Gene organization of chicken anemia virus

Abstract

The genomic DNA of chicken anemia virus (CAV) was cloned and sequenced from a Japanese isolate CAA82-2. The nucleotide sequence of CAA82-2 isolate was 98% identical with that of the European Cuxhaven-1 strain (Noteborn et al., J. Virol. 65, 3131-3139, 1991). Nine open reading frames (ORFs) consisting of more than 100 nucleotides were found, i.e., four ORFs (CA1- CA4) on the plus strand and five ORFs (CA1R-CA5R) on the minus strand. These ORFs with the exception of CA4 are conserved between the two CAV isolates. All of these ORFs were expressed in Escherichia coli as fusion proteins with β-galactosidase. By Western blot analysis, the CA2 and CA3 fusion proteins were found to react with CAV-infected chicken sera. Rabbit hyperimmune sera against the CA1, CA2, and CA3 fusion proteins were produced and tested their reactivity to CAV-infected cells. Two vital proteins with the apparent size of 54 and 16 kDa reacted with the antibodies against CA1 and CA3 fusion proteins, respectively. The 16-kDa protein, CA3, was suggested to be a major immunogen on CAV infection. © 1995 Academic Press, Inc.