Pollen tube growth requires a Ca2+ gradient, with elevated levels of cytosolic Ca2+ at the growing tip. This gradient's magnitude oscillates with growth oscillation but is always maintained. Ca2+ influx into the growing tip is necessary, and its magnitude also oscillates with growth. It has been widely assumed that stretch-activated Ca2+ channels underlie this influx, but such channels have nev...

Argiotoxin, a component of the spider venom from Argiope lobata, blocks AMPA receptor channels expressed in homomeric and heteromeric configuration in Xenopus oocytes. Argiotoxin acts as an open channel blocker in a voltage-dependent manner and discriminates between the functionally diverse AMPA receptors. Importantly, a transmembrane region 2 determinant for divalent cation permeability also d...

According to a recent global literature survey, total of 39 out the 129 known spider families (∼30%) contain species capable capturing vertebrate prey. The finding that percentage engaged in predation is so high novel. Two groups vertebrate-eating spiders are distinguished: “habitual vertebrate-eaters” vs. “occasional vertebrate-eaters”. habitual vertebrate-eaters comprise ten (Araneidae, Atrac...

Spiders are useful models for testing different hypotheses and methodologies relating to animal personality behavioral syndromes because they show a range of types unique physiological traits (e.g., silk venom) that not observed in many other animals. These characteristics allow understanding how physiology, plasticity, interact across contexts affect spider's individual fitness survival. Howev...

Spider venoms are a complex mixture of peptides with a large number of neurotoxins targeting ion channels. Although thousands of peptide toxins have been identified from venoms of numerous species of spiders, many unknown species urgently need to be investigated. In this study, a novel sodium channel inhibitor, µ-TRTX-Hl1a, was identified from the venom of Haplopelma lividum. It contained eight...

ArachnoServer (www.arachnoserver.org) is a manually curated database providing information on the sequence, structure and biological activity of protein toxins from spider venoms. These proteins are of interest to a wide range of biologists due to their diverse applications in medicine, neuroscience, pharmacology, drug discovery and agriculture. ArachnoServer currently manages 1078 protein sequ...

Theraphosid spiders (tarantulas) are venomous arthropods found in most tropical and subtropical regions of the world. Tarantula venoms are a complex cocktail of toxins with potential use as pharmacological tools, drugs and bioinsecticides. Although numerous toxins have been isolated from tarantula venoms, little research has been carried out on the venom of Australian tarantulas. We therefore i...

1. Dept. Physiology, University of Toronto, 1 King’s College Circle, Toronto, ON, Canada M5S 1A8. 2. Instituto Butantan, Lab. of Pharmacology, Biochemistry and Immunochemistry, respectively, São Paulo, SP, Brazil. 3. Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON, Canada M5G 1X5. 4. Current address: Department of Biological Science, Barnard College...