An apparent deletion of an oligonucleotide detected by RNA fingerprint in the nondiabetogenic B variant of encephalomyocarditis virus is caused by a point mutation.
The diabetogenic D variant of encephalomyocarditis virus (EMC-D) was previously shown to be different from the nondiabetogenic B variant of encephalomyocarditis virus (EMC-B) by a single spot in an oligonucleotide fingerprint after RNase T1 digestion of their genomic RNAs. An oligoribonucleotide was missing from EMC-B but was present in EMC-D. The oligoribonucleotide specific to EMC-D was isolated from a two-dimensional polyacrylamide gel and sequenced as 5'-ACAAUCUCACUUUUCCAACAACAG-3'. Molecular hybridizations of EMC-D and EMC-B genomic RNAs with a DNA primer complementary to the EMC-D-specific oligoribonucleotide revealed that the absence of a corresponding spot in EMC-B was due to a point mutation rather than a deletion. By sequencing a cloned cDNA of EMC-B corresponding to the EMC-D-specific oligoribonucleotide, the point mutation was identified as a G for EMC-B and an A for EMC-D transversion at base 9 of the oligonucleotide. Comparative sequence analysis of eight randomly picked RNA segments around the EMC-D-specific oligoribonucleotide revealed that there were no base changes between EMC-D and EMC-B. It is concluded that the diabetogenic EMC-D viral genome differs from the nondiabetogenic EMC-B viral genome by at least a point mutation.
Yoon
J W
JW
Department of Microbiology and Infectious Diseases, Julia McFarlane Diabetes Research Center, University of Calgary Health Sciences Centre, Alberta, Canada.
Wong
A K
AK
Bae
Y S
YS
Eun
H M
HM
D000818:Animals; D001483:Base Sequence; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D003921:Diabetes Mellitus, Experimental / Q000382:microbiology; D004686:Encephalomyocarditis virus / Q000235:genetics*; D005814:Genes, Viral; D008297:Male; D051379:Mice; D009154:Mutation; D009693:Nucleic Acid Hybridization; D009710:Nucleotide Mapping; D009843:Oligoribonucleotides / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D009843:Oligoribonucleotides; D012367:RNA, Viral