Norman F. Moore

General Characteristics, Gene Organization and Expression of Small RNA Viruses of Insects

Introduction. Small RNA-containing viruses (less than 40 nm diameter) have been isolated from a wide range of insect species, and the infection of insect cell cultures by several of these viruses has permitted an examination of their replicative events. Much of the research in insect virology has been directed towards the use of viruses as field control agents for pest species, but it is unlikely that small RNA viruses will be used extensively for this purpose until more is known about their molecular biology, pathology and host range. A major problem regarding their potential use as insect control agents is created by several reported interactions between small RNA viruses of insects and antibodies in mammalian sera (Longworth et al., 1973b; MacCallum et al., 1979; Scotti & Longworth, 1980; Moore et al., 1981b). It is likely that inadequate monitoring of baculovirus preparations used in field control of pest insects has led to the accidental spread of small RNA viruses (Hess et al., 1977, 1978).

The polypeptides induced in Drosophila cells by Drosophila C virus (strain Ouarzazate)

The Ouarzazate strain of Drosophila virus (DCV0) was grown in Drosophila melanogaster tissue culture cells, and [35S]methionine-labeled virions were found to contain a group of major structural proteins with a molecular weight of approximately 30,000 as well as several minor proteins of higher molecular weight and a protein of approximately 10,000 daltons. Using a range of pulses, chases and gel systems, examination of the intracellular proteins induced by DCV0 showed the presence of 17 polypeptides not found in uninfected cells. The synthesis of virus-induced polypeptides was extremely asymmetric with a rapid appearance of the major virus structural proteins and a much slower appearance of the lowest molecular weight structural protein (VP4). Processing of virus-induced proteins including the appearance of VP4 was demonstrated using pulse-chase after pulsing with [35S]methionine. While the highest molecular weight induced protein found in infected cells was 146,000, pretreatment of cells with iodoacetamide resulted in the appearance of a protein with a molecular weight of approximately 200,000. The evidence presented in this paper supports the inclusion of DCV0 in the Picornaviridae group.

Envelope proteins of vesicular stomatitis virions: Accessibility to iodination

Abstract The glycoprotein and, to a lesser extent, the matrix membrane protein of intact vesicular stomatitis virions were specificially iodinated by oxidation with lactoperoxidase or chloramine T. The virion envelope provided an effective barrier against iodination of nucleocapsid proteins. Selective removal of glycoprotein by trypsin or Triton X-100 exposed the membrane matrix protein to somewhat more extensive iodination but the nucleocapsid N protein became only slightly more accessible to iodination; the nucleocapsid L and NS proteins remained unlabeled.

Cholesterol Oxidase as a Probe for Studying Membrane Composition and Organization

Lipid bilayers of biological membranes often contain sterols (mainly cholesterol) as a major component. Membrane cholesterol content has been examined in some detail and is often quantitated in relation to phospholipid concentration. The ratio of cholesterol to phospholipid appears to affect many physical and biological properties of a membrane (Cooper, 1977). Several model membrane systems are now providing a better understanding of the interaction at the molecular level of cholesterol and various phospholipids (Huang, 1977; Thompson and Huang, 197 8; Demel and DeKruijff, 1976). Such information may provide better insight into biological functions of cell membranes.

Oligonucleotide Fingerprinting of the RNA Species Obtained from Six Drosophila C Virus Isolates

Summary The virion RNAs of six independent isolates of Drosophila C virus (DCV) have been characterized by ribonuclease T1 oligonucleotide fingerprinting. All six isolates share common large oligonucleotides. Two of the isolates, from Vigier and Charolles, are closely related while a third French isolate from Gif is more distantly related. The other three isolates, two from Morocco (Taroudant and Ouarzazate) and one from the French Antilles were mixtures of more than one variant of DCV, but were clearly related to the three French isolates.