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

Hum Mol Genet. 2000 Jan 22;9(2):311-9. doi: 10.1093/hmg/9.2.311.

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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

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

Substances

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

Associated data

  • GENBANK/AF000979
  • GENBANK/AF159127
  • GENBANK/AF159128
  • GENBANK/AF159129