ABSTRACT
Historically, murine λ Ig light chains and genes are the first system which allowed to understand how the mammals (i.e., human and mouse) generate a vast diversity of antibody molecules from a limited genome by a combinatorial process. Further, it showed how somatic mutations can increase this diversity as well as result in the maturation of antibody affinity. The λ locus of the laboratory mouse is the simplest Ig locus known in mammals to date. The κ/λ ratio is one of oldest points of conflict in Immunology. Two principal concepts are often proposed with a tendency to consider them mutually exclusive. The first claims that κ B cells have the same chance to emerge during B cell differentiation as do λ B cells and that the κ/λ ratio in the periphery results from only selective processes.
