Abstract
Abstract: :
Purpose: Congenital glaucoma gene Cyp1b1 encodes enzyme capable of metabolizing ligands for the nuclear receptor family such as steroids and retinoids. Due to their relatively small size and lipophilicity, these molecules can readily diffuse from the site of their synthesis forming either gradient or sharply demarcated patterns. These patterns might then be translated into spatial patterns of cellular differentiation as a result of steroid and retinoid abilities to modulate gene transcription via binding to various nuclear receptors. Our objective was to study the expression domains of Cyp1b1 and nuclear receptors for estrogen and retinoic acid during the early stages of mouse eye development Methods: FVB/NcrlBR mouse embryos staged at 9.5 dpc were obtained by timed breeding experiments. Antibodies against estrogen receptors alpha and beta, retinoic acid receptors alpha and beta and retinoic X receptors alpha and gamma were purchased from Santa Cruz Biotechnology, Inc., Santa Cruz, CA and Alpha Diagnostic International, San Antonio, TX. Immunohistochemical staining was performed on frozen tissue sections. Results: In the developing mouse eye Cyp1b1, estrogen receptor beta, and retinoid X receptor alpha displayed restricted expression along the dorso–distal / proximo–ventral axis of the developing eye. These proteins were detected in the surface ectoderm overlying the optic vesicle and in the dorsal half of the future neural retina. Under the experimental conditions used we observed no appreciable positive staining with antibodies raised against estrogen receptor alpha and retinoic acid receptor alpha. Positive staining for retinoic acid receptor beta and retinoid X receptor gamma was observed only in the surface ectoderm overlying the optic vesicle. Conclusions: Our study suggests that estrogen receptor beta and retinoid X receptor alpha may be candidates for the nuclear receptors responsible for the downstream signal transduction in the Cyp1b1 pathway.
Keywords: gene/expression • immunohistochemistry