cDNA clone encoding a complete rabbit immunoglobulin kappa light chain of b4 allotype

Area of Science:

• Immunogenetics
• Molecular Biology
• Rabbit Genetics

Background:

• The kappa light chain is a crucial component of the antibody structure.
• Rabbit allotypes, such as b4, are genetically determined variations in immunoglobulin proteins.
• Understanding immunoglobulin gene rearrangement is vital for immunology.

Purpose of the Study:

• To clone and sequence a cDNA encoding the rabbit b4 kappa light chain.
• To investigate the genetic basis of rabbit kappa light chain diversity.
• To compare rabbit kappa V-J recombination with other species and immunoglobulin types.

Main Methods:

• cDNA cloning from a rabbit-mouse hybridoma.
• Nucleotide sequence analysis of the cloned gene (pB4D5).
• Genomic Southern blot analysis using a V region-specific probe.
• Sequence comparisons with germ-line DNA and published sequences.

Main Results:

• Successfully cloned and sequenced the complete variable (V) and constant (C) regions of a b4 kappa light chain.
• The translated amino acid sequence matched the secreted protein.
• Genomic analysis indicated a complex V gene repertoire.
• Identified unusual V-J recombination features in rabbit kappa chains.

Conclusions:

• The cloned cDNA (pB4D5) represents a functional b4 kappa light chain.
• Rabbit kappa V-J recombination exhibits characteristics distinct from typical kappa systems, resembling mouse and human heavy chain recombination.
• This finding provides new insights into immunoglobulin gene diversification mechanisms.