Insertion in the 3' end of the gene (exon 7) resulting a slightly truncated transcript.
Sensitive to 0.002% nitrogen mustard treatment: treated homozygous larvae do not survive. Adult survivors of lower dose treatments exhibit an incompletely penetrant held up wing phenotype, with reduced flight ability.
Three additional alleles, named "mus308D11", "mus308D12" and "mus308D13", that are likely to represent the same mutational event share the same restriction fragment length polymorphisms as mus308D10.