Characterization of genes encoding translation initiation factor eIF-2gamma in mouse and human: sex chromosome localization, escape from X-inactivation and evolution

Hum Mol Genet. 1998 Oct;7(11):1725-37. doi: 10.1093/hmg/7.11.1725.

Abstract

The Delta Sxrb interval of the mouse Y chromosome is critical for spermatogenesis and expression of the male-specific minor transplantation antigen H-Y. Several genes have been mapped to this interval and each has a homologue on the X chromosome. Four, Zfy1 , Zfy2 , Ube1y and Dffry , are expressed specifically in the testis and their X homologues are not transcribed from the inactive X chromosome. A further two, Smcy and Uty , are ubiquitously expressed and their X homologues escape X-inactivation. Here we report the identification of another gene from this region of the mouse Y chromosome. It encodes the highly conserved eukaryotic translation initiation factor eIF-2gamma. In the mouse this gene is ubiquitously expressed, has an X chromosome homologue which maps close to Dmd and escapes X-inactivation. The coding regions of the X and Y genes show 86% nucleotide identity and encode putative products with 98% amino acid identity. In humans, the eIF-2gamma structural gene is located on the X chromosome at Xp21 and this also escapes X-inactivation. However, there is no evidence of a Y copy of this gene in humans. We have identified autosomal retroposons of eIF-2gamma in both humans and mice and an additional retroposon on the X chromosome in some mouse strains. Ark blot analysis of eutherian and metatherian genomic DNA indicates that X-Y homologues are present in all species tested except simian primates and kangaroo and that retroposons are common to a wide range of mammals. These results shed light on the evolution of X-Y homologous genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blotting, Northern
  • Chromosome Mapping
  • Chromosomes, Human
  • Chromosomes, Human, Pair 12
  • Cloning, Molecular
  • Dosage Compensation, Genetic*
  • Eukaryotic Initiation Factor-2 / genetics*
  • Eukaryotic Initiation Factor-2 / metabolism
  • Evolution, Molecular*
  • Female
  • Humans
  • Male
  • Mammals / genetics
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Inbred CBA
  • Mice, Inbred Strains
  • Molecular Sequence Data
  • Retroelements*
  • Sequence Homology, Amino Acid
  • Sex Chromosomes*
  • X Chromosome
  • Y Chromosome

Substances

  • Eukaryotic Initiation Factor-2
  • Retroelements

Associated data

  • GENBANK/AJ006584
  • GENBANK/AJ006585
  • GENBANK/AJ006586
  • GENBANK/AJ006587
  • GENBANK/AJ006932