fd68A16 mutants carry a deletion of 2bp at the insertion site of P{EP}fd68AEP3428 and a deletion in exon 2 (of 962bp) that generates a new ORF containing a STOP codon. This encodes a chimeric protein that shares the first 26 amino acids with fd68A, but the predicted new frame eliminates both the FH and the FHA domains and introduces 66 new amino acids.
Stage 16 fd68A16 embryos display normal ventral nerve cord morphology.
Homozygous fd68A16 embryos exhibit no obvious morphological abnormalities in early and intermediate stages of development. However midgut differentiation is abnormal in late embryos.
Early midgut differentiation is normal in fd68A16 mutant embryos until stage 15, when the midgut is composed of a single vesicle. During stage 16 three constrictions generate the four vesicles of the normal midgut. However, fd68A16 embryos fail to complete the first midgut constriction. The midgut does not develop further.
