Divergent transcriptional responses to low temperature among populations of alpine and lowland species of New Zealand stick insects (Micrarchus)
Divergent transcriptional responses to low temperature among populations of alpine and lowland species of New Zealand stick insects (Micrarchus)
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DOI：
10.1111/mec.12767
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发表时间：
2014-06-01
影响因子：
4.9
通讯作者：
Buckley, Thomas R.
中科院分区：
文献类型：
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作者：
Dunning, Luke T.;Dennis, Alice B.;Buckley, Thomas R.
在分布广泛且具有遗传结构的种群中，温度变化可能导致种群间热生物学的分化。新西兰竹节虫属Micrarchus包含四种栖息在不同热环境中的昆虫，其中两种在地理上分布广泛。利用RNA-Seq和定量PCR研究了低地和高山植物对冷激的转录反应，以确定不同物种之间的冷反应转录本，并确定基因表达是否存在种内地理变异。我们还使用了线粒体DNA，核28 S核糖体DNA和转录组范围的SNP来确定基因地理结构和遗传背景差异的潜力，以促进基因表达的变化。RNA-Seq鉴定了2160个单一基因，这些基因在来自两个物种（M.hystriculeus和M.nov. sp. 2）的三个种群中由于低温暴露而差异表达，其中大多数（68%+/- 20%）是种群特异性的。这种广泛的地理变异是一致的，多年来，可能是由于遗传漂变和可能的地方适应造成的人群之间的背景遗传差异。高山M.nov. sp. 2种群对冷休克的反应包括表皮结构相关转录物的富集，这表明表皮修饰可能伴随着低温高山环境的定殖和更耐寒表型的发展。
In widespread and genetically structured populations, temperature variation may lead to among-population differentiation of thermal biology. The New Zealand stick insect genus Micrarchus contains four species that inhabit different thermal environments, two of which are geographically widespread. RNA-Seq and quantitative PCR were used to investigate the transcriptional responses to cold shock among lowland and alpine species to identify cold-responsive transcripts that differ between the species and to determine whether there is intraspecific geographical variation in gene expression. We also used mitochondrial DNA, nuclear 28S ribosomal DNA and transcriptome-wide SNPs to determine phylogeographic structure and the potential for differences in genetic backgrounds to contribute to variation in gene expression. RNA-Seq identified 2160 unigenes that were differentially expressed as a result of low-temperature exposure across three populations from two species (M.hystriculeus and M.nov. sp. 2), with a majority (68%+/- 20%) being population specific. This extensive geographical variation is consistent across years and is likely a result of background genetic differences among populations caused by genetic drift and possibly local adaptation. Responses to cold shock shared among alpine M.nov. sp. 2 populations included the enrichment of cuticular structure-associated transcripts, suggesting that cuticle modification may have accompanied colonization of low-temperature alpine environments and the development of a more cold-hardy phenotype.