A whole-animal tissue section in situ hybridization (ISH) system with radio-labeled probes was developed to detect differential gene expression among tissues of the small, oviparous teleost fish, Japanese medaka (Oryzias latipes). Because of its tissue- and gender-specific expression, gonadal aromatase (CYP19a) was selected as a model gene to demonstrate the potential of the system. The ISH system was validated with a 7 d exposure to the model aromatase inhibitor, fadrozole. Fadrozole did not affect the magnitude of gene expression in testes, but significantly up-regulated CYP19a gene expression in ovaries. These results were confirmed with quantitative real-time-polymerase chain reaction (RT-PCR). Histological evaluation revealed that females exposed to 100 μg/L fadrozole lacked mature oocytes. Male gonadal morphology was normal in all treatments. The ISH method developed in this study allowed tissue-specific resolution of gene expression in a whole animal model, as well as the ability to analyze cellular morphological detail in the same organism. Copyright © 2008 Elsevier Inc. All rights reserved.
CitationTompsett, A. R., Park, J. W., Zhang, X., Jones, P. D., Newsted, J. L., Au, D. W. T., . . . Hecker, M. (2009). In situ hybridization to detect spatial gene expression in medaka. Ecotoxicology and Environmental Safety, 72(4), 1257-1264. doi: 10.1016/j.ecoenv.2008.10.013
- Oryzias latipes
- Gene expression
- Endocrine disruption