Science Inventory

Sex-specific gonadal and gene expression changes throughout development in fathead minnow

Citation:

Leet, J., K. Lesteberg, H. Schoenfuss, A. Olmstead, J. Amberg, G. Ankley, AND M. Sepúlveda. Sex-specific gonadal and gene expression changes throughout development in fathead minnow. Sexual Development. Karger Libri AG, Basel, Switzerland, 7(6):303-307, (2013).

Impact/Purpose:

Although fathead minnows (Pimephales promelas) are commonly used as a model fish in endocrine disruption studies, none have characterized sex-specific baseline expression of genes involved in sex differentiation during development in this species. Using a sex-linked DNA marker to verify gender, we evaluated the expression of genes involved in sex differentiation (dmrt1, cyp19a, cyp17, star, esr1, ar) in developing fathead minnows (10 45 days post hatch; dph). There was 100% agreement between gender determination using the DNA sex marker and histology in samples when sex could be identified histologically. Similarly to other teleosts, we observed non-overlapping sex-specific gene expression for dmrt1 and cyp19a in females and cyp17 in males. Expression of star, esr1 and ar was not as sexually dimorphic, although expression of esr1 was higher in females after 40 dph. Regardless of gender and with exception of star, there was an overall increase in gene expression throughout development. Evaluation of these molecular markers in combination with gender identification will help us better understand the mechanisms regulating sex differentiation in fathead minnows and how endocrine disrupting chemicals may alter these processes.

Description:

Although fathead minnows (Pimephales promelas) are commonly used as a model fish in endocrine disruption studies, none have characterized sex-specific baseline expression of genes involved in sex differentiation during development in this species. Using a sex-linked DNA marker to verify gender, we evaluated the expression of genes involved in sex differentiation (dmrt1, cyp19a, cyp17, star, esr1, ar) in developing fathead minnows (10 45 days post hatch; dph). There was 100% agreement between gender determination using the DNA sex marker and histology in samples when sex could be identified histologically. Similarly to other teleosts, we observed non-overlapping sex-specific gene expression for dmrt1 and cyp19a in females and cyp17 in males. Expression of star, esr1 and ar was not as sexually dimorphic, although expression of esr1 was higher in females after 40 dph. Regardless of gender and with exception of star, there was an overall increase in gene expression throughout development. Evaluation of these molecular markers in combination with gender identification will help us better understand the mechanisms regulating sex differentiation in fathead minnows and how endocrine disrupting chemicals may alter these processes.

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Record Details:

Record Type: DOCUMENT (JOURNAL/NON-PEER REVIEWED JOURNAL)
Product Published Date: 12/01/2013
Record Last Revised: 04/06/2015
OMB Category: Other
Record ID: 264692

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LABORATORY

MID-CONTINENT ECOLOGY DIVISION