Gametogenetin (GGN)

The N-terminal half of Ggn2 is identical to that of Ggn1, including the first transmembrane domain, but it has a unique C terminus. Ggn3 is identical to the C-terminal 137 amino acids of Ggn1, including both nucleolar targeting sequences. RT-PCR of several mouse tissues detected Ggn expression in testis and ovary only.

In adult testis, Ggn was specifically expressed in germ cells from the late pachytene spermatocyte to the round spermatid stages; it was not expressed in somatic, Sertoli, or Leydig cells. Fluorescence-tagged Ggn1, Ggn2, and Ggn3 localized along the nuclear membrane, in the cytoplasm, and in the nucleus/nucleoli of transfected HeLa cells, respectively.The International Radiation Hybrid Mapping Consortium mapped the GGN gene to chromosome 19