Stronger dorsalising phenotype at 18oC than 29oC. Transheterozygotes with pll4 are moderately dorsalised, the phenotype of pll4Tl3p/pll9 is unchanged from the transheterozygote. Heterozygotes produced some dorsalised phenotypes at 29oC when also heterozygous for Df(3R)XM3.
pll4/pll9 is a cold sensitive combination. Cold sensitive period for pelle function is around stage 4 of development, coinciding with the nuclear import of dorsal protein.
Weak pll allele.