Lta^hlb382

This phenotypic mutant was identified in an ENU mutagenesis screen. An insertion of a cytosine occurred between nucleotides 16 and 17 of the second exon. This is predicted to cause a frameshift mutation from amino acid 6 and translation of a theoretical new peptide of 173 amino acids with a premature stop codon in exon 4. Because Ltb and Tnf are found in nearby genomic locations, their sequence and expression were analyzed and found to be normal. Intra-cell flow cytometry failed to detect any Lta expression in activated B-cells.