Linked Life Data

8375665

Source:http://linkedlifedata.com/resource/pubmed/id/8375665

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-10-21
pubmed:databankReference
pubmed:abstractText
Esterase 6 (Est-6/EST6) is the major beta-carboxylesterase in D. melanogaster and its siblings D. simulans and D. mauritiana. It is expressed in several tissues but its major site of expression is the sperm ejaculatory duct of the adult male. Although EST6 activity affects reproductive fitness, there are high levels of electrophoretic and activity polymorphism, at least within D. melanogaster and D. simulans. Here we present the nucleotide sequences of an Est-6 allele and its flanking regions from each of D. simulans and D. mauritiana and compare them with the published D. melanogaster sequences. As might be expected, replacement sites are significantly less divergent than exon silent sites in all comparisons, suggesting that selection is acting to maintain EST6 structure and function among the three species. Nevertheless, the ratio of the levels of replacement to silent site divergence is still much higher for Est-6 than for seven of ten other genes (including both isozyme-coding loci) for which comparable data have been published for these species. This is consistent with the high levels of EST6 electrophoretic polymorphism within D. melanogaster and D. simulans and implies that selective constraints against amino acid change are relatively weak for EST6. By contrast, comparisons involving promotor sequences show that the level of divergence in the first 350bp 5' of the gene is significantly lower than those for four of the six other loci for which comparable data have been published for these species. In particular, there are two perfectly conserved stretches (-1 to -158bp and -219 to -334bp) each over 100bp long included in this 350bp region. Thus the data suggest a relatively low level of selective constraint on the amino acid sequence of EST6 but a relatively high level of constraint on sequences affecting aspects of its expression.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0016-6707
pubmed:author
pubmed:issnType
Print
pubmed:volume
88
pubmed:geneSymbol
Est-6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11-28
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:8375665-Amino Acid Sequence, pubmed-meshheading:8375665-Animals, pubmed-meshheading:8375665-Base Sequence, pubmed-meshheading:8375665-Biological Evolution, pubmed-meshheading:8375665-Carboxylesterase, pubmed-meshheading:8375665-Carboxylic Ester Hydrolases, pubmed-meshheading:8375665-Conserved Sequence, pubmed-meshheading:8375665-Drosophila, pubmed-meshheading:8375665-Drosophila Proteins, pubmed-meshheading:8375665-Drosophila melanogaster, pubmed-meshheading:8375665-Genes, Insect, pubmed-meshheading:8375665-Genetic Variation, pubmed-meshheading:8375665-Molecular Sequence Data, pubmed-meshheading:8375665-Promoter Regions, Genetic, pubmed-meshheading:8375665-Sequence Homology, Amino Acid, pubmed-meshheading:8375665-Sequence Homology, Nucleic Acid, pubmed-meshheading:8375665-Species Specificity
pubmed:year
1993
pubmed:articleTitle
Conservation and change in structural and 5' flanking sequences of esterase 6 in sibling Drosophila species.
pubmed:affiliation
Molecular Biology and Physiology Section, CSIRO Division of Entomology, Canberra A.C.T., Australia.
pubmed:publicationType
Journal Article, Comparative Study