ABSTRACT
The Serra de Piquiatuba is situated in the area of the 8th Battalion of Engineering and Construction—8° BEC, located at km 8 of the Santarém–Cuiabá highway, in the municipality of Santarém, Pará, Brazil. This region is characterized by a hot and humid climate with rainfall exceeding 1900 mm p.a. In this study, we present a species list of scorpions from the Serra de Piquiatuba, based on data collected from September to November 2010. Five species were recorded, all common in the Amazon, belonging to the families Buthidae and Chactidae. The observed diversity patterns are discussed considering other scorpion inventories carried out in Brazil and possible sampling biases. The present study raises methodological questions to be further addressed in scorpion community ecology studies.
ABSTRACT
BACKGROUND: Except for the northern region, where the Amazonian black scorpion, T. obscurus, represents the predominant and most medically relevant scorpion species, Tityus serrulatus, the Brazilian yellow scorpion, is widely distributed throughout Brazil, causing most envenoming and fatalities due to scorpion sting. In order to evaluate and compare the diversity of venom components of Tityus obscurus and T. serrulatus, we performed a transcriptomic investigation of the telsons (venom glands) corroborated by a shotgun proteomic analysis of the venom from the two species. RESULTS: The putative venom components represented 11.4% and 16.7% of the total gene expression for T. obscurus and T. serrulatus, respectively. Transcriptome and proteome data revealed high abundance of metalloproteinases sequences followed by sodium and potassium channel toxins, making the toxin core of the venom. The phylogenetic analysis of metalloproteinases from T. obscurus and T. serrulatus suggested an intraspecific gene expansion, as we previously observed for T. bahiensis, indicating that this enzyme may be under evolutionary pressure for diversification. We also identified several putative venom components such as anionic peptides, antimicrobial peptides, bradykinin-potentiating peptide, cysteine rich protein, serine proteinases, cathepsins, angiotensin-converting enzyme, endothelin-converting enzyme and chymotrypsin like protein, proteinases inhibitors, phospholipases and hyaluronidases. CONCLUSION: The present work shows that the venom composition of these two allopatric species of Tityus are considerably similar in terms of the major classes of proteins produced and secreted, although their individual toxin sequences are considerably divergent. These differences at amino acid level may reflect in different epitopes for the same protein classes in each species, explaining the basis for the poor recognition of T. obscurus venom by the antiserum raised against other species.
Subject(s)
Gene Expression Regulation , Proteome/metabolism , Scorpion Venoms/genetics , Scorpion Venoms/metabolism , Scorpions/metabolism , Transcriptome , Amino Acid Sequence , Animals , Phylogeny , Proteomics , Scorpions/classification , Scorpions/genetics , Sequence Homology , Species SpecificityABSTRACT
Two new species of Bothriurid scorpions, Bothriurus delmari n. sp. and B. aguardente n. sp., are described from Bahia, Northeastern Brazil. These species are included in the asper group owing to the peculiar hemispermatophore morphology. These two newly described species increases to 47 the number of known and valid Bothriurus species. Additionaly, the known distribution of Bothriurus asper is updated.
