Many social behaviors in mice, such as aggression, mating and territorial marking, are mediated by the major urinary proteins (MUPs) present in their urine. While the mouse genome codes for 21 MUPs, any given male mouse only expresses a subset of these proteins at a defined concentration. Mice are able to detect the identity and concentration of the MUPs they encounter, and as such, these proteins appear to act as an “individuality signal.” However, how a unique subset of MUPs is chosen for expression remains largely unknown. This study focuses on the control of gene expression of the 21 MUP genes, consisting of the highly similar “central” MUPs and the variable, divergent “peripheral” MUPs. Using hormone treatments on a cultured liver cell line, the expression of MUPs can be induced and studied, which allows for the manipulation of regulatory mechanisms. In an effort to understand the mechanisms controlling MUP choice and expression, this study explores the role that testosterone, dihydrotestosterone, and growth hormone treatments play in AML12 male hepatocytes. Utilizing RNA isolation, cDNA synthesis, and Polymerase Chain Reaction (PCR), the effects of these hormones on MUP expression were analyzed and studied using gel electrophoresis. Identification of mouse growth hormone receptor (mGHR) and mouse androgen receptor (mAR) expression as well as methylation inhibition treatments provide greater insight toward the results of the hormone treatments. Because of their complex expression patterns, the MUPs serve as a good model system to study long standing molecular biology questions regarding mechanisms controlling gene expression.
