LHX2 in germ cells control tubular organization in the developing mouse testis

Abstract

In the gonads of mammalian XY embryos, the organization of cords is the hallmark of testis development. This organization is thought to be controlled by interactions of the Sertoli cells, endothelial and interstitial cells with little or no role of germ cells. Challenging this notion, herein we show that the germ cells play an active role in the organization of the testicular tubules. We observed that the LIM-homeobox gene, Lhx2 is expressed in the germ cells of the developing testis between E12.5-E15.5. In Lhx2 knockout-fetal testis there was altered expression of several genes not just in germ cells but also in the supporting (Sertoli) cells, endothelial cells, and interstitial cells. Further, loss of Lhx2 led to disrupted endothelial cell migration and expansion of interstitial cells in the XY gonads. The cords in the developing testis of Lhx2 knockout embryos are disorganized with a disrupted basement membrane. Together, our results show an important role of Lhx2 in testicular development and imply the involvement of germ cells in the tubular organization of the differentiating testis. HighlightO_LILhx2 is expressed in germ cells of developing mouse testis but is dispensable for germ cell and Sertoli cell specification C_LIO_LILoss of Lhx2 disrupts testicular vascularization, leads to the expansion of interstitial cells, and alters the tubular organization C_LIO_LIGerm cells govern the tubular organization in the developing testis C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=105 SRC="FIGDIR/small/522214v2_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@1a1761dorg.highwire.dtl.DTLVardef@1519f12org.highwire.dtl.DTLVardef@1a263baorg.highwire.dtl.DTLVardef@4167f2_HPS_FORMAT_FIGEXP M_FIG C_FIG