|CHEN, WEIGUO - South China Agricultural University|
|YANG, LIU - South China Agricultural University|
|LI, HONGXING - South China Agricultural University|
|CHANG, SHUANG - Shandong Agricultural University|
|SHU, DINGMING - Guangdong Academy Of Agricultural Sciences|
|CHEN, FENG - South China Agricultural University|
|XIE, QINGMEI - South China Agricultural University|
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/17/2015
Publication Date: 4/15/2015
Publication URL: http://handle.nal.usda.gov/10113/60956
Citation: Chen, W., Yang, L., Li, H., Chang, S., Shu, D., Zhang, H., Chen, F., Xie, Q. 2015. Intronic deletions of tva receptor gene decrease the susceptibility to infection by subgroup A avian sarcoma and leukosis virus subgroup A. Scientific Reports. 5:9900. doi: 10.1038/srep09900.
Interpretive Summary: Avian leucosis virus (ALV) is one of major tumor viruses causing cancerous like diseases in chickens. Specific gene forms can confer or mediate the viral infection in chicken. This study in systematic examination of some Chinese commercial broilers led to discovery of two varied forms of a chicken gene, resulted from two short deletions of the gene, which displayed resistance to a specific subgroup of ALV infection. This finding is of great interests in understanding the functionality of the gene in relation to DNA sequence alteration and in genetic improvement of disease resistance in chickens by selection.
Technical Abstract: The group of avian sarcoma and leukosis virus (ASLV) in chickens contains six highly related subgroups, A to E and J. Four genetic loci, tva, tvb, tvc and tvj, encode for corresponding receptors that determine the susceptibility to the ASLV subgroups. The prevalence of ASLV in hosts may have imposed strong selection pressure toward resistance to ASLV infection, and the resistant alleles in all four receptor genes have been identified. In this study, two new alleles of the tva receptor gene, tvar5 and tvar6, with similar intronic deletions were identified in Chinese commercial broilers. These natural mutations delete the deduced branch point signal within the first intron, disrupting mRNA splicing of the tva receptor gene and leading to the retention of intron 1 and introduction of premature TGA stop codons in both the longer and shorter tva isoforms. As a result, decreased susceptibility to subgroup A ASLV in vitro and in vivo was observed in the subsequent analysis. In addition, we identified two groups of heterozygous allele pairs which exhibited quantitative differences in host susceptibility to ASLV-A. This study demonstrated that defective splicing of the tva receptor gene can confer genetic resistance to ASLV subgroup A in the host.