The Relationship Between the Alternative exon 7 Splice Variant of the BF Gene and MHC-Related Marek's Disease Resistance in Chickens

The study was to analyse the relationship between the alternative exon 7 splice variant of the BF gene and MHC-related Marek's disease (MD) resistance in chickens. The experiment first determined whether or not the cocks of Xiayan chickens have alternative splicing-out of the exon 7 of the BF gene from peripheral blood leucocytes (PBLs). Then, selected two groups: Group K included the offspring of the selected cocks which have no alternative splicing-out of the exon 7 of the BF gene; Group Y included the offspring of the selected cocks which have alternative splicing-out of the exon 7 of the BF gene. All hens used in the cross-breeding were non-selected. The experimental chickens were challenged with a very virulent strain of Marek's disease virus (MDV) at 4 days old and were raised for 12 weeks. At this time, all the surviving chickens were killed and necropsy was also performed during the experiment whenever chickens died from the infection. Tumour incidence and mortality were calculated using SPSS, and the tissues were collected to detect MDV by PCR. The results showed that the mortalities of Group K and Y were 52.75% and 70.65%, respectively; and that the tumour incidences of non-alternative splicing-out of the exon 7 of the BF for Groups K and Y were 15.38% and 38.89%, respectively; the tumour incidences for the alternative splicing-out of the exon 7 were 46.15% and 56.76%, respectively. The results demonstrated the tumour incidence was highly related with the alternative exon 7 splice variant of the BF gene (P < 0.05).