Identification of a unique lamprey gene with tandemly repeated sequences and pharyngeal chondrocyte-specific expression
Identification of a unique lamprey gene with tandemly repeated sequences and pharyngeal chondrocyte-specific expression
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鉴定具有串联重复序列和咽软骨细胞特异性表达的独特七鳃鳗基因
DOI：
10.1016/j.gene.2019.02.094
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发表时间：
2019
期刊：
影响因子：
3.5
通讯作者：
Wada Hiroshi
中科院分区：
文献类型：
--
作者：
Yokoyama Hiromasa;Morino Yoshiaki;Wada Hiroshi
最近的研究揭示了脊椎动物、头索动物和节肢动物之间共同的软骨遗传调控网络。有人提出，该网络最初是为祖先无脊椎动物的致密结缔组织而建立的，随后被招募用于各种谱系的软骨细胞分化。这一推理引发了人们的疑问：从致密结缔组织进化而来的软骨是否发生在脊椎动物的共同祖先中。或者，软骨的进化可能在无颌动物和颌口动物中独立发生，因为已知现存的无颌动物（环口动物）具有与颌口动物不同的基质组成。在这里，我们鉴定了可能编码七鳃鳗软骨特有的基质蛋白之一的基因，我们将其命名为pharymprin。Pharymprin在幼虫咽软骨细胞中表现出特异性表达。与七鳃鳗小梁软骨的已知基质蛋白七鳃鳗蛋白一样，咽蛋白也由重复序列组成。然而，重复序列与灯蛋白的重复序列不同。七鳃鳗软骨中存在两种不同的基质蛋白，支持了圆口动物和颌口动物中真正的软骨独立进化的假设。
Recent studies have revealed a common cartilage genetic regulatory network among vertebrates, cephalochordates, and arthropods. It has been proposed that this network was originally established for the dense connective tissues of ancestral invertebrates and subsequently recruited for chondrocyte differentiation in various lineages. This reasoning prompted questions about whether the evolution of cartilage from dense connective tissues occurred in the common ancestors of vertebrates. Alternatively, the evolution of cartilage may have occurred independently in agnathans and in gnathostomes, because extant agnathans (cyclostomes) are known to possess a matrix composition different from that of gnathostomes. Here, we identified the gene which is likely to encode one of the matrix proteins unique to lamprey cartilage, which we designatedpharymprin.Pharymprinshows specific expression in larval pharyngeal chondrocytes. Like lamprins, which are the known matrix proteins of lamprey trabecular cartilage, pharymprin is also composed of repeated sequences. However, the repeated sequence is distinct from that of lamprins. The presence of two distinct matrix proteins in lamprey cartilage supports the hypothesis that true cartilage evolved independently in cyclostomes and gnathostomes.