Exon-Enriched Libraries Reveal Large Genic Differences Between Aedes aegypti from Senegal, West Africa, and Populations Outside Africa
Exon-Enriched Libraries Reveal Large Genic Differences Between Aedes aegypti from Senegal, West Africa, and Populations Outside Africa
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DOI：
10.1534/g3.116.036053
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发表时间：
2017-02-01
影响因子：
2.6
通讯作者：
Black, William C.
中科院分区：
文献类型：
--
作者：
Dickson, Laura B.;Campbell, Corey L.;Black, William C.
埃及伊蚊是研究最多的蚊子之一，也是几种对人类致病的虫媒病毒的主要媒介。近期观察到伊蚊产卵失败、繁殖力低、卵到成虫存活率差。将来自西非塞内加尔的埃及伊蚊与伊蚊杂交。埃及伊蚊（Aaa）来自非洲以外，并在SenAae交叉路口。荧光原位杂交分析显示1号染色体重排，2号和3号染色体中心倒位。本研究采用高通量测序（HTS）技术对泰国农村和墨西哥的Aaa型菌株、塞内加尔东南部的森林型菌株（PK10）和塞内加尔西部的城市型菌株（Kaolack）的染色体遗传多样性进行了比较。分析了泰国和PK10的性别特异性多态性，以评估两性之间的遗传差异。期望杂合度在SenAae中最高。4个种质的F-ST分布中，15735个基因的两两比较表明，墨西哥和泰国种质的F-ST分布相似，而PK10和考拉之间的F-ST分布不同。SenAae与Aaa的四项比较均显示分化严重。在泰国的所有染色体中，F-ST在两性之间是一致的，但在PK10中，尤其是在性常染色体1上，F-ST是不同的。这些模式与前面提到的生殖隔离有关。我们假设神秘的Ae。埃及伊蚊分类群可能存在于西非，本研究中发现的Aaa和SenAae之间的巨大基因差异是在异域种群中染色体重排的进化过程中积累起来的，当这些种群成为同域种群时，这些染色体重排随后导致生殖隔离。
Aedes aegypti is one of the most studied mosquito species, and the principal vector of several arboviruses pathogenic to humans. Recently failure to oviposit, low fecundity, and poor egg-to-adult survival were observed when Ae. aegypti from Senegal (SenAae) West Africa were crossed with Ae. aegypti (Aaa) from outside of Africa, and in SenAae intercrosses. Fluorescent in situ hybridization analyses indicated rearrangements on chromosome 1, and pericentric inversions on chromosomes 2 and 3. Herein, high throughput sequencing (HTS) of exon-enriched libraries was used to compare chromosome-wide genetic diversity among Aaa collections from rural Thailand and Mexico, a sylvatic collection from southeastern Senegal (PK10), and an urban collection from western Senegal (Kaolack). Sex-specific polymorphisms were analyzed in Thailand and PK10 to assess genetic differences between sexes. Expected heterozygosity was greatest in SenAae. F-ST distributions of 15,735 genes among all six pairwise comparisons of the four collections indicated that Mexican and Thailand collections are genetically similar, while F-ST distributions between PK10 and Kaolack were distinct. All four comparisons of SenAae with Aaa indicated extreme differentiation. F-ST was uniform between sexes across all chromosomes in Thailand, but were different, especially on the sex autosome 1, in PK10. These patterns correlate with the reproductive isolation noted earlier. We hypothesize that cryptic Ae. aegypti taxa may exist in West Africa, and the large genic differences between Aaa and SenAae detected in the present study have accumulated over a long period following the evolution of chromosome rearrangements in allopatric populations that subsequently cause reproductive isolation when these populations became sympatric.