Figure 7

Embryonic expression patterns of Sp genes in Folsomia candida. (a, b) Expression of the Sp1-4 representative at early germ band retraction (a) and beginning dorsal extension (b). (c-e) Expression of the Sp5/btd representative at mid germ band extension (c), late germ band extension (d, note that the anterior head has been lost during preparation), and early germ band retraction (e). The arrowheads in c-d point to metameric stripes. The arrows in d, e point to expression in the developing ventral nervous system. (f-i) Expression of the Sp6-9 representative at early germ band extension (f), mid germ band extension (g), and late germ band retraction (h). The asterisks in f denote expression in the limb buds of the maxillary and labial segment. The arrowheads in f-h point to expression spots in the brain and neural tissue of the head segments. The arrow in h points to punctate expression in the developing ventral nerve cord. (i) shows dissected legs of an embryo after dorsal closure. Note that the first thoracic leg has been damaged during preparation. Anterior is to the left in panels a-h. All panels show ventral aspects except for b, f, g which are lateral views. In i distal is to the right. Abbreviations see Fig. 4. Additional abbreviations: an, antennal segment/appendage; lr, labrum; ic, intercalary segment.