Structural and evolutionary comparisons of four alleles of the mouse Igk-J locus which encodes immunoglobulin kappa light chain joining (J kappa) segments.
The Igk-J locus of the mouse encodes the immunoglobulin kappa light chain joining (J) segments. Four Igk-J alleles have been described on the basis of restriction enzyme length polymorphisms. The nucleotide sequences of the Igk-Ja allele (type strain, C.C58), Igk-Jc allele (type strain, SJL/J), and Igk-Jd allele (type strain, SK/CamRk) have been determined and are compared with the previously reported Igk-Jb allele sequence (type strain, BALB/c). The mouse sequences are also compared with published sequences for rat and human J kappa sequences. Far more differences were found between the Igk-Ja allele and the other mouse alleles than between any two of the latter. These result in two amino acid substitutions which distinguish the J2 and J3' segments of the Igk-Ja allele from the other three alleles. Use of the Phylogenetic Analysis Using Parsimony program to generate a phylogenetic tree strongly indicates that after divergence from the rat ancestor, there appears to have been an early split between the Igk-Ja allele and the evolutionary precursor of the other mouse alleles. There also appears to have been far less divergence from the ancestral condition in the Igk-Ja allele than in the other alleles. Also, the presence of only one convergent mutation among the four mouse alleles provides strong evidence against any crossing over within the Igk-J locus during the history of these alleles. Finally, the differences in rates of evolution of the Igk-J alleles are in marked contrast to the relatively uniform rates of divergence of four alleles of a mouse V kappa gene, Igk-VSer.
Ponath
P D
PD
Department of Microbiology, University of Texas, Austin 78712.
Boyd
R T
RT
Hillis
D M
DM
Gottlieb
P D
PD
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D015139:Blotting, Southern; D005803:Genes, Immunoglobulin; D007133:Immunoglobulin Joining Region / Q000235:genetics* / Q000302:isolation & purification; D007145:Immunoglobulin kappa-Chains / Q000235:genetics* / Q000302:isolation & purification; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012689:Sequence Homology, Nucleic Acid
D007133:Immunoglobulin Joining Region; D007145:Immunoglobulin kappa-Chains