P-element insertion in exon 4 on siz. (Exon 4 is the first common exon of transcript 1 (sizP1; RE44556) and transcript 2 (sizP2; LP01489)).
lethal
larval ventral nerve cord commissure
The number of commissural fibers crossing the ventral midline of stage 16 embryos is reduced in sizC1-28 mutants. This effect is seen most strongly in abdominal segments A1-A4.
A.Carpenter