The regulation of gonadal growth and development in fishes prior to the onset of puberty
While much is known about the regulation of gonadal development after puberty in vertebrates, relatively little is known about the biochemical and molecular processes involved in early gonadal growth and development. I am particularly interested in early ovarian development and the transition between primary and secondary ovarian follicle growth (i.e. transition from immaturity to sexual maturity). Early ovarian development is of particular interest because this is when stockpiles of maternal RNAs and proteins, which will eventually support embryonic development, are laid down. The proteins incorporated into the developing egg are thought to contribute to high quality eggs resulting in more robust larvae and increased survivorship. Additionally, in seasonally breeding animals, absolute fecundity, the maximum number of eggs that could potentially be ovulated per animal, is thought to be determined prior to puberty.
The Forsgren lab focuses on the factors that regulate and influence early embryonic and gonadal development in fishes. Our investigations encompass three areas of research: 1) the role of hormones in the control of growth and development, 2) the identification and function of putative proteins that are involved in regulating early embryonic and gonadal development, and 3) the impacts of endocrine disrupting compounds (anthropogenic chemicals that mimic native sex steroid hormones) on reproductive physiology.
Forsgren KL, S Qu, D Cwiertny, D Schlenk. 2014. Trenbolone acetate metabolites promote ovarian growth and development in adult Japanese medaka (Oryzias latipes). General and Comparative Endocrinology 202: 1-7
Forsgren KL, N Riar, D Schlenk. 2013. The effects of the pyrethroid insecticide, bifenthrin, on steroid hormone levels and gonadal development of steelhead (Oncorhynchus mykiss) under hypersaline conditions. General and Comparative Endocrinology 186: 101-107
Forsgren, KL, X Deng, G Lu, SM Bay, DE Vidal-Dorsch, J Armstrong, J Gully and D Schlenk. 2012. Annual and seasonal evaluation of reproductive status in hornyhead turbot at municipal wastewater outfalls in the southern California bight. Environmental Toxicology and Chemistry 31: 1-11
Forsgren, KL and G Young. 2012. Stage-specific effects of androgens and estradiol-17 beta on the development of late primary and early secondary ovarian follicles of coho salmon (Oncorhynchus kisutch) in vitro. Biology of Reproduction 87: 1-14
Forsgren, KL and KA Young. 2008. Weedy seadragon (Phyllopteryx taeniolatus) gonadal morphology: characterization of ovarian and testicular development. Australian Journal of Zoology 56: 441-446