title: The transcriptome recipe for the venom cocktail of Tityus bahiensis scorpion.
abstract: 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.
authors.affiliation: Laboratório Especial de Toxinologia Aplicada, CeTICS, Instituto Butantan, Brazil.
authors.forename: Ursula Castro
authors.initials: UC
authors.lastname: de Oliveira
authors.affiliation: Laboratório de Artrópodes, Instituto Butantan, Brazil.
authors.forename: Denise Maria
authors.initials: DM
authors.lastname: Candido
authors.affiliation: Laboratório de Farmacologia, Instituto Butantan, Brazil.
authors.forename: Valquíria Abrão Coronado
authors.initials: VA
authors.lastname: Dorce
authors.affiliation: Laboratório Especial de Toxinologia Aplicada, CeTICS, Instituto Butantan, Brazil. Electronic address: inacio.azevedo@butantan.gov.br.
authors.forename: Inácio de Loiola Meirelles
authors.initials: Ide L
authors.lastname: Junqueira-de-Azevedo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001938:Brazil; D019295:Computational Biology; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D020869:Gene Expression Profiling / Q000379:methods; D005786:Gene Expression Regulation; D015723:Gene Library; D045726:Metalloproteases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D015221:Potassium Channels / Q000633:toxicity; D012604:Scorpion Venoms / Q000737:chemistry*; D012605:Scorpions / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D015222:Sodium Channels / Q000633:toxicity; D059467:Transcriptome
chemical_list: D018076:DNA, Complementary; D015221:Potassium Channels; D012604:Scorpion Venoms; D015222:Sodium Channels; D045726:Metalloproteases
keywords: Scorpion; Tityus bahiensis; Transcriptome; Venom; Venom gland