近日，中國科學(xué)院水生生物研究所關(guān)于魚類低溫適應(yīng)機(jī)制研究的論文“Transcriptomic characterization of cold acclimation in larval zebrafish”在BMC genomics在線發(fā)表,。該論文首次報(bào)道了斑馬魚早期幼體具備建立低溫耐受的機(jī)制,。
低溫暴露不但影響魚類的生長和發(fā)育，嚴(yán)重時(shí)還可導(dǎo)致魚體死亡,。魚類的低溫耐受能力受遺傳,、熱歷程和發(fā)育階段等因素的影響。近年來,，魚類低溫適應(yīng)機(jī)制逐漸成為研究熱點(diǎn),，然而魚類發(fā)育的早期階段是否具備低溫適應(yīng)能力，以及低溫適應(yīng)過程中的轉(zhuǎn)錄和轉(zhuǎn)錄后調(diào)控機(jī)制尚不清楚。
中科院水生所崔宗斌研究員課題組以斑馬魚為模型研究魚類的低溫適應(yīng)機(jī)制,。研究發(fā)現(xiàn)斑馬魚受精后96h幼體低溫（12℃）暴露前先在16℃處理24h可以顯著降低死亡率,，說明其具備在較低溫度條件下形成低溫耐受的能力。RNA-seq分析鑒定出1431個(gè)低溫誘導(dǎo)基因和399個(gè)抑制基因,。生物信息學(xué)分析結(jié)果表明,，低溫誘導(dǎo)表達(dá)的基因主要參與RNA剪接、核糖體生物發(fā)生,、蛋白質(zhì)分解代謝和RNA轉(zhuǎn)運(yùn)等生物學(xué)過程,。由于RNA-seq具有全基因組范圍內(nèi)檢測基因表達(dá)的技術(shù)優(yōu)勢,，本研究還鑒定到大量受低溫調(diào)控的可變剪接和可變啟動(dòng)子使用事件,。該論文和本課題組前期研究（PLoS ONE,， 2012,， 7(5)： e37209）結(jié)果為后續(xù)深入研究魚類低溫適應(yīng)過程中的信號(hào)傳導(dǎo)機(jī)制及關(guān)鍵基因功能提供了重要線索。
該研究工作得到國家自然科學(xué)基金資助,，由龍勇助理研究員等人完成,。（生物谷Bioon.com）
生物谷推薦的英文摘要
BMC genomics doi:10.1186/1471-2164-14-612
Transcriptomic characterization of cold acclimation in larval zebrafish
Yong Long1,， Guili Song1， Junjun Yan12,， Xiaozhen He12,， Qing Li1 and Zongbin Cui1
Background
Temperature is one of key environmental parameters that affect the whole life of fishes and an increasing number of studies have been directed towards understanding the mechanisms of cold acclimation in fish. However， the adaptation of larvae to cold stress and the cold-specific transcriptional alterations in fish larvae remain largely unknown. In this study,， we characterized the development of cold-tolerance in zebrafish larvae and investigated the transcriptional profiles under cold stress using RNA-seq.
Results
Pre-exposure of 96,？hpf zebrafish larvae to cold stress (16°C) for 24 h significantly increased their survival rates under severe cold stress (12°C). RNA-seq generated 272 million raw reads from six sequencing libraries and about 92% of the processed reads were mapped to the reference genome of zebrafish. Differential expression analysis identified 1，431 up- and 399 down-regulated genes. Gene ontology enrichment analysis of cold-induced genes revealed that RNA splicing,， ribosome biogenesis and protein catabolic process were the most highly overrepresented biological processes. Spliceosome,， proteasome,， eukaryotic ribosome biogenesis and RNA transport were the most highly enriched pathways for genes up-regulated by cold stress. Moreover,， alternative splicing of 197 genes and promoter switching of 64 genes were found to be regulated by cold stress. A shorter isoform of stk16 that lacks 67 amino acids at the N-terminus was specifically generated by skipping the second exon in cold-treated larvae. Alternative promoter usage was detected for per3 gene under cold stress,， which leading to a highly up-regulated transcript encoding a truncated protein lacking the C-terminal domains.
Conclusions
These findings indicate that zebrafish larvae possess the ability to build cold-tolerance under mild low temperature and transcriptional and post-transcriptional regulations are extensively involved in this acclimation process.
