Guelbeogo W M, Grushko O, Boccolini D, Ouédraogo P A, Besansky N J, Sagnon N F, Costantini C
University of Ouagadougou, Burkina Faso.
Med Vet Entomol. 2005 Dec;19(4):458-69. doi: 10.1111/j.1365-2915.2005.00595.x.
The analysis of chromosomal polymorphism of paracentric inversions in anopheline mosquitoes has often been instrumental to the discovery of sibling species complexes and intraspecific genetic heterogeneities associated with incipient speciation processes. To investigate the population structure of Anopheles funestus Giles (Diptera: Culicidae), one of the three most important vectors of human malaria in sub-Saharan Africa, a three-year survey of chromosomal polymorphism was carried out on 4,638 karyotyped females collected indoors and outdoors from two villages of central Burkina Faso. Large and temporally stable departures from Hardy-Weinberg equilibrium due to significant deficits of heterokaryotypes were found irrespective of the place of capture, and of the spatial and temporal units chosen for the analysis. Significant linkage disequilibrium was observed among inversion systems on independently assorting chromosomal arms, indicating the existence of assortative mating phenomena. Results were consistent with the existence of two chromosomal forms characterized by contrasting degrees of inversion polymorphism maintained by limitations to gene flow. This hypothesis was supported by the reestablishment of Hardy-Weinberg and linkage equilibria when individual specimens were assigned to each chromosomal form according to two different algorithms. This pattern of chromosomal variability is suggestive of an incipient speciation process in An. funestus populations from Burkina Faso.
对按蚊副着丝粒倒位的染色体多态性进行分析，常常有助于发现与初始物种形成过程相关的同胞物种复合体和种内遗传异质性。为了研究在撒哈拉以南非洲作为人类疟疾三种最重要传播媒介之一的冈比亚按蚊（双翅目：蚊科）的种群结构，对从布基纳法索中部两个村庄室内和室外采集的4638只进行了核型分析的雌性按蚊进行了为期三年的染色体多态性调查。无论捕获地点以及为分析所选的空间和时间单位如何，均发现由于异核型的显著不足而导致与哈迪-温伯格平衡存在较大且随时间稳定的偏差。在独立分配的染色体臂上的倒位系统之间观察到显著的连锁不平衡，表明存在选型交配现象。结果与存在两种染色体形式一致，这两种形式的特征是通过基因流限制维持的倒位多态性程度不同。当根据两种不同算法将个体标本分配到每种染色体形式时，哈迪-温伯格平衡和连锁平衡的重建支持了这一假设。这种染色体变异性模式表明布基纳法索的冈比亚按蚊种群中存在初始物种形成过程。
