Folliculogenesis-specific basic helix-loop-helix, also known as factor in the germline alpha (FIGalpha) or transcription factor FIGa, is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
that in humans is encoded by the ''FIGLA''
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
.
The FIGLA gene is a germ cell-specific transcription factor preferentially expressed in oocytes that can be found on human chromosome 2p13.3.
Function
This gene encodes a protein that functions in postnatal
oocyte
An oocyte (, ), oöcyte, or ovocyte is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in a female fetus in the ovary during female gametogenesis. The femal ...
-specific gene expression. The protein is a
basic helix-loop-helix
BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College ...
transcription factor that regulates multiple
oocyte
An oocyte (, ), oöcyte, or ovocyte is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in a female fetus in the ovary during female gametogenesis. The femal ...
-specific genes, including genes involved in
folliculogenesis
:''Although the process is similar in many animals, this article will deal exclusively with human folliculogenesis.''
In biology, folliculogenesis is the maturation of the ovarian follicle, a densely packed shell of somatic cells that contains a ...
, oocyte differentiation, and those that encode the
zona pellucida
The zona pellucida (plural zonae pellucidae, also egg coat or pellucid zone) is a specialized extracellular matrix that surrounds the plasma membrane of mammalian oocytes. It is a vital constitutive part of the oocyte. The zona pellucida first ap ...
.
FIGLA is related to the zona pellucida genes ZP1, ZP2, and ZP3.
Clinical significance
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.
References
Further reading
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Transcription factors
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