Fernandes Jorge M O, Mackenzie Matthew G, Elgar Greg, Suzuki Yuzuru, Watabe Shugo, Kinghorn James R, Johnston Ian A
Gatty Marine Laboratory, School of Biology, University of St. Andrews, St. Andrews, Fife, United Kingdom.
Physiol Genomics. 2005 Aug 11;22(3):327-38. doi: 10.1152/physiolgenomics.00087.2005. Epub 2005 May 31.
Little is known about the transcriptional networks that regulate myotube production in vertebrates. In the present study, we have used a genomic approach to discover novel genes associated with myotube formation in fast muscle of the tiger puffer fish, Takifugu rubripes. The number of fast muscle fibers per myotome increased until 1.2 kg body mass, and subsequent growth was by fiber hypertrophy alone. Forward and reverse subtracted cDNA libraries were prepared from a 180-g (myotube +) and a 3.4-kg (myotube -) fish, and 1,452 expressed sequence tags (ESTs) were obtained. After these ESTs were grouped into nonredundant clusters and housekeeping and structural genes were eliminated, 57 genes were selected and quantitative PCR was used to investigate their expression levels in different tissues from independent groups of myotube(-) and myotube(+) fish acclimated to the same environmental conditions and diet. Eleven novel genes were found to be consistently differentially expressed, but only four showed appropriate tissue-specific expression. These four genes were upregulated 5-25 times in fast muscle of myotube(-) relative to myotube(+) growth stages, while their expression remained unchanged in the other tissues studied. The novel genes identified, which are also present in other vertebrate genomes, may play a role in inhibiting myotube formation in vertebrate muscle.
关于调节脊椎动物肌管生成的转录网络，我们了解得还很少。在本研究中，我们采用了一种基因组学方法，来发现与红鳍东方鲀（Takifugu rubripes）快肌中肌管形成相关的新基因。每个肌节的快肌纤维数量在体重达到1.2千克之前不断增加，随后的生长仅通过纤维肥大来实现。我们从一条180克（有肌管）和一条3.4千克（无肌管）的鱼中制备了正向和反向消减cDNA文库，并获得了1452个表达序列标签（EST）。在将这些EST分组为非冗余簇并剔除管家基因和结构基因后，选择了57个基因，并使用定量PCR来研究它们在适应相同环境条件和饮食的无肌管和有肌管鱼的独立组的不同组织中的表达水平。发现有11个新基因持续差异表达，但只有4个显示出适当的组织特异性表达。相对于有肌管生长阶段，这4个基因在无肌管鱼的快肌中上调了5至25倍，而它们在其他研究组织中的表达保持不变。所鉴定出的这些新基因在其他脊椎动物基因组中也存在，可能在抑制脊椎动物肌肉中的肌管形成中发挥作用。
