Differential expression of two nonallelic MyoD genes in developing and adult myotomal musculature of the trout (Oncorhynchus mykiss)
Differential expression of two nonallelic MyoD genes in developing and adult myotomal musculature of the trout (Oncorhynchus mykiss)
复制标题
DOI：
10.1007/s004270050274
复制
发表时间：
1999-07-01
影响因子：
2.4
通讯作者：
Rescan, PY
中科院分区：
文献类型：
--
作者：
Delalande, JM;Rescan, PY
之前我们在虹鳟鱼中鉴定了两个非等位基因 MyoD 编码基因。这两个 MyoD 基因（TMyoD 和 TMyoD2）在鲑鱼基因组四倍化过程中被复制。在这项研究中，我们表明 TMyoD 和 TMyoD2 表现出独特的时空表达模式，定义了发育体节中离散的细胞群。 TMyoD 表达首先在伸长的胚胎盾两侧的原肠中部检测到。在体节形成的前后波期间，TMyoD 转录物最初存在于体节前中胚层和形成体节的近轴细胞中。仅当肌节获得其特征性的指向喙部的 V 形形状时，TMyoD 表达的横向延伸才会发生。相比之下，TMyoD2 的初始表达发生在已经形成的体节中，并且仅限于体节的后室。此外，在鳟鱼幼体中，我们观察到 TMyoD 和 TMyoD2 基因在具有不同表型的肌纤维中存在差异表达。总的来说，这些数据提供了证据，证明两个鳟鱼 MyoD 编码基因已经进化出功能上的不同。通过比较两种鳟鱼 MyoD 基因与肌细胞生成素的表达模式，我们可以将它们定位在导致肌肉分化的调节途径中。
Previously we identified two nonallelic MyoD encoding genes in the rainbow trout. These two MyoD genes (TMyoD and TMyoD2) were duplicated during the tetraploidization of the salmonid genome. In this study we show that TMyoD and TMyoD2 exhibit a distinct spa tiotemporal pattern of expression that defines discrete cell populations in the developing somite. TMyoD expression is first detected in the mid-gastrula on either side of the elongating embryonic shield. During the anterior-to-posterior wave of somite formation the TMyoD transcript is initially present in adaxial cells of both the presomitic mesoderm and the forming somites. A lateral extension of TMyoD expression occurs only when the myotomes acquire their characteristic chevron shape pointing rostrally. By contrast, the initial expression of TMyoD2 occurs in somites that have already formed and is limited to the posterior compartment of somites. Further, in postlarval trout we observed a differential expression of TMyoD and TMyoD2 genes in muscle fibers with differing phenotype. Collectively, these data provide evidence that the two trout MyoD encoding genes have evolved to become functionally different. A comparison of the expression patterns of the two trout MyoD genes with that of myogenin allowed us to position them in the regulatory pathway leading to muscle differentiation.