2.7 odd-expressing pericardial cells and 7.6 cardioblasts develop per abdominal hemisegment in Df(3R)ZZ27 mutant embryos (in contrast to the wild-typenumber of 4.2 odd-expressing pericardial cells and 6.0 cardioblasts per abdominal hemisegment).

Homozygous embryos show RP2sib to RP2 transformation with respect to marker gene expression but not with respect to cell or nuclear size.

eve-expressing pericardial cells are almost completely absent in Df(3R)ZZ27/spdo^K433 embryos, although the presence of the DA1 muscles is unaffected. Two RP2 cells are formed per hemisegment in homozygous embryos. This phenotype is unaffected if the embryos are also homozygous for numb¹.

The RP2 motoneuron duplicated at the expense of the RP2sib. The aCC motoneuron is duplicated at the expense of the pCC interneuron. The Usib fates are duplicated at the expense of the U neurons. The dMP2 is duplicated at the expense of the vMP2. No change was observable in EL cell fate. This phenotype is the reciprocal of that shown for numb mutants. Mutant embryos do not show excess neuroblast formation characteristic of N mutants. The phenotype of numb; Df(3R)ZZ27 double mutants is identical to embryos Df(3R)ZZ27 mutants alone. The eve⁺ EL neurons are completely rescued.