Figure 6.

Expression of D-stathmin during embryonic development. The orientation is anterior to the left and dorsal to the top. (A–I) Sagittal (A and B, D and E, and G and H) and cross-section (C, F, and I) in situ hybridization views of D-stathmin mRNA distribution at successive stages of Drosophila embryonic development. Strong expression of D-stathmin mRNA in a stage 4 embryo (A). In the gastrulating embryo (B) D-stathmin expression is restricted to the migrating pole cells and at stage 9 (C) to pole cells in the posterior midgut. At stages 12 (D) and 13 (E and F, same embryo) D-stathmin starts to be expressed in the developing CNS (white arrowhead) and is still expressed in the migrating pole cells (black arrowhead). At stage 14 (G and H, two optical sagittal sections; and I, cross section of the same embryo) D-stathmin is expressed in the pole cells within the already formed gonads (black arrowhead) as well as in the CNS, and starts to be expressed in the developing peripheral nervous system (asterisk). (J–Q) Immunohistochemical distribution of D-stathmin protein at successive stages of embryonic development. At stage 4 (J) D-stathmin is evenly distributed throughout the embryo, but starts to accumulate in the forming pole cells where it becomes restricted at stage 10 (K). At stage 12 (L–P) it is present in migrating pole cells and begins to be expressed in the developing CNS, as best visualized on the ventral view of a dissected embryo (M, and at higher magnification N). At stage 14 (O–Q) expression in the CNS and in the pole cells is illustrated in a sagittal optical section (O) and a ventral view of a dissected embryo (P). Expression in the peripheral nervous system becomes also clearly visible, as shown in a lateral confocal section (Q) in the chordotonal organs (white arrowhead).