gain of function allele
lethal - all die before end of pupal stage
some die during pupal stage
visible | dominant
metatarsus
tarsal segment
tarsal segment 2
tarsal segment (with Ablp1)
Heterozygotes are viable, and show fusion of the metatarsal and second tarsal segments. Alp1/Alp2 animals die as pupae with more extreme tarsal fusions.