Membrane interiorization by phagocytosing macrophages — an ultrastructural morphometric approach

Summary Stereological methods have been used to quantify selected membrane compartments of normal and activated rat peritoneal macrophages, before and after phagocytosis of latex beads. Despite being rounder, activated cells are more efficient phagocytes: 30 min after latex challenge they suffer a greater nett depletion of plasma membrane and sequester more and larger phagocytic vacuoles. However, phagocytosis of latex is not the major route of membrane interiorization.We wish to thank Professor R. Barer for his advice and criticism. The work was undertaken by L.O. as a research project in partial fulfilment of requirements for a B.Sc. degree in Human Biology and Anatomy, University of Sheffield.     

Identification of gamma-tubulin, a new member of the tubulin superfamily encoded by mipA gene of Aspergillus nidulans

Microtubules, which are essential for mitosis and many other cytoskeletal functions, are composed primarily of alpha- and beta-tubulin. The properties of microtubules are due, in part, to proteins other than tubulins that are part of, or interact with, microtubules and the identification and characterization of such proteins is important to understanding how microtubules function. Analyses of mutations at the mipA (microtubule interacting protein) locus of Aspergillus nidulans have suggested that the product of mipA interacts specifically, probably physically, with beta-tubulin in vivo and is involved in microtubule function. We have cloned and sequenced the wild-type mipA gene as well as complementary DNA copies of its messenger RNA. Comparisons of the predicted product of mipA with tubulins from diverse organisms reveal that mipA is a previously undiscovered member of the tubulin superfamily of genes; the only member yet discovered that does not encode alpha- or beta-tubulin. We propose that the product of mipA be called gamma-tubulin.     

Methiothepin and a 5-HT pathway to rat substantia nigra

Summary Methiothepin reduced both median-raphe evoked and exogenous 5-HT depression of single substantia nigra neurones. While this is compatible with a serotonin releasing pathway, additional interactions of methiothepin with exogenous dopamine suggest the need for further pharmacological confirmation.Acknowledgment. This work was supported by an MRC Programme Grant to Prof. D. W. Straughan     

Sequencing of Aspergillus nidulans and comparative analysis with A. fumigatus and A. oryzae

The aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. Here we report the genome sequence of the model organism Aspergillus nidulans, and a comparative study with Aspergillus fumigatus, a serious human pathogen, and Aspergillus oryzae, used in the production of sake, miso and soy sauce. Our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. It also led to an experimentally validated model of mating-type locus evolution, suggesting the potential for sexual reproduction in A. fumigatus and A. oryzae. Our analysis of sequence conservation revealed over 5,000 non-coding regions actively conserved across all three species. Within these regions, we identified potential functional elements including a previously uncharacterized TPP riboswitch and motifs suggesting regulation in filamentous fungi by Puf family genes. We further obtained comparative and experimental evidence indicating widespread translational regulation by upstream open reading frames. These results enhance our understanding of these widely studied fungi as well as provide new insight into eukaryotic genome evolution and gene regulation.     

First record of the spotted bat ( Euderma maculatum ) from Oregon

A spotted bat ( Euderma maculatum ) was taken at Mickey Springs, 28 km northeast of Andrews, Harney County, Oregon. This represents a 225 km range extension and a new record for Oregon.     

Projections from nucleus accumbens to globus pallidus and substantia nigra in the rat

Stimulation of nucleus accumbens produces inhibition and facilitation of neuronal activity in the ipsilateral globus pallidus and substantia nigra. Small lesions in the accumbens reduce pallidal but not nigral GABA content.     

Projections from nucleus accumbens to globus pallidus and substantia nigra in the rat

Summary Stimulation of nucleus accumbens produces inhibition and facilitation of neuronal activity in the ipsilateral globus pallidus and substantia nigra. Small lesions in the accumbens reduce pallidal but not nigral GABA content.Acknowledgment. This work was supported by an MRC grant to Prof. D. W. Straughan.