Pitx2 deletion in pituitary gonadotropes is compatible with gonadal development, puberty, and fertility

Abstract

This report introduces a gonadotrope-specific cre transgenic mouse capable of ablating floxed genes in mature pituitary gonadotropes. Initial analysis of this transgenic line, Tg(Lhb-cre)1Sac , reveals that expression is limited to the pituitary cells that produce luteinizing hormone beta, beginning appropriately at e17.5. Cre activity is detectable by a reporter gene in nearly every LHΒ-producing cell, but the remaining hormone-producing cell types and other organs exhibit little to no activity. We used the Tg(Lhb-cre)1Sac strain to assess the role Pitx2 in gonadotrope function. The gonadotrope-specific Pitx2 knockout mice exhibit normal expression of LHΒ, sexual maturation, and fertility, suggesting that Pitx2 is not required for gonadotrope maintenance or for regulated production of gonadotropins. genesis 46:507–514, 2008. © 2008 Wiley-Liss, Inc.