de Oliveira Ursula Castro, Candido Denise Maria, Dorce Valquíria Abrão Coronado, Junqueira-de-Azevedo Inácio de Loiola Meirelles
Laboratório Especial de Toxinologia Aplicada, CeTICS, Instituto Butantan, Brazil.
Laboratório de Artrópodes, Instituto Butantan, Brazil.
Toxicon. 2015 Mar;95:52-61. doi: 10.1016/j.toxicon.2014.12.013. Epub 2014 Dec 29.
Scorpion venom is a mixture of peptides, including antimicrobial, bradykinin-potentiating and anionic peptides and small to medium proteins, such as ion channel toxins, metalloproteinases and phospholipases that together cause severe clinical manifestation. Tityus bahiensis is the second most medically important scorpion species in Brazil and it is widely distributed in the country with the exception of the North Region. Here we sequenced and analyzed the transcripts from the venom glands of T. bahiensis, aiming at identifying and annotating venom gland expressed genes. A total of 116,027 long reads were generated by pyrosequencing and assembled in 2891 isotigs. An annotation process identified transcripts by similarity to known toxins, revealing that putative venom components represent 7.4% of gene expression. The major toxins identified are potassium and sodium channel toxins, whereas metalloproteinases showed an unexpected high abundance. Phylogenetic analysis of deduced metalloproteinases from T. bahiensis and other scorpions revealed a pattern of ancient and intraspecific gene expansions. Other venom molecules identified include antimicrobial, anionic and bradykinin-potentiating peptides, besides several putative new venom components. This report provides the first attempt to massively identify the venom components of this species and constitutes one of the few transcriptomic efforts on the genus Tityus.
蝎毒是多种肽的混合物，包括抗菌肽、缓激肽增强肽和阴离子肽以及中小分子蛋白质，如离子通道毒素、金属蛋白酶和磷脂酶，这些物质共同导致严重的临床表现。巴氏肥尾蝎是巴西第二大具有重要医学意义的蝎种，除北部地区外，在该国广泛分布。在此，我们对巴氏肥尾蝎毒腺的转录本进行了测序和分析，旨在鉴定和注释毒腺表达的基因。通过焦磷酸测序共产生了116,027条长读段，并组装成2891个重叠群。通过与已知毒素的相似性进行注释过程，发现推定的毒液成分占基因表达的7.4%。鉴定出的主要毒素是钾离子和钠离子通道毒素，而金属蛋白酶的丰度意外地高。对巴氏肥尾蝎和其他蝎子推导的金属蛋白酶进行系统发育分析，揭示了古老和种内基因扩增的模式。鉴定出的其他毒液分子包括抗菌肽、阴离子肽和缓激肽增强肽，以及几种推定的新毒液成分。本报告首次尝试大规模鉴定该物种的毒液成分，是对肥尾蝎属为数不多的转录组学研究之一。
