Tex 19 paralogs exhibit a gonad and placenta-specific expression in the mouse.

We have previously suggested that TEX19, a mammalian-specific protein of which two paralogs exist in rodents, could be implicated in stem cell self-renewal and pluripotency. We have established here the expression profiles of Tex19.1 and Tex19.2 during mouse development and adulthood. We show that both genes are coexpressed in the ectoderm and then in primordial germ cells (PGCs). They are also coexpressed in the testis from embryonic day 13.5 to adulthood, whereas only Tex19.1 transcripts are detected in the developing and adult ovary as well as in the placenta and its precursor tissue, the ectoplacental cone. The presence of both Tex19.1 and Tex19.2 in PGCs, gonocytes and spermatocytes opens the possibility that these two genes could play redundant functions in male germ cells. Furthermore, the placental expression of Tex19.1 can explain why Tex19.1 knockout mice show embryonic lethality, in addition to testis defects.