关键词: MHC-B单倍型, SPF鸡, 禽白血病, 抗性

Abstract: Abstract:Objective To study the resistance difference of different MHC-B haplotype chicken lines to AL and establish finally a more resistant and susceptible inbred lines. Method The chicks of G1, G5, G6 and G8 were inoculated with standard strain RAV-1 of ALV A subgroup and 6 chicks of G8 line were randomly selected as control group. All died and remaining survival chicks at the end of experiment were necropsied to examine gross lesions. The serum antibody titers of all chicks were tested by the ELISA detection kit of ALV. The virus copies per 107 lymphocytes (virus load) of chicks were quantified by the duplex qRT-PCR assay. The resistance-related indexes of mortality, lesion scores, antibody titer and virus load were used to assess the AL resistance of all infected lines. Result The mortality of G5 was higher than other lines while G1 was the lowest. The antibody titer of G1 was higher than other lines from the 5 wpi to the end of the experiment while G5 was the lowest during this period. Furthermore, the antibody titer of G1 was statistically significantly (P <0.05) higher than G5 from 8 wpi to 11 wpi and from 15 wpi to the end. The lowest virus load was found on G1 from 7 wpi to 15 wpi and the virus load of G5 was statistically significantly (P < 0.01) higher than G1 from 9 wpi to 13 wpi. Conclusion All these data indicated that the G1 line was able to produce a stronger genetic resistance to the infection of ALV while G5 line was more susceptible. This study not only provides a powerful experiment data for establishing more resistant and susceptible inbred lines, but also provides significant evidence for studying the correlation between MHC and AL resistance.

Key words: MHC-B haplotype, SPF chicken, avian leukosis, resistance