Figure 3

Posterior localization of ApVas1 during cellularization of the syncytial blastoderm. Staining with ApVas1 antibody was performed on eggs collected within 16 to 28 hAEL. Embryo presented in (D) was hybridized with the Apvas1 antisense riboprobe. Status of cellularization was monitored by the expression of the polymerized F-actin using an anti-actin antibody. Anterior of egg chamber is to the left. Bacteria (b) are located in the posteriormost region of the eggs. (A-A”) Eggs collected during 16 to 24 hAEL. Actin caps (dashed circle) were visualized. In (A), localization of ApVas1 remained in the posterior cortex, forming a stripe anterior to the bacteria. (A’) is a magnification of the inset in (A): expression of ApVas1 was identified in the cytoplasm associated with the energid nuclei. (A”) Schematic illustration of ApVas1 expression shown in (A) and (A’). (B-D) Eggs collected during 24 to 28 hAEL. In (B), localization of ApVas1 remained in the egg posterior. (B’) is a magnification of the inset shown in (B): F-actin was located at the inner periphery of the forming cell membrane. (B”) Schematic illustration of ApVas1 expression shown in (B) and (B’). Embryos in (C) and (C’) belong to the same preparation but are shown at different focal planes. In (C), where the focal plane was internal, activity of F-actin was not detected; however, F-actin expression was detected in the cortex region shown in (C’). (C”) is a magnification of the inset shown in (C’): the intensity of ApVas1 and F-actin, in contrast to (B’), is increased. This suggests that the embryo in (C) is more mature than that in (B). (D) Posterior localization of Apvas1 mRNA. Transcripts of Apvas1 were restricted within a cortical stripe in the posterior region of the egg. Brackets in (C’) and (D) highlight locations of ApVas1/Apvas1 enrichment. Scale bars: 100 μm.