Eccles institute of Human Genetics, University of Utah, and School of Medicine, Salt Lake City, UT 84112, USA.
BMC Genomics. 2011 Jan 25;12:60. doi: 10.1186/1471-2164-12-60.
The venomous marine gastropods, cone snails (genus Conus), inject prey with a lethal cocktail of conopeptides, small cysteine-rich peptides, each with a high affinity for its molecular target, generally an ion channel, receptor or transporter. Over the last decade, conopeptides have proven indispensable reagents for the study of vertebrate neurotransmission. Conus bullatus belongs to a clade of Conus species called Textilia, whose pharmacology is still poorly characterized. Thus the genomics analyses presented here provide the first step toward a better understanding the enigmatic Textilia clade.
We have carried out a sequencing survey of the Conus bullatus genome and venom-duct transcriptome. We find that conopeptides are highly expressed within the venom-duct, and describe an in silico pipeline for their discovery and characterization using RNA-seq data. We have also carried out low-coverage shotgun sequencing of the genome, and have used these data to determine its size, genome-wide base composition, simple repeat, and mobile element densities.
Our results provide the first global view of venom-duct transcription in any cone snail. A notable feature of Conus bullatus venoms is the breadth of A-superfamily peptides expressed in the venom duct, which are unprecedented in their structural diversity. We also find SNP rates within conopeptides are higher compared to the remainder of C. bullatus transcriptome, consistent with the hypothesis that conopeptides are under diversifying selection.
有毒的海洋腹足纲动物，圆锥蜗牛（属 Conus），向猎物注射致命的混合 Conopeptides，这是一种富含半胱氨酸的小肽，每种肽都对其分子靶标（通常是离子通道、受体或转运体）具有很高的亲和力。在过去的十年中， Conopeptides 已被证明是研究脊椎动物神经传递不可或缺的试剂。 Conus bullatus 属于圆锥蜗牛科的一个称为 Textilia 的进化枝，其药理学仍未得到充分描述。因此，这里呈现的基因组学分析为更好地了解神秘的 Textilia 进化枝提供了第一步。
我们对 Conus bullatus 基因组和毒管转录组进行了测序调查。我们发现 Conopeptides 在毒管中高度表达，并描述了一种使用 RNA-seq 数据发现和描述它们的计算管道。我们还对基因组进行了低覆盖率的鸟枪法测序，并使用这些数据确定了其大小、全基因组碱基组成、简单重复和移动元件密度。
我们的结果提供了任何圆锥蜗牛毒管转录的首个全局视图。 Conus bullatus 毒液的一个显著特征是在毒管中表达的 A-超家族肽的广度，其结构多样性是前所未有的。我们还发现 Conopeptides 中的 SNP 率高于 C. bullatus 转录组的其余部分，这与 Conopeptides 受到多样化选择的假设一致。
