Origins and functional evolution of Y chromosomes across mammals.
Nature
; 508(7497): 488-93, 2014 Apr 24.
Article
em En
| MEDLINE
| ID: mdl-24759410
ABSTRACT
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.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cromossomo Y
/
Evolução Molecular
/
Mamíferos
Limite:
Animals
Idioma:
En
Revista:
Nature
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Suíça