NCBI Summary:
This gene is a germ cell-specific gene that encodes proteins that interact with POG (proliferation of germ cells). Alternatively spliced transcript variants of a similar mouse gene encode at least three different proteins, namely gametogenetin protein 1a, gametogenetin protein 2, and gametogenetin protein 3, which show a perinuclear, cytoplasmic, and nucleolar localization, respectively. These proteins regulate the localization of POG and may play a role in spermatogenesis. [provided by RefSeq]
General function
Comment
Cellular localization
Cytoplasmic, Nuclear
Comment
Ovarian function
Comment
Expression regulated by
Comment
Ovarian localization
Oocyte, Cumulus, Granulosa
Comment
GGN1 in the testis and ovary and its variance within the Australian fertile and infertile male population. Jamsai D et al. Mouse gametogenetin (Ggn) is a testis-enriched gene that encodes multiple spliced transcripts giving rise to three predicted protein isoforms: GGN1, GGN2 and GGN3. Of these, GGN1 has been linked to germ cell development. Based on the spatial and temporal expression pattern of GGN1 during mouse spermatogenesis, it has been proposed as a candidate human infertility gene. Here, we report the localization of GGN1 in the human testis and ovary compared with the mouse orthologue. Within the testis, GGN1 was confined to pachytene spermatocytes and spermatids. During mid-prophase GGN1 redistributes from a solely cytoplasmic localization to both cytoplasmic and nuclear in late prophase spermatocytes and round spermatids, and is ultimately incorporated into the sperm tail. Within both mouse and human ovaries, GGN1 was localized within granulosa cells. Lower levels of expression were observed in mouse oocytes and the cumulus cells. Furthermore, to define the level of sequence variation in the fertile population and to assess the potential for an association with male infertility, we sequenced the coding region of human GGN in 100 idiopathic oligospermic infertile and 100 control men. Fifteen genetic variants were identified, of which 10 had not previously been reported. No significant associations with fertility status were observed, suggesting that variance in the GGN gene are not a common cause of oligospermic infertility in Australian men.
Follicle stages
Comment
Phenotypes
Mutations
1 mutations
Species: mouse
Mutation name: None
type: null mutation fertility: embryonic lethal Comment: Loss of GGN Leads to Pre-Implantation Embryonic Lethality and Compromised Male Meiotic DNA Double Strand Break Repair in the Mouse. Jamsai D et al. The integrity of male germ cell genome is critical for the correct progression of spermatogenesis, successful fertilization, and proper development of the offspring. Several DNA repair pathways exist in male germ cells. However, unlike somatic cells, key components of such pathways remain largely unidentified. Gametogenetin (GGN) is a testis-enriched protein that has been shown to bind to the DNA repair protein FANCL via yeast-two-hybrid assays. This finding and its testis-enriched expression pattern raise the possibility that GGN plays a role in DNA repair during spermatogenesis. Herein we demonstrated that the largest isoform GGN1 interacted with components of DNA repair machinery in the mouse testis. In addition to FANCL, GGN1 interacted with the critical component of the Fanconi Anemia (FA) pathway FANCD2 and a downstream component of the BRCA pathway, BRCC36. To define the physiological function of GGN, we generated a null mouse line. A complete loss of GGN resulted in embryonic lethality at the very earliest period of pre-implantation development, with no viable blastocysts observed. This finding was consistent with the observation that mRNA was also expressed in lower levels in the oocyte and pre-implantation embryos. Moreover, pachytene spermatocytes of the heterozygous knockout mice showed an increased incidence of unrepaired DNA double strand breaks (DSBs). Together, our results suggest that GGN plays a role in male meiotic DSB repair and is absolutely required for the survival of pre-implantation embryos.