Figure 7. Germline expression of histone H1.1::GFP in hermaphrodites (A) and males (C). In addition to many somatic nuclei, germ nuclei of any state of the adult hermaphrodite (A, arrow points to the distal end of the gonad) and germ nuclei of any state of the male (C, arrow points to the distal end of the gonad) show intense GFP fluorescence. (B,D) The corresponding Nomarski micrographs. Gut autofluorescence is visible in A,C. The weak H1.1::GFP fluorescence of oocytes (A) and sperm (B) is not represented in the photographic reproduction but was clearly detected during the observation. Scale bar: 20 um.
Figure 3. Indirect immunofluorescence detection of histone H1. (A) Four-cell stage embryo (arrow points to the P-cell; (B) corresponding Nomarski micrograph. (C) Male gonad (arrowheads point (from top to bottom) to sperm, spermatocytes, and to the transition zone, (D) shows the Hoechst DNA staining. Scale bars: 20 um.
Figure 5. The expression of histone H1.X::GFP in head neurons and marginal cells (A) as well as in an excretory channel cell (C). H1.X::GFP is a cytoplasmic protein in both cell types. The neuronal projections are visualized by H1.X::GFP fluorescence. (B,D) are the corresponding Nomarski micrographs. Bars, 20 um.
Figure 2. H1.X detection in the marginal cells of the C. elegans pharynx. (A) represents an antibody labeling performed with anti-H1.X-11; (B) represents the corresponding Nomarski micrograph. (C) represents an antibody labeling performed with anti-H1.X-101. (D) shows H1.X::GFP expression in the marginal cells in a view lateral to the flat cell bodies. Here the tonofilaments are viewed in lateral orientation. (E) is the corresponding Nomarski micrograph. (F) shows H1.X::GFP expression in the marginal cells in an optical cross-section of the flat cell bodies. Here the tonofilaments appear in axial orientation as bright green fluorescent dots. H1.X::GFP shows a cytoplasmic as well as a nuclear localization (arrows point to the nuclei) of the fusion protein. Bar, 20 um.
Figure 6. Nucleolar localization of H1.X (A) shows a Nomarski micrograph of the nuclear region of a polyploid gut cell in a hermaphrodite C. elegans with the nucleolus and its substructures visualized by differential interference contrast. (B) H1.X detected with the antibody anti-H1.X-101 localizes to the nucleolus; (C) corresponds to DAPI DNA staining; and (D) shows the indirect immunfluorescence detection of the nucleolar protein fibrillarin with the specific monoclonal antibody P2G3 (from M. Christensen). Bar, 10 um.
Figure 4. The expression of histone H1.X::GFP in C. elegans body muscle cells (A,C) and in the vulva muscle cells (E). H1.X::GFP is prominently localized in the cytoplasm but also enriched in the nuclei. (B,D,F) represent the corresponding Nomarski micrographs. The arrows points to individual body-wall muscle cells and the nuclei therein and to the vulva opening. Bars, 20 um.
Fig. 7. Embryonic expression and subnuclear localization of H1.X. (A,B) show H1.X::GFP fluorescence detection in a few cells in the periphery of a >100-cell stage embryos. In (A), a fixed specimen shows a shallow fluorescence of the nucleoplasm and bright fluorescence of the nucleoli, whereas in (B), a live observation shows a shallow fluorescence in the cytoplasm and a bright fluorescence of the nucleoplasm. The brightest spots in the nucleoplasm correspond to the nucleoli. Bars, 20 μm.
(A) The expression of maIs138[mir-84p::GFP], stIs11748 [tag-97::H1-wCherry], and zwEx113[inx-13p::GFP] in ALM and PLM neurons from wild-type, egl-5mutants, and animals carrying a mec-17p::egl-5 transgene. The scale bars represent 10 um.
Figure 8. Expression of H1.X::GFP in living (A) and in formaldehyde-fixed HeLa cells (C). The nucleoli are prominently fluorescent in the fixed and extracted cells, whereas in living cells the whole nucleoplasm fluoresces. The brightest spots in the nucleoplasm of the living cells correspond to the nucleoli. (B,D) represent the corresponding Nomarski micrographs. Bars, 10 um.
Figure S4. CYY-1 can activate CDK-5 and Subcellular localization of PCT-1, CYY-1, CDK-5, and CDKA-1/p35, related to Figure 4. (A) C. elegans CDK-5-HA and CYY-1-FLAG were co-expressed in HEK 293T cells as indicated. Expression of CDK-5 alone exhibits no kinase activity, while co-expression with CYY-1 significantly increases the kinase activity of CDK-5. Lysate was immunoprecipitated with HA antibody and then subjected to kinase assay using Histone H1 protein as a substrate.