Serological screening for MHC (B)-polymorphism in indigenous chickens

Area of Science:

• Immunogenetics
• Poultry Science
• Comparative Genomics

Background:

• Understanding immune responses in indigenous chicken lines is crucial for genetic improvement and disease resistance.
• MHC class IV (BG) polymorphism plays a vital role in immune function and disease susceptibility in poultry.
• Indigenous chicken populations represent a valuable, yet understudied, genetic resource.

Purpose of the Study:

• To serologically screen Bolivian and Indian indigenous chickens for Major Histocompatibility Complex (MHC) class IV (BG) polymorphism.
• To characterize the distribution of specific B-haplotypes within these distinct indigenous chicken populations.
• To identify potential unique genetic variations within the Indian chicken lines' B-haplotypes.

Main Methods:

• Direct haemagglutination assays were performed using haplotype-specific antisera.
• Screening included 95 Bolivian indigenous chickens and 119 Indian backyard chickens (Yellow Aseel, Kadaknath, frizzled typed, naked neck).
• Haplotypes analyzed included B2, B4, B12, B13, B14, B15, B19, and B21.

Main Results:

• The majority of chickens tested were haplotyped as B2, B15, B19, and B21.
• Bolivian chickens showed high heterozygosity (34.6%) and homozygosity (54.9%), with a notable absence of B2-like haplotypes.
• Indian chicken lines exhibited varied MHC (BG)-like protein detection rates, with B2 haplotype present in all lines; many Indian birds possessed unknown haplotypes.

Conclusions:

• Significant differences in B-haplotype distribution exist between Bolivian and Indian indigenous chicken populations.
• The high prevalence of unknown haplotypes in Indian chickens suggests a rich and potentially novel genetic pool for immunogenetic research.
• Further investigation into these unique B-haplotypes could reveal important insights into chicken immune diversity and disease resistance.