Linked Life Data

17244601

Source:http://linkedlifedata.com/resource/pubmed/id/17244601

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2007-3-29
pubmed:abstractText
Although sexual selection has been predominantly used to explain the rapid evolution of sexual traits, eggs of oviparous organisms directly face both the challenges of sexual selection as well as natural selection (environmental challenges, survival in niches, etc.). Being the outermost membrane in most insect eggs, the chorion layer is the interface between the embryo and the environment, thereby serving to protect the egg. Adaptive ecological radiations such as divergence in ovipositional substrate usage and host-plant specializations can therefore influence the evolution of eggshell proteins. We can hypothesize that proteins localized on the outer eggshell may be affected to a greater degree by ecological challenges compared with inner eggshell proteins, and therefore, proteins localized in the outer eggshell (chorion membrane) may evolve differently (faster) than proteins localized in the inner egg membrane (vitelline membrane). We compared the evolutionary divergence of vitelline with chorion membrane proteins in species of the melanogaster subgroup and found that chorion proteins as a group are indeed evolving faster than vitelline membrane proteins. At least one vitelline membrane protein (Vm32E), specifically localized on the outer eggshell, is also evolving faster than other vitelline membrane proteins suggesting that all proteins localized on the outer eggshell may be evolving rapidly. We also found evidence that specific codons in chorion proteins cp15 and cp16 are evolving under positive selection. Polymorphism surveys of cp16 revealed inflated levels of divergence relative to polymorphism in specific regions of the gene, indicating that these regions are under strong selection. At the morphological level, we found notable difference in eggshell surface morphologies between specialist (Drosophila sechellia and Drosophila erecta) and generalist species of Drosophila. We do not know if any of the chorion proteins actually interact with spermatozoids, therefore leaving the possibility of rapid evolution through gametic interaction wide open. At this point, however, our results support previous suggestions that divergences in ecology, particularly, ovipositional substrate divergences may be a strong force driving the evolution of eggshell proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0737-4038
pubmed:author
pubmed:issnType
Print
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
929-38
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Rapid evolution of outer egg membrane proteins in the Drosophila melanogaster subgroup: a case of ecologically driven evolution of female reproductive traits.
pubmed:affiliation
Department of Biology, McMaster University, Hamilton, Ontario, Canada.
pubmed:publicationType
Journal Article