Molecular cloning and functional analysis of the FSH receptor gene promoter from the volcano mouse (Neotomodon alstoni alstoni)

Abstract

To gain further insights on the genetic divergence and the species-specific characteristics of the follicle-stimulating hormone receptor (FSHR), we cloned 946 bp of the 5'-flanking region of the FSHR gene from the volcano mouse (Neotomodon alstoni alstoni), and compared its features with those from other mammalian species. The sequence of neotomodon FSHR (nFSHR) gene from the translation initiation site to -946 is 74, 71, 64, and 59% homologous to rat, mouse (129/J), human, and sheep, respectively. The nFSHR 5'-flanking region exhibits new interesting putative cis-regulatory elements including those for the SRY transcription factor, which had not been previously related to the FSHR gene. The transcriptional regulation properties of nFSHR gene were studied in mouse Sertoli (MSC-1) and non-Sertoli (H441) cell lines, and compared with those obtained with similar 129/J constructs. All constructs tested were more active in H441 than in MSC-1 cells. The low transcription levels detected in MSC-1 cells probably reflect the recruitment of Sertoli cells-specific nuclear factors that repress transcription of the FSHR gene. In H441 cells, 129/J constructs were more active than their neotomodon counterparts, indicating important species-specific differences in their transcription pattern. Functional analysis of a series of progressive 5'-deletion mutants identified regions involved in positive and negative transcriptional regulation as well as the strongest minimal promoter spanning 260 bp upstream the translation initiation site. The identification of inhibitory nuclear transcription factors, which are apparently expressed in MSC-1 cells, may contribute to a better understanding of the transcriptional regulation of the FSHR gene.