rRNA及MaSp1基因证据不支持圆网蛛类(蜘蛛目:妖面蛛总科+园蛛总科)的单系起源

圆网蛛类(妖面蛛总科 园蛛总科)是否为单系,圆网究竟经历一次进化还是多次进化,这是多年来有争论的、悬而未决的蛛形学难题之一。本文测定了包括妖面蛛总科、园蛛总科和非圆网蛛类等类群在内的9科10种蜘蛛线粒体12S rDNA、16S rDNA及核18S rDNA、28S rDNA等4个基因片段序列,并基于4个基因序列的整合数据,分别通过邻接(NJ)法、最大简约(MP)法、最大似然(ML)法和贝叶斯法(Bayesian)分析,对园蛛总科和妖面蛛总科蜘蛛之间的分子系统关系进行了探讨。系统发生结果表明:1)园蛛总科和妖面蛛总科蜘蛛不是姊妹群,从而支持这两个类群的圆网是平行演化而非同源演化的观点;2)筛器类蜘蛛并非单系发生而为多系发生。另外,依据编码大壶状腺丝蛋白-1(MaSp1)C末端非重复氨基酸序列区段的核酸序列重建的系统发生树也证实圆网蛛类并非单系发生。

rRNA and MaSp1 gene do not support the monophyly of Orbiculariae(Araneae: Deinopoidea + Araneoidea)

The present study examined whether orb web spiders(Deinopoidea Araneoidea)are monophyletic or polyphyleticin origin? Mitochondrial 12S, 16S and nuclear 18S, 28S rDNA fragments of ten species of spiders were amplified and sequenced. Using neighbor-joining(NJ), maximum parsimony(MP), maximum likelihood(ML)methods and Bayesian analyses, the phylogenetic relationship between Deinopoidea and Araneoidea was inferred from the combined DNA sequences of 12S, 16S, 18S and 28S rDNA fragments. The resulting phylogeny indicated that: 1)Deinopoidea and Araneoidea did not form single clade. This finding well supports that the orb-web similarities between Deinopoidea and Araneoidea are more likely the result of convergent rather than homologous evolution; 2)Cribellate spiders are polyphyletic. In addition, the reconstructed phylogenetic tree based on cDNA and DNA sequences encoding C-terminal non-repetitive region of MaSp1(Major ampullate spidroin-1)also showed that Deinopoidea and Araneoidea are not sister groups .