MHC-DRB1 exon 2 polymorphism and its association with mycoplasma ovipneumonia resistance or susceptibility genotypes...

Area of Science:

• Animal Genetics
• Immunology
• Veterinary Pathology

Background:

• Major histocompatibility complex (MHC) polymorphisms are implicated in various animal and human diseases.
• Limited research exists on the association between MHC polymorphisms and Mycoplasma ovipneumonia (MO) in sheep.

Purpose of the Study:

• To identify MHC genotypes associated with resistance or susceptibility to MO in sheep.
• To investigate the clinical, pathological, and immunological differences between MO-resistant and susceptible sheep.
• To elucidate the molecular mechanisms underlying MO resistance and susceptibility.

Main Methods:

• Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotyping to identify MHC polymorphisms.
• Assessment of clinical and pathological features in sheep experimentally infected with MO.
• Analysis of immune factor responses, including cytokine expression (TNFa, IFNc, IL-4, IL-6, IL-1b, IL-2, IL-10).

Main Results:

• The Hu population exhibited dominant MvaI bb and HaeIII ee genotypes, correlating with MO susceptibility.
• Dorper and D 9 H hybrid populations showed dominant MvaI cc and HaeIII dd genotypes, associated with MO resistance.
• Susceptible genotypes were linked to more severe clinical signs and pathological changes, with heightened inflammatory responses (high TNFa, IFNc, IL-4, IL-6, IL-1b).
• Resistant genotypes were associated with inhibited inflammatory responses (increased IL-2, IL-10 expression).

Conclusions:

• MvaI cc and HaeIII dd genotypes are potentially associated with MO resistance in sheep.
• Distinct immune factor expression profiles differentiate MO-resistant and susceptible genotypes.
• Findings provide a theoretical basis for breeding sheep with enhanced MO resistance.