团头鲂jphs家族基因的克隆及表达分析

以团头鲂为研究对象,扩增获得Junctophilin(Jph)家族4个成员,jph1a、jph1b、jph2和jph3的cDNA编码序列,分别为2 031、2 016、2 358和2361 bp,分别编码676、671、785和786 aa。团头鲂jphs均由5个外显子和4个内含子组成,与大多数物种的JPHs基因结构相似;结构域预测显示出8个MORN和1个TM结构域,且蛋白多序列比对分析显示Jphs在进化上非常保守。基于qRT-PCR(quantitative real-time PCR)分析显示,这4个基因呈现出组织特异性表达,其中jph1a、jph1b和jph2主要在肌肉和心脏中表达,而jph3主要表达于心脏、血液和大脑。在早期发育过程中,jph1a、jph1b、jph2和jph3的mRNA表达模式类似,分别在原肠胚期、心跳期和25 dph(days post hatching)达到高峰。综上研究结果表明,鱼类jphs基因在心脏和肌肉等组织中发挥重要作用,并且其功能可能不同于哺乳动物。

Molecular cloning and expression analysis of jphs in Megalobrama amblycephala

Four members,jph1a,jphb, jph2 and jph3,of the junctophilin family were isolated and characterized in Megalobrama amblycephala,an important freshwater fish. The jph1a,jph1b, jph2 and jph3 cDNA contained an open reading frame (ORF) of 2 031 bp,2 016 bp,2 358 bp and 2 361 bp,encoding 676 aa,671 aa,785 aa and 786 aa,respectively. Structure analysis showed that all the M. amblycephala jphs consisted of 5 exons and 4 introns,which is consistent with that of other species. All the 4 M. amblycephala Jph proteins were composed of 8 MORN motifs and a TM motif,and multiple sequence alignment showed that these MORN and TM domains were highly conserved. Based on quantitative real-time PCR (qRT-PCR), the 4 jph genes exhibited tissue-specific expression,of which jph1a,jph1b,and jph2 were abundant in the muscle and heart,and jph3 was mainly expressed in the heart,blood and brain. During early development,the jph1a,jph1b, jph2 and jph3 mRNA levels peaked at the gastrula stage,heartbeat stage and 25 dph (days post hatching),respectively. These results suggest that Jphs may play important roles in some tissues such as the heart and muscle,and may have more extensive functions in fish compared to mammals.