MICRORNAS AS REGULATORS OF LUTEAL FUNCTION

The decline in reproductive efficiency of dairy cows has resulted in substantial economic loss to farmers. Most failed pregnancy are due to embryonic death, which could be due to inadequate function of the corpus luteum (CL). The CL is a structure on the ovary that secretes progesterone, which is essential for survival of the embryo. The long term goal of this research program is to increase understanding of the function of the bovine corpus luteum (CL). The global hypothesis to be addressed is that optimal function of the CL is regulated by small nucleic acid molecules, called microRNAs. The specific objectives of the project are to: 1: Determine the role of microRNAs in regulation of the luteal development, 2: Evaluate the role of microRNA in regulating processes that result in regression or rescue of the CL, 3: Determine if hormones that are known to alter function of the CL act by changing expression of microRNAs in luteal cells, and 4: Precisely quantify all microRNAs in the CL. The results of this project will provide entirely new information about the role of specific microRNAs in the function of the CL and will identify microRNAs that may be uniquely expressed in the CL or in cows. These will be the first such reports of microRNA expression and function in the CL of cows. Understanding how miRNAs regulate the CL will fill a critical gap in our current knowledge of luteal function and may lead to new methods to enhance reproductive efficiency of dairy cattle and lower the costs of food production.