Parallel molecular routes to cold adaptation in eight genera of New Zealand stick insects.
Parallel molecular routes to cold adaptation in eight genera of New Zealand stick insects.
复制标题
在八个新西兰棍棒昆虫中，平行分子途径可冷落。
DOI：
10.1038/srep13965
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发表时间：
2015-09-10
影响因子：
4.6
通讯作者：
Buckley TR
中科院分区：
文献类型：
--
作者：
Dennis AB;Dunning LT;Sinclair BJ;Buckley TR
获得生理策略以耐受新的热条件允许生物体利用新的环境。因此，耐热性是生物多样性全球分布的一个关键决定因素，但对其进化的限制还没有得到很好的理解。在这里，我们调查的耐寒性在新西兰竹节虫，一个地方性的辐射包含三个montane发生的物种的平行进化。使用一个由274个直向基因构建的基因组，我们表明，竹节虫独立殖民山地环境至少两次。我们比较了8属10种植物的过冷却点和内部结冰的存活率，并确定了不同山地谱系的抗冻性和抗冻性。在低地和山地种群的一个单一的，地理分布广泛的物种，抗冻性也得到了验证。冷休克后的转录组测序鉴定了一组结构表皮基因，这些基因在每个物种中都受到差异调节并处于正序列选择下。然而，虽然表皮蛋白一般与整个胚胎发育中的冷休克有关，但不同物种之间起作用的特定基因不同。因此，虽然与表皮结构相关的过程始终与适应寒冷有关，但这可能不是共同祖先遗传限制的结果。
The acquisition of physiological strategies to tolerate novel thermal conditions allows organisms to exploit new environments. As a result, thermal tolerance is a key determinant of the global distribution of biodiversity, yet the constraints on its evolution are not well understood. Here we investigate parallel evolution of cold tolerance in New Zealand stick insects, an endemic radiation containing three montane-occurring species. Using a phylogeny constructed from 274 orthologous genes, we show that stick insects have independently colonized montane environments at least twice. We compare supercooling point and survival of internal ice formation among ten species from eight genera, and identify both freeze tolerance and freeze avoidance in separate montane lineages. Freeze tolerance is also verified in both lowland and montane populations of a single, geographically widespread, species. Transcriptome sequencing following cold shock identifies a set of structural cuticular genes that are both differentially regulated and under positive sequence selection in each species. However, while cuticular proteins in general are associated with cold shock across the phylogeny, the specific genes at play differ among species. Thus, while processes related to cuticular structure are consistently associated with adaptation for cold, this may not be the consequence of shared ancestral genetic constraints.