蜜蜂属六蜂种间MRJP2基因C-端重复序列的比较分析

构建了中华蜜蜂（Apis cerana cerana，中蜂）8日龄工蜂头部cDNA文库，获得了中蜂王浆主蛋白2（major royal jelly protein 2，MRJP2）的全长cDNA序列，该序列长1 605bp，包含一个编码468个氨基酸的开放阅读框（open reading frame，ORF）。在中蜂MRJP2的cDNA序列的C-端，首次发现存在串联重复片段长度多态性（variable numbers of tandem repeat，VNTR）。克隆并测定了蜜蜂属Apis内其他5个种的MRJP2基因的C-端重复序列，结果表明: 在蜜蜂属的其他5个种中，C-端重复片段的核心序列是以碱基高度突变方式而表现出个体之间的多态性，而重复片段长度基本一致。中蜂与西方蜜蜂A. mellifera，大蜜蜂A. dorsata与黑大蜜蜂A. laboriosa，以及小蜜蜂A. florea与黑小蜜蜂A. andreniformis分别形成3个进化枝。中蜂和西方蜜蜂与大蜜蜂和黑大蜜蜂之间的亲缘关系较近，而与小蜜蜂和黑小蜜蜂的亲缘关系较远。

Comparative analysis of C-terminal repetitive sequences of MRJP2 among six species of the genus Apis

The cDNA library was constructed with heads of 8-day old workers of Apis cerana cerana. cDNA sequence of major royal jelly protein 2 (MRJP2), which includes 1 605 bp and an open reading frame (ORF) encoding 468 amino acid residues, was screened and obtained from this library. A repetitive fragment of variable numbers of tandem repeat (VNTR) was found at the C-terminal sequence of A. cerana cerana MRJP2 for the first time. C-terminal repetitive sequences of MRJP2 were also cloned and sequenced for other five species of Apis. The results showed that in the other five species the sequences of the C-terminal repetitive fragment performed individual polymorphism based on core bases mutation instead of different duplications, while the lengths of the repetitive sequences were almost the same among different individuals belonging to one species. A. cerana cerana and A. mellifera, A. dorsata and A. laboriosa, and A. florea and A. andreniformis formed three evolutionary branches, respectively. The branch of A. cerana and A. mellifera showed a closer relationship with the branch of A. dorsata and A. laboriosa than that with the branch of A. florea and A. andreniformis.