A synaptic laminin-calcium channel interaction organizes active zones in motor nerve terminals

Synapse formation requires the differentiation of a functional nerve terminal opposite a specialized postsynaptic membrane. Here, we show that laminin beta2, a component of the synaptic cleft at the neuromuscular junction, binds directly to calcium channels that are required for neurotransmitter release from motor nerve terminals. This interaction leads to clustering of channels, which in turn recruit other presynaptic components. Perturbation of this interaction in vivo results in disassembly of neurotransmitter release sites, resembling defects previously observed in an autoimmune neuromuscular disorder, Lambert-Eaton myasthenic syndrome. These results identify an extracellular ligand of the voltage-gated calcium channel as well as a new laminin receptor. They also suggest a model for the development of nerve terminals, and provide clues to the pathogenesis of a synaptic disease.     

A search for life on Earth from the Galileo spacecraft

In its December 1990 fly-by of Earth, the Galileo spacecraft found evidence of abundant gaseous oxygen, a widely distributed surface pigment with a sharp absorption edge in the red part of the visible spectrum, and atmospheric methane in extreme thermodynamic disequilibrium; together, these are strongly suggestive of life on Earth. Moreover, the presence of narrow-band, pulsed, amplitude-modulated radio transmission seems uniquely attributable to intelligence. These observations constitute a control experiment for the serach for extraterrestrial life by modern interplanetary spacecraft.     

Cancer gene discovery in solid tumours using transposon-based somatic mutagenesis in the mouse

Retroviruses, acting as somatic cell insertional mutagens, have been widely used to identify cancer genes in the haematopoietic system and mammary gland. An insertional mutagen for use in other mouse somatic cells would facilitate the identification of genes involved in tumour formation in a wider variety of tissues. Here we report the ability of the Sleeping Beauty transposon to act as a somatic insertional mutagen to identify genes involved in solid tumour formation. A Sleeping Beauty transposon, engineered to elicit loss-of-function or gain-of-function mutations, transposed in all somatic tissues tested and accelerated tumour formation in mice predisposed to cancer. Cloning transposon insertion sites from these tumours revealed the presence of common integration sites, at known and candidate cancer genes, similar to those observed in retroviral mutagenesis screens. Sleeping Beauty is a new tool for unbiased, forward genetic screens for cancer genes in vivo.     

Proximate humid and dry regions in Jupiter's atmosphere indicate complex local meteorology

Models of Jupiter's formation and structure predict that its atmosphere is enriched in oxygen, relative to the Sun, and that consequently water clouds should be present globally near the 5-bar pressure level. Past attempts to confirm these predictions have led to contradictory results; in particular, the Galileo probe revealed a very dry atmosphere at the entry site, with no significant clouds at depths exceeding the 2-bar level. Although the entry site was known to be relatively cloud-free, the contrast between the observed local dryness and the expected global wetness was surprising. Here we analyse near-infrared (around 5 microm) observations of Jupiter, a spectral region that can reveal the water vapour abundance and vertical cloud structure in the troposphere. We find that humid and extremely dry regions exist in close proximity, and that some humid regions are spatially correlated with bright convective clouds extending from the deep water clouds to the visible atmosphere.     

A comparison between the free grafting of sliced and intact muscles in the rat-1.

Transverse slicing is a new technique whereby a mammalian muscle can be freely grafted with success. This method eliminates contamination of the early graft by surviving muscle fibres and allows one to measure the development of contractile properties on a uniform population of regenerating muscle fibres.?IOAuthor     

Attraction of the male house fly to cuticular hydrocarbons and feces of several other dipteran species

Zusammenfassung Männchen vonMusca domestica werden von Kohlenwasserstoffextrakten aus der Cuticula weiblicherMusca domestica, M. autumnalis undHaematobia irritan angelockt (gleiche oder ähnliche Pheromone), nicht aber von entsprechenden Extrakten ausStomoxys calitrans, Glossina morsitans, G. austeni, Fannia canicularis undCochliomyia hominivorax.

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The authors thankDr. P. A. Langley, University of Bristol, for his geneous aid in providing cuticular washes and feces of tsetse flies;Dr. C. M. Jones, USDA, for face fly samples;Dr. R. L. Harris, USDA, for horn fly samples;Dr. B. G. Hightower and R. R. Grabbe, USDA, for screwworm samples andDr. W. M. Rogoff, USDA, for little house fly samples.