Fig. 4. pointed promotes pericardial cell development. Dorsal (A,B) and high magnification lateral (C,D) views of stage 16 (A,B) and early stage 13 (C,D) wild-type (A,C) and pnt (B,D) embryos labeled for ZFH1 to mark pericardial cells (A-C; red in C) and Mef2 (C,D; green). (A) In wild-type embryos, two bilateral stripes of pericardial cells (arrows) develop lateral to the cardioblasts (position of cardioblasts indicated by asterisks). (B) pnt embryos exhibit a severe reduction in pericardial cell number (arrows). (C) In early stage 13 wild-type embryos, pericardial cells (red cells; arrowheads) develop ventral and slightly interior to cardioblasts (green cells; arrows). (D) In early stage 13 pnt embryos, ectopic cardioblasts (arrowheads) arise in the location normally occupied by pericardial cells just ventral to the position of the endogenous cardioblasts (arrows). Anterior is towards the left.