A fusion protein required for vesicle-mediated transport in both mammalian cells and yeast

A protein sensitive to N-ethylmaleimide catalyses the fusion of transport vesicles with Golgi cisternae in a mammalian cell-free system. By cloning and sequencing its gene from Chinese hamster ovary cells and by use of in vitro assays, we show that this fusion protein is equivalent to the SEC18 gene product of the yeast Saccharomyces cerevisiae, known to be essential for vesicle-mediated transport from the endoplasmic reticulum to the Golgi apparatus. The mechanism of vesicular fusion is thus highly conserved, both between species and at different stages of transport.     

The Pristionchus pacificus genome provides a unique perspective on nematode lifestyle and parasitism

Here we present a draft genome sequence of the nematode Pristionchus pacificus, a species that is associated with beetles and is used as a model system in evolutionary biology. With 169 Mb and 23,500 predicted protein-coding genes, the P. pacificus genome is larger than those of Caenorhabditis elegans and the human parasite Brugia malayi. Compared to C. elegans, the P. pacificus genome has more genes encoding cytochrome P450 enzymes, glucosyltransferases, sulfotransferases and ABC transporters, many of which were experimentally validated. The P. pacificus genome contains genes encoding cellulase and diapausin, and cellulase activity is found in P. pacificus secretions, indicating that cellulases can be found in nematodes beyond plant parasites. The relatively higher number of detoxification and degradation enzymes in P. pacificus is consistent with its necromenic lifestyle and might represent a preadaptation for parasitism. Thus, comparative genomics analysis of three ecologically distinct nematodes offers a unique opportunity to investigate the association between genome structure and lifestyle.     

Differences in cerebral morphology in 2 stocks of mutant mice heterozygous for the loop-tail (Lp)-gene

Summary Adult loop-tail heterozygotes (Lp/+) from a stock ofLp-mice which consistently fail to show head wobbling exhibit normal brain morphology with respect to size and shape of lateral ventricles and nearby nuclei. Loop-tail heterozygotes from a head wobbling stock ofLp-mice show enlargement and deformity of the lateral ventricles.Supported by research grant HD09562 from the National Institutes of Health.     

Chronic mercury vapor poisoning of aphids

Summary Exposure of green peach aphids,Myzus persicae (Sulz.), to an atmosphere containing mercury vapor resulted in a curtailment ofembryogenesis and larviposition by adults, and in the development by larvae and adults of a cuticular darkening of their legs, head capsule, antennae, cornicles and cauda. Mortality of affected larvae resulted from molting difficulties, particularly by last-instar alatiform female and male larvae. Greenbugs,Schizaphis graminum (Rond.), and pea aphids,Acyrthosiphon pisum (Harr.), responded to mercury vapor exposure in similar ways.     

Synaptic vesicle depletion and glutamate uptake in a nerve-muscle preparation of the locust,Locusta migratoria L

Summary Excitatory terminals, depleted of their synaptic vesicles by stimulation at high frequency, were incubated in the radiolabelled putative neurotransmitter, L-glutamate. Quantitative electron microscope autoradiography revealed that the axoplasm of these recovering terminals had accumulated the³H L-glutamate.Acknowledgment. The authors wish to thank Dr N. M. Blackett for running the computer analyses of the autoradiographical results. R. P. Botham gratefully acknowledges the SRC for financial assistance.     

Familial association in serum IgE levels.

The serum IgE levels measured by RIST correlated closely with those obtained by the single radioimmunodiffusion method. Values for husband and wife were closely related as were those between father and daughter but in contrast to previous observations no significant relationship existed between IgE levels for mother and son.     

Stimulation induced depletion of the synaptic vesicles in excitatory motor nerve terminals of the locust,Locusta migratoria L

Summary Neural stimulation at high frequency induced gross changes in the ultrastructural properties and depleted the synaptic vesicles in fast axon terminals of locust extensor tibiae muscles. After a 1-h-rest the synaptic vesicle populations recovered and the ultrastructural properties of these recovering neuromuscular junctions closely resembled those of the controls.Acknowledgment. The authors wish to thank Mr M. J. Parker for invaluable help with the statistical analyses. R. P. Botham gratefully acknowledges the SRC for financial assistance.