Project description:Venoms are biochemical arsenals that have emerged in numerous animal lineages, where they have coevolved with morphological and behavioural traits for venom production and delivery. In centipedes, venom evolution is thought to be constrained by the morphological complexity of their venom glands due to physiological limitations on the number of toxins produced by their secretory cells. Here, we show that the uneven toxin expression that results from these limitations have enabled giant centipedes to regulate the composition of their secreted venom despite having morphologically undifferentiated venom glands. We show that this control is likely achieved by the complex neuronal networks that innervate each venom gland subunit and is facilitated by morphological adaptations that circumvent the physiological evolutionary constraints on venom production. Our results suggest behavioural control over venom composition may be an overlooked aspect of venom biology and provide an example of how exaptation can facilitate evolutionary innovation and novelty.
Project description:The Tibellus genus spider is an active hunter that does not spin webs and remains highly underinvestigated in terms of the venom composition. Here, we present a combination of venom glands transcriptome cDNA analysis, venom proteome analysis for unveiling of the Tibellus genus spider venom composition.
Project description:High-throughput sequencing of RNA from secretory tissues of reptiles.Tissues were dissected from freshly-euthanised individuals and either snap-frozenin liquid nitrogen or stored short-term in RNAlater (Ambion). Total RNA was extracted from approximately 30mg of tissue using the Qiagen RNeasy Mini kit according to manufacturer instructions, with on-column DNase treatment. Typically, single whole scent glands and venom/salivary glands were used in the relevant extractions and skin samples were taken from the dorsal side at approximately mid-body level.This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/
Project description:We generated ATAC-seq data for pre- and post-extraction venom gland samples and H3K4me3, H3K27ac, and CTCF ChIP-seq from post-extraction venom gland samples from the Prairie Rattlesnake to investigate patterns of chromatin accessibility, transcription factor binding, and insulation during venom production, and to identify open promoters and active enhancer regions.
Project description:The soldier fly is an endemic pest of sugarcane in Australia. Small numbers of larvae can cause significant damage to roots and reduce the crop yields. Little is known about the composition and function of the soldier fly salivary gland, its secretions, and their roles in insect-plant interactions. In this study, we performed transcriptome analysis of the salivary glands of starved and sugarcane root-fed soldier fly larvae. A total of 31,119 highly expressed assembled contigs were identified in the salivary glands and almost 50% of them showed high levels of similarity to known proteins in Nr databases. Of all the obtained contigs, only 9,727 sequences contain an open reading frame of over 100 amino acids. Around 31% of contigs were predicted to encode secretory proteins, including some digestive and detoxifying enzymes and potential effectors. Some known salivary secreted peptides such as serine protease, cysteine proteinase inhibitors, antimicrobial peptides and venom proteins were among the top 100 highly expressed genes. Differential gene expression analysis revealed significant modulation of 850 transcripts in salivary glands upon exposure to plant roots or starvation stress. Here, we identified some venom proteins which were significantly upregulated in the salivary glands of soldier fly larvae exposed to sugarcane roots. In other insects and nematodes some of these proteins have been used to manipulate host plant defense systems and facilitate the invasion of the host plant. These findings provide a further insight into the identification of potential effector proteins involved in soldier fly- sugarcane interactions.