3个基因共调控下莱茵衣藻的转录组分析

Transcriptome analysis of Chlamydomonas reinhardtii under the co-regulation of three genes

为研究多基因调控下微藻油脂合成调控的分子机制,对acs2-cis1-dof基因共调控的莱茵衣藻藻株DLC进行转录组测序及分析,获得749个差异表达基因.通过京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)聚类分析发现,有51个差异表达基因参与碳水化合物代谢,15个差异表达基因参与脂质代谢,差异基因主要富集在甘油酯代谢、脂肪酸降解、糖酵解及糖异生、淀粉和蔗糖代谢等通路中.采用BODIPY 505/515荧光染色法检测发现,热激后莱茵衣藻藻株DLC细胞内的甘油三酯质量较野生型提高了193%,通过检测吸光度发现藻细胞的淀粉质量降低了45%,说明基因共调控不仅增强了脂质合成代谢,还使得糖代谢中的碳流重新定向.研究工作为探究基因共调控下脂质合成代谢的分子机理以及微藻产油基因工程提供理论参考.

In order to study the regulatory roles of multiple genes in microalgal lipid metabolism,a Chlamydomonas reinhardtii strain DLC is constructed with overexpression of DOF transcription regulator and silencing of acs2 and cis1. Transcriptome sequencing and analysis are conducted and 749 differentially expressed genes( DEGs) are identified. According to the result of KEGG( Kyoto encyclopedia of genes and genomes) classification,51 and 15 DEGs are involved in carbohydrate metabolism and lipid metabolism respectively. These DEGs mainly play key roles in glyceride metabolism,fatty acid degradation,glycolysis/gluconeogenesis and starch and sucrose metabolism. In addition,triacylglycerol( TAG) and starch content are analyzed by BODIPY505/515 fluorescence analysis and absorbance detection,which shows that intracellular TAG increases by 193% as compared with wild-type,while starch content decreases by 45%. These results further indicate that the co-regulation of the three genes not only enhances the lipid anabolism,but also reorients the carbon flux in the saccharide metabolism. The research reveals the molecular mechanism of lipid overproduction under co-regulation of three genes and provides a theoretical reference for the genetic engineering of microalgae lipid production.