A Short-Term In Vivo Screening System For Endocrine Disruptors Utilizing Mosquitofishes (Gambusia affinis and G. holbrooki)
EPA Grant Number: R826130Title: A Short-Term In Vivo Screening System For Endocrine Disruptors Utilizing Mosquitofishes (Gambusia affinis and G. holbrooki)
Investigators: Angus, Robert , Blanchard, Paul , Howell, W. Mike , Watson, R. Douglas
Institution: University of Alabama at Birmingham , Samford University
EPA Project Officer: Turner, Vivian
Project Period: October 1, 1997 through September 30, 2000 (Extended to December 31, 2001)
Project Amount: $320,982
RFA: Endocrine Disruptors (1997) RFA Text | Recipients Lists
Research Category: Economics and Decision Sciences , Health , Safer Chemicals , Endocrine Disruptors
Description:
To establish and document the use of mosquitofish (Poeciliidae Gambusia affinis and G. holbrooki) as highly sensitive bioindicator organisms for use in screening substances with suspected endocrine activity, either singly or in complex mixtures. Expression of the (normally female-limited) vitellogenin gene in males will be used to test chemicals for estrogenic activity. A morphological trait (modified anal fin called a gonopodium) will be used to test for androgenic activity. The gonopodium is not found in normal females, but is readily induced to develop in females exposed to chemicals with androgenic activity. In addition to their utility as laboratory test organisms, these fish will be shown to be suitable as sentinel species for the detection of endocrine disruptors in a variety of fresh- and salt-warmwater aquatic environments. The mosquitofish test system will be a unique and extremely useful addition to our currently available procedures for laboratory and field studies of suspected endocrine-disrupting chemicals.
Approach:
The proposed research has the following main components: (1) Develop a quantitative enzyme-linked immunosorbent assay (ELISA) for vitellogenin (VTG) which can be used to detect this egg yolk protein in the serum of male mosquitofish. This will be used to identify and quantify the effects of estrogenic chemicals. (2) Develop a quantitative index of the effects of androgenic chemicals on the anal fin morphology of females. (3) Perform dose-response experiments on the effects of estrogenic organochlorine insecticides (singly, and in mixtures) on VTG expression in male mosquitofish. (4) Perform dose-response experiments on the effects of androgenic chemicals on the anal fin morphology of females. (5) Investigate the effects of prior hormone exposures on reproductive function of female mosquitofish. (6) Perform laboratory and field tests of selected potential endocrine disruptors.
Expected Results:
(1) Development of a short-term screening system that reflects both exposure to, and effects of endocrine disruptors; (2) Information on latency - effects of prenatal exposure on reproductive characteristics of adults; (3) Information on the effects of low-dose exposures reflecting realistic environmental levels; and (4) Information on the effects of mixtures of chemicals in an in vitro test system.