Cloning and sequencing of the porcine complement factor B

Area of Science:

• Genomics
• Immunogenetics
• Comparative Genomics

Background:

• Complement factor B (BF) is a key component of the complement system and a major histocompatibility complex class III antigen.
• Understanding the genetic structure of BF is crucial for immunogenetic studies in domestic animals.

Purpose of the Study:

• To isolate and characterize the porcine complement factor B (BF) gene.
• To investigate the genetic diversity and evolutionary conservation of the BF gene between pigs and humans.

Main Methods:

• Isolation of a porcine genomic clone (SSBf1) containing the BF gene.
• Partial sequencing of the porcine BF gene and comparison with the human BF gene.
• Southern blot analysis to determine BF gene copy number.
• Restriction fragment length polymorphism (RFLP) typing using Taq I to assess BF-haplotypes.

Main Results:

• The porcine BF gene was successfully isolated and partially sequenced.
• Seven exons encoding the Ba and Bb subunits of BF were identified.
• Protein sequence similarity between porcine and human BF averaged 87%.
• Southern blot analysis confirmed the presence of a single BF gene per haploid genome.
• RFLP typing identified at least three distinct porcine BF-haplotypes.

Conclusions:

• The porcine BF gene shares significant structural and sequence homology with its human counterpart.
• The genetic characterization of porcine BF provides a foundation for further immunogenetic research in pigs.
• The identified BF-haplotypes suggest genetic diversity within the porcine population relevant to immune response.