Sum Jia-Siang, Lee Wenn-Chyau, Amir Amirah, Braima Kamil A, Jeffery John, Abdul-Aziz Noraishah M, Fong Mun-Yik, Lau Yee-Ling
Tropical Infectious Disease Research and Education Center (TIDREC), Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
Parasit Vectors. 2014 Jul 3;7:309. doi: 10.1186/1756-3305-7-309.
Molecular techniques are invaluable for investigation on the biodiversity of Anopheles mosquitoes. This study aimed at investigating the spatial-genetic variations among Anopheles mosquitoes from different areas of Peninsular Malaysia, as well as deciphering evolutionary relationships of the local Anopheles mosquitoes with the mosquitoes from neighbouring countries using the anopheline ITS2 rDNA gene.
Mosquitoes were collected, identified, dissected to check infection status, and DNA extraction was performed for PCR with primers targeting the ITS2 rDNA region. Sequencing was done and phylogenetic tree was constructed to study the evolutionary relationship among Anopheles mosquitoes within Peninsular Malaysia, as well as across the Asian region.
A total of 133 Anopheles mosquitoes consisting of six different species were collected from eight different locations across Peninsular Malaysia. Of these, 65 ITS2 rDNA sequences were obtained. The ITS2 rDNA amplicons of the studied species were of different sizes. One collected species, Anopheles sinensis, shows two distinct pools of population in Peninsular Malaysia, suggesting evolvement of geographic race or allopatric speciation.
Anopheles mosquitoes from Peninsular Malaysia show close evolutionary relationship with the Asian anophelines. Nevertheless, genetic differences due to geographical segregation can be seen. Meanwhile, some Anopheles mosquitoes in Peninsular Malaysia show vicariance, exemplified by the emergence of distinct cluster of An. sinensis population.
分子技术对于按蚊生物多样性的研究具有重要价值。本研究旨在调查马来西亚半岛不同地区按蚊的空间遗传变异，以及利用按蚊内转录间隔区2（ITS2）核糖体DNA（rDNA）基因解析当地按蚊与邻国按蚊之间的进化关系。
收集蚊子，进行鉴定、解剖以检查感染状况，并提取DNA，使用针对ITS2 rDNA区域的引物进行聚合酶链反应（PCR）。进行测序并构建系统发育树，以研究马来西亚半岛内以及亚洲区域按蚊之间的进化关系。
从马来西亚半岛的八个不同地点共收集了133只按蚊，分属于六个不同物种。其中，获得了65条ITS2 rDNA序列。所研究物种的ITS2 rDNA扩增子大小不同。所收集的一个物种中华按蚊在马来西亚半岛显示出两个不同的种群库，表明地理宗的进化或异域物种形成。
马来西亚半岛的按蚊与亚洲按蚊显示出密切的进化关系。然而，可以看到由于地理隔离导致的遗传差异。同时，马来西亚半岛的一些按蚊表现出地理隔离分布，中华按蚊种群出现明显聚类就是例证。
