Studies On Molecule Evolution Of Antivirus Gene Of BF And Mx In Phasianidae Birds

Currently, the variety of birds in the spread of infectious diseases indiscriminately,posing a threat to the population.Now,how to improve the birde’s ability to cope with variety of the virus has became the primary problem.Both BF gene and Mx gene are disease resistance gene under the action of natural selection,and some researchers have indicated that polymorphism of BF gene and Mx gene play an important role in anti-infection and autoimmune disease of birds.Moreover,these two genes is valid candidate genes in breeding for disease resistance of poultry.This research used 10 species of Phasianidae birds as research object and obtained BF exon2-8 sequences from 3 individuals of Tragopan cabot,BF exon2、3 sequences from 5 species of Phasianidaes birds and Mx gene exon13 and exon14 from 10 species of Phasianidaes birds by sequencing or cloning method. Discussed gene polymorphism and evolution in order to lay the theoretical foundation for further study disease resistance of bird’s BF gene and Mx gene.The results are as follows:1.Partial sequence of BF gene was obtained from 3 Cabot’s tragopan,which consist of complete sequence of 7 exon (exon2 to exon8) and 6 introns.9 haplotypes were defined.The le sequence varied from 1803-1828bp and coding region is 1010bp, encoding 335aa.The most aboundant mutation sites exist in piptide binding region (PBR) formed by al and a2 domain.2.20 haplotypes of BF exon2 and exon 3 were defined from 125 sequences from 25 individuals of 5 species of Phasianidae birds.The length of sequence is 544bp encoding 181aa.192 variation sites have been detected, of which there are 126 simple information spots.3.Exon13 and exon 14 of Mx gene were abtained from 10 species of Phasianidae birds.18 haplotypes of Mx exon 13 are defined from 40 sequences and 13 haplotypes of Mx exon 14 are defined from 58 sequences.It indicated the Mx exon14 is more conservative.4.The PBR of BF-α1 domain is effected by positive selection and non-PBR is effected by negative selection. The BF-α2 region is effected by negative selection no matter in PBR or non-PBR region, but the nonsynonymous substitutions rate of PBR region is faster than that of non-PBR region. The GED region of Mx gene and S631N that control the antiviral activity of Mx protein in GED region are effected by negative selection.5.Both BF and Mx gene have the shared haplotype between genara and intergenera, and the phylogenetic trees of BF gene reflect the transspecies evolutionary phenomena of BF gene.6.The 631 st amino acids are all Ser in Mx from 10 species of Phasianidae birds in this research, so it’s inferred that these 10 wild Phasianidae birds in this study belong to vulnerable groups.