Project description:Most species of bee are capable of delivering a defensive sting which is often painful. A solitary lifestyle is the ancestral state of bees and most extant species are solitary, but information on bee venoms comes predominantly from studies on eusocial species. In this study we investigated the venom composition of the Australian great carpenter bee, Xylocopa aruana Ritsema, 1876. We show that the venom is relatively simple, composed mainly of one small amphipathic peptide (XYTX1-Xa1a), with lesser amounts of an apamin homologue (XYTX2-Xa2a) and a venom phospholipase-A2 (PLA2). XYTX1-Xa1a is homologous to, and shares a similar mode-of-action to melittin and the bombilitins, the major components of the venoms of the eusocial Apis mellifera (Western honeybee) and Bombus spp. (bumblebee), respectively. XYTX1-Xa1a and melittin directly activate mammalian sensory neurons and cause spontaneous pain behaviours in vivo, effects which are potentiated in the presence of venom PLA2. The apamin-like peptide XYTX2-Xa2a was a relatively weak blocker of small conductance calcium-activated potassium (KCa) channels and, like A. mellifera apamin and mast cell-degranulating peptide, did not contribute to pain behaviours in mice. While the composition and mode-of-action of the venom of X. aruana are similar to that of A. mellifera, the greater potency, on mammalian sensory neurons, of the major pain-causing component in A. mellifera venom may represent an adaptation to the distinct defensive pressures on eusocial Apidae.
Project description:The great tit is a widely studied passerine bird species in ecology that, in the past decades, has provided important insights into speciation, phenology, behavior and microevolution. After completion of the great tit genome sequence, a customized high density 650k SNP array was developed enabling more detailed genomic studies in this species.
Project description:Genome-wide mRNA expression profiles of 70 primary gastric tumors from the Australian patient cohort. Like many cancers, gastric adenocarcinomas (gastric cancers) show considerable heterogeneity between patients. Thus, there is intense interest in using gene expression profiles to discover subtypes of gastric cancers with particular biological properties or therapeutic vulnerabilities. Identification of such subtypes could generate insights into the mechanisms of cancer progression or lay the foundation for personalized treatments. Here we report a robust gene-xpression-based clustering of a large collection of gastric adenocarcinomas from Singaporean patients [GSE34942 and GSE15459]. We developed and validated a classifier for the three subtypes in Australian patient cohort.