一項研究說,，先進的DNA測序技術可能有助于科研人員探明哪種珊瑚更有可能比其他珊瑚在未來的全球氣候變化中生存下來,。近來的研究已經證明了某些珊瑚能比其他一些珊瑚更好地承受環(huán)境壓力,，諸如珊瑚白化,，但是這種適應力增強的基礎尚不清楚,。Daniel J. Barshis及其同事選擇了兩個珊瑚種群,，其中一個對溫度變化敏感,，而另一個對溫度變化有適應力，他們比較了這些生物的基因表達并且發(fā)現(xiàn)了在這兩個種群中,，熱應力改變了數(shù)百種基因的表達,。這組作者然后確定具有適應力的珊瑚在正常環(huán)境下高度表達了60種基因,。其中某些基因編碼的蛋白質起到了一種“前置”保護作用，這些蛋白質參與了已知的耐熱機制,，包括熱激蛋白和抗氧化酶,，以及其他與免疫應答有關的蛋白質。這組作者提出,，這一組基因可能保護那些常常遇到會帶來壓力的環(huán)境變化的珊瑚,。制造珊瑚礁的珊瑚已經在全世界衰退，人們預計它們將隨著氣候變化的加劇而面臨急劇的流失,。這組作者說,，這些發(fā)現(xiàn)證明了DNA測序可以提供對某些生物如何應對未來全球氣候變化的見解。(生物谷Bioon.com)
doi: 10.1073/pnas.1210224110
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Genomic basis for coral resilience to climate change
Daniel J. Barshis1,2, Jason T. Ladner, Thomas A. Oliver, François O. Seneca, Nikki Traylor-Knowles, and Stephen R. Palumbi
Recent advances in DNA-sequencing technologies now allow for in-depth characterization of the genomic stress responses of many organisms beyond model taxa. They are especially appropriate for organisms such as reef-building corals, for which dramatic declines in abundance are expected to worsen as anthropogenic climate change intensifies. Different corals differ substantially in physiological resilience to environmental stress, but the molecular mechanisms behind enhanced coral resilience remain unclear. Here, we compare transcriptome-wide gene expression (via RNA-Seq using Illumina sequencing) among conspecific thermally sensitive and thermally resilient corals to identify the molecular pathways contributing to coral resilience. Under simulated bleaching stress, sensitive and resilient corals change expression of hundreds of genes, but the resilient corals had higher expression under control conditions across 60 of these genes. These “frontloaded” transcripts were less up-regulated in resilient corals during heat stress and included thermal tolerance genes such as heat shock proteins and antioxidant enzymes, as well as a broad array of genes involved in apoptosis regulation, tumor suppression, innate immune response, and cell adhesion. We propose that constitutive frontloading enables an individual to maintain physiological resilience during frequently encountered environmental stress, an idea that has strong parallels in model systems such as yeast. Our study provides broad insight into the fundamental cellular processes responsible for enhanced stress tolerances that may enable some organisms to better persist into the future in an era of global climate change.
