基于Illumina测序的厚壳贻贝足组织转录组研究

Illumina-based De novo Sequencing and Characterization of Mytilus coruscus Foot Transcriptome

贻贝足丝是贻贝足组织分泌的足丝蛋白形成的非细胞组织,具有在水环境下的极强粘附性能,是当前生物粘附剂及抗腐蚀材料的研发热点.为进一步了解贻贝足丝蛋白的分子多样性特征,采用新一代Illumina高通量测序平台对厚壳贻贝(Mytilus coruscus)足组织进行转录组测序,首次构建了厚壳贻贝足组织的转录组数据库.共计获得7 199 799 840 nt的碱基数据.经过序列拼接和组装,获得88 825条unigene.对上述unigene开展了序列注释,共计37 007条unigene获得注释.在此基础上,经序列检索和比对,从中筛选出与目前已知的11种足丝蛋白同源的56条unigene序列并进行分析.结果表明,厚壳贻贝足丝蛋白具有明显的氨基酸偏好性,部分足丝蛋白具有重复序列,且厚壳贻贝足丝蛋白与其他种类的贻贝足丝蛋白具有较高的序列相似性.上述结果为后续贻贝足丝蛋白的批量鉴定以及在此基础上的贻贝足丝形成、固化以及粘附机制相关研究奠定了基础.

Mussel byssus is a non-cell tissue of many secreted proteins from the byssal foot. The extremely adhesiveness of the native byssal proteins made them a promising source for moisture-resistant adhesion and anticorrosive coatings. Eleven byssal proteins were previously identified. The protein composition of byssus has not yet been fully understood. In order to increase genomic resources and identify mussel byssal proteins in mussel Mytilus coruscus,high-throughput illuminance sequencing was undertaken on the foot and 79 997 776 paired-ends reads were generated,yielding a library containing 88825 foot unigenes. After functional analysis,56 foot unigenes encoding proteins with homology with reported mussel byssal proteins were detected,including homologues of MFP1 ~ 6,pre-collagens,and thread matrix proteins. Most unigenes encoded proteins with unusual amino acid composition and internal repeats. Furthermore,protein polymorphism was found in the most of characterized unigene in this study.Comparison sequence searches showed that the foot unigene of M. coruscus encoded putative proteins exhibiting sequence homology with previously characterized byssal proteins of other Mytilus,indicating a common originate for these byssal proteins. Our work presents a comprehensive transcriptome resource for the mussel foot and provides insight into the protein composition of byssus. The transcriptomic resourcecould provide a foundation for future investigations into the formation,curing,and adhesion of mussel byssus.