Identification And Application Of A Subgroup Avian Leukosis Genetic Resistance Sites In Yellow-feather Broilers

A Subgroup Avian Leukosis is a chicken neoplastic and immunosuppressive disease caused by the Avian Leukosis Virus subgroup A（ALV-A）,that it caused huge economic losses to China’s poultry industry.The tva receptor gene encodes a receptor protein that mediates ALV-A infection,its genetic mutation can cause the host to produce genetic resistance to ALV-A infection.The previous research in this laboratory found that the 260th base of the coding region of the DNA sequence of tva receptor was mutated from G to A in the Chinese chickens,named tva^260G>A.In order to further study the effect of tva^260G>A mutation on host infection with ALV-A,we conducted the following studies.In this study,RCASBP（A）-GFP fluorescent reporter virus and ALV-A wild virus were used to infect tva^260G/GCEF、tva^260G/ACEF and tva^260A/ACEF,the result shows:tva^260G>Amutation can reduce ALV-A infection in host vitro,ALV-A in vivo infection test results show:tva^260G>Amutation can reduce ALV-A infection in host vitro that can produce genetic resistance.In order to evaluate the genetic resistance of ALV-A in different yellow feather broiler breeds（lines）,this study analysis of the genotype of tva260G>A resistance sites in 15local chicken breeds and 10 yellow feather broiler lines,the results showed that the tva260G>A mutations existed in Xinghua chicken,Huaixiang chicken,Longshengfeng and Kangle chickens and yellow feather broiler lines A01,A08,and A10,the frequency of resistance genotype tva^260A/A for these breeds is 0.25,0.19,0.13,0.14,0.10,0.15 and 0.23.The above experimental results show that the tva260G>A mutation site was identified as the genetic resistance site of ALV-A,and the resistance site can be used to screen out breeding materials resistant to ALV-A from yellow feather broiler breeds（strains）,it provides new ideas and technical support for the disease-resistant breeding of yellow feather broiler ALV-A.