Fig. 1

Schematic comparison of extra-embryonic tissues in dipteran insects. In A. gambiae (Culicidae), embryo (yellow) is surrounded by two extra-embryonic membranes, amnio (blue) and serosa (red). In lower cyclorraphan flies, as M. abdita (Phoridae), the serosa still covers the whole embryo, but the amnio is located dorsally. In higher cyclorraphan flies, like M. domestica or D. melanogaster, a unique tissue, the amnioserosa (dark blue), is develop in the dorsal domain of the embryo