Publication Date:
1999-11-05
Description:
Human sex chromosomes evolved from autosomes. Nineteen ancestral autosomal genes persist as differentiated homologs on the X and Y chromosomes. The ages of individual X-Y gene pairs (measured by nucleotide divergence) and the locations of their X members on the X chromosome were found to be highly correlated. Age decreased in stepwise fashion from the distal long arm to the distal short arm in at least four "evolutionary strata." Human sex chromosome evolution was probably punctuated by at least four events, each suppressing X-Y recombination in one stratum, without disturbing gene order on the X chromosome. The first event, which marked the beginnings of X-Y differentiation, occurred about 240 to 320 million years ago, shortly after divergence of the mammalian and avian lineages.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lahn, B T -- Page, D C -- HG00257/HG/NHGRI NIH HHS/ -- New York, N.Y. -- Science. 1999 Oct 29;286(5441):964-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10542153" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Cell Line
;
Chromosome Mapping
;
*Evolution, Molecular
;
Genetic Linkage
;
Humans
;
Recombination, Genetic
;
*X Chromosome
;
*Y Chromosome
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
