Rearrangement of genetic information may produce immunoglobulin diversity.

The nearly complete amino-acid sequences of 22 closely related immunoglobulin kappa variable (Vkappa) regions from the inbred NZB mouse are presented. This group of Vkappa regions is encoded by at least six germline Vkappa genes. These data also suggest that the mouse kappa gene is divided into three segments termed V or variable (residues 1 to 98 or 99), J or joining (residues 99 or 100 to 112) and C or constant (residues 113--219). Tonegawa et la. have recently described a similar J segment for mouse lambda chains. Inbred mice contain multiple Vkappa and Jkappa gene segments. Therefore, different combinations of V and J gene segments may be joined at the DNA level during the differentiation of individual lymphocytes to contribute to antibody diversity.