Allelic immunoglobulin VH genes in two mouse strains: possible germline gene recombination.

Abstract

The nucleotide sequence of two germline immunoglobulin heavy chain variable region (VH) genes of mouse BALB/c origin was determined. These two genes are highly homologous to each other. They both have the unusual codon CCT for proline at position 7, which so far has been found only in a specific set of VH genes, called the Npb family. We show that the two VH genes belong to this set. One of our BALB/c genes, VH124, is more homologous to a C57BL/6 Npb VH gene than to any BALB/c VH gene, and we propose that these two genes are alleles. A comparison of the substitutions between these two genes with published sequences of all other BALB/c and C57BL/6 Npb VH genes reveals evidence for past homologous recombination events between related germline VH genes. Homologous recombination may play an important role in the diversification of germline immunoglobulin VH genes.

Evolution of the porcine (Sus scrofa domestica) immunoglobulin kappa locus through germline gene conversion

“…The pattern of variation may be due to evolution through non-crossover homologous recombination events, namely gene conversion. Evidence for germline gene conversion was also observed in the human IGKV (Bentley and Rabbitts 1983) and mouse IGHV (Cohen and Givol 1983) genes and in the human IGHC genes (Flanagan et al 1984; Lefranc et al 1986; Huck et al 1989). IG gene conversion is generally presented as a mechanism of somatic antibody diversification, especially in chickens and rabbits which utilize a diverse array of pseudogenes as templates for functional IG gene assembly during B cell development to diversify limited functional germline repertoires (recently reviewed by Kurosawa and Ohta (2011)).…”

Molecular characterization of the murine cytotoxic T-cell membrane glycoprotein Ly-3 (CD8).

“…21). This is higher than the homology between the Ly-3 V-like region and immunoglobulin VK (23) and VH (25) regions and T-cell receptor chain Vp region (28) (SD scores of 3.70, 2.48, and 3.44, respectively) but not as high as with the immunoglobulin VA region (24) (SD score of 6,16). Whereas it is likely that the ancestral Ly-3 gene of the immunoglobulin lineage postdated the evolutionary split into separate V and C segments, it is not clear that the ancestral Ly-3 gene was already part of the VA lineage despite the high SD score between Ly-3 and VA, as some identities between Ly-3 and a particular member of the VA repertoire may be due to random drift rather than to conservation of ancestral features.…”

“…The first, V (Fig. la), is a hydrophilic region of 102 amino acids and is assigned by its homology to the variable (V) regions of immunoglobulin K (23) and X (24) light chains (VK and VAJ and immunoglobulin heavy chain (VH) (25) (Fig. 3) (26).…”

T-Cell-Dependent Antibody Response to the Dominant Epitope of Streptococcal Polysaccharide,N-Acetyl-Glucosamine, Is Cross-Reactive with Cardiac Myosin

“…Although five hybridomas expressed J558 V H family genes, they were encoded by distinct V H germline segments (7,(26)(27)(28)32). The sixth hybridoma, 11C6-E3, expressed a VGAM3.8 V H family gene and was encoded by the BALB/c VFM1 germline gene (30).…”