Abstract:
Body shape and size diversity and their evolutionary rates correlate with species richness at the macroevolutionary scale. However, the molecular genetic mechanisms underlying the morphological diversification across related species are poorly understood. In beetles, which account for one-fourth of the known species, adaptation to different trophic niches through morphological diversification appears to have contributed to species radiation. Here, we explored the key genes for the morphological divergence of the slender to stout body shape related to divergent feeding methods on large to small snails within the genus Carabus. We show that the zinc-finger transcription factor encoded by odd-paired (opa) controls morphological variation in the snail-feeding ground beetle Carabus blaptoides. Specifically, opa was identified as the gene underlying the slender to stout morphological difference between subspecies through genetic mapping and functional analysis via gene knockdown. Further analyses revealed that changes in opa cis-regulatory sequences likely contributed to the differences in body shape and size between C. blaptoides subspecies. Among opa cis-regulatory sequences, single nucleotide polymorphisms on the transcription factor binding sites may be associated with the morphological differences between C. blaptoides subspecies. opa was highly conserved in a wide range of taxa, especially in beetles. Therefore, opa may play an important role in adaptive morphological divergence in beetles.
摘要:
身体形状和大小多样性及其进化速率与宏观进化尺度上的物种丰富度相关。然而,对相关物种形态多样化的分子遗传机制知之甚少。在甲虫中,占已知物种的四分之一,通过形态多样化适应不同的营养生态位似乎有助于物种辐射。这里,我们探索了细长体形与粗壮体形的形态差异的关键基因,这些差异与Carabus属中的大蜗牛到小蜗牛的不同喂养方法有关。我们表明,由奇数配对(opa)编码的锌指转录因子控制蜗牛饲喂地面甲虫的形态变异。具体来说,通过基因敲低的遗传作图和功能分析,将opa鉴定为亚种之间细长至粗壮形态差异的潜在基因。进一步的分析表明,opa顺式调节序列的变化可能导致了C.blaptoides亚种之间体形和大小的差异。在opa顺式调节序列中,转录因子结合位点上的单核苷酸多态性可能与胚乳杆菌亚种之间的形态差异有关。opa在广泛的分类单元中高度保守,尤其是甲虫。因此,opa可能在甲虫的适应性形态分化中起重要作用。