微小按蚊复合体rDNA-ITS2序列差异及遗传多态性研究

STUDIES ON THE DIFFERENCE OF SEQUENCES OF rDNA-ITS2 SPACER OF ANOPHELES MINIMUS COMPLEX AND THEIR INHERITANCE VARIATIONS

本研究对我国微小按蚊广西、云南、海南 6个地理株和越南Caonguen株rDNA ITS2PCR扩增片段和序列差异作分析 ,获得基因片段总长为 5 6 1bp～ 5 6 3bp ,发现地理株间ITS2序列差异程度不同 ,分析表明元江株为微小按蚊C型 ;其余 6个地理株为A型。应用限制性内切酶Sau96Ⅰ对微小按蚊复合体rDNA ITS2PCR扩增片段作酶切分型 ,结果同样显示两型差异 。

To divide forms in An.minimus complex and study their inherited variations,the second internal transcribed spacer of ribosomal DNA have been sequenced and compared in seven geographical strains collected from different areas,including Longsheng county of Guangxi Auto.Reg., Simao、Mengla and Yuanjiang countys of Yunnan province、 Wenchang and Baoting countys of Hainan province in our country and Caonguen area of Vietnam.With PCR amplification from the genome DNA, the lengths of acquired fragment in seven geographical strains were from 561bp to 563bp.The diversity among geographical strains exist difference.It was found Yuanjiang strain could be classified as C form of An.minimus. Although there was a slight difference,other six geographical strains can be classified as A form of An.minimus. It was the first time to established a method to separate different forms of An.minimus complex by applying restriction DNA endonuclease Sau 96Ⅰ to digested the PCR amplified fragments of rDNA ITS2 of An.minimus complex.The results showed clear differences in two forms,and indicated that the method can be applied to discriminate An.minimus complex simply,economically and reliably.