Characterization of the colocalization between lipid rafts and follicle stimulating hormone receptor using immunofluoresence confocal microscopy

Follicle stimulating hormone (FSH) is an important hormone in both male and female reproduction. By studying the mechanisms of action of this hormone, it is then possible to be able to come up with ways to disrupt these pathways, leading to advances in birth control. Specifically, FSH stimulates the ovarian follicles to grow in females and it stimulates spermatogenesis in males. This hormone transmits its signal by binding to G protein coupled receptors on the cell surface. In the cell membrane, there are specific domains called lipid rafts. These domains are often associated with being a central area for signal transduction in cells. The main goal of our research was to determine if the FSH receptor resides in a lipid raft. One way to identify lipid rafts is by the presence of a membrane sphingolipid called ganglioside GM1. By staining cells with antibodies that recognize the FSH receptor and an antibody that stains for GM1 we used fluorescence and confocal microscopy to try to determine if the two signals coincide. The two signals showed limited colocalization. This is consistent with our model which suggests that only some FSHR is in lipid rafts, and only some lipid rafts contain FSHR.