Molecular Cloning And Expression Analysis Of The Oryctolagus Cuniculus Gene In MHC ? DQ

The Major Histocompatibility Complex?MHC?is a highly polymorphic gene group encoding immunoglobulin-like receptors found in vertebrates,whose expression products are distributed on the surface of various cells.It is called MHC molecule and plays a very important antigen presentation role in the body's immune system.It is not only related to transplant rejection,but also closely related to some economic traits of animals.MHC antigen participates in the body's immune response and plays an important role in the body's immune response regulation,antigen recognition and presentation.At the same time,differences in the genetic background of MHC and the level of diversity between different individuals can lead to differences in individual resistance to disease and susceptibility.Therefore,MHC as a candidate gene for disease resistance and susceptibility has become a hot spot in genetic breeding research,and it is also receiving more and more attention from ecologists,population geneticists and animal genetics breeders.1.The complete cDNA sequence of rabbit MHCII DQ gene was cloned by RACE technology,and the structure and function of the gene were analyzed and predicted by bioinformatics technology.The full-length cDNA of MHCII DQ gene is 1148 bp?GenBank accession number: XM₀02714510.3?,5'UTR21 bp,3'UTR318 bp.The CDS region is 768 bp and encodes 255 amino acids.The MHCII DQ protein has a molecular weight of 28.094 kDa and a theoretical isoelectric point: pI=5.23.The secondary structure is mostly ?-helix and?-sheet.It has a distinct transmembrane region and belongs to the secreted protein.The amino acid sequence encoded by the gene exists.N-linked glycosylation,no O-linked glycosylation sites.The mature protein instability index?II?is 45.89,which is a stable protein;it contains 28 negative amino acid residues?Asp + Glu?and 20 positively charged amino acid residues?Arg+ Lys?.It has a total average hydropathicity?GRAVY?of 0.076 and belongs to hydrophobin.In alignment with other animal sequences,the nucleotide sequence and amino acid sequencehave the highest homology with bovine and equine.2.2At the mRNA level,MHCII DQ is a broad-spectrum expression gene that is widely found in the liver and spleen and is detectable in the heart,liver,spleen,lung,kidney,stomach,brain,and ileum,and in the spleen.There was significant tissue differential expression between the brain and the brain?P<0.05?.It is expressed in the kidney and heart and is the lowest in the brain.MHCII DQ gene mRNA expression: spleen> liver> lung> ileum> heart>kidney> stomach> brain,indicating the presence of high expression of MHCII DQ gene in immune organs.