Cloning and expression patterns of two Smad genes during embryonic development and shell formation of the Pacific oyster Crassostrea gigas
Cloning and expression patterns of two Smad genes during embryonic development and shell formation of the Pacific oyster Crassostrea gigas
复制标题
DOI：
10.1007/s00343-014-3360-7
复制
发表时间：
2014-11-01
影响因子：
--
通讯作者：
Liu Baozhong
中科院分区：
文献类型：
--
作者：
Liu Gang;Huan Pin;Liu Baozhong
越来越多的证据表明转化生长因子β（TGF-β）信号通路在软体动物的早期发育中发挥着许多重要作用。然而，关于其详细机制的信息有限。在这里，我们描述了来自太平洋牡蛎巨牡蛎的两个 Smad 基因的鉴定、克隆和表征，这两个基因是 TGF-β 信号通路的关键组成部分。对命名为 cgi-smad1/5/8 和 cgi-smad4 的两个基因的序列分析揭示了保守的功能特征。这两个基因在胚胎和幼虫中广泛表达，表明在巨线虫早期发育中发挥多种作用。聚集在D象限的两个基因的mRNA和cgi-smad4在原肠胚的背侧高表达，表明TGF-β信号通路可能参与了C. gigas的背腹模式。此外，这两个基因在不同阶段胚胎壳区中的高表达水平表明TGF-β信号通路在壳发育的特定阶段中发挥重要作用，包括初始壳区的形成和幼虫壳的生物矿化。这项研究的结果为阐明TGF-β信号通路如何参与双壳类软体动物的早期发育提供了基础支持，并表明为此需要进一步的工作。
Increasing evidence indicates that transforming growth factor beta (TGF-beta) signaling pathways play many important roles in the early development of mollusks. However, limited information is known concerning their detailed mechanisms. Here, we describe the identification, cloning and characterization of two Smad genes, the key components of TGF-beta signaling pathways, from the Pacific oyster Crassostrea gigas. Sequence analysis of the two genes, designated as cgi-smad1/5/8 and cgi-smad4, revealed conserved functional characteristics. The two genes were widely expressed in embryos and larvae, suggesting multiple roles in the early development of C. gigas. The mRNA of the two genes aggregated in the D quadrant and cgi-smad4 was highly expressed on the dorsal side of the gastrula, indicating that TGF-beta signaling pathways may be involved in dorsoventral patterning in C. gigas. Furthermore, high expression levels of the two genes in the shell fields of embryos at different stages suggested important roles for TGF-beta signaling pathways in particular phases of shell development, including the formation of the initial shell field and the biomineralization of larval shells. The results of this study provide fundamental support for elucidating how TGF-beta signaling pathways participate in the early development of bivalve mollusks, and suggest that further work is warranted to this end.