SOHLH1 and SOHLH2 directly down-regulate stimulated by retinoic acid 8 (STRA8) expression

MG Desimio, F Campolo, S Dolci, M De Felici, D Farini - Cell cycle, 2015 - Taylor & Francis
Cell cycle, 2015Taylor & Francis
As the name implies, Stimulated by Retinoic Acid 8 is an early retinoic acid (RA) responsive
gene pivotal for the beginning of meiosis in female and male germ cells. Its expression is
strictly time-dependent and cell-specific (pre-meiotic germ cells) and likely requires a
complex mechanism of regulation. In this study, we demonstrate a direct negative control of
SOHLH1 and SOHLH2, 2 germ cell specific bHLH transcription factors, on Stra8 expression.
We observed a negative correlation between STRA8 and SOHLH1 expression in prepuberal …
As the name implies, Stimulated by Retinoic Acid 8 is an early retinoic acid (RA) responsive gene pivotal for the beginning of meiosis in female and male germ cells. Its expression is strictly time-dependent and cell-specific (pre-meiotic germ cells) and likely requires a complex mechanism of regulation. In this study, we demonstrate a direct negative control of SOHLH1 and SOHLH2, 2 germ cell specific bHLH transcription factors, on Stra8 expression. We observed a negative correlation between STRA8 and SOHLH1 expression in prepuberal differentiating mouse KIT+ spermatogonia and found that SOHLH1 and SOHLH2 were able to directly and cooperatively repress STRA8 expression in cell lines in vitro through binding to its promoter. We also identified 2 canonical E-Box motives in the Stra8 promoter that mediated the negative regulation of SOHLH1 and SOHLH2 on these gene both in the cell lines and KIT+ spermatogonia. We hypothesize that this novel negative activity of SOHLH1and SOHLH2 in male cooperates with that of other transcription factors to coordinate spermatogonia differentiation and the RA-induced meiosis and in female ensures STRA8 down-regulation at mid-end stages of meiotic prophase I.
Taylor & Francis Online