McVeigh Paul, Leech Suzanne, Mair Gunnar R, Marks Nikki J, Geary Timothy G, Maule Aaron G
Parasitology Research Group, School of Biology & Biochemistry, Medical Biology Centre, 97 Lisburn Road, Queen's University Belfast, Belfast, BT9 7BL, UK.
Int J Parasitol. 2005 Sep;35(10):1043-60. doi: 10.1016/j.ijpara.2005.05.010.
This study reports a series of systematic BLAST searches of nematode ESTs on the Genbank database, using search strings derived from known nematode FLPs (those encoded by Caenorhabditis elegans flp genes as well as those isolated from other nematodes including Ascaris suum), as well as query sequences representative of theoretical FLPs. Over 1000 putative FLP-encoding ESTs were identified from multiple nematode species. A total of 969 ESTs representing sequelogs of the 23 known C. elegans flp genes were identified in 32 species, from clades I, III, IV and V. Numerical analysis of EST numbers suggests that flp-1, flp-11 and flp-14 are amongst the most highly expressed flp genes. Speculative BLAST searches were performed using theoretical FLP C-termini as queries, in an attempt to identify putative novel FLP sequences in the EST database. These searches yielded eight multi-species sequelogs encoding FLPs with novel signatures that are believed to identify distinct flp genes. These novel genes encode 25 distinct previously unidentified FLPs, and raise the current total of known nematode flp genes to 31. Additionally, software-based analyses of the presence of signal peptides were performed, with signal peptides being identified on at least one member of each group of flp ESTs, further confirming their status as secreted peptides. The data reveal that nematode FLPs encompass the most complex neuropeptide family known within the metazoa. Moreover, individual FLPs and FLP motifs are highly conserved across the nematodes with little evidence for inter-clade or inter-lifestyle variation, supporting their fundamental role in free-living and parasitic species.
本研究报告了一系列在Genbank数据库中对线虫EST进行的系统BLAST搜索，使用从已知线虫FLP（由秀丽隐杆线虫flp基因编码的那些以及从包括猪蛔虫在内的其他线虫中分离的那些）衍生的搜索字符串，以及代表理论FLP的查询序列。从多个线虫物种中鉴定出1000多个假定的FLP编码EST。在来自进化枝I、III、IV和V的32个物种中，共鉴定出969个代表23个已知秀丽隐杆线虫flp基因后续同源物的EST。EST数量的数值分析表明，flp-1、flp-11和flp-14是表达量最高的flp基因之一。使用理论FLP C末端作为查询进行推测性BLAST搜索，试图在EST数据库中鉴定假定的新型FLP序列。这些搜索产生了8个多物种后续同源物，它们编码具有新特征的FLP，据信这些特征可识别不同的flp基因。这些新基因编码25个以前未鉴定的不同FLP，并使已知线虫flp基因的总数增加到31个。此外，还进行了基于软件的信号肽存在分析，在每组flp EST的至少一个成员上鉴定出了信号肽，进一步证实了它们作为分泌肽的状态。数据显示，线虫FLP包含后生动物中已知的最复杂的神经肽家族。此外，单个FLP和FLP基序在整个线虫中高度保守，几乎没有进化枝间或生活方式间变异的证据，支持它们在自由生活和寄生物种中的基本作用。
