The Study On The Correlation Of Swine MHC And Transferrin Polymorphism With Piglets E.coli K88 Diarrhea

In the research, the method of direct sequence of PCR product,PCR-SSCP and discontinuous electrophoresis method were used to study the polymorphism of SLA-DQB-Exon2, SLA-DRB-Exon2 SLA-DQB-URR, SLA-DRB-URR and Transferrin in sib and half-sib family piglets consisted of Jiuyang-xiang pig,Jianbai-xiang pig and Landrace. The correlation of polymorphic sites found in the research with the E.coli K88 adhension and the content of serum IgG were analyzed. Aims of this present study were to detect relationship of SLA and Transferrin polymorphism with E.coli K88ab, K88ac, K88ad adhension of piglets, so useful heredity markers were perhaps found to applied in the disease resistance breeding.The results indicate that:(l)There exist abundant polymorphic sites in SLA-DQB-Exon2 and SLA-DRB-Exon2.There are 38 polymorphic sites in SLA-DQB-Exon2 and 62 polymorphic sites in SLA-DRB-Exon2.(2) The influence of sites UK 113, 114, 142, 184 in SLA-DQB-Exon2 and 29, 149, 170 in SLA-DRB-Exon2 on content of serum IgG of 0-28 days piglets were significant (p<0.05) .The difference of serum IgG content of different genotypes in some sites was significant (p<0.05) ,but the genotype which least square value of serum IgG content is highest was not existed in one or some breeds specially. The gene frequencies of these 8 sites were different in 3 breeds significantly (p<0.01).(3)The correlation don't exist between all polymorphic sites in SLA-DQB-Exon2 and E.coli K88ab, K88ac, K88ad adhension of piglets.there exist significant correlation between sites 29 in SLA-DRB-Exon2 and E.coli K88ad adhension of piglets (p<0.01)(4) The sequence of SLA-DQB (GenBank accession number:AY456637) and SLA-DRB (GenBank accession number:AY365420) 5' proximal regulatory region were firstly cloned. The analysis results showed that there exist highly conserved regulatory elements as X box, W box, Y box, CCAAT.TATA box, these elements have strict spacial order. 12 SLA-DRB-URR and 14 SLA-DQB-URR alleles were found through PCR-SSCP and sequencing. These 26 sequences all have regulatory elements as X box, W box, Y box, CCAAT, TATA box and strict spacial order.(5) 9 polymorphic sites in SLA-DQB-URR and 24 polymorphic sites in SLA-DRB-URR were found. Regulatory elements Y box in SLA-DRB-URR were polymorphic, but other regulatory elements in SLA-DQB-URR and SLA-DRB-URR are all conserved.(6)The influence of sites -12,-28 in SLA-DRB-URR on content of serum IgG of 0-28 days piglets were significant (p<0.05), but all polymorphic sites in SLA-DQB-URR on content of serum IgG of 0-28 days piglets were not significant (p>0.05) .The correlation don't exist between all polymorphic sites in SLA-DRB-URR with E.coli K88ab,K88ac,K88ad adhension of piglets, but there exist significant correlation between sites -20 in SLA-DQB-URR and E.coli K88ab adhension of piglets (p<0.01) .(7)The Transferrin gene was correlated with E.coli K88ab,K88ac adhension of piglets significantly(p<0.01) ,but the correlation don't exist between transferrin gene and E.coli K88ad adhension of piglets (p>0.01) .