Publication Date:
2014-04-25
Description:
Y chromosomes underlie sex determination in mammals, but their repeat-rich nature has hampered sequencing and associated evolutionary studies. Here we trace Y evolution across 15 representative mammals on the basis of high-throughput genome and transcriptome sequencing. We uncover three independent sex chromosome originations in mammals and birds (the outgroup). The original placental and marsupial (therian) Y, containing the sex-determining gene SRY, emerged in the therian ancestor approximately 180 million years ago, in parallel with the first of five monotreme Y chromosomes, carrying the probable sex-determining gene AMH. The avian W chromosome arose approximately 140 million years ago in the bird ancestor. The small Y/W gene repertoires, enriched in regulatory functions, were rapidly defined following stratification (recombination arrest) and erosion events and have remained considerably stable. Despite expression decreases in therians, Y/W genes show notable conservation of proto-sex chromosome expression patterns, although various Y genes evolved testis-specificities through differential regulatory decay. Thus, although some genes evolved novel functions through spatial/temporal expression shifts, most Y genes probably endured, at least initially, because of dosage constraints.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cortez, Diego -- Marin, Ray -- Toledo-Flores, Deborah -- Froidevaux, Laure -- Liechti, Angelica -- Waters, Paul D -- Grutzner, Frank -- Kaessmann, Henrik -- England -- Nature. 2014 Apr 24;508(7497):488-93. doi: 10.1038/nature13151.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland [2] Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland. ; The Robinson Research Institute, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia 5005, Australia. ; Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland. ; School of Biotechnology and Biomolecular Sciences, UNSW Australia, Sydney, New South Wales 2052, Australia.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24759410" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Birds/genetics
;
Conserved Sequence/genetics
;
*Evolution, Molecular
;
Female
;
Gene Dosage/genetics
;
Genes, sry/genetics
;
Genomics
;
High-Throughput Nucleotide Sequencing
;
Male
;
Mammals/*genetics
;
Marsupialia/genetics
;
Receptors, Peptide/genetics
;
Receptors, Transforming Growth Factor beta/genetics
;
Selection, Genetic/genetics
;
Sex Chromosomes/genetics
;
Spatio-Temporal Analysis
;
Spermatogenesis/genetics
;
Testis/metabolism
;
Transcriptome/genetics
;
Y Chromosome/*genetics
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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