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Updated: Aug 8, 2026
Generation of Human CD40-activated B cells
Published on: October 17, 2009
Genomic structure and chromosomal mapping of the murine CD40 gene
J C Grimaldi1, R Torres, C A Kozak
1Department of Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304.
Insights
Researchers isolated murine CD40 genomic clones, revealing nine exons spanning 16.3 kb. The CD40 gene structure is similar to the nerve growth factor receptor gene, with functional domains on separate exons.
Area of Science:
- Immunology
- Molecular Biology
- Genetics
Background:
- CD40 is a B cell-associated surface molecule crucial for B cell expansion and T cell interaction.
- Understanding the CD40 gene structure is vital for comprehending its role in immune responses.
Purpose of the Study:
- To isolate and characterize the genomic structure of murine CD40.
- To compare the intron/exon organization of the CD40 gene with its homologues.
Main Methods:
- Isolation of murine CD40 genomic clones from a mouse liver genomic DNA library.
- Comparison of genomic sequence with murine CD40 cDNA.
- Southern blot analysis for gene copy number and mapping.
Main Results:
- Nine exons comprising the murine CD40 coding region were identified, spanning approximately 16.3 kb of genomic DNA.
- The intron/exon structure of the CD40 gene mirrors that of the nerve growth factor receptor gene.
- Murine CD40 was confirmed as a single-copy gene located on mouse chromosome 2.
Conclusions:
- The genomic organization of murine CD40, with functional domains distributed across exons, provides insights into its gene regulation.
- The structural similarity to the nerve growth factor receptor gene highlights conserved evolutionary features of these related receptors.
Abstract:
The B cell-associated surface molecule, CD40, is likely to play a central role in the expansion of Ag-stimulated B cells, and their interaction with activated Th cells. In our study we have isolated genomic clones of murine CD40 from a mouse liver genomic DNA library. Comparison with the murine CD40 cDNA sequence revealed the presence of nine exons that together contain the entire murine CD40 coding region, and span approximately 16.3 kb of genomic DNA. The intron/exon structure of the CD40 gene resembles that of the low affinity nerve growth factor receptor gene, a close homolog of both human and murine CD40. In both cases the functional domains of the receptor molecules are separated onto different exons throughout the genes. Southern blot analysis demonstrated that murine CD40 is a single copy gene that maps in the distal region of mouse chromosome 2.
