A human sex-chromosomal gene family expressed in male germ cells and encoding variably charged proteins.

Abstract

Approximately 12 X-Y homologous gene pairs have been identified in the non-recombining portions of human sex chromosomes. These X-Y gene pairs fall into two categories. In the first category, both X and Y homologs are ubiquitously expressed. In the second category, the X homolog is ubiquitously expressed, whereas the Y homolog is expressed exclusively in the testis. Here we describe a family of human X-Y genes that cannot be assigned to either category. Designated VCX / Y ( Variable Charge X / Y; VCY previously known as BPY1 ), this gene family has multiple members on both X and Y, and all appear to be expressed exclusively in male germ cells. Members of the VCX / Y family share a high degree of sequence identity, with the exception that a 30 nucleotide unit is tandemly repeated in X-linked members but is present only once in Y-linked members. These atypical features suggest that the VCX / Y family has evolved in a manner previously unrecognized for mammalian X-Y genes. We also found that a copy of VCX is present in CRI-S232, a previously described genomic fragment derived from the X chromosome. Studies have shown that aberrant recombination between arrays of CRI-S232-homologous repeats flanking the steroid sulfatase ( STS ) gene results in STS deletion, which is manifested clinically as X-linked ichthyosis. The revelation that CRI-S232 contains VCX offers a more precise description of the genetic etiology of X-linked ichthyosis: it results from aberrant recombination between VCX gene arrays that flank the STS locus.

• Authors: B T Lahn, D C Page
• Journal: Human molecular genetics (Hum Mol Genet) Vol. 9 Issue 2 Pg. 311-9 (Jan 22 2000) ISSN: 0964-6906 [Print] England
• PMID: 10607842 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Nuclear Proteins
• VCX protein, human
• VCY protein, human

Topics

• Adult
• Amino Acid Sequence
• Base Sequence
• Gene Expression Regulation, Developmental (genetics)
• Humans
• Male
• Molecular Sequence Data
• Multigene Family (genetics)
• Nuclear Proteins (biosynthesis, genetics)
• Pedigree
• Spermatozoa (metabolism)
• X Chromosome (genetics)
• Y Chromosome (genetics)