In silico characterization of the insect diapause-associated protein couch potato (CPO) in Calanus finmarchicus (Crustacea: Copepoda)
In silico characterization of the insect diapause-associated protein couch potato (CPO) in Calanus finmarchicus (Crustacea: Copepoda)
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DOI：
10.1016/j.cbd.2012.11.002
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发表时间：
2013-03-01
影响因子：
3
通讯作者：
Lenz, Petra H.
中科院分区：
文献类型：
--
作者：
Christie, Andrew E.;Roncalli, Vittoria;Lenz, Petra H.
沙发马铃薯(CPO)是一种与RNA结合的蛋白质，参与昆虫神经系统发育和成虫滞育的调节。在昆虫中，这种蛋白质是高度保守的，但在另一个大型节肢动物群体甲壳纲中还没有发现它。在这里，功能基因组学被用来鉴定桡足类Calanus finmarchicus中推测的CPO同源物，Calanus finmarchicus是一种经历季节性滞育的浮游甲壳动物。在硅胶挖掘中，表达序列标签(EST)和454焦磷酸测序数据导致鉴定出两个全长CPO蛋白，每个205个氨基酸增加长。两个C finmarchicus CPO(Calfi-CPO I和II)在序列上相同，但有三个氨基酸不同，据预测具有单一的RNA识别基序(RRM)。两个CalFI-CPO与昆虫的序列比较表明，它们具有很高的氨基酸保守性，特别是在它们的RRMS中。以C finmarchicus序列为查询，从另外两种甲壳类寄生的桡足类动物--斑节对虾和斑节对虾中鉴定出编码部分CPO的EST。令人惊讶的是，在拥有非常大(100,000)EST数据集的甲壳类物种(例如凡纳滨对虾、丽蚤和鲑鱼)中没有发现令人信服的CPO编码转录本，这表明CPO转录本/蛋白可能在非常低的水平表达，或者在一些甲壳类中不表达。RNA-Seq数据表明CPO在C finmarchicus中的表达具有阶段特异性，在卵(代表混合胚胎期)和成体中几乎不存在转录，在无节幼体和肋足类中表达水平较高；CPo高表达的阶段与其在神经元发育中的作用相一致。(C)2012 Elsevier Inc.保留所有权利。
Couch potato (CPO) is an RNA-binding protein involved in the regulation of nervous system development and adult diapause in insects. Within insects, this protein is highly conserved, yet it has not been identified in another large arthropod group, the Crustacea. Here, functional genomics was used to identify putative CPO homologs in the copepod Calanus finmarchicus, a planktonic crustacean that undergoes seasonal diapause. In silica mining of expressed sequence tag (EST) and 454 pyrosequencing data resulted in the identification of two full-length CPO proteins, each 205 amino adds long. The two C finmarchicus CPOs (Calfi-CPO I and II) are identical in sequence with the exception of three amino acids, and are predicted to possess a single RNA recognition motif (RRM). Sequence comparison of the two Calfi-CPOs with those of insects shows high levels of amino acid conservation, particularly in their RRMs. Using the C finmarchicus sequences as queries, ESTs encoding partial CPOs were identified from two other crustaceans, the parasitic copepod Lernaeocera branchialis and shrimp Penaeus monodon. Surprisingly, no convincing CPO-encoding transcripts were identified from crustacean species with very large (>100,000) EST datasets (e.g. Litopenaeus vannamei, Daphnia pulex and Lepeophtheirus salmonis), suggesting that CPO transcript/protein may be expressed at very low levels or absent in some crustaceans. RNA-Seq data suggested stage-specific expression of CPO in C finmarchicus, with few transcripts present in eggs (which represent mixed embryonic stages) and adults, and high levels in nauplii and copepodites; stages exhibiting high CPO expression are consistent with a role for it in neuronal development. (C) 2012 Elsevier Inc. All rights reserved.