Intronic deletions of tva receptor gene decrease the susceptibility to infection by avian sarcoma and leukosis virus...

Area of Science:

• Poultry genetics
• Virology
• Molecular biology

Background:

• Avian sarcoma and leukosis virus (ASLV) poses a significant threat to poultry health.
• Host susceptibility to ASLV is determined by specific genetic receptor loci, including tva.
• Previous research identified resistant alleles, but novel resistance mechanisms are continually sought.

Purpose of the Study:

• To identify and characterize new genetic resistance factors to ASLV in Chinese commercial broilers.
• To investigate the molecular mechanisms underlying ASLV resistance conferred by novel tva receptor gene alleles.
• To assess the impact of these genetic variations on host susceptibility to ASLV subgroup A.

Main Methods:

• Identification and sequencing of novel tva receptor gene alleles (tva(r5) and tva(r6)) in Chinese broilers.
• Analysis of intronic deletions and their effect on mRNA splicing and protein isoforms.
• In vitro and in vivo assays to evaluate host susceptibility to ASLV subgroup A.

Main Results:

• Two new tva alleles, tva(r5) and tva(r6), were identified, characterized by similar intronic deletions.
• These deletions disrupt mRNA splicing, leading to intron retention and premature stop codons in tva isoforms.
• Reduced susceptibility to ASLV subgroup A was observed in vitro and in vivo, with quantitative differences in heterozygous pairs.

Conclusions:

• Defective splicing of the tva receptor gene confers genetic resistance to ASLV subgroup A.
• Novel mutations in the tva gene provide a potential genetic tool for controlling ASLV infections in poultry.
• Understanding these resistance mechanisms is crucial for developing effective disease management strategies.