Tan Xungang, Zhang Yuqing, Zhang Pei-Jun, Xu Peng, Xu Yongli
Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, P.R. China.
Comp Biochem Physiol B Biochem Mol Biol. 2006 Oct;145(2):204-13. doi: 10.1016/j.cbpb.2006.07.008. Epub 2006 Aug 1.
Myf-5, a member of the myogenic regulatory factors (MRF), has been shown to be expressed in muscle precursors in early stage zebrafish embryos. The MRFs, including MyoD, Myf-5, Myogenin and MRF4, belong to the basic Helix-Loop-Helix transcription factors that contain a conserved basic Helix-Loop-Helix (bHLH) domain. To better understand the role of Myf-5 in the development of fish muscles, we have isolated the Myf-5 genomic sequence and cDNA from Flounder (Paralichthys olivaceus), and analyzed its structures and patterns of expression. Promoter analysis identified several putative transcription factor binding sites such as an E-box, NF-Y sites that might confer muscle-specific expression. Myf-5 transcripts were first detected in the paraxial mesoderm that gives rise to slow muscles. During somitogenesis, Myf-5 expression was found in developing somites. Myf-5 expression decreased gradually in somites in the anterior region, but remained strong in the newly formed somites. In the hatching stage, the expression was also detected in other muscle cells such as head muscle and fin muscle. In the growing fish, RT-PCR results showed that Myf-5 was expressed in the skeletal muscle and intestine.
Myf-5是生肌调节因子（MRF）的成员之一，已证实在斑马鱼胚胎早期的肌肉前体细胞中表达。MRF包括MyoD、Myf-5、肌细胞生成素和MRF4，属于包含保守的碱性螺旋-环-螺旋（bHLH）结构域的碱性螺旋-环-螺旋转录因子。为了更好地理解Myf-5在鱼类肌肉发育中的作用，我们从牙鲆（Paralichthys olivaceus）中分离出Myf-5基因组序列和cDNA，并分析了其结构和表达模式。启动子分析确定了几个推定的转录因子结合位点，如可能赋予肌肉特异性表达的E盒、NF-Y位点。Myf-5转录本首先在产生慢肌的体节中胚层中被检测到。在体节形成过程中，在发育中的体节中发现了Myf-5的表达。Myf-5在前部区域体节中的表达逐渐降低，但在新形成的体节中仍保持较强表达。在孵化阶段，在其他肌肉细胞如头部肌肉和鳍部肌肉中也检测到了该表达。在生长的鱼类中RT-PCR结果显示，Myf-5在骨骼肌和肠道中表达。
