Figure 1
Expression of ApVas1 in the oviparous ovarioles. Each ovariole is composed of a germarium plus 1 to 2 egg chambers accommodating the developing oocytes. Color keys that indicate staining signals of ApVas1, F-actin (Rhodamine Phalloidin), and nuclear DNA (DAPI) in the ovariole are highlighted under the figure. Anterior of egg chamber is to the left. (A) Detection of ApVas1 in vitro: western blot. On a membrane blotted with the ApVas1-4 fusion proteins, only ApVas 1 was detected by the ApVas1 antibody. On another membrane blotted with the total protein extracted from unfertilized eggs and fertilized eggs, ApVas1 antibody detected a major band with the expected molecular weight (62.8 kD, arrowhead) of ApVas1. This major band could not have been ApVas2 (75.7 kD) and ApVas3 (71.7 kD), but it was close to ApVas4 (61.65 kD). (B-E) Detection of ApVas1 in vivo: immunostaining. (B, C) Previtellogenic oocytes. Oocyte in (C), with longer egg length, was more mature than that shown in (B). Expression of ApVas1 was evenly distributed in the cytoplasm of nurse cells (in germaria) and oocytes. Nuclei of nurse cells and oocytes were devoid of staining. (D) Vitellogenic oocytes. Preferential expression of ApVas1 (arrowheads) was identified in both anterior and posterior regions of the egg. (E) Mature oocytes subjected to oviposition. Signals of ApVas1 were almost not detected. Invading bacterial endosymbionts (bacteria) were observed in the egg posterior. (F) Negative control. Antibody against ApVas1, the primary antibody, was not applied to staining. Abbreviations: b, bacteria; fc, follicle cells; Fer, fertilized eggs; g, germaria; gl, germarial lumen; kD, kilodalton; nc, nurse cells; nn, nurse-cell nuclei; o, oocytes; on, oocyte nuclei; Unfer, unfertilized eggs. Scale bars: 100 μm.