Clusters of genes encoding mouse transplantation antigens

Area of Science:

• Immunogenetics
• Molecular Biology
• Genomics

Background:

• Transplantation antigens, also known as class I molecules, are crucial for immune responses.
• Understanding the organization and variability of these genes is essential for immunology and transplantation research.

Purpose of the Study:

• To construct and analyze a cosmid library of mouse transplantation antigen genes.
• To investigate the structure, organization, and polymorphism of class I gene clusters in mice.

Main Methods:

• Construction of a cosmid library from BALB/c mouse sperm DNA.
• Isolation and mapping of cosmid clones using cDNA probes for class I molecules.
• Restriction mapping, Southern blot analysis, and hybridization studies.

Main Results:

• Identified 64 cosmid clones containing 36 distinct class I genes within 13 gene clusters.
• Mapped gene clusters to the L and Qa-2,3 regions of the major histocompatibility complex.
• Demonstrated gene duplication and deletion as mechanisms altering gene cluster organization and contributing to polymorphism.
• Found the third external domain exon to be more conserved than the first and second external domains.

Conclusions:

• Gene duplication and deletion are significant mechanisms for generating polymorphism in mouse class I genes.
• Variability in exon conservation suggests differential functional importance within transplantation antigens.