Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2008-11-21
pubmed:abstractText
The innate immune system constitutes the front line of host defense against pathogens. Toll-like receptors (TLRs) recognize molecules derived from pathogens and play crucial roles in the innate immune system. Here, we provide evidence that the TLR-related genes have come under natural selection pressure in the course of primate evolution. We compared the nucleotide sequences of 16 TLR-related genes, including TLRs (TLR1-10), MYD88, TILAP, TICAM1, TICAM2, MD2, and CD14, among seven primate species. Analysis of the non-synonymous/synonymous substitution ratio revealed the presence of both strictly conserved and rapidly evolving regions in the TLR-related genes. The genomic segments encoding the intracellular Toll/interleukin 1 receptor domains, which exhibited lower rates of non-synonymous substitution, have undergone purifying selection. In contrast, TLR4, which carried a high proportion of non-synonymous substitutions in the part of extracellular domain spanning 200 amino acids, was found to have been the suggestive target of positive Darwinian selection in primate evolution. However, sequence analyses from 25 primate species, including eight hominoids, six Old World monkeys, eight New World monkeys, and three prosimians, showed no evidence that the pressure of positive Darwinian selection has shaped the pattern of sequence variations in TLR4 among New World monkeys and prosimians.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1432-1211
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
60
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
727-35
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:18810425-Adaptor Proteins, Vesicular Transport, pubmed-meshheading:18810425-Amino Acid Sequence, pubmed-meshheading:18810425-Animals, pubmed-meshheading:18810425-Antigens, CD14, pubmed-meshheading:18810425-Consensus Sequence, pubmed-meshheading:18810425-Evolution, Molecular, pubmed-meshheading:18810425-Humans, pubmed-meshheading:18810425-Molecular Sequence Data, pubmed-meshheading:18810425-Multigene Family, pubmed-meshheading:18810425-Myeloid Differentiation Factor 88, pubmed-meshheading:18810425-Phylogeny, pubmed-meshheading:18810425-Primates, pubmed-meshheading:18810425-Protein Structure, Tertiary, pubmed-meshheading:18810425-Selection, Genetic, pubmed-meshheading:18810425-Sequence Alignment, pubmed-meshheading:18810425-Sequence Homology, Amino Acid, pubmed-meshheading:18810425-Species Specificity, pubmed-meshheading:18810425-Toll-Like Receptors
pubmed:year
2008
pubmed:articleTitle
Natural selection in the TLR-related genes in the course of primate evolution.
pubmed:affiliation
Laboratory of Genome Diversity, School of Biomedical Science, Tokyo Medical and Dental University, Tokyo, Japan. tnakajima.tis@mri.tmd.ac.jp
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't