Figure 6.

(A–C) Three mAbs specific for nucleolar proteins were injected into the cytoplasm of CHX-treated oocytes: mAb No114 against Nopp140, mAb No63 against NO38/B23, and mAb b7–6E7 against nucleolin. After 18 h, GV spreads were prepared for staining with Cy3-conjugated goat anti-mouse antibody. All three antibodies were readily detectable, indicating that their corresponding antigens shuttle. mAb No114 (A) localized in the dense fibrillar component of nucleoli and in the matrix of coiled bodies (arrowhead). In contrast, mAbs No63 (B) and b7–6E7 (C) were distributed uniformly in nucleoli but were absent from the coiled bodies. (D) An antibody against the splicing factor SC35 was not detected in GV spreads after cytoplasmic injection, suggesting that SC35 does not shuttle in the oocyte. As expected, when injected into the GV, the antibody was detected in B-snurposomes and the matrix of coiled bodies (arrowhead) but not in nucleoli (arrow).