Insertion of 4kb in the fourth exon, resulting in a 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.
Induced in a screen designed to mobilize the P elements of the Birmingham-2 chromosome, however no new P element is detectable in the mus308D15 strain as judged by Southern analysis.