Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2000-1-20
pubmed:abstractText
In most mammals lactase activity declines after weaning when lactose is no longer part of the diet, but in many humans lactase activity persists into adult life. The difference responsible for this phenotypic polymorphism has been shown to be cis-acting to the lactase gene. The causal sequence difference has not been found so far, but a number of polymorphic sites have been found within and near to the lactase gene. We have shown previously that in Europeans there are two polymorphic sites in a small region between 974 bp and 852 bp upstream from the start of transcription, which are detectable by denaturing gradient gel electrophoresis (DGGE). In this study, analysis of individuals from five other population groups by the same DGGE method reveals four new alleles resulting from three additional nucleotide changes within this very small region. Analysis of sequence in four primate species and comparison with the published pig sequence shows that the overall sequence of this highly variable human region is conserved in pigs as well as primates, and that it lies within a 1kb region which has been shown to control lactase downregulation in pigs. Electrophoretic mobility shift assay (EMSA) studies were carried out to determine whether common variation affected protein-DNA binding and several binding activities were found using this technique. A novel two base-pair deletion that is common in most populations tested, but is not present in Europeans, caused no change in binding activity. However, a previously published C to T transition at -958bp dramatically reduced binding activity, although the functional significance of this is not clear.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1018-4813
pubmed:author
pubmed:issnType
Print
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
791-800
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:10573012-Adult, pubmed-meshheading:10573012-African Continental Ancestry Group, pubmed-meshheading:10573012-Animals, pubmed-meshheading:10573012-Asian Continental Ancestry Group, pubmed-meshheading:10573012-Base Sequence, pubmed-meshheading:10573012-Cell Line, pubmed-meshheading:10573012-DNA, pubmed-meshheading:10573012-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:10573012-Genetic Variation, pubmed-meshheading:10573012-Haplotypes, pubmed-meshheading:10573012-Humans, pubmed-meshheading:10573012-Lactase, pubmed-meshheading:10573012-Molecular Sequence Data, pubmed-meshheading:10573012-Nuclear Proteins, pubmed-meshheading:10573012-Polymorphism, Genetic, pubmed-meshheading:10573012-Primates, pubmed-meshheading:10573012-Protein Binding, pubmed-meshheading:10573012-Sequence Analysis, DNA, pubmed-meshheading:10573012-Sequence Deletion, pubmed-meshheading:10573012-Swine, pubmed-meshheading:10573012-beta-Galactosidase
pubmed:articleTitle
Common polymorphism in a highly variable region upstream of the human lactase gene affects DNA-protein interactions.
pubmed:affiliation
MRC Human Biochemical Genetics Unit, University College London, UK.
pubmed:publicationType
Journal Article