Author(s): Lisette Partipilo
Mentor(s): Zoe Thompson
Institution UVU
The pro-opiomelanocortin (POMC) gene is expressed in the hypothalamus and the pituitary gland. Once cleaved, the POMC protein is converted into several different peptide hormones, including melanocyte-stimulating hormone (MSH), which is responsible for providing a satiety signal after food intake. Another important product of the POMC gene is adrenocorticotropic hormone (ACTH), a precursor for the synthesis of cortisol, which is known as the stress hormone, and is directly involved in the regulation of the hypothalamus pituitary-adrenal axis and blood glucose levels, among other roles. POMC mutations in humans cause the production of an abnormal POMC protein, resulting in the loss of a major satiety signal, leading to hyperphagia (e.g. overeating), obesity and suspected infertility. In this experiment, we will use a mouse model of POMC deficiency, and we plan to measure the concentration of total cortisol in dried feces as an indicator of general stress levels, which may potentially affect fertility. Free cortisol concentration will be determined by using a competitive enzyme-linked immunosorbent assay (ELISA). We will compare levels among wildtype, heterozygous, and homozygous POMC-deficient males & females. Our hypothesis is that POMC-deficient mice have lower levels of cortisol and that may potentially play a role in their reproductive function. Also, although our mice are housed in a generally low-stress environment, we are also interested in characterizing the cortisol levels for our wildtype mice, in order to assess their current housing situation, and be able to use this baseline as a comparison for future studies.