Molecular histochemical analysis of estrogen receptor α and β expressions in the mouse ovary: in situ hybridization and Southwestern histochemistry

It is well known that estrogen plays important roles in the female reproductive organs, including the ovary, through estrogen receptors (ERα and ERβ). It is suggested that selective effects of estrogen on a discrete set of genes may reside in promoters that are differentially responsive to ERα and ERβ, while the relative biological significance of ERα and ERβ is unclear. Therefore, for a better understanding of the physiological and pathological states of ovarian cells, it seems to be essential to analyze the cellular expression of ERα and ERβ, at both the protein and mRNA levels. For this purpose, we have optimized the protocols for immunohistochemistry and nonradioactive in situ hybridization, respectively, using the mouse ovary. These techniques have been established as useful histochemical methods for the localization of specific protein and/or mRNA expression at the cellular level. Moreover, we also attempted to evaluate ERs as binding proteins to estrogen responsive elements, using Southwestern histochemistry, which permits us to analyze the localization in situ of transcription regulatory proteins. By employing these methods, more precise understanding of specific gene expression and evaluation of its biological significance in the ovary would be possible.