Molecular genotyping of recombinant congenic lines provides evidence for crossing-over within the B-G region of the major histocompatibility complex of the chicken

cDNA cloning, genomic structure and expression analysis of the goose (Anser cygnoides) MHC class I gene

To provide data for studies on avian disease resistance, goose MHC class I cDNA (Ancy-MHC I) was cloned from a goose cDNA library, it's genomic structure and expression analysis were investigated. The mature peptides of Ancy-MHC I cDNA encoded 333 amino acids. The genomic organization is composed of eight exons and seven introns. Based on the genetic distance, six Ancy-MHC I genes from six individuals can be classified into four lineages. A total of nineteen amino acid positions in peptide-binding domain showed high scores by Wu-kabat index analysis. The Ancy-MHC I amino acid sequence displayed seven critical HLA-A2 amino acids that bind with antigen polypeptides, and have an 85.4-98.9% amino acid homology with each genes, and a 59.8-66.0% amino acid homology with chicken MHC class I. Expression analyses using Q-RT-PCR to detect the tissue-specific expression of Ancy-MHC I mRNA in an adult goose. The result appeared that Ancy-MHC I cDNA was expressed in the liver, spleen, intestine, kidney, lung, pancreas, heart, brain, and skin. The phylogenetic tree appears to branch in an order consistent with accepted evolutionary pathways.

Utility of three restriction fragment length polymorphism probes for genotyping of the chicken major histocompatibility complex class IV region

Three chicken B-G cDNA probes (gene 8.5, bg28, and bg32.1) were used to detect restriction fragment length polymorphisms (RFLP) in the chicken MHC class IV (B-G). By using inbred and selected chicken lines with different B haplotypes identified by hemagglutination, we identified B haplotypes (B2, B9, B11, B12, B15, B19, B21, B31, and B32) by RFLP using the three probes following digestion of genomic DNA with four restriction endonucleases (BglII, EcoRI, HaeIII, and PvuII). The GSP inbred line, previously shown to contain B-F21 by the use of a monoclonal antibody, did not contain B-G21, based on RFLP tests, whereas line N had B-F21 and B-G21. Consequently, the RFLP typing with the clone of B-G cDNA was able to determine the B haplotype in more detail than typing by hemagglutination. In inbred and selected lines, three B-G cDNA are useful DNA probes for RFLP to identify B genotypes. Two families of chickens with segregating B haplotypes were analyzed by RFLP using these probes; however, identification of the B genotype by this method was difficult in the randomly bred population. Genotypic comparisons of RFLP with gene 8.5 and BglII and bg 28 as probes and digestion by the endonucleases EcoRI, HaeIII, and PvuII between the parents and their offspring were generally compatible within the expectations of Mendelian inheritance.