Contact information
GenoSpectra, Inc.
6519 Dumbarton Circle
Fremont, CA 94555
Tel: 510.818.2674
Fax: 510.818.2650
e-mail: mfielden@genospectra.com

Education
B.Sc. Toxicology 1997, University of Guelph, Ontario, Canada.
Ph.D Biochemisty and Environmental Toxicology. May 2002.

Research Project

Reproductive and Genomic Effects of Male Endocrine Disruptors

Many studies suggest that gestational and lactational exposure to endocrine disrupting chemicals can adversely affect reproductive function at later stages of life.Studies on the male reproductive system emphasize the importance of hormonal timing during gestation and neonatal life for normal development of the reproductive system. Variations in the timing of hormonal interference can result in cryptorchidism, incomplete genitalia development, and incomplete maturation of germ cells and the supporting Sertoli and Leydig cells of the testes which may result in reduced sperm production and/or testicular and germ cell cancers. Mechanistic studies and epidemiological evidence of decreasing sperm quality supports the hypothesis that human male fertility may be at risk due to exposure to exogenous estrogenic chemicals during development. To assess the effects of developmental exposure to exogenous estrogenic chemicals, both natural and synthetic, requires a comprehensive understanding of their effects at the molecular, cellular and tissue level within the context of the whole organism and its genome. To address these needs, we are employing a comprehensive strategy in order to assess the effects of male endocrine disruptors on development, spermatogenesis and testicular gene expression.

Using the mouse as our model system, we are examining exposed offspring at the tissue, cell and molecular level and at two developmental stages; early and late adulthood. Tissue level effects are assessed by examing testicular histology and development of other hormone-dependent tissues. Cellular level effects are assessed using a computer-assisting sperm analysis system and an in vitro fertilization assay (IVF) to examine spermatogenesis. In order to study the effects of male endocrine disruptors at the molecular level, a testis-specific DNA microarray (dbTEST) is being developed in our lab to measure testicular gene expression profiles in affected male offspring. Integration of tissue, cellular and molecular level effects should point to many new hypotheses as to the mechanisms of action of a diverse set of endocrine disruptors and may also reveal new insights into the role of estrogens in male reproductive development and spermatogenesis.