Project description:Gonadotropin surge acts on the preovulatory follicle of the ovary to induce luteinization of follicular cells, oocyte meiotic maturation, cumulus expansion and follicular rupture leading to ovulation. These processes are brought about by spatial and temporal changes in transcriptional regulation of genes in the follicular cells in response to the gonadotropin surge. Analysis of gene expression changes in the periovulatory follicular cells will help in delineating the signal transduction pathways involved in the above mentioned processes. In monoovulatory species like bovines, the time interval of 24-28 hours between gonadotropin surge and ovulation provides distinct advantage for studying the temporal changes in the gene expression pattern. Thus, in the present study, we attempt to identify the temporal changes in the global gene expression profile in the periovulatory follicle of buffalo cows in response to gonadotropin surge and the results suggest the involvement of Insulin-like Growth Factor 1 and cytokine signaling pathways in the periovulatory events. Experiment Overall Design: To study the periovulatory gene expression changes in buffalo cows, an induced-ovulation model system involving sequential treatment with PGF2alpha and GnRH was standardized. The follicular wave containing at least one large follicle of ~7mm size was determined by ultrasonography on day 7 of the estrous cycle before administering exogenous PGF2alpha to induce luteolysis and follicular growth. Exogenous GnRH (100µg i.m) was administered 36h post PGF2alpha to induce LH surge. The time course of increase in LH levels post GnRH injection was monitored. Since peak LH levels are attained 2 h post GnRH administration, the time intervals of 3 h post GnRH (corresponding to1 h post LH surge) and 24 h post GnRH (corresponding to 22 h post LH surge) were chosen to identify the gene expression profile associated with immediate early and delayed changes in periovulatory follicle respectively. Thus ovaries were collected before, 1 h and 22 h post LH surge and follicle wall and granulosa cells were isolated from the ovaries and snap frozen for the purpose of RNA isolation.
Project description:The domestic buffalo (Bubalus bubalis) has presented an important role in the livestock industry, contributing to milk and meat production worldwide, especially in developing countries. However, little is known about its reproductive particularities. Studies regarding protein composition of buffalo SP are still limited and a complete mapping of buffalo SP proteins is still lacking in the literature. Hence, a comprehensive study of SP proteome is of great importance to better understand the mechanisms involved in male reproduction and to optimize the reproductive biotechnologies of farm animal species. Therefore, the aim of this study is to describe for the first time the Bubalus bubalis seminal plasma proteome using a label free shotgun HDMS approach. This type of analysis is interesting since it yields a high number of detected proteins, generating a dataset that is useful for further characterizing the buffalo SP.
Project description:Sperm carries information to the presumptive embryo upon fertilization in terms of epigenetic codes and transcripts along with the haploid genome. The epigenetic code includes DNA methylation and histone modifications. During spermatogenesis, the DNA of sperm undergoes overall methylation changes and this could have some role to play in fertilizing ability of the sperm. Many of the studies have shown that the altered methylation can cause sub fertility. In the present study we report the development of first comprehensive 4X180K buffalo (Bubalus bubalis) CpG island/promoter microarray for studying the global DNA methylation profile of buffalo sperm. The array has been developed by employing microarray based comparative genomic hybridization (aCGH) technique with bovine and buffalo DNA using bovine genome sequence as reference. The array represents 157084 features assembled from CDS, Promotor and CpG regions covering 2,967 unique genes. We also report the comparison of genome wide methylation differences in buffalo sperm from high fertile and sub fertile bulls which indicated profound discrepancies in their methylation status. A total of 96 individual genes along with another 55 genes covered under CpG islands were found differentially methylated and and were associated with different cellular functions and biological processes affecting germ cell development, spermatogenesis, capacitation and embryonic development.