Project description:Both single cell and bulk RNA sequencing was performed on expanding or differentiating snake venom gland organoids (from Aspidelaps Lubricus Cowlesi and Naja Nivea), or tissue (Aspidelaps Lubricus Cowlesi). Bulk RNA sequencing from the snake venom gland, liver and pancreas was performed to construct a de novo transcriptome using Trinity.
Project description:Cellular and inflammatory events were evaluated in mouse muscle after snake venoms Daboia russelii and Bothrops asper injection over time. A murine model of muscle necrosis based on venom injection was used to investigate up to 800 genes involved in fibrosis diseases and tissue regeneration using the multiplex RNA panel Fibrosis V2 from NanoString technology.
Project description:The synthesis of snake venom proteins is subjected to finely regulated processes in the specialized secretory epithelium within the venom gland. Such processes occur within a defined time frame in the cell and at specific cellular locations. Thus, the determination of subcellular proteomes allows the characterization of protein groups for which the site may be relevant to their biological roles, thereby allowing the deconvolution of complex biological circuits into functional information. In the case of snake venom glands, subcellular proteome analysis could help understand the molecular basis of venom variability. Consequently, knowing the functional implications of such phenotypic plasticity could prove relevant in envenoming treatment and biological research. In this regard, we performed subcellular fractionation of proteins from B. jararaca snake venom gland, focusing on nuclear proteins since this cellular compartment comprises key effectors that shape gene expression. Our results provided a snapshot of B. jararaca's subcellular venom gland proteome. They pointed to a 'conserved' proteome core among different life stages (newborn and adult) and between genders (adult male and female).
Project description:While cellular transcripts encode rich information that provide key features to understand the molecular basis of snake venom variation, their presence/ abundance does not necessary imply/correlate in the translation of a functional (protein) product. In this study we carried out an analysis of the venom gland proteome of Bothrops jararaca taking into account two distinct phases of its ontogenetic development (i.e. newborn and adult specimens) and the marked sexual dimorphism recently reported on its venom proteome. Proteomic data analysis showed wider dynamic range for toxins when comparing to non-toxins and a dynamic proteome rearrangement in cellular proteins upon B. jararaca development. Differentially expressed proteins covered a number of biological pathways related to protein synthesis, including proteins related to transcription and translation, which were found to be significantly higher expressed in the newborn venom gland. Our results showed that the variation in the expression levels of cellular proteins gives rise to an even higher variation in the dynamic range of the expressed toxins. Upon ageing, the molecular constraints related to protein synthesis together with ecological traits would likely have an impact on the toxin repertoire, which, in the case of B. jararaca species, would enable the species to deal with different prey types during its lifespan.
Project description:Snake venoms are extremely active biological secretions containing primarily various classes of enzymes. The genus Bothrops comprises various pit viper species that represent the most medically significant taxa in Central and South America, accounting for more human envenomations and fatalities than any other snake taxa. Venom proteomes of many Bothrops species have been characterized but, although proteins of molecular mass higher than 100 kDa have been documented in Bothrops venoms, these large proteins have not yet been closely investigated. This study sought to achieve detailed identification of major components in the high molecular mass subproteome of venoms from eight Bothrops species (B. brazili, B. cotiara, B. insularis, B. jararaca, B. jararacussu, B. leucurus, B. moojeni and B. neuwiedi). The identification of proteins eluting in the first fractions of a size-exclusion chromatography of these venoms revealed that they are comprised mainly of enzymes, including minor components such as 5'-nucleotidase, aminopeptidase, phosphodiesterase, and phospholipases A2 and B, but with metalloproteinases and L-amino acid oxidases representing the most abundant components. Most of these components disappeared in electrophoretic profiles under reducing conditions suggesting that they may be composed of more than one polypeptide chain. A significant shift in the molecular masses of these protein bands was observed after enzymatic N-deglycosylation, indicating that they may contain N-glycans. Furthermore, the finding that none of the high molecular mass proteins is shared by all eight species reveals a high level of interspecies venom variability among these components.