Project description:Chromosomal instability (CIN) occurs at high frequency during early in vitro embryogenesis and is known to be associated with early embryonic loss in humans. The chromosomal stability of in vivo-conceived cleavage stage embryos largely remains unknown. Here, we applied haplotyping and copy number profiling to investigate genomic architecture of 171 single bovine blastomeres and to compare the nature and frequency of CIN between in vivo embryos, in vitro embryos produced from ovum pick up with ovarian stimulation (OPU-IVF), and in vitro produced embryos from in vitro matured oocytes without ovarian stimulation (IVM-IVF). Our data shows that CIN is significantly lower in in vivo conceived cleavage stage embryos when compared to in vitro cultured embryos, as genomic stability of single blastomeres in both IVF embryos was severely compromised (P<0.0001)
Project description:Somatic cells surrounding the oocyte were sampled at the following stages: developmentally incompetent or poorly competent prophase I oocytes (NC1 oocytes), developmentally competent prophase I oocytes (C1 oocytes), and developmentally competent metaphase II oocytes (C2 oocytes). NC1 cumulus cells (CC) were sampled from immature calf oocytes, C1 samples from immature cow oocytes, and C2 samples from in vivo matured cow oocytes. Global transcriptional profiling was performed using cumulus cells collected from bovine ovarian follicles during in vivo oocyte developmental competence acquisition. Cumulus cells were collected at 3 stages: early stage follicles (prophase I arrested oocytes, meiotically competent but developmentally incompetent, n=6), late stage follicles (prophase I arrested oocytes, meiotically competent and developmentally competent, n=6) and ovulatory follicles collected by ovum pick-up (OPU) in vivo (metaphase II arrested oocytes, developmentally fully competent, n=5).
Project description:In a reproductive strategy that is considered unique to the mammalian lineage, spermatozoa must undergo a series of physiological changes, termed capacitation, in the female reproductive tract prior to developing their capacity to fertilize an ovum. Here, we have employed a comparative proteomic strategy to explore the biological significance of this form of post-testicular maturation in the ancient reptilian species of the Australian saltwater crocodile (Crocodylus porosus).
Project description:In vitro maturation (IVM) of the oocytes is a routine method in bovine embryo production. The competence of bovine oocytes to develop into embryo after IVM and in vitro fertilization (IVF) is lower as compared to in vivo preovulatory oocytes. Cumulus cells (CC) that enclose an oocyte are involved in the acquisition of oocyte quality during maturation. Using transcriptomic approach we compared cumulus cells gene expression during IVM with that in vivo preovulatory period. Global transcriptional profiling was performed using cumulus cells collected from mature bovine oocytes (metaphase-II stage) after maturation performed either in vivo or in vitro. In vivo matured cumulus cells were collected from ovulatory follicles of Montbeliard adult cows by ovum pick-up in vivo (OPU, n=4). In vitro matured cumulus cells were recovered from the oocytes after 22h of in vitro culture of cumulus-oocyte complexes (50 COC per experiment) from 2-6 mm ovarian follicles of adult cows (MIV, n=4). Gene expression analysis was carried out between in vivo and in vitro matured cumulus representing a total of 8 slides (dye swap protocol)