title: Genotypic variability at the major histocompatibility complex (B and Rfp-Y) in Camperos broiler chickens.
abstract: Evidence for the importance of major histocompatibility complex (MHC) genotype in immunological fitness of chickens continues to accumulate. The MHC B haplotypes contribute resistance to Marek's and other diseases of economic importance. The Rfp-Y, a second cluster of MHC genes in the chicken, may also contribute to disease resistance. Nevertheless, the MHC B and Rfp-Y haplotypes segregating in broiler chickens are poorly documented. The Camperos, free-range broiler chickens developed in Argentina, provide an opportunity to evaluate MHC diversity in a genetically diverse broiler stock. Camperos are derived by cross-breeding parental stocks maintained essentially without selection since their founding. We analysed 51 DNA samples from the Camperos and their parental lines for MHC B and Rfp-Y variability by restriction fragment pattern (rfp) and SSCP typing methods for B-G, B-F (class Ia), B-Lbeta (class II) and Y-F (class Ib) diversity. We found evidence for 38 B-G genotypes. The Camperos B-G patterns were not shared with White Leghorn controls, nor were any of a limited number of Camperos B-G gene sequences identical to published B-G sequences. The SSCP assays provided evidence for the presence of at least 28 B-F and 29 B-Lbeta genotypes. When considered together B-F, B-L, and B-G patterns provide evidence for 40 Camperos B genotypes. We found even greater Rfp-Y diversity. The Rfp-Y class I-specific probe, 163/164f, revealed 44 different rfps among the 51 samples. We conclude that substantial MHC B and Rfp-Y diversity exists within broiler chickens that might be drawn upon in selecting for desirable immunological traits.
authors.affiliation: Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: G M
authors.initials: GM
authors.lastname: Iglesias
authors.forename: L A
authors.initials: LA
authors.lastname: Soria
authors.forename: R M
authors.initials: RM
authors.lastname: Goto
authors.forename: A M
authors.initials: AM
authors.lastname: Jar
authors.forename: M C
authors.initials: MC
authors.lastname: Miquel
authors.forename: O J
authors.initials: OJ
authors.lastname: Lopez
authors.forename: M M
authors.initials: MM
authors.lastname: Miller
mesh_terms: D000818:Animals; D015139:Blotting, Southern; D002645:Chickens / Q000235:genetics / Q000276:immunology*; D014644:Genetic Variation; D005838:Genotype; D008285:Major Histocompatibility Complex / Q000235:genetics*