Linked Life Data

10555294

Source:http://linkedlifedata.com/resource/pubmed/id/10555294

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1999-11-23
pubmed:abstractText
DNA variability was investigated in the last intron of the Y-chromosome-specific zinc finger gene, ZFY, and its X homolog on Xp21.3, ZFX. No polymorphisms were found in the 676-bp ZFY segment in a sample of 205 world-wide-distributed Y chromosomes, other than a solitary nucleotide variant in one individual (nucleotide diversity pi = 0.0014%). In contrast, 10 segregating sites (pi = 0.082%) were identified within 1,089 bp of the ZFX sequence in a sample of 336 X chromosomes. Four of these polymorphisms, which contributed most of the diversity, were located within an Alu insert disrupting the ZFY-ZFX homology (pi Alu = 0.24%). The diversity in the homologous portion of the ZFX intron, although higher than that in ZFY, was lower than that found in genomic segments believed to evolve neutrally; interspecies divergence in both segments was also reduced. Although this suggests that the evolution of both ZFY and ZFX homologs may not be entirely neutral, both Tajima and HKA tests did not reject neutrality. The lack of statistical significance may be attributed to a lack of power in these tests (the low divergence and variability values reduce the power of the HKA and Tajima tests, respectively); furthermore, Homo sapiens has recently undergone a rapid population growth, and selection is more difficult to detect in an expanding population. Therefore, the failure to reject neutrality does not necessarily indicate the absence of selection. In this context, the phylogenetic argument was given more weight in out interpretations. The high level of sequence identity in ZFY and ZFX segments, in spite of their separation 80-130 MYA, reflects a lower mutation rate as compared with other segments believed to undergo unconstrained evolution. Thus, the possibility of weak selection contributing to the low level of nucleotide diversity in the last ZFY intron cannot be excluded and should be kept in mind in the population genetics studies based on Y chromosome variability.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0737-4038
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1633-40
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Is selection responsible for the low level of variation in the last intron of the ZFY locus?
pubmed:affiliation
Institute of Human Genetics, Polish Academy of Sciences, Strzeszynska, Poland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't