Rabies virus was found on mouse diaphragms and on cultured chick myotubes in a distribution coinciding with that of the acetylcholine receptor. Treatment of the myotubes with alpha-bungarotoxin and d-tubocurarine before the addition of the virus reduced the number of myotubes that became infected with rabies virus. These findings together suggest that acetylcholine receptors may serve as receptors for rabies virus. The binding of virus to acetylcholine receptors, which are present in high density at the neuromuscular junction, would provide a mechanism whereby the virus could be locally concentrated at sites in proximity to peripheral nerves facilitating subsequent uptake and transfer to the central nervous system.

No abstract

Suspensions of FMD virus treated with 0·05% formalin at 26° C. for periods up to 144 hr. remained infective for cattle, although the infectivity could not be detected in the presence of aluminium hydroxide. Infectivity was detected in similar virus suspensions which had been treated with 0·05% AEI at 37° C. for 8 hr. but not in suspensions treated for 12 hr.Vaccines prepared from these suspensions were antigenically potent and serum neutralization tests demonstrated the development and regression of serum antibody. The AEI vaccines were at least as potent as the corresponding formalin vaccines.

No abstract

SUMMARYThe RNA-containing components of vesicular stomatitis virus were labelled with asp by growing the virus in a phosphate-deficient medium containing a2PO 4 and Actinomycin-D. Centrifugation of the virus suspensions in a sucrose gradient gave four radioactive fractions. The most rapidly sedimenting fraction contained the infective component of the virus, whereas most of the interfering activity was in the second fraction, which contained 'caps', filaments and rosette-like structures. The interfering activity was associated with the 'cap', which could be separated from the filaments and rosettes by centrifuging in a potassium tartrate gradient.The viral RNA sedimented predominantly in the 36 to 4o S position in sucrose gradients prepared in o.I M-acetate buffer but frequently exhibited a more heterogeneous profile. The percentage distribution of 32p in the four nucleotides was A = 29"3, C = 2i.i, G = 2o'9 and U = 28"7. Ribonucleic acid from the interfering component invariably gave a sharp profile with a sedimentation coefficient of I8 to 2oS and the percentage distribution of 32p was A = 27"I, C = 2I'9, G = 2o'3 and U --30"7. Both nucleic acids were hydrolysed to low molecular weight materials by ribonuclease o.m /zg./ml.