Genotypic variability at the major histocompatibility complex (B and Rfp-Y) in Camperos broiler chickens

• Published in: Animal genetics 2003-04, Vol.34 (2), p.88-95
• Main Authors: Iglesias, G. M., Soria, L. A., Goto, R. M., Jar, A. M., Miquel, M. C., Lopez, O. J., Miller, M. M.
• Format: Article
• Language: English
• Subjects: Animals; Blotting, Southern; broilers; chicken; Chickens - genetics; Chickens - immunology; genetic variability; Genetic Variation; Genotype; major histocompatibility complex; Major Histocompatibility Complex - genetics
• ISSN: 0268-9146; 1365-2052
• DOI: 10.1046/j.1365-2052.2003.00944.x

Summary 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‐Lβ (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‐Lβ 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.