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General Comment |
ZFX lies within the critical region for ovarian failure and maps to Xp22.2p21.3. It encodes a ubiquitously expressed zinc finger transcription factor of unknown function (Page et al., 1987). ZFX was cloned as a homologue of ZFY, a former candidate for the testis determining factor on the Y chromosome. It escapes inactivation, and therefore deletions or mutations in one of its copies might cause haploinsufficiency (Schneider-Gadicke et al., 1989).
Page et al. (1987) identified a Y-encoded zinc finger protein, which was thought to be the testis-determining factor (TDF). A very similar DNA sequence (ZFX) was identified on the X chromosome. The location of ZFX is Xp22.3-p21.2. Chong et al. (1993) developed a PCR strategy for sex determination at the single cell level by simultaneous amplification and subsequent restriction fragment analysis of the homologous but nonallelic ZFX and ZFY genes. They showed that XY cells could be correctly genotyped as ZFX/ZFY and XX cells as ZFX only.
NCBI Summary:
This gene on the X chromosome is structurally similar to a related gene on the Y chromosome. It encodes a member of the krueppel C2H2-type zinc-finger protein family. The full-length protein contains an acidic transcriptional activation domain (AD), a nuclear localization sequence (NLS) and a DNA binding domain (DBD) consisting of 13 C2H2-type zinc fingers. Studies in mouse embryonic and adult hematopoietic stem cells showed that this gene was required as a transcriptional regulator for self-renewal of both stem cell types, but it was dispensable for growth and differentiation of their progeny. Multiple alternatively spliced transcript variants encoding different isoforms have been identified, but the full-length nature of some variants has not been determined. [provided by RefSeq, May 2010]
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Mutations |
1 mutations
Species: mouse
Mutation name: None
type: null mutation
fertility: subfertile
Comment: Luoh et al. (1997) showed that Zfx mutant mice were smaller, less viable, and had fewer germ cells than wild-type mice, features also found in human females with an XO karyotype (Turner syndrome). Homozygous mutant XX animals were fully feminized, with ovaries and female genitalia, but showed a shortage of oocytes resulting in diminished fertility and shortened reproductive lifespan, as in premature ovarian failure in humans. Mutant XY animals were fully masculinized, with testes and male genitalia, and were fertile, but sperm counts were reduced by one half.
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