The embryonic cuticular phenotype (dorsal closure defects) and lethality of yrt3 homozygous mutants is significantly suppressed by combination with chem1 in heterozygous state and majority of the animals progress to larval stage. Over half of yrt3/yrt3;chem1/+ larvae (when cultures separately) manage to pupariate. Conversely, the embryonic phenotypes of chem1 homozygotes are slightly but significantly improved by combination with a single copy of yrt3. The cuticular phenotype of yrt3;chem1 double homozygous embryos is improved relative to yrt3 single mutants but worsened relative to chem1 homozygotes. Similarly, the embryonic cuticular defects and lethality observed in crb8F105 homozygotes are weakly suppressed by combination with single copy of chem1 and more strongly so by combination with two copies. Some crb8F105 mutant embryos heterozygous or homozygous for chem1 reach adulthood when cultured separately without larvae of other genotypes. Conversely, crb8F105 heterozygosity partially suppresses chem1 mutant embryonic cuticular defects and lethality and the surviving larvae (cultured separately) reach the adult stage at the same rate as sibling double heterozygotes. The cuticular phenotype of crb8F105;chem1 homozygous double mutants is improved relative to crb8F105 single mutants but worsened relative to chem1 homozygotes.
The frequency and severity of cuticular defects observed in both cora2 and chem1 homozygous embryos are significantly increased by combination with a single copy of either chem1 or cora2, respectively, as well as in cora2;chem1 double homozygotes compared to the single homozygotes.