Pol32-Pol31 interaction is essential for Pol32 function.

A. Constructs used in rescuing experiments and their effects on the mutant phenotypes. The 431aa Pol32 protein is denoted as a rectangular box with domains of interest labelled in black. The names of the domain are on top of the boxes with the range in amino acids in parentheses. For the Polα-interacting DPIM and the PCNA-interacting PIP domain, the amino acid sequences of the domain are listed underneath with the conserved residues in Bold and a larger Font. For constructs with a deletion, the deleted range in amino acids is shown under the name of the mutant construct and proceeded by a “Δ”. For constructs with residues changed to Alanine, the mutant composition of the mutated domain is shown underneath and the mutated domain denoted with an “*”. The constructs were tested for their abilities to rescue two mutant phenotypes. “Bristle” indicates shorten or missing bristles in pol32 adults. “Fertility” indicates female sterility of pol32 mutants. “+” indicates that a construct can recue the phenotype when introduced into a pol32 mutant background, while “-” cannot. B. The levels of Pol32 mutant proteins. Western blots using total extracts from either ovaries or embryos were probed with antibodies indicated to the left of the images. The animals are pol32 homozygotes with a rescuing construct listed on top of the images and shown in A. Tubulin was used as a general loading control. For the two wHTH mutants, the level of PolD was also measured (right panels in B). C. The effect of Pol31 RNAi on the level of Pol δ. Two transgenes carrying different RNAi hairpins were used to knockdown Pol31 in larval tissues. The levels of Pol32 and PolD were assayed by Western blotting. “+” indicates samples from animals with the hairpin construct, while “-” from control animals without the construct.