ANALYSIS OF TRANSGENIC MOUSE MODELS TO STUDY MAMMALIAN SPERMATOGONIA

Abstract

Spermatogenesis in the mammalian testis results in the daily production of millions of spermatozoa. This developmental process is founded upon the actions of a small population of spermatogonial stem cells (SSCs). As SSCs divide, their progeny must either remain an SSC to maintain the stem cell pool (self-renewal) or become an undifferentiated progenitor spermatogonium that proliferates prior to differentiating in response to retinoic acid (RA) and entering meiosis. Our laboratory is focused on understanding the mechanisms that regulate these fate decisions as well as defining the changes that occur downstream of RA that prepare spermatogonia for entry into meiosis. Currently, researchers have been unable to readily isolate pure populations of spermatogonia in the developing or adult testis. To address this, I have examined multiple transgenic mouse models to identify those with germ cell-specific expression of fluorescent reporter genes that will enable us to isolate spermatogonia using fluorescence-activated cell sorting (FACS). The results in this thesis describe these efforts, and document the identification of an excellent mouse model for future studies in our laboratory to understand the mechanisms underlying spermatogonial development. This work was supported by a grant from the NIH/NICHD (HD090083) to C.B.G.