title: Mutation affecting the expression of immunoglobulin variable regions in the rabbit.
abstract: We have found a variant of the allotype allele a2 in the rabbit, which presumably arose by mutation, that segregates as expected for an allele at the a locus. This allele is called "ali" and the corresponding rabbit strain is called "Alicia." In heterozygous animals (ali/a1 and ali/a3) the concentration of a2 molecules is lower by a factor of 1000 than in standard a2/a2 homozygotes. In homozygous ali/ali individuals the a2 concentration varies with age--i.e., very low in young rabbits and higher in older ones--but it never reaches normal levels. The low level of a2 is compensated by increased amounts of a-negative molecules. Southern blot analysis did not reveal any gross changes in the intron between JH and C mu (joining region of immunoglobulin heavy chain and constant region of immunoglobulin mu chain) or in the number of VH gene segments encoding a locus specificities. We suggest that the ali phenotype is due to a mutation in a control element.
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D004262:DNA Restriction Enzymes; D005786:Gene Expression Regulation; D005796:Genes; D007126:Immunoglobulin Allotypes / Q000235:genetics*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D009154:Mutation; D010375:Pedigree; D011817:Rabbits
chemical_list: D007126:Immunoglobulin Allotypes; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; D004262:DNA Restriction Enzymes