Anne N. Hirshfield, Ph.D.
Laboratory of Ovarian Embryology and Toxicology
Most of our knowledge concerning follicular development is restricted to events that occur during the final phases of growth. The earlier aspects of folliculogenesis remain largely unexplored. My studies address fundamental questions concerning early folliculogenesis such as: (1) What are the cell lineages of granulosa and theca cells? (2) How do cells become committed to differentiate into granulosa cells or theca cells? (3) How are primordial follicles assembled? (4) What induces the formation of the follicular basement membrane during the assembly of primordial follicles? (5) What rouses dormant primordial follicles to begin growth? These questions are central to issues of fertility control, ovarian aging and the etiology of ovarian cancers. An additional research focus in this laboratory is reproductive toxicology. My studies of the normal ovary have led me to ask questions concerning the possible impact of environmental toxicants on the ovary and other hormone responsive tissues. Some of these questions are: (1) How can we screen suspected toxicants for their potential to cause damage to hormonally regulated tissues? (2) Does subtle damage to primordial follicles have an impact on overall fertility? (3) Do oocytes at different stages of development vary in their susceptibility to environmental mutagens? (4) Does exposure to endocrine disruptors during development have consequences that are not manifested until later in life? These questions are being addressed with in vivo and in vitro experimental approaches, using rats as the animal model. Methods include immunohisto-chemistry, in situ hybridization, autoradiography, quantitative morphometry (computerized image analysis), and cell cycle analysis.
Recent PublicationsHirshfield AN 1991 Development of follicles in the mammalian ovary. International Review of Cytology 124:43-101.
Hirshfield AN 1994 The relationship between the supply of primordial follicles and the onset of follicular growth in rats. Biology of Reproduction 50:421-428.
Hirshfield AN, DeSanti AM 1995 Patterns of ovarian cell proliferation in rats during the embryonic period and the first three weeks postpartum. Biology of Reproduction 53:1208-1221.
Flaws JA, Abbud R, Mann RJ, Nilson JH, Hirshfield AN 1997 Chronically elevated luteinizing hormone depletes primordial follicles in the mouse ovary. Biology of Reproduction, in press.
