Fast skeletal muscle myosin heavy chain gene cluster of medaka Oryzias latipes enrolled in temperature adaptation
Fast skeletal muscle myosin heavy chain gene cluster of medaka Oryzias latipes enrolled in temperature adaptation
复制标题
DOI：
10.1152/physiolgenomics.00078.2006
复制
发表时间：
2007-04-24
影响因子：
4.6
通讯作者：
Watabe, Shugo
中科院分区：
文献类型：
--
作者：
Liang, Chun-Shi;Kobiyama, Atsushi;Watabe, Shugo
为了揭示鱼类肌肉温度适应的机制，我们克隆了宽温性青鳉肌球蛋白重链基因（MYH）。我们克隆的cDNA编码快速骨骼肌肌球蛋白重链（MYH）异构体的青鳉的cDNA文库驯化到10和30 C，并观察到不同的MYH cDNA克隆表达在两个温度驯化的鱼。随后，我们从青鳉基因组文库中分离出几个重叠的MYH重叠群。219 kbp的完整青鳉MYH（mMYH）基因座的重叠群组装揭示了一个串联排列的11 mMYH簇，其中8个基因实际上是转录的，其余3个是假基因。转录基因的表达分析显示，两个基因在适应于10和30 ℃的青鳉中均高度表达，而相对较低的表达水平仅在适应于30 ℃的青鳉中观察到。其余基因的cDNA在文库中的代表性太低，无法确定表达水平，只能通过逆转录-聚合酶链反应获得转录本。推导的氨基酸序列在环1和环2区域的mMYH是高度可变的，这表明这些亚型是功能不同的。本研究结果巩固了我们对硬骨鱼MYH多基因家族的认识，并将进一步深入了解MYH分子表达随环境温度波动而微调的机制，并对相关基因进行进一步的功能分析。
To disclose mechanisms involved in temperature acclimation of fish muscle, we subjected eurythermal fish of medaka Oryzias latipes to cloning of myosin heavy chain genes (MYHs). We cloned cDNAs encoding fast skeletal muscle myosin heavy chain (MYH) isoforms from cDNA libraries of medaka acclimated to 10 and 30 C and observed that different MYH cDNA clones are expressed in the two temperature-acclimated fish. Subsequently, we isolated several overlapping MYH contigs by shotgun cloning strategy from a medaka genomic library. Contig assembly of the complete medaka MYH (mMYH) locus of 219 kbp revealed a cluster of tandemly arrayed 11 mMYHs, in which eight genes are actually transcribed, with the remaining three being pseudogenes. Expression analysis of the transcribed genes revealed that two genes were each highly expressed in medaka acclimated to 10 and 30 C, whereas comparatively lower expression levels of the three genes were exclusively observed in medaka acclimated to 30 C. cDNAs of the remaining genes were too underrepresented in the libraries to determine the expression levels, and the transcripts could only be obtained by reverse transcription-polymerase chain reaction. Deduced amino acid sequences in the loop 1 and loop 2 regions of mMYHs were highly variable, suggesting that these isoforms were functionally different. The present findings consolidate our knowledge on teleost MYH multigene family and would provide further insight into the mechanisms by which expressions of individual MYH molecules are fine-tuned with environmental temperature fluctuations with further functional analysis of the genes concerned.