Presenter: Samuel Lewis
Authors: Samuel Lewis, Zoe Thompson
Faculty Advisor: Zoe Thompson
Institution: Utah Valley University
The pro-opiomelanocortin (POMC) gene is expressed in the hypothalamus and pituitary and is cleaved into several peptide hormones. One of these is melanocyte-stimulating hormone (MSH), which is involved in food intake and energy expenditure. A mutation in the POMC gene can result in a rare condition in which the subject displays early-onset obesity characterized by severe hyperphagia (i.e. excess hunger). Affected subjects may also show a lack of pubertal development. In this experiment, we will study mice with a mutation in the POMC gene. They show some of the same symptoms as humans with a POMC mutation, including hyperphagia, obesity & infertility. Specifically, we will investigate the estrous cycle in female mice to determine if they are cycling normally. The estrous cycle, similar to the menstrual cycle in humans, is characterized by changes in reproductive hormones, and can be divided into four stages: proestrus, estrus, metestrus, and diestrus. Cells lining the surface of the vagina have been previously collected using a pipette smear technique. Each stage can be characterized by the proportion of three cell types: epithelial cells, cornified cells, and leukocytes. These cells correspond to the fluctuating hormone levels during the estrous cycle. Images of these samples will be assessed for the composition of cells to determine the stage of the estrus cycle, and whether or not the cycle displays normal patterning. Because POMC-deficient mice are infertile, we hypothesize their estrous cycles may be atypical. For example, the estrous cycle of the POMC-deficient mice may appear in irregular order or with one stage being predominant over the rest. If the estrous cycle is atypical, then we will measure the hormones directly to confirm that the infertility is caused by changes in hormonal regulation. This will help us to understand more about how the POMC gene affects reproductive function.