Director Medical Education
Department of Anatomy and Cell Biology
Ph.D.: 1983, University of California, San Francisco
Postdoctoral: Harvard Medical School, Boston
Research interests include understanding how spermatogenesis is regulated on a cellular level with specific attention to: 1) the molecular cloning and characterization of a mouse germ cell nuclear antigen (mGCNA1) uniquely expressed during spermatogenesis and oogenesis; 2) characterization of the unique properties of the seminiferous tubule basement membrane; 3) determining the factors that control and regulate embryonic germ cell number.
The major focus of my work is to the characterize mGCNA1 that is present only in germ cells (Enders and May, 1994) and serves as a marker of early germ cell tumors (Wang and Enders, 1996). The antigen is recognized by a rat monoclonal antibody, 10D9G11, that recognized mGCNA1 in both male and female germ cells from embryonic day 11 until the dictyate stage of the first meiotic division (females, neonatally; males, throughout life). Thus, mGCNA1 is expressed during the mitotic expansion of both the female and male populations.
In collaboration with James L. Resnick at the University of Florida, Gainesville we have determined that activin and transforming growth factor ß limit the proliferation murine primordial germ cells (Richards et al., 1999a). We will be examined the proliferation and migration of embryonic germ cells numbers, using mGCNA1 at a marker, in two transgenic mouse models that lack activin receptors (ActR-IIB) and transforming growth factor receptors (TbR-II).