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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
1999-11-17
pubmed:abstractText
Approximately two thirds of all knockouts of individual mouse genes give rise to viable fertile mice. These genes have thus been termed 'non-essential' in contrast to 'essential' genes, the knockouts of which result in death or infertility. Although non-essential genes are likely to be under selection that favours sequence conservation [1], it is predicted that they are less subject to such stabilising selection than essential genes, and hence evolve faster [2]. We have addressed this issue by analysing the molecular evolution of 108 non-essential and 67 essential genes that have been sequenced in both mouse and rat. On preliminary analysis, the non-essential genes appeared to be faster evolving than the essential ones. We found, however, that the non-essential class contains a disproportionate number of immune-system genes that may be under directional selection (that is, selection favouring change) because of host-parasite coevolution. After correction for this bias, we found that the rate at which genes evolve does not correlate with the severity of the knockout phenotype. This was corroborated by the finding that, whereas neuron-specific genes have significantly lower rates of change than other genes, essential and non-essential neuronal genes have comparable rates of evolution. Our findings most probably reflect strong selection acting against even very subtle deleterious phenotypes, and indicate that the putative involvement of directional selection in host-parasite coevolution and gene expression within the nervous system explains much more of the variance in rates of gene evolution than does the knockout phenotype.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0960-9822
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
747-50
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Do essential genes evolve slowly?
pubmed:affiliation
Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK. l.d.hurst@bath.ac.uk
pubmed:publicationType
Journal Article