Positive and negative selection in the DAZ gene family

被引:57
作者
Bielawski, JP [1 ]
Yang, ZH [1 ]
机构
[1] UCL, Galton Lab, Dept Biol, London NW1 2HE, England
关键词
DAZ; DAZL1; gene family; maximum likelihood; codon model; positive selection;
D O I
10.1093/oxfordjournals.molbev.a003831
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Because a microdeletion containing the DAZ gene is the most frequently observed deletion in infertile men, the DAZ gene was considered a strong candidate for the azoospermia factor. A recent evolutionary analysis, however suggested that DAZ was free from functional constraints and consequently played little or no role in human spermatogenesis. The major evidence for this surprising conclusion is that the nonsynonymous substitution rate is similar to the synonymous rate and to the rate in introns. In this study, we reexamined the evolution of the DAZ gene family by using maximum-likelihood methods, which accommodate variable selective pressures among sites or among branches. The results suggest that DAZ is not free from functional constraints. Most amino acids in DAZ are under strong selective constraint, while a few sites are under diversifying selection with nonsynonymous/ synonymous rate ratios (d(N)/d(S)) well above 1. As a result, the average d(N)/d(S) ratio over sites is not a sensible measure of selective pressure on the protein. Lineage-specific analysis indicated that human members of this gene family were evolving by positive Darwinian selection, although the evidence was not strong.
引用
收藏
页码:523 / 529
页数:7
相关论文
共 39 条
[1]   Evolution of the DAZ gene family suggests that Y-linked DAZ plays little, or a limited, role in spermatogenesis but underlines a recent African origin for human populations [J].
Agulnik, AI ;
Zharkikh, A ;
Boettger-Tong, H ;
Bourgeron, T ;
McElreavey, K ;
Bishop, CE .
HUMAN MOLECULAR GENETICS, 1998, 7 (09) :1371-1377
[2]   Analysis of HIV-1 env gene sequences reveals evidence for a low effective number in the viral population [J].
Brown, AJL .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1997, 94 (05) :1862-1865
[3]   A murine homologue of the human DAZ gene is autosomal and expressed only in male and female gonads [J].
Cooke, HJ ;
Lee, M ;
Kerr, S ;
Ruggiu, M .
HUMAN MOLECULAR GENETICS, 1996, 5 (04) :513-516
[4]   Parallel evolution of drug resistance in HIV: Failure of nonsynonymous/synonymous substitution rate ratio to detect selection [J].
Crandall, KA ;
Kelsey, CR ;
Imamichi, H ;
Lane, HC ;
Salzman, NP .
MOLECULAR BIOLOGY AND EVOLUTION, 1999, 16 (03) :372-382
[5]   Molecular genetics of ecological diversification:: Duplication and rapid evolution of toxin genes of the venomous gastropod Conus [J].
Duda, TF ;
Palumbi, SR .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1999, 96 (12) :6820-6823
[6]  
DYKHUIZEN D, 1980, GENETICS, V96, P801
[7]   The molecular genetics of male infertility [J].
Elliott, DJ ;
Cooke, HJ .
BIOESSAYS, 1997, 19 (09) :801-809
[8]   Human male infertility and Y chromosome deletions:: role of the AZF-candidate genes DAZ, RBM and DFFRY [J].
Ferlin, A ;
Moro, E ;
Garolla, A ;
Foresta, C .
HUMAN REPRODUCTION, 1999, 14 (07) :1710-1716
[9]  
GOLDMAN N, 1994, MOL BIOL EVOL, V11, P725
[10]   The Old World monkey DAZ (Deleted in AZoospermia) gene yields insights into the evolution of the DAZ gene cluster on the human Y chromosome [J].
Gromoll, J ;
Weinbauer, GF ;
Skaletsky, H ;
Schlatt, S ;
Rocchietti-March, M ;
Page, DC ;
Nieschlag, E .
HUMAN MOLECULAR GENETICS, 1999, 8 (11) :2017-2024