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Biomedical subjects

B M Gorman

Publications and source records attributed to B M Gorman.

At least 37 records · Page 2Linked to original sources
PubMed1984

Comparison of dengue viruses and some other flaviviruses by cDNA-RNA hybridization analysis and detection of a close relationship between dengue virus serotype 2 and Edge Hill virus.

Variable amounts of cDNA were synthesized in vitro from RNA extracted from several flaviviruses, including the four prototype dengue (DEN) virus serotypes. The synthesis was carried out using an oligo(dT) primer, suggesting the presence of a short poly(A) region at or near the 3' end of some flavivirus genomes. The DEN-1 and DEN-2 prototype strains produced the largest amount of cDNA and were therefore used to investigate further the relatedness of flavivirus genomes by cDNA-RNA hybridization. The flaviviruses studied are related to each other to some extent since the hybrids formed exhibited about 30% S1 nuclease resistance, but a closer relationship was detected between dengue viruses of serotype 1 and 4 and between dengue virus serotype 2 and Edge Hill virus. A monoclonal antibody to the envelope protein (V3) of dengue viruses reacted with Edge Hill virus, confirming the genetic relationship between the viruses.

Antigens, Viral↗
PubMed1983

On the evolution of orbiviruses.

The genomes of orbiviruses consist of 10 segments of double-stranded RNA. In cells simultaneously infected with two or more related viruses, recombinants are derived by independent reassortment of parental genes. The process is analogous to sexual reproduction in higher organisms and provides a mechanism for generating extensive diversity within this group of viruses. This genetic diversity can be explained by reference to modern concepts of the structure of natural populations of organisms. A species in the phylogenetic sense is the largest aggregate of individual organisms that evolves as a unit. The biological species concept stresses the community gene pool and reproductive isolation. The orbiviruses are now classified into 13 distinct serological groups, but confusion exists in defining species. Classification by reference to concepts of evolutionary species would define genetically interacting groups, estimate the extent of diversity within these groups, and establish phylogenetic relationships between species.

Biological Evolution↗
PubMed1982

Application of RNase T1 one- and two-dimensional analyses to the rapid identification of foot-and-mouth disease viruses.

The analysis of several isolates of foot-and-mouth disease virus by RNase T1 fingerprinting of the 32P-labeled RNA is described. It has been shown that use of the 35S induced RNA instead of the virus particle RNA has two advantages. (i) About 40 times more radioactivity is incorporated into the induced RNA. (ii) The RNA can be prepared much more rapidly, thus increasing the value of the technique in rapid diagnosis. One-dimensional maps, in which the RNase T1 oligonucleotides are separated according to size, have been shown to provide a valuable screening method for distinguishing between viruses. Those viruses giving similar one-dimensional maps also gave similar two-dimensional maps. The value of using the length of the polycytidylic acid tract of foot-and-mouth disease virus as a diagnostic tool is also discussed.

Aphthovirus↗
PubMed1981

Comparison of bluetongue type 20 with certain viruses of the bluetongue and Eubenangee serological groups of orbiviruses.

The genome of bluetongue virus type 20 consists of 10 segments of double-stranded RNA each of which contains unique sequences as determined by oligonucleotide mapping. The 10 polypeptide products of the virus genome were detected in virus-infected cells, and in pulse--chase experiments there was no secondary cleavage of the primary gene products. Using stringent conditions for RNA--RNA reassociation, no significant homology could be detected between the genomes of bluetongue type 20 isolated in Australia and representative serotypes isolated in other geographic regions. The results suggest sequence divergence between geographically isolated viruses and not the recent introduction of a bluetongue virus into Australia.

Base Sequence↗
PubMed1980

Biochemical aspects of variation in foot-and-mouth disease virus.

The biochemical basis for variation in foot-and-mouth disease virus (FMDV) has been explored by analysis of the virus RNA and the virus-induced and structural proteins of three isolates of the virus. Two of the isolates were from serotype A and the third was from serotype O. Hybridization studies of the RNAs showed greater than 80% homology between the two type A viruses and about 65% homology between the two type A viruses and the virus of type O. The ribonuclease T1 maps of the three viruses gave distinct patterns typical of FMDV, but did not show that any two of the three viruses were more closely related. The virus-induced primary translation products, P88, P52 and P100 isolated from infected cells, were compared by tryptic peptide analysis. Combinations of 3H- and 14C-leucine-labelled polypeptides were hydrolysed with trypsin and resolved on an ion-exchange column. Much greater differences were found in P88 than in P52 or P100, indicating that the major variation occurs in the region of the genome coding for the structural proteins. Similar analysis of combinations of the structural proteins of the three viruses showed that there were differences in VP1, VP2 and VP3 and these results were supported by those obtained by PAGE analysis of the Staphylococcus aureus V8 protease cleavage products.

Aphthovirus↗
PubMed1980

Genetic Analysis of Orbiviruses by Using RNase T(1) Oligonucleotide Fingerprints.

Corresponding double-stranded RNA segments of the related orbiviruses Wallal and Mudjinbarry produced distinctly different RNase T(1) fingerprint patterns. No extensive sequence reiteration was observed between segments of Mudjinbarry virus. Fingerprint analysis of the genome of recombinant orbiviruses confirmed segment reassortment as a mechanism of interchange of genetic information. When temperature-sensitive mutants of each virus were crossed in mixed infection, a consistent pattern of segment reassortment was correlated with generation of the wild-type phenotype. Thus, the temperature-sensitive lesion of group II Wallal serogroup mutants was mapped to segment 1. The group I mutant lesion appears to be located in segment 2.

Journal Article↗
PubMed1978

Susceptibility of orbiviruses to low pH and to organic solvents.

Six orbiviruses, Corriparta, Wallal, Eubenangee, D'Aguilar, Warrego and Mitchell River, were inactivated within 30 min in solutions of pH less than 6. All but Wallal virus resisted treatment with ether at 1 degrees for 22 h but only Corriparta virus resisted treatment with chloroform at 1 degrees for 22 h. The genomes of the orbiviruses, including Corriparta virus, after electrophoresis in acrylamide gels separated into basically similar patterns which were distinct from the pattern of reovirus RNA.

Chloroform↗
PubMed1978

The RNA genome of Tilligerry virus.

RNA extracted from Tilligerry virus, a member of the Eubenangee group of orbiviruses, separated into ten segments after electrophoresis in acrylamide gels. The molecular weights of most segments differed from the corresponding segments of Eubenangee virus.

Electrophoresis, Polyacrylamide Gel↗
PubMed1978

The isolation of recombinants between related orbiviruses.

Temperature-sensitive mutants of the related orbiviruses, Wallal and Mudjinbarry, recombine with high frequency when grown in pairs in cell culture. The genome of each virus consists of discrete segments of double-stranded RNA and high frequency recombination suggests that reassortment of genome segments occurs rather than classical recombination. Electrophoresis in acrylamide gels of RNA extracted from the progeny of a cross between Wallal ts 101 and Mudjinbarry ts 3 mutants, revealed that three plaque isolates of 60 tested differed in RNA pattern from each of the parent viruses and from each other. Further analysis of the electrophoretic profiles suggested that the isolates were recombinants with RNA segments derived from each of the parent viruses.

Arboviruses↗
PubMed1977

Isolation of Sindbis (alphavirus) and Leanyer viruses from mosquitoes collected in the Northern Territory of Australia, 1974.

Mosquitoes collected near Darwin, Northern Territory, in 1974 yielded two virus strains. One was identified as Sindbis virus, not previously isolated from the Northern Territory. The other is antigenically distinct from viruses previously isolated from arthropods in Australia, and the name "Leanyer" is proposed for it. Its properties suggest that it may be a togavirus serologically unrelated to available alphaviruses and flaviviruses.

Animals↗