Shared hemocyte- and intestine-dominant expression profiles of intelectin genes in ascidian Ciona intestinalis: insight into the evolution of the innate immune system in chordates
Shared hemocyte- and intestine-dominant expression profiles of intelectin genes in ascidian Ciona intestinalis: insight into the evolution of the innate immune system in chordates
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DOI：
10.1007/s00441-017-2647-3
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发表时间：
2017-10-01
影响因子：
3.6
通讯作者：
Ogasawara, Michio
中科院分区：
文献类型：
--
作者：
Hayashibe, Minoru;Nakayama, Satoshi;Ogasawara, Michio
Intelectin是一种可溶性凝集素，被称为先天免疫系统的模式识别受体或肠乳铁蛋白受体。已在许多脊索动物中发现了肠凝集素基因，并且在它们的肠吸收区域中的共同表达模式已被广泛认可。脊索动物的intelectins有一个共同的结构域的结构与纤维蛋白原相关的结构域和intelectin结构域和一个额外的序列已被报道，只有海鞘海鞘intelectins。然而，很少有人知道海鞘intelectins的分子特征，包括额外的序列在海鞘中的分布。因此，我们专注于海鞘物种，可用于基因组DNA序列搜索和调查intelectin基因，特别是参考额外的序列。我们还评估了透明的青少年和成人标本中的透明的青少年和成人标本通过原位杂交的玻璃海鞘intelectin基因转录本的分布，并揭示血细胞占主导地位的表达，以及胃排他的表达。比较基因表达分析与分泌消化酶和吸收相关的蛋白质在玻璃海鞘中发现，intelectin和分泌消化酶在胃上皮的同一区域中表达。由于结构域结构的intelectin和血细胞占主导地位的基因表达的intelectin似乎相关的ficolin，intelectin基因可能已经从一个ficolin样的祖先基因与血细胞表达的早期脊索动物进化。
Intelectin is a soluble lectin known as a pattern-recognition receptor for the innate immune system or as an intestinal lactoferrin receptor. Intelectin genes have been identified in a wide range of chordates and the shared expression pattern in their absorptive intestinal regions has been widely recognized. The chordate intelectins have a shared domain structure with a fibrinogen-related domain and an intelectin domain and an additional sequence has been reported only in ascidian Ciona intestinalis intelectins. However, little is known about the molecular features of the ascidian intelectins, including the distribution of the additional sequence in ascidians. Therefore, we focus on the ascidian species that are available for genome DNA sequence searches and survey intelectin genes with special reference to the additional sequence. We also assess the distribution of Ciona intelectin gene transcripts in transparent juveniles and adult specimens by means of in situ hybridization and reveal hemocyte-dominant expressions as well as stomach-exclusive expression. Comparative gene expression analysis with secretory digestive enzymes and absorption-related proteins in Ciona revealed that intelectin and secretory digestive enzymes were expressed in the same region of the stomach epithelium. Since the domain structure of intelectins and the hemocyte-dominant gene expression of intelectins seem relevant to ficolin, intelectin genes may have evolved from a ficolin-like ancestral gene with hemocytic expression in early chordate evolution.