Structure and spatio temporal expression of the full length DNA complementary to RNA coding for alpha2 type I collagen of zebrafish.
Structure and spatio temporal expression of the full length DNA complementary to RNA coding for alpha2 type I collagen of zebrafish.
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DOI：
10.1016/s0378-1119(02)00770-9
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发表时间：
2002-07
期刊：
影响因子：
3.5
通讯作者：
Ghislaine Morvan Dubois;Zofia Haftek;C. Crozet;R. Garrone;D. Le Guellec
中科院分区：
文献类型：
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作者：
Ghislaine Morvan Dubois;Zofia Haftek;C. Crozet;R. Garrone;D. Le Guellec
到目前为止，已经确定了20种不同的胶原蛋白遗传类型。其结构和功能尚未完全阐明。我们选择斑马鱼作为模型，以提供有关胶原蛋白在胚胎发生过程中的作用的信息。在本研究中，我们分离出四个重叠的DNA互补的RNA克隆覆盖4879个核苷酸的斑马鱼信使RNA（mRNA）编码的纤维状前胶原链。与已知的其他脊椎动物胶原蛋白的一级结构的比较允许得出结论，它编码胶原蛋白pro-α2（I）链。5′端非翻译区具有典型的茎环结构，含有三个ATG密码子，在哺乳动物I型和III型胶原链中发现（但在II型胶原链中没有），它们在相同的组织中表达。这表明茎环结构的假定调节作用可能是组织特异性的。通过比较几个物种的螺旋结构域中沿着发现的Gly-Gly双联体，可以推测Gly-Gly重复序列可能是一种变温特征。采用逆转录-聚合酶链反应（RT-PCR）和原位杂交技术，对斑马鱼全胚胎和组织切片中pro-α2（I）的表达进行了研究。col 1a 2在受精后10 h开始表达，在20和48 h出现两个表达高峰。α2 mRNA的存在表明胶原合成，主要在20-72 hpf胚胎周围的表面细胞层中检测到，其特征在于无细胞胶原层。在26-30天，成纤维细胞侵入真皮并从上皮细胞接管以合成胶原。这表明这些细胞中胶原蛋白合成的精细调节仍有待阐明。在尾鳍原基和脊索原基等组织中也检测到α2 mRNA，提示I型胶原参与了脊索和尾的形成途径。
Twenty distinct genetic types of collagen have been identified up to now. Their structure and function are not completely elucidated. We have chosen zebrafish as a model to bring information about the role of collagen during embryogenesis. In the present study, we isolated four overlapping DNA complementary to RNA clones covering the 4879 nucleotides of a zebrafish messenger RNA (mRNA) encoding a fibrillar procollagen chain. The comparison of its primary structure with known other vertebrate collagens allowed to conclude that it encodes collagen pro-α2(I) chain. The 5′ untranslated region showed a typical stem-loop structure with three ATG codons which is found in mammals types I and III collagen chains (but not in type II), which are expressed in the same tissues. This suggests that the supposed regulatory role of the stem loop structure could be tissue specific. The comparison of the Gly-Gly doublets found along the helical domain of several species allowed to speculate that the Gly-Gly repeats could be a poikilotherm feature. Expression of pro-α2(I) was examined during zebrafish development by reverse transcriptase-polymerase chain reaction and in situ hybridization on whole embryo and tissue section. Col1a2 was expressed as early as stage10 h post fertilization (hpf) and two peaks of expression were observed at 20 and 48 hpf. α2 mRNAs, whose presence suggests a collagen synthesis, were detected principally in the superficial cell layers surrounding 20–72 hpf embryos which are characterized by an acellular collagen stratum. At 26–30 days, fibroblasts invade the dermis and take over from the epithelial cells to synthesize collagen. This suggests a fine regulation of collagen synthesis in these cells that remains to be elucidated. α2 mRNA were also detected in other tissues such as the tail fin primordium and the notochord primordium suggesting a participation of type I collagen in a pathway for notochord and tail formation.