Picture from Maruyama R et al. (2007) Curr Biol "EGG-3 regulates cell-surface and cortex rearrangements during egg activation ...."

GFP:EGG-3 Is Associated with Oocyte Membranes.(A) GFP:EGG-3 is associated with oocyte plasma membranes and formed foci after fertilization. Arrowheads indicate foci.(B) mCherry:EGG-3 leaves membranes and forms foci from anaphase I. meta I, metaphase I; ana I, anaphase I; magenta, mCherry:EGG-3; green, GFP:histone.Scale bars represent 10 um.

Picture from Speliotes EK et al. (2000) Mol Cell "The survivin-like C. elegans BIR-1 protein acts with the Aurora-like kinase ...."

Figure 2. BIR-1 Localizes to Chromosomes and to the Spindle Midzone during Mitosis and Meiosis. Wild-type fertilized oocytes, embryos, and worms were stained with anti-BIR-1 antibody, anti-a-tubulin antibody, and DAPI to visualize BIR-1 (green), a-tubulin (red), and DNA (blue), respectively.(A) One-cell embryos in different stages of mitosis.(B) Oocyte most proximal to spermatheca (OOCYTE) and spermatocytes in hermaphrodite gonad (SPERM). Female meiosis occurring at the anterior of the fertilized oocyte: metaphase I (META I), anaphase I (ANA I), metaphase II (META II), or anaphase II (ANA II). Arrows indicate BIR-1-positive structures. Closed arrowheads, chromosomes (chr); long arrows, spindle midzone (smz); short arrow, cytokinetic remnant (rem); open arrowheads, polar bodies (pb). Mitosis, SPERM (and OOCYTE) scale bars, 20 um. Meiosis scale bar, 5 um.

Picture from Lee KK et al. (2000) Mol Biol Cell "C. elegans nuclear envelope proteins emerin, MAN1, lamin, and nucleoporins ...."

Immunofluorescence localization of Ce-lamin at different stages of mitosis in 2- to 24-cell C. elegans embryos (A) and 30-cell C. elegans embryos (B). Embryos were doubly stained for DNA with the use of Hoechst 33258 (D) and by indirect immunofluorescence (IF) with the use of antibodies specific for Ce-lamin. A representative nucleus from each stage is shown: INT, interphase; PRO, prophase; PROM, prometaphase; META, metaphase; ANA, anaphase; and TELO, telophase.

Picture from Maruyama R et al. (2007) Curr Biol "EGG-3 regulates cell-surface and cortex rearrangements during egg activation ...."

Figure 2. GFP:EGG-3 Is Associated with Oocyte Membranes and Its Localization Is Dependent on chs-1.(A) GFP:EGG-3 is associated with oocyte plasma membranes and formed foci after fertilization. The bulk of GFP:EGG-3 is cytoplasmic in chs-1(ok1120) mutants. Arrowheads indicate foci.(B) mCherry:EGG-3 leaves membranes and forms foci from anaphase I. meta I, metaphase I; ana I, anaphase I; magenta, mCherry:EGG-3; green, GFP:histone.Scale bars represent 10 um.

Picture from Lee KK et al. (2000) Mol Biol Cell "C. elegans nuclear envelope proteins emerin, MAN1, lamin, and nucleoporins ...."

Immunofluorescence localization of Ce-emerin at different stages of mitosis in 2- to 24-cell C. elegans embryos (A) and 30-cell C. elegans embryos (B). Embryos were doubly stained for DNA with the use of Hoechst 33258 (D) and by indirect immunofluorescence (IF) with the use of antibodies specific for Ce-emerin. A representative nucleus from each stage is shown: INT, interphase; PRO, prophase; PROM, prometaphase; META, metaphase; ANA, anaphase; and TELO, telophase. All Ce-emerin immunofluorescence images were obtained by confocal microscopy.

Picture from Hagstrom KA et al. (2002) Genes Dev "C. elegans condensin promotes mitotic chromosome architecture, centromere ...."

Figure 7. SMC-4 and MIX-1 co-localize with centromere proteins on meiotic chromosomes, and their depletion impairs chromosome segregation in meiosis II but not meiosis I. (A-D) Meiosis I bivalents stained with a DNA dye (blue, A), SMC-4 antibody (green, B), and an antibody to centromere protein HCP-3 (red, C). SMC-4 is concentrated at the periphery of the chromosomes and colocalizes with HCP-3. (D) SMC-4 and HCP-3 overlap (yellow). (E-H) Images of anaphase I (ana I) and anaphase II (ana II) from time-lapse movies of meiosis in a strain carrying histone H2-GFP. Normal segregation of homologs at anaphase of meiosis I is observed in wild-type (E) and smc-4(RNAi) embryos (F). Sister chromatids separate normally at anaphase of meiosis II in wild-type embryos (G; PB1 is first polar body from meiosis I), but anaphase II chromatin bridges are observed in smc-4(RNAi) embryos (H; PB1 is out of focus). (I-J) DNA-stained wild-type (I) and smc-4(RNAi) (J) embryos after formation of the first and second polar bodies (PB1 and PB2) and migration and fusion of the oocyte (O) and sperm (S) pronuclei. In smc-4(RNAi) embryos, the oocyte pronucleus remains connected to the second polar body by a long chromatin bridge; condensation of prophase chromosomes in the pronuclei is abnormal (J).

Picture from Lee KK et al. (2000) Mol Biol Cell "C. elegans nuclear envelope proteins emerin, MAN1, lamin, and nucleoporins ...."

Figure 5. Immunofluorescence localization of endogenous nuclear envelope proteins at different stages of mitosis in 2- to 24-cell C. elegans embryos (A) and 30-cell C. elegans embryos (B). Embryos were doubly stained for DNA with the use of Hoechst 33258 (D) and by indirect immunofluorescence (IF) with the use of antibodies specific for nuclear pore complexes (mAb414; Nups), Ce-lamin, Ce-emerin, or Ce-MAN1. A representative nucleus from each stage is shown: INT, interphase; PRO, prophase; PROM, prometaphase; META, metaphase; ANA, anaphase; and TELO, telophase. All Ce-emerin immunofluorescence images, plus the panel showing nucleoporin metaphase staining in early embryos and most Ce-MAN1 early embryo images, were obtained by confocal microscopy; all others were imaged by fluorescence microscopy.

Picture from Nakamura K et al. (2005) Genes Dev "Wnt signaling drives WRM-1/beta-catenin asymmetries in early C. elegans ...."

Figure 2. Cell cycle-dependent asymmetric localization of WRM-1::GFP. (A,B) Nomarski (left columns) and fluorescence micrographs (right columns) of wild-type WRM-1::GFP transgenic animals taken during EMS and ABal cell divisions. (Top panels) White arrowheads indicate the faint, initially similar levels of WRM-1::GFP in early telophase nuclei. Double-headed arrows indicate the nuclei of anterior and posterior sisters. White arrows indicate the cortical localization of WRM-1::GFP. Black arrows indicate the corresponding structures in each Nomarski image. In this and subsequent figures, the bars indicate 10 μm and anterior is to the left. (C,D) Graphic depictions of the temperature-sensitive (ts) periods for gut induction in mom-2(ne874) (C) and wrm-1(ne1982ts) (D). The embryos were either up-shifted (black squares or circles) or down-shifted (white squares or circles) at the indicated cell stage (X-axis), and incubated further to score for gut induction (Y-axis). Shifts were done at two times during the EMS cell cycle: metaphase/anaphase (meta-ana) and telophase (as indicated).

Picture from Davison EM et al. (2011) Genetics "The LIN-15A and LIN-56 transcriptional regulators interact to negatively ...."

Figure 2. LIN-56 is broadly expressed and localized to nuclei. (A) Immunoblot of wild-type and lin-56(n2728) protein extracts probed with anti-LIN-56 antibodies. The arrow indicates the band that corresponds to LIN-56. Molecular weights of marker proteins are indicated at left in kilodaltons. (B-E) Whole-mount staining with anti-LIN-56 antibodies (red), DAPI (blue), and either anti-tubulin antibody (green) in embryos or MH27 antibody (green) in larvae as a fixation control. Scale bars, 5 um. Anterior is to the left in all images. pb, polar body. (B and C) LIN-56 staining is observed in the nuclei of most if not all cells throughout embryonic development. Shown are (B) four-cell and (C) late-stage wild-type embryos. (D) Nuclear staining is never observed with anti-LIN-56 antisera in lin-56(n2728) animals. Shown is a four-cell lin-56(n2728) embryo. (E) LIN-56 is present in the P(3-8).p vulval equivalence group and in their descendants during wild-type vulval development. Shown is the midbody of a wild-type L2 larva. Arrowheads point to nuclei of P(3-8).p. MH27 stains the apical borders between the Pn.p cells. (F and G) LIN-56 does not colocalize with chromatin during metaphase or anaphase. F and G show two-cell wild-type embryos. ana, anaphase; meta, metaphase; pro, prophase; telo, telophase.

Picture from Romero-Aranda C et al. (2024) MicroPubl Biol "Integrator complex subunit 6 (INTS-6) mediates DNA damage response in ...."

Figure 1. Integrator complex subunit 6 (INTS-6) mediates DNA damage response in Caenorhabditis elegans: (A) INTS-6-associated proteins identified by anti-FLAG affinity purification. In addition to members of the Integrator complex, other proteins were immunoprecipitated along with INTS-6::3xFLAG::GFP, including some related to DNA damage response, such as LAF-1 and NABP-1 (adapted from Gomez-Orte et al., 2019).(B) Immunofluorescence images of RAD-51 foci formed after ionizing radiation. ints-6 knockdown impairs RAD-51 recruitment to DSBs following IR. As shown in the pictures, there are no RAD-51 foci before IR, either in worms fed the L4440 bacterial RNAi clone (panel 1, 5, 9) or fed the ints-6 bacterial RNAi clone (panel 2, 6, 10). Following irradiation, RAD-51 foci can be observed in the gonads of worms treated with the L4440 bacterial RNAi clone (panel 3, 7, 11) but no RAD-51 foci are observed in the mitotic region of gonads of worms treated with the bacterial RNAi clone of ints-6 (panel 4, 8, 12). Scale bar: 10 μm.Immunofluorescence images of phosphorylated CDK-1. ints-6 knockdown abrogates Tyr15 CDK-1 phosphorylation in response to DNA damage. Tyr15 CDK-1 phosphorylation was detected in the nuclei of control gonads after irradiation (panel 15,19,23). However, in the gonads of worms knocked down for ints-6, phosphorylation of Tyr15 CDK-1 following IR was not detected (panel 16, 20, 24). Scale bar: 10 μm.(C) Proposed model. Upon the occurrence of a double strand break in DNA, the MRN complex together with ATM senses it. MRN then activates ATM triggering the DNA damage response pathway. One of the targets of ATM is hSSB1, which is phosphorylated and mobilized to the site of damage. It interacts directly with MRN complex stimulating its recruitment to the break site. The DNA end resection is then initiated, creating single stranded DNA overhangs. Based on our results and others previously published, we believe that at this point INTS-6 acts. These ssDNA ends are then coated with the RPA protein. Finally, RPA is replaced by RAD-51 and the resulting RAD-51 coated filament performs homology search and strand invasion, allowing DNA synthesis at the resected strand and subsequent repair.