Project description:The liver of dairy cows naturally displays a series of metabolic adaptation during the periparturient period in response to the increasing nutrient requirement of lactation. The hepatic adaptation is partly regulated by insulin resistance and it is affected by the prepartal energy intake level of cows. We aimed to investigate the metabolic changes in the liver of dairy cows during the periparturient at gene expression level and to study the effect of prepartal energy level on the metabolic adaptation at gene expression level.B13:N13
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)
Project description:We used MethylCap-seq and RRBS to profile methylomes of purified human ovarian granulosa cells. Genomic DNA methylation patterns in ovarian granulosa cells were compared between two groups of women: i) oocyte donors (n=20) who were young (age 26 ± 2.2 years) and had robust response to ovarian stimulation during assisted reproductive technology (ART) (mean number of oocytes retrieved = 25); versus ii) poor responders (n=20) who were older (age 40 ± 2.3 years) and responded poorly to ovarian stimulation during ART (oocytes retrieved ≤4 and peak estradiol level ≤ 1000 pg/ml). The first group served as healthy control. The second group represented the majority of women in their early 40s who have the natural age-related decline of ovarian functions and therefore respond poorly to ovarian stimulation during ART. We compared DNA methylomes in ovarian granulosa cells from oocyte donors versus poor responders using two approaches: MethylCap-seq for broader genomic coverage, and RRBS for absolute quantification. Due to very limited amount of materials available from each poor responder, samples containing equal amounts of granulosa cell DNA were pooled from 10 individuals in each group. A second set of experiments pooling granulosa cell DNA samples from independent donor and poor responder groups (ten individuals each) was then performed.