Fig. 6.
Germ layer- and cell-specific requirements of Tup at various stages of cardiogenesis. Drosophila embryos at stage 12 (A-F) or between stages 10 and 11 (G-I), shown from the lateral side with anterior to the left; or at stage 15/16 (J-M) or 14 (N) shown from the dorsal side. (A,B,D) Mesodermal and ectodermal inhibition of Tup function by expressing UAS-tupΔHD results in a reduction of Tin-positive cells (arrows in B,D). (C,E) Full-length tup (UAS-tup) can partially restore Tin when co-expressed in the ectoderm but not in the mesoderm. (F) Mesodermal expression of a Tup construct lacking the LIM domains (UAS-tupΔLIM) also affects Tin expression (arrows). (G-I) Tup is required for normal dpp expression as shown by in situ hybridization. dpp is reduced after ectodermal inhibition of Tup function (arrows in H). dpp is strongly reduced in tupisl-1 mutants (I). (J-K′) Mesodermal expression of UAS-tupΔHD results in a reduced number of Dmef2-positive myocardial cells. (K′) An enlargement of the two segments (as delineated by the vertical lines) indicated by the brackets in K. (L-N) Inhibition of Tup function in the pericardial cell lineage results in loss of Odd-positive cells (arrow in M), including a subset of Odd-expressing lymph gland cells (arrowhead in M). Overexpression of Tup in this lineage induces additional Odd-positive pericardial cells (arrows in N). Odd expression in the lymph glands appears unaffected (arrowhead in N).