Differential gene expression in incipient species of Anopheles gambiae
Differential gene expression in incipient species of Anopheles gambiae
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DOI：
10.1111/j.1365-294x.2008.03774.x
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发表时间：
2008-05-01
影响因子：
4.9
通讯作者：
Besansky, Nora J.
中科院分区：
文献类型：
--
作者：
Cassone, Bryan J.;Mouline, Karine;Besansky, Nora J.
非洲疟疾的主要媒介冈比亚按蚊正在经历物种形成过程。被称为 M 和 S 形式的选型交配的早期物种会差异性地利用与不同生态环境相关的幼虫繁殖地。然而，M 和 S 之间一些正在进行的基因流限制了显着的基因组分化，主要限制在 X 和 2L 染色体上的小着丝粒近端区域，称为“物种形成岛”，期望它们包含负责生殖隔离的基因。由于物种形成岛表现出重组减少和多态性低，因此使用精细尺度绘图进行更详细的遗传分析是不切实际的。我们使用寡核苷酸微阵列测量了 M 和 S 之间的全局基因表达差异，目的是识别可能参与这一正在进行的物种形成过程的候选基因。在感兴趣的三个发育时期（第四龄幼虫、处女雌性和妊娠雌性）的每一个时期，在两种形式的两个独立群体中检查基因表达谱。使用来自喀麦隆和布基纳法索收集的实验室群体和野生蚊子的 RNA 样本的定量实时逆转录聚合酶链反应，对基因子集的模式进行了验证。考虑到所有三个发育时期，差异表达基因占所有表达基因的 1-2%。尽管 X 物种形成岛中的基因比例不成比例，但绝大多数基因位于任何物种形成岛之外。与其他发育时期的样本相比，处女雌性的差异表达基因数量是其两倍多，最显着的是那些与嗅觉和潜在的配偶识别有关的基因。
A speciation process is ongoing in the primary vector of malaria in Africa, Anopheles gambiae. Assortatively mating incipient species known as the M and S forms differentially exploit larval breeding sites associated with different ecological settings. However, some ongoing gene flow between M and S limits significant genomic differentiation mainly to small centromere-proximal regions on chromosomes X and 2L, termed 'speciation islands' with the expectation that they contain the genes responsible for reproductive isolation. As the speciation islands exhibit reduced recombination and low polymorphism, more detailed genetic analysis using fine-scale mapping is impractical. We measured global gene expression differences between M and S using oligonucleotide microarrays, with the goal of identifying candidate genes that could be involved in this ongoing speciation process. Gene expression profiles were examined in two independent colonies of both forms at each of three developmental periods of interest: fourth instar larvae, virgin females, and gravid females. Patterns were validated on a subset of genes using quantitative real-time reverse transcription polymerase chain reaction of RNA samples from laboratory colonies and wild mosquitoes collected from Cameroon and Burkina Faso. Considered across all three developmental periods, differentially expressed genes represented similar to 1-2% of all expressed genes. Although disproportionately represented in the X speciation island, the vast majority of genes were located outside any speciation island. Compared to samples from the other developmental periods, virgin females were characterized by more than twice as many differentially expressed genes, most notably those implicated in olfaction and potentially, mate recognition.