmental competence of oocytes and steroidogenesis of granulosa cells derived from early antral follicles. Bovine oocyte–cumulus–granulosa complexes collected from early antral follicles were cultured for 12 days in the presence or absence (control) of 500µM Ax. The viability of oocytes and antrum formation in the granulosa cell layer during IVG culture were greater in the presence than absence of Ax (P&lt;0.05). Regardless of Ax treatment, 17β-oestradiol production increased during IVG culture; however, progesterone production was significantly lower in the presence than absence of Ax (P&lt;0.05). Reactive oxygen species levels were lower in Ax-treated oocytes than in controls after IVG (P&lt;0.05). Although nuclear maturation and cleavage rates did not differ between the Ax-treated and control groups, Ax treatment led to weaker cathepsin B activity in oocytes and better blastocyst rates than in controls (P&lt;0.05). Accordingly, Ax treatment during IVG increased the total number of cells in blastocysts (P&lt;0.05). These results indicate that Ax supplementation of IVG medium improves the quality of bovine oocytes due to its antioxidative effects on growing oocytes and its suppression of the luteinisation of granulosa cells.


1976 ◽  
Vol 56 (2) ◽  
pp. 105-119 ◽  
Author(s):  
R. D. BAKER ◽  
C. POLGE

Fertilization and its prerequisites, i.e. sperm transport, capacitation and oocyte maturation, were discussed with emphasis on the occurrence of these processes in the pig and cow. Attempts to fertilize porcine and bovine ova in a micro-droplet system which was used successfully to fertilize mouse and hamster ova were not successful. Many droplets contained highly motile spermatozoa which were effective in removing the follicular cells from around the zonae. Spermatozoa attached to the zonae but did not penetrate the ova in vitro. No motile bull or boar spermatozoa with an "acrosome reaction" were observed in the droplets. When droplets which contained boar spermatozoa and pig follicular oocytes for 4 h were transferred into the oviducts of estrous females, spermatozoa exhibited acrosome reactions and ova were penetrated. Reducing oocyte maturation time and injecting progesterone before ovulation increased (P < 0.05) the incidence of polyspermy in pigs. Bovine oocytes underwent maturation and were penetrated by bull spermatozoa in pig oviducts. Culture systems, other than the oviduct, did not provide satisfactory conditions for fertilization of bovine or porcine ova.


Author(s):  
Er-Meng Gao ◽  
Bongkoch Turathum ◽  
Ling Wang ◽  
Di Zhang ◽  
Yu-Bing Liu ◽  
...  

AbstractThis study evaluated the differences in metabolites between cumulus cells (CCs) and mural granulosa cells (MGCs) from human preovulatory follicles to understand the mechanism of oocyte maturation involving CCs and MGCs. CCs and MGCs were collected from women who were undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment. The differences in morphology were determined by immunofluorescence. The metabolomics of CCs and MGCs was measured by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) followed by quantitative polymerase chain reaction (qPCR) and western blot analysis to further confirm the genes and proteins involved in oocyte maturation. CCs and MGCs were cultured for 48 h in vitro, and the medium was collected for detection of hormone levels. There were minor morphological differences between CCs and MGCs. LC-MS/MS analysis showed that there were differences in 101 metabolites between CCs and MGCs: 7 metabolites were upregulated in CCs, and 94 metabolites were upregulated in MGCs. The metabolites related to cholesterol transport and estradiol production were enriched in CCs, while metabolites related to antiapoptosis were enriched in MGCs. The expression of genes and proteins involved in cholesterol transport (ABCA1, LDLR, and SCARB1) and estradiol production (SULT2B1 and CYP19A1) was significantly higher in CCs, and the expression of genes and proteins involved in antiapoptosis (CRLS1, LPCAT3, and PLA2G4A) was significantly higher in MGCs. The level of estrogen in CCs was significantly higher than that in MGCs, while the progesterone level showed no significant differences. There are differences between the metabolomes of CCs and MGCs. These differences may be involved in the regulation of oocyte maturation.


Zygote ◽  
2014 ◽  
Vol 23 (3) ◽  
pp. 416-425 ◽  
Author(s):  
Yan Yun ◽  
Peng An ◽  
Jing Ning ◽  
Gui-Ming Zhao ◽  
Wen-Lin Yang ◽  
...  

SummaryOocyte-specific linker histone, H1foo, is localized on the oocyte chromosomes during the process of meiotic maturation, and is essential for mouse oocyte maturation. Bovine H1foo has been identified, and its expression profile throughout oocyte maturation and early embryo development has been established. However, it has not been confirmed if H1foo is indispensable during bovine oocyte maturation. Effective siRNAs against H1foo were screened in HeLa cells, and then siRNA was microinjected into bovine oocytes to down-regulate H1foo expression. H1foo overexpression was achieved via mRNA injection. Reverse transcription polymerase chain reaction (RT-PCR) results indicated that H1foo was up-regulated by 200% and down-regulated by 70%. Based on the first polar body extrusion (PB1E) rate, H1foo overexpression apparently promoted meiotic progression. The knockdown of H1foo significantly impaired bovine oocyte maturation compared with H1foo overexpression and control groups (H1foo overexpression = 88.7%, H1foo siRNA = 41.2%, control = 71.2%; P < 0.05). This decrease can be rescued by co-injection of a modified H1foo mRNA that has escaped from the siRNA target. However, the H1e (somatic linker histone) overexpression had no effect on PB1E rate when compared with the control group. Therefore we concluded that H1foo is essential for bovine oocyte maturation and its overexpression stimulates the process.


2021 ◽  
Author(s):  
◽  
Zaramasina Clark

<p>The number of cycles of assisted reproductive technologies (ART) performed increased by ~9.5 % globally between 2008 and 2010. In spite of this, the success rate in terms of delivery was only ~19.0 % (Dyer et al., 2016). This discrepancy between the demand for, and success of, these technologies necessitates the development of tools to improve ART efficiency. To facilitate this, a better understanding of how the microenvironment changes within the developing follicle to culminate in a mature, developmentally-competent oocyte is required. This study employed an in vivo and in vitro ovine model to investigate the relationship between the surrounding microenvironment and oocyte maturation, and in particular, the attainment of oocyte developmental competency and high-quality embryos.  The first objective of this PhD study was to comprehensively investigate the changing microenvironment of in vivo matured, presumptive preovulatory (PPOV) follicles from wild-type (++) and high ovulation rate (OR; I+B+) ewes. The high OR ewes were heterozygous carriers of mutations in BMP15 (I+) and BMPRIB (B+). Functional differences in follicular somatic (granulosa and cumulus) cells between these genotypes, including differential gonadotropin responsiveness of granulosa cells, composition of follicular fluid and gene expression profiles in cumulus cells were evident. These differences emerged as part of a compensatory mechanism by which oocytes from smaller follicles, containing fewer granulosa cells, achieved developmental competency in I+B+ ewes.  The second objective of this PhD study was to develop new approaches for improving current in vitro maturation (IVM) strategies. The first approach utilised in this study focused on developing biomarkers that could be used to improve prediction of developmental competency in oocytes and in vitro produced embryos. This involved interrogating the hypothesis that a combination of molecular and morphokinetic biomarkers would better predict the developmental competency of oocytes and embryos compared to using these biomarkers alone. The second approach utilised in this PhD study tested the effects of modulating IVM conditions to better mimic the follicular microenvironment of a high, compared to a low, OR species on oocyte developmental competency and embryo quality. This involved supplementing IVM media with different ratios of two oocyte-secreted growth factors, i.e. GDF9:BMP15, that were representative of low or high OR species. These approaches demonstrated significant potential and warrant further investigation.  The most significant finding of this study was that despite variances in the surrounding microenvironment during in vivo and in vitro oocyte maturation that culminated in differential gene expression patterns in cumulus cells, and divergent gonadotropin-responsiveness of granulosa cells, the gene expression signatures of developmentally-competent oocytes and the morphokinetics of high-quality embryos were unaltered. This confirms the value of developing such biomarkers for oocyte development competency and embryo quality that remain unaltered despite a changing surrounding environment. Interestingly, simulating the ratio of GDF9:BMP15 that oocytes from high OR species are exposed to during maturation improved developmental competency in oocytes as demonstrated by increased blastocyst rates. Furthermore, this study has demonstrated that combinations of molecular (cumulus cell gene expression) and morphokinetic biomarkers improved the ability to predict developmental competency in oocytes and embryos. Overall, this study revealed novel information regarding the follicular microenvironment during final maturation and identified several novel approaches to improving the efficiency of ART.</p>


2019 ◽  
Vol 86 (12) ◽  
pp. 1874-1886
Author(s):  
Francisco Taiã G. Bezerra ◽  
Francisco Edilcarlos O. Lima ◽  
Laís Rayani F. M. Paulino ◽  
Bianca R. Silva ◽  
Anderson W. B. Silva ◽  
...  

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