Zhan Lei-Lei, Tian Jun, Liu Can, Ke Fang, Yang Yong, Li Chun-Xuan, Qian Yuan-Huai, Zeng Qing-Tao
College of Life Science, Hubei University, Wuhan 430062, People's Republic of China.
J Hered. 2008 Jul-Aug;99(4):417-20. doi: 10.1093/jhered/esn006. Epub 2008 Feb 28.
Drosophila focal adhesion kinase (Dfak) gene is a single-copy nuclear gene. Previous study revealed that Drosophila melanogaster and Drosophila simulans had lost an intron precisely within the tyrosine kinase (TyK) domain of this gene. However, this did not happen in several other Drosophila species, including Drosophila elegans, Drosophila ficusphila, Drosophila biarmipes, Drosophila jambulina, Drosophila prostipennis, Drosophila takahashii, and Drosophila pseudoobscura. In the current study, homologous sequences of Drosophila sechellia, Drosophila mauritiana, Drosophila yakuba, Drosophila teissieri, Drosophila santomea, and Drosophila erecta were amplified by polymerase chain reaction, and further sequencing analysis indicated that these species were missing a TyK domain intron, indicating they were closely related. The relationship of the D. melanogaster species group was reconstructed using TyK domain nucleotide sequences. The resulting phylogenetic tree revealed that these 8 species were the most related species in the melanogaster group. These results strongly support previously proposed classifications based on morphological and molecular data.
果蝇粘着斑激酶（Dfak）基因是一个单拷贝核基因。先前的研究表明，黑腹果蝇和拟果蝇在该基因的酪氨酸激酶（TyK）结构域内恰好缺失了一个内含子。然而，在包括秀丽果蝇、榕果蝇、双臂果蝇、贾氏果蝇、前突果蝇、高桥氏果蝇和伪暗果蝇在内的其他几种果蝇物种中并未发生这种情况。在本研究中，通过聚合酶链反应扩增了塞舌尔果蝇、毛里求斯果蝇、雅库巴果蝇、泰氏果蝇、圣多美果蝇和直立果蝇的同源序列，进一步的测序分析表明这些物种缺失了一个TyK结构域内含子，这表明它们亲缘关系密切。利用TyK结构域核苷酸序列重建了黑腹果蝇物种组的关系。所得的系统发育树表明，这8个物种是黑腹果蝇组中亲缘关系最密切的物种。这些结果有力地支持了先前基于形态学和分子数据提出的分类。
