Author(s): Mariah McDonald, Kaden Smith
Mentor(s): Zoe Thompson
Institution UVU
The pro-opiomelanocortin (POMC) gene codes for several peptides that support a variety of functions in the body. There are 3 main peptides that are synthesized from the POMC gene. Those peptides are adrenocorticotropic hormone (ACTH), alpha-melanocyte-stimulating hormone (a-MSH), and β-endorphin. ACTH causes cortisol release as part of the regulation of stress and metabolism. The role of a-MSH is to act as a hormone that regulates food intake based on energy expenditure and calorie consumption. β-endorphin functions as a natural painkiller and is involved with reward and energy homeostasis. POMC mutations result in a loss of these peptide products, and results in early onset obesity due to hyperphagia (over-eating). In humans, this may also associated with infertility. We have a mouse model of POMC-deficiency, and are using it to study the relationship between obesity & infertility. Female POMC-deficient mice also seem to be infertile. Female mice have a cycle known as the estrus cycle. This cycle is similar to the menstrual cycle in humans, but only lasts 4-5 days; it includes four stages; proestrus, estrus, metestrus, and diestrus. We hypothesize that the estrus cycles of the POMC-deficient mice are abnormal. We will track the estrus cycle by capturing the cells in the vaginal canal using a pipette smearing technique and 0.9% saline solution. These samples will be observed under a microscope and cell types present will be analyzed. There are three types of cells that could be present in the samples which are epithelial cells, cornified cells, and leukocytes. The proportion of cell types in these samples will determine which stage of the estrus cycle the female mouse is currently in. We will collect samples from POMC-deficient female mice and compare to wildtype female mice as the control. These results will hopefully help us understand more about the relationship between obesity & infertility in mice, which may translate to humans as well.