Ndassa Arouna, Mimpfoundi Remy, Elizabeth McClymont
General Biology Laboratory, Faculty of Science, University of Yaounde I, PO Box 812, Yaoundé, Cameroon.
Infect Genet Evol. 2007 Jan;7(1):103-9. doi: 10.1016/j.meegid.2006.05.003. Epub 2006 Jun 30.
Bulinus sp. (2n=36) is a diploid freshwater snail found in Cameroon crater lakes; it belongs to a group of medically important freshwater snails. Some members (Bulinus truncatus, Bulinus tropicus) of this group had been reported to be involved in the transmission of parasites (Schistosoma sp. and Calicophoron microbothrium) to human and livestock in tropical Africa. Yet, understanding of the evolutionary identity of the diploid snail such as its phylogenetic position and the genetic divergence among populations, remains limited. In this study, we constructed the molecular phylogeny of Bulinus sp. using sequences of mitochondrial cytochrome oxydase subunit 1 (CO-1, 365 nucleotides). Partial sequences of CO-1 were obtained and genetic divergences between populations estimated after the alignment of 365 nucleotides from each studied population. The lack of deep molecular divergences between populations of Bulinus sp. from western Cameroon crater lakes may indicate that they belong to the same lineage; therefore, it implies that diploid B. truncatus/tropicus complex snail-like in Cameroon share a common ancestor. The CO-1 of the three studied populations of Bulinus sp., clustered together with other diploid pan-African representatives of the B. truncatus/tropicus complex, showed little evidence of genetic similarities.
布氏螺属（2n = 36）是一种二倍体淡水螺，发现于喀麦隆火山口湖；它属于一类具有重要医学意义的淡水螺。据报道，该类群的一些成员（截形布氏螺、热带布氏螺）在热带非洲将寄生虫（血吸虫属和微小双盘吸虫）传播给人类和牲畜。然而，对于这种二倍体螺的进化身份，如其系统发育位置和种群间的遗传差异，了解仍然有限。在本研究中，我们利用线粒体细胞色素氧化酶亚基1（CO - 1，365个核苷酸）序列构建了布氏螺属的分子系统发育。获得了CO - 1的部分序列，并在对每个研究种群的365个核苷酸进行比对后估计了种群间的遗传差异。喀麦隆西部火山口湖的布氏螺属种群之间缺乏深度分子差异，这可能表明它们属于同一谱系；因此，这意味着喀麦隆类似截形布氏螺/热带布氏螺复合体的二倍体螺有一个共同的祖先。所研究的三个布氏螺属种群的CO - 1与截形布氏螺/热带布氏螺复合体的其他二倍体泛非代表聚集在一起，几乎没有显示出遗传相似性的证据。
