Spermatogenesis And Oogenesis Specific Basic Helix Loop Helix 1 (SOHLH1)

SOHLH1 shares 86% identity in the bHLH region with the human protein. RT-PCR analysis detected expression in mouse ovary and testis only. In embryos, expression was abundant in ovaries after embryonic day 15.5. Immunohistochemistry of adult mice showed nuclear and cytoplasmic expression of Sohlh1 protein in germ cell cysts, primordial follicles, and primary, but not secondary, follicles.Immunohistochemical analysis of Sohlh1mice demonstrated normal expression of Gcna1, but expression of Msy2 (YBX2) occurred only in oocytes and putative primordial follicles, indicating a defect in follicle development. In situ hybridization and RT-PCR showed that Sohlh1 ovaries expressed less Figla and Nobox than wildtype ovaries. Microarray and in situ hybridization indicated that Lhx8 was also drastically downregulated in Sohlh1ovaries.