Figure 1. Expression of
gpb-1. (A-G and L) Immunolocalization of anti-GPB-1 antiserum in wild-type animals. Shown are the following: 2-cell embryo, with staining concentrated at the region between the cells (A); 4-cell embryo (B); 12-cell embryo (C); 20-cell embryo (D); cleavage stage, about 200 cells (E); and a comma-stage embryo (F). In (A)-(F), staining is at the cell membrane and appears equally intense in all cells. In (B), (C), and (D), arrowheads mark staining that colocalizes with the asters.(G) L2 larva. Staining is brightest in neuronal cells. Green arrow, ventral nerve cord; green arrowhead, dorsal nerve cord; white arrow, gonad. The circumpharyngeal nerve ring, which also shows strong staining, is out of this focal plane.(L) A portion of the meiotic germline syncytium in a distal gonadal arm of a wild-type hermaphrodite. GPB-1 (green) is found at the membrane of developing gametes. Red staining shows P granules, a germline-specific marker used as a control.(H, I, and M) Rescued
gpb-1(
pk44 df); pkEx179 animals.(H) 20-cell embryo, showing weaker staining than wild-type (compare with [A]-[E]).(I) Comma-stage embryo with wild-type level of staining (compare with [F]).(M) Germline from adult hermaphrodite, most of whose progeny lived; staining is weaker than wild-type (compare with [L]).(J, K, N, and O)
gpb-1(
pk44 df); pkEx179 probable mosaic animals.(J) and (K) show a 4-cell and a 200-cell embryo, respectively, laid by
gpb-1(
pk44 df); pkEx179 probable germline mosaic mother, all of whose progeny died. There is no detectable GPB-1 staining in these embryos. The images were made very bright to show that there is no membrane-associated staining. The embryos were costained with an anti-P granule antibody as a control for permeability.(N and O) Probable mosaic germlines from
gpb-1(
pk44 df); pkEx179 mothers (all progeny from these mothers died as embryos). Staining is undetectable in (N) and very weak in (O). In (L)-(O), GPB-1 is green and P granules are red.All pictures are single-plane confocal images. Merging and false color in (L)-(O) was added using Adobe Photoshop software.