Gene discovery and comparative analysis of X-degenerate genes from the domestic cat Y chromosome

Genomics. 2008 Nov;92(5):329-38. doi: 10.1016/j.ygeno.2008.06.012. Epub 2008 Aug 28.


Mammalian sex chromosomes are the remnants of an ancient autosomal pair present in the ancestral mammalian karyotype. As a consequence of random decay and chromosome rearrangements over evolutionary time, Y chromosome gene repertoires differ between eutherian lineages. To investigate the gene repertoire and transcriptional analysis of the domestic cat Y chromosome, and their potential roles in spermatogenesis, we obtained full-length cDNA sequences for all known Y genes and their X chromosome gametologues and used those sequences to create a BAC-based physical map of the X-degenerate region. Our results indicate the domestic cat Y chromosome has retained most X-degenerate genes that were present on the ancestral eutherian Y chromosome. Transcriptional analysis revealed that most feline X-degenerate genes have retained housekeeping functions shared by their X chromosome partners and have not been specialized for testis-specific functions. Physical mapping data indicate that the cat SRY gene is present as multiple functional copies and that very little of the felid Y chromosome may be single copy. X-Y gene divergence time estimates obtained using Bayesian methods confirm an early origin of Stratum 1 genes prior to the origin of therian mammals. We observed no statistical difference in the ages of Stratum 2 and Stratum 3 gene pairs, suggesting that eutherian and marsupial Stratum 2 genes may have been independently retained in each lineage.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Domestic / genetics
  • Cats
  • Chromosomes, Artificial, Bacterial
  • DNA, Complementary / genetics*
  • DNA, Complementary / metabolism
  • Dogs
  • Evolution, Molecular*
  • Gene Expression Profiling
  • Gene Library
  • Humans
  • Molecular Sequence Data
  • Phylogeny
  • Physical Chromosome Mapping*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Analysis, DNA
  • Sex-Determining Region Y Protein / genetics
  • X Chromosome / genetics*
  • Y Chromosome / genetics*


  • DNA, Complementary
  • Sex-Determining Region Y Protein

Associated data

  • GENBANK/EU879967
  • GENBANK/EU879968
  • GENBANK/EU879969
  • GENBANK/EU879970
  • GENBANK/EU879971
  • GENBANK/EU879972
  • GENBANK/EU879973
  • GENBANK/EU879974
  • GENBANK/EU879975
  • GENBANK/EU879976
  • GENBANK/EU879977
  • GENBANK/EU879978
  • GENBANK/EU879979
  • GENBANK/EU879980
  • GENBANK/EU879981
  • GENBANK/EU879982
  • GENBANK/EU879983
  • GENBANK/EU879984
  • GENBANK/EU879985
  • GENBANK/EU879986
  • GENBANK/EU879987
  • GENBANK/EU879988