Linked Life Data

18032407

Source:http://linkedlifedata.com/resource/pubmed/id/18032407

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2008-1-21
pubmed:abstractText
An elevated rate of substitution characterizes the molecular evolution of reproductive proteins from a wide range of taxa. Although the selective pressures explaining this rapid evolution are yet to be resolved, recent evidence implicates sexual selection as a potentially important explanatory factor. To investigate this hypothesis, we sought evidence of a high rate of adaptive gene evolution linked to postcopulatory sexual selection in muroid rodents, a model vertebrate group displaying a broad range of mating systems. Specifically, we sequenced 7 genes from diverse rodents that are expressed in the testes, prostate, or seminal vesicles, products of which have the potential to act in sperm competition. We inferred positive Darwinian selection in these genes by estimation of the ratio of nonsynonymous (d(N), amino acid changing) to synonymous (d(S), amino acid retaining) substitution rates (omega = d(N)/d(S)). Next, we tested whether variation in this ratio among lineages could be attributed to interspecific variation in mating systems, as inferred from the variation in these rodents' relative testis sizes (RTS). Four of the 7 genes examined (Prm1, Sva, Acrv1, and Svs2, but not Svp2, Msmb, or Spink3) exhibit unambiguous evidence of positive selection. One of these, the seminal vesicle-derived protein Svs2, also shows some evidence for a concentration of positive selection in those lineages in which sperm competition is common. However, this was not a general trend among all the rodent genes we examined. Using the same methods, we then reanalyzed previously published data on 2 primate genes, SEMG1 and SEMG2. Although SEMG2 also shows evidence of positive selection concentrated in lineages subject to high levels of sperm competition, no such trend was found for SEMG1. Overall, despite a high rate of positive selection being a feature of many ejaculate proteins, these results indicate that the action of sexual selection potentially responsible for elevated evolutionary rates may be difficult to detect on a gene-by-gene basis. Although the extreme diversity of reproductive phenotypes exhibited in nature attests to the power of sexual selection, the extent to which this force predominates in driving the rapid molecular evolution of reproductive genes therefore remains to be determined.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1537-1719
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
207-19
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Sexual selection and the adaptive evolution of mammalian ejaculate proteins.
pubmed:affiliation
Mammalian Behaviour and Evolution Group, Faculty of Veterinary Science, University of Liverpool, Liverpool, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't