Folliculogenesis-specific basic helix-loop-helix, also known as factor in the germline alpha (FIGalpha) or transcription factor FIGa, is a protein that in humans is encoded by the FIGLAgene. The FIGLA gene is a germ cell-specific transcription factor preferentially expressed in oocytes that can be found on human chromosome 2p13.3.
This gene encodes a protein that functions in postnatal oocyte-specific gene expression. The protein is a basic helix-loop-helix transcription factor that regulates multiple oocyte-specific genes, including genes involved in folliculogenesis, oocyte differentiation, and those that encode the zona pellucida. FIGLA is related to the zona pellucida genes ZP1, ZP2, and ZP3.
Mutation in the FIGLA gene are associated with premature ovarian failure. Premature ovarian failure is a genetic disorder that leads to hypergonadotropic ovarian failure and infertility. It is believed that premature ovarian failure in humans is caused by FIGLA haploninsuffciency, which disrupts the formation of the primordial follicles. This was observed in FIGLA mice knockouts which had diminished follicular endowment and accelerated oocyte loss throughout their reproductive life span. Women with mutations in their FIGLA were shown to have a form of premature ovarian failure. As well as the failure to form primordial follicles, knockout mice also lacked zona pellucida genes Zp1, Zp2, and ZP3 expression.
^Huntriss J, Gosden R, Hinkins M, Oliver B, Miller D, Rutherford AJ, Picton HM (December 2002). "Isolation, characterization and expression of the human Factor In the Germline alpha (FIGLA) gene in ovarian follicles and oocytes". Molecular Human Reproduction8 (12): 1087–95. doi:10.1093/molehr/8.12.1087. PMID12468641.
Törmälä RM, Jääskeläinen M, Lakkakorpi J, Liakka A, Tapanainen JS, Vaskivuo TE (July 2008). "Zona pellucida components are present in human fetal ovary before follicle formation". Molecular and Cellular Endocrinology289 (1-2): 10–5. doi:10.1016/j.mce.2008.01.029. PMID18502569.
van Dooren MF, Bertoli-Avellab AM, Oldenburg RA (August 2009). "Premature ovarian failure and gene polymorphisms". Current Opinion in Obstetrics & Gynecology21 (4): 313–7. PMID19610175.
Bayne RA, Martins da Silva SJ, Anderson RA (June 2004). "Increased expression of the FIGLA transcription factor is associated with primordial follicle formation in the human fetal ovary". Molecular Human Reproduction10 (6): 373–81. doi:10.1093/molehr/gah056. PMID15044608.