ZFIN ID: ZDB-PUB-030806-4
Comparative mapping of Z-orthologous genes in vertebrates: implications for the evolution of avian sex chromosomes
Nanda, I., Haaf, T., Schartl, M., Schmid, M., and Burt, D.W.
Date: 2002
Source: Cytogenetic and genome research 99(1-4): 178-184 (Journal)
Registered Authors: Schartl, Manfred
Keywords: none
MeSH Terms:
  • Animals
  • Chickens
  • Chromosome Mapping
  • Evolution, Molecular*
  • Humans
  • Sex Chromosomes/genetics*
  • Synteny
  • Vertebrates/genetics*
  • X Chromosome/genetics
  • Y Chromosome/genetics
PubMed: 12900562 Full text @ Cytogenet. Genome Res.
ABSTRACT
Sex chromosomes of birds and mammals are highly differentiated and share several cytological features. However, comparative gene mapping reveals extensive conserved synteny between the chicken Z sex chromosome and human chromosome 9 but not the human X sex chromosome, implying an independent origin of avian and mammalian sex chromosomes. To better understand the evolution of the avian Z chromosome we analysed the synteny of chicken Z-linked genes in zebrafish, which is the best-mapped teleost genome so far. Existing zebrafish maps do not support the existence of an ancestral Z linkage group in the zebrafish genome, whereas mammalian X-linked genes show at least some degree of synteny conservation. This is consistent with in situ hybridisation mapping data in the freshwater pufferfish, TETRAODON NIGROVIRIDIS where mammalian X-linked genes show a much higher degree of conserved synteny than human chromosome 9 or the avian Z chromosome. Collectively, these data argue in favour of a more recent evolution of the avian Z chromosome, compared with the mammalian X.
ADDITIONAL INFORMATION