Fig. 5.

Genetic interactions between tup, tin, pnr and Doc. The cardiac phenotypes in transheterozygotic Drosophila embryos demonstrate that tup interacts genetically with all three factors. The phenotypes were compared with those of the cardiac markers in single heterozygotes, and were evaluated statistically for Dmef2 (see Tables 1 and 2). (A-D) Dmef2 expression in the wild type (A) and in embryos transheterozygotic for tup^isl-1 and pnr^VX6 (B), tup^isl-1 and tin³⁴⁶ (C), tup^isl-1 and Df(3L)DocA (D). Dorsal views of embryos at stage 15/16 are shown. Arrows point to gaps in the myocardial rows of the dorsal vessel. (E,F) Pnr is reduced in tup/tin transheterozygotic embryos (arrows in F). A lateral view of a stage 11 embryo is shown. (G-I) Tin expression in the wild type (G), and in embryos transheterozygotic for tup and pnr (H), and tup and DocA (I). Reduced Tin expression is seen in both cases (arrows in H,I). Dorsal views of stage 14 embryos are shown.