Successive rearrangement of the immunoglobulin light-chain variable segments can increase probability for cell-surface expression of the B cell receptor
-Rearrangement of only one allele at a time -repeated rearrangements of unused V and J segments of each allele -The chances for generating an intact light chain are increased -Isotypic exclusion: the production of a light chain from only one of the two light chain loci, κ or λ -κ vs λ-expression: varies in different speciesè correlates with numbers of V κ or Vλ gene segments.
Ex. Rats= 95:5 ; cats= 5:95
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