1: Development. 2006 Apr;133(8):1519-27. Epub 2006 Mar 15.

FGF9 promotes survival of germ cells in the fetal testis.

DiNapoli L, Batchvarov J, Capel B.

Department of Cell Biology, Duke University Medical Center, Durham, NC 27710,
USA.

In addition to its role in somatic cell development in the testis, our data have 
revealed a role for Fgf9 in XY germ cell survival. In Fgf9-null mice, germ cells 
in the XY gonad decline in numbers after 11.5 days post coitum (dpc), while germ 
cell numbers in XX gonads are unaffected. We present evidence that germ cells
resident in the XY gonad become dependent on FGF9 signaling between 10.5 dpc and 
11.5 dpc, and that FGF9 directly promotes XY gonocyte survival after 11.5 dpc,
independently from Sertoli cell differentiation. Furthermore, XY Fgf9-null gonads
undergo true male-to-female sex reversal as they initiate but fail to maintain
the male pathway and subsequently express markers of ovarian differentiation (Fst
and Bmp2). By 14.5 dpc, these gonads contain germ cells that enter meiosis
synchronously with ovarian gonocytes. FGF9 is necessary for 11.5 dpc XY gonocyte 
survival and is the earliest reported factor with a sex-specific role in
regulating germ cell survival.

PMID: 16540514 [PubMed - indexed for MEDLINE]

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