Zurovcová Martina, Tatarenkov Andrey, Berec Ludek
Institute of Entomology, Czech Academy of Sciences and Faculty of Biological Sciences, University of South Bohemia, Branisovská 31, 370 05 Ceské Budejovice, Czech Republic.
Gene. 2006 Oct 15;381:24-33. doi: 10.1016/j.gene.2006.06.011. Epub 2006 Jun 28.
We describe DNA sequence polymorphisms at six loci (Acp26Aa, Acp26Ab, Acp29AB, Idgf1, Idgf3 and Ddc), all on the second chromosome of Drosophila melanogaster in one natural European population. Previous studies considering these loci separately showed that some of them were affected by natural selection. However, demographic processes or population admixture can produce footprints similar to natural selection. Simultaneous consideration of several genes may help to discern between selective and demography/admixture scenarios because the latter are expected to affect a majority of loci in a similar manner. Such an effect is not necessarily uniform among genes, but can be modified by rates of recombination and substitution. Since different evolutionary forces shaped the variation of the studied genes, our aim is to examine if their physical linkage could have affected the observed pattern. Fisher's conservative test of linkage disequilibrium is not significant. Lewontin's sign test pointed to linkage disequilibrium both within and between loci levels, though, none of the loci exhibits haplotype structure. Coupled with other results, the possibility of demography being the exclusive explanation for the observed variability is ruled out.
我们描述了欧洲一个自然种群中，位于黑腹果蝇第二条染色体上的六个基因座（Acp26Aa、Acp26Ab、Acp29AB、Idgf1、Idgf3和Ddc）的DNA序列多态性。之前单独研究这些基因座的结果表明，其中一些受到了自然选择的影响。然而，人口统计学过程或种群混合也可能产生与自然选择相似的痕迹。同时考虑多个基因可能有助于区分选择和人口统计学/混合情况，因为预计后者会以类似方式影响大多数基因座。这种影响在基因之间不一定是均匀的，但可能会受到重组率和替代率的影响。由于不同的进化力量塑造了所研究基因的变异，我们的目的是研究它们的物理连锁是否会影响观察到的模式。费舍尔连锁不平衡保守检验不显著。不过，莱文廷符号检验表明基因座内部和基因座之间均存在连锁不平衡，尽管没有一个基因座表现出单倍型结构。结合其他结果，排除了人口统计学是观察到的变异性唯一解释的可能性。
