Martin M. Shapiro

Replication and serial passage of infectious Heliothis nucleopolyhedrosis virus in an established line of Heliothis zea cells

Abstract An established cell line derived from the ovary of adults of the cotton bollworm, Heliothis zea, supported growth of the Heliothis nucleopolyhedrosis virus (NPV). Typical NPV symptoms were obtained when infected cells were fed to neonatal bollworms; however, the cell line never produced free virions or inclusion bodies containing virions. Infectious virus was passed through the cell line 7 consecutive times, using only infected cells from the previous pass. Infectivity at the 7th serial-pass represented a dilution of >10−8 of the original inoculum.

Dehiscence of Coelomomyces psorophorae sporangia from Aedes taeniorhynchus: Induction by amines and amino acids

Abstract The effect of various chemicals on induction of dehiscence of nonsterile Coelomomyces psorophorae sporangia from Aedes taeniorhynchus larvae was examined. Tests were made with various salts, reducing agents, chelating agents, buffers, alcohols, carbohydrates, fatty acids and derivatives, amino acids and derivatives, peptides, amines, purines and pyrimidines, antibiotics, and plant hormones. The most active compound was Tris [tris(hydroxymethyl)aminomethane]. Tris was most effective at p H 8–9, and a concentration of 1–20 mM . Structure-activity studies indicated that active compounds had a basic requirement for ue5f8NH 2 and either ue5f8COOH or ue5f8CH 2 OH attached to the alpha carbon, but only certain amino acids and amines were highly active. Preparations virtually free of host debris were not responsive to Tris, but addition of bacteria-free homogenates of A. taeniorhynchus larvae restored responsiveness. Dehiscence of C. psorophorae sporangia from Psorophora howardii was also enhanced by exposure to Tris.