Submitted to: International Conference on Animal Genetics
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2004
Publication Date: 9/11/2004
Citation: Zhang, H., Bacon, L.D. 2004. Evaluation of avian leukosis virus subgroup A (ALVA) and subgroup B (ALVB) receptor genes in recombinant congenic strains of chickens [abstract]. International Conference on Animal Genetics. p. 115.
Technical Abstract: To dissect the genetic makeup of complex traits we are developing 19 recombinant congenic strains (RCS) of chickens. Inbred lines 63 and 72 were crossed, followed by two consecutive backcrosses to line 63. Then sib matings were applied within 19 families for 13 generations to form the 6C.7 RCS. Line 63 is susceptible to ALV of subgroups A, B, and E whereas line 72 is resistant to these viruses, which reduce productivity. To examine genetic resistance to ALV approximately 9 adults from lines 63 and 72 and each of the RCS were subcutaneously injected with subgroup A Rous sarcoma virus (RSV) in one wing-web and subgroup B RSV in the other wing-web. DNA typing by a SNP assay was developed to assess the TVB receptor alleles. All of the chickens in line 63 and in 18 of the RCS were homozygous for TVB susceptible alleles, i.e., TVB*S1/*S1. All of the line 63 and 94% of the RCS chickens from the 18 RCS had tumors 12 days after subgroup B injection. In contrast, the line 72 and 7 chickens from the RCS 6C.7G were homozygous resistant, i.e., TVB*R/*R, and they did not develop tumors. Two additional chickens of the RCS 6C.7G were heterozygous, i.e., TVB*S1/*R, and developed tumors as expected. After subgroup A RSV injection all the chickens in the line 63 and in 16 RCS had tumors. However, line 72 and 22-45% of the chickens in 3 other RCS lacked tumors. A molecular assay is in development to analyze the TVA receptor allele in these chickens. We conclude that the TVA and TVB receptor genes from line 72 were randomly assorted in the 19 RCS and remain in 1-3 RCS. These data establish the value of developing of the 6C.7 RCS for identifying, evaluating and characterizing genes underlying traits of economic interest.