Picture from Browning H et al. (1996) Development "A sperm-supplied factor required for embryogenesis in C. elegans."
Figure 6. Immunofluorescence analyses of SPE-11 localization during spermatogenesis. In each confocal micrograph (A,C,D) spermatogenesis proceeds from left to right. SPE-11 is stained with affinity purified antiserum to SPE-11, DNA is stained with propidium iodide or 4, 6 diamidino-2-phenylindole (DAPI), andnuclear envelopes are stained with a monoclonal antibody (mAb414) to nuclear pore complex (NPC) proteins (Davis and Blobel, 1986). Scale bar, 10 µm. (A) Confocal images of a wild-type male gonad double labeled with antiserum to SPE-11 and propidium iodide. Each micrograph is the projection of a Z series containing seven sequential focal planes including approximately half the gonad thickness. SPE-11 first appears as dots in the nuclei of primary spermatocytes. The dots appear to coalesce before the first meiotic division. During the first and second meiotic divisions, SPE-11 is diffuse throughout the cells (bracket). SPE-11 is localized in a ring around the nuclei of sperm. (B) Conventional epifluorescence micrographs of sperm double labeled with antiserum to SPE-11 and DAPI. SPE-11 is perinuclear in sperm. Inset: Four spermatids attached to a single residual body. Some staining is detectable in the residual body. (C) Confocal images of primary spermatocytes double labeled with antiserum to SPE-11 and propidium iodide. The micrographs are projections of a Z series that includes the entire depth of the tissue. As the DNA becomes condensed in preparation for the first meiotic division, SPE-11 forms a fenestrated ring around the DNA. As discrete chromosomes become visible, SPE-11 relocalizes throughout the nucleus and is sometimes localized between the chromosomes. (This is also evident from analysis of individual focal planes; data not shown.) (D) Confocal images of primary spermatocytes double labeled with antiserum to SPE-11 and NPC antibodies. The micrographs are projections of a Z series that include the entire depth of the tissue. A merge of the NPC and SPE-11 projections demonstrates that the dynamic relocalization that SPE-11 undergoes in primary spermatocytes occurs within the nucleus. Spermatogenesis proceeds from left to right, with the exception of a few sperm (small rings stained with antiserum to SPE-11) in the upper left portion of the micrographs. There is no detectable staining of these sperm with the NPC antibody.