Fig. 2.

Overexpression of Trafs and components of the TNF and JNK pathways. (A) The JNK pathway and Traf proteins were overexpressed in the mesoderm of wild-type embryos or embryos derived from homozygous mutant bsk germ line clones using a Twist-Gal4 driver line. Embryos were fixed and stained with antibodies against Twist and Even-skipped and sorted under a dissecting microscope into groups at three different stages of gastrulation (shown as three columns for each genotype) judged on the depth of the head fold and the appearance of dorsal folds (see Materials and Methods). In each group, the embryos were sorted into those without any apparent defects and those with delayed or defective ventral furrows. The percentage of the latter is shown as red bars. With the exception of the UAS-Msn construct, all constructs were derived from homozygous fathers, such that all embryos had both the Twist-Gal4 construct and the UAS construct. In the case of UAS-Msn, only half of the embryos carry both constructs. (B) Examples of the phenotypes scored in panel A. Each set of three images depicts the same embryo in a ventral midsagittal section, a ventral surface view, and a lateral midsagittal section. An early stage (top photographs, representative of column 2 in the graph above) and a late stage (bottom photographs, representative of column 3) are shown for each genotype.