Abstract: Tumor Virus locus B (TVB) encodes the cellular receptor for ALV subgroups B, D and E. Two Single Nucleotide Polymorphisms (SNPs) at nucleotide positions 172 (C/T) and 184 (T/A) together differentiate the allelic transcripts for TVB*S1, TVB*S3 and TVB*R. Genetic diversity at the TVB locus of chickens was investigated in Chinese indigenous chickens and the White Leghorns. An earlier undescribed nucleotide substitution at 184 (G to T) has been identified in Chinese native chicken breeds using the direct sequencing. Researchers found that the novel allele TVB*S� was in all of Chinese native breeds but TC and homozygous TVB*S'/*S' genotype found in ZZG, XSBNG and CHC, theirs frequencies were 0.28, 0.26 and 0.57, respectively. Except CHC, Chinese native chicken breeds have higher homozygous TVB*S1/*S1 frequency than WL populations. The resistant allele TVB*R was found in WL populations and TC flocks with a frequency of 0.44 and 0.11, respectively.
J.C. Yu, Z.H. Ning and M. Bao, 2012. Genetic Variation at the TVB Locus in Chinese Native Chicken Breeds. Journal of Animal and Veterinary Advances, 11: 4226-4229.