Kolaczan C R, Heard S B, Segraves K A, Althoff D M, Nason J D
Department of Biology, University of New Brunswick, Fredericton, NB, Canada.
J Evol Biol. 2009 Jun;22(6):1275-83. doi: 10.1111/j.1420-9101.2009.01742.x. Epub 2009 Apr 21.
Host-associated differentiation (HAD) appears to be an important driver of diversification in the hyperdiverse phytophagous and parasitoid insects. The gallmaking moth Gnorimoschema gallaesolidaginis has undergone HAD on two sympatric goldenrods (Solidago), and HAD has also been documented in its parasitoid Copidosoma gelechiae, with the intriguing suggestion that differentiation has proceeded independently in multiple populations. We tested this suggestion with analysis of Amplified Fragment Length Polymorphism (AFLP) markers for C. gelechiae collections from the midwestern and northeastern United States and eastern Canada. AFLP data were consistent with the existence of HAD, with between-host F(ST) significant before Bonferroni correction in two of seven sympatric populations. amova analysis strongly rejected a model of HAD with a single historical origin, and thus supported the repeated-HAD hypothesis. Copidosoma gelechiae shows significant host-associated divergence at a number of allozyme loci (Stireman et al., 2006), but only weak evidence via AFLPs for genome-wide differentiation, suggesting that this species is at a very early stage of HAD.
宿主关联分化（HAD）似乎是超多样的植食性昆虫和寄生性昆虫多样化的一个重要驱动因素。造瘿蛾Gnorimoschema gallaesolidaginis在两种同域分布的一枝黄花（Solidago）上经历了宿主关联分化，并且在其寄生蜂Copidosoma gelechiae中也记录到了宿主关联分化，有趣的是，有迹象表明分化在多个种群中是独立进行的。我们通过对来自美国中西部、东北部以及加拿大东部的C. gelechiae样本进行扩增片段长度多态性（AFLP）标记分析来验证这一推测。AFLP数据与宿主关联分化的存在相一致，在七个同域种群中的两个种群中，宿主间的F(ST)在进行Bonferroni校正之前具有显著性。方差分析强烈拒绝了具有单一历史起源的宿主关联分化模型，因此支持了重复宿主关联分化假说。Copidosoma gelechiae在多个等位酶位点上表现出显著的宿主关联分化（Stireman等人，2006年），但通过AFLP仅能得到全基因组分化的微弱证据，这表明该物种正处于宿主关联分化的非常早期阶段。
