Pseudorecombinants between Cloned DNAs of Two Isolates of Cassava Latent Virus

Abstract

SUMMARYInfective clones of the Nigerian isolate of cassava latent virus (CLV) have been obtained. The apparent molecular weight of the capsid protein of this isolate is slightly higher than that produced in plants infected with cloned DNAs of the Kenyan isolate of CLV. Pseudorecombinant experiments using heterologous combinations of cloned DNAs have confirmed that the physical properties of the capsid protein are encoded on DNA 1 and at least some determinants of symptom induction are also located on this DNA. Comparison between the nucleotide sequences of the open reading frames encoding the two capsid proteins shows several nucleotide differences which affect the amino acid composition but which do not significantly alter the potential molecular weight of the product. In vitro translation of poly(A) ÷ RNAs shows that the differences in electrophoretic mobility are not due to differences in host-directed post-translational processing.

Pseudorecombination between infectious cloned DNA components of tomato mottle and bean dwarf mosaic geminiviruses

“…Hidayat, R. L. Gilbertson & D. P. Maxwell, unpublished results). Pseudorecombination between components of geminiviruses has been reported previously for ACMV (Stanley et al, 1985;Morris et al, 1990), BGMV (Faria et al, 1990), SqLCV (Lazarowitz, 1991) and TGMV (von Arnim & Stanley, 1992), but these pseudorecombinants were combinations of closely related geminivirus isolates or strains, which originated from the same plant species collected from different geographical locations (ACMV, BGMV and TGMV) or from a single infected plant (SqLCV). For the ACMV, BGMV and SqLCV pseudorecombinants, the CRs of the DNA-A and DNA-B components were nearly identical.…”

Fate of African Cassava Mosaic Virus Coat Protein Deletion Mutants after Agroinoculation

“…Due to the difficulty of cloning multimeric forms of DNA A from the Kenyan isolate of ACMV, a tandem repeat of DNA A was cloned into the BamHI site of pBin 19 using the full-length BamHI clone (pNIG008; Stanley et al, 1985) constructed from the closely related Nigerian isolate of ACMV to give pBin. N2A.…”

“…The genomic components of the Kenyan and Nigerian isolates are considered to be interchangeable in these experiments because, although the isolates are distinguishable by the relative mobilities of their coat proteins in polyacrylamide gels and the symptoms they induce in Nieotiana tabacum, the cloned DNAs are highly homologous, can form viable pseudorecombinants, are equally infectious and elicit similar symptoms in N. benthamiana (Stanley et al, 1985). A construct containing 1.3 copies of DNA A of the Kenyan isolate (pBin.…”

Nucleotide sequence evidence for the occurrence of three distinct whitefly-transmitted, Sida-infecting bipartite geminiviruses in Central America.

“…Although bipartite geminiviruses are closely related, the production of viable pseudorecombinants by reassortment of infectious cloned components is generally limited to strains of a particular virus (Stanley et al, 1985 ;Lazarowitz, 1991 ;von Arnim & Stanley, 1992 ;Frischmuth et al, 1993 ;Sung & Coutts, 1995). An exception to this, i.e.…”