The first nucleotide downstream of the first Madm exon is mutated, thus disrupting the splice donor site.
G5744116H
Unspecified nucleotide change in splice donor site; G to ?.
Madm7L2 mutants exhibit a small head (pinhead) phenotype.
Development of Madm7L2 mutant larvae ceases mostly in the third larval instar and in the pre-pupal stage. The onset of the pre-pupal stage is delayed by 2 to 10 days. Madm7L2 mutants do not exhibit any reduction in larval size.
Madm7L2 mutant eye clones have significantly fewer ommatidia compared to control mosaic eyes. Madm7L2 mutant rhabdomeres and photoreceptor cell bodies are smaller than controls. This reduction is cell autonomous as only homozygous mutant photoreceptor cells are affected.
Madm7L2 is rescued by MadmUAS.cGa/Scer\GAL4arm.PS
Based on the severity of the pinhead phenotype, when the mutant is over Df(3R)Exel7283, the following Madm alleles can be ranked from the most severe to the weakest: Madm2D2 = Madm2U3 = Madm3G5 > Madm3Y2 = Madm4S3 = Madm7L2 > Madm3T4.