Picture from Lee KK et al. (2002) Mol Biol Cell "Lamin-dependent localization of UNC-84, a protein required for nuclear ...."

Figure 6. UNC-84 localization during mitosis. Wild-type embryos (100-300 cells) were stained with rat anti-UNC-84 antibodies (right panels) and Hoechst 33258 to stain DNA (left panels), viewed by fluorescence microscopy and photographed at different stages of the cell cycle. A representative nucleus from each stage is shown: IP, interphase; EP, early prophase; LP, late prophase; PM, prometaphase; MT, metaphase; EA, early anaphase; LA, late anaphase and TL, telophase. Nuclear staining was detected in all stages of mitosis except late anaphase, consistent with other nuclear membrane markers (Lee et al., 2000).

Picture from Ronald Ellis et al. (2007) WormBook "Sex determination in the germ line."

Figure 4. An early point following the switch from hermaphrodite spermatogenesis to oogenesis. In situ hybridization of the rme-2 yolk receptor mRNA to a dissected L4 hermaphrodite gonad: left, DIC image with rme-2 staining in purple; right, fluorescence microscopy image of DAPI staining to visualize chromosome morphology; distal tip on the lower left. Shown are the meiotic prophase stages leptotene and zygotene (indicated 'trans' for transition zone) as well as pachytene. Germ cells in the proximal end of the gonad are undergoing spermatogenesis and do not express the rme-2 yolk receptor mRNA. Germ cells located just distally, from the transition zone to the loop (bend in gonad) are undergoing oogenesis and express rme-2 mRNA (M. H. Lee and T. Schedl, unpublished results). Thus, at this time point, there are both male and female pachytene stage germ cells.

Picture from Siete C et al. (2024) MicroPubl Biol "Immobilization of C. elegans with different concentrations of an ...."

Figure 1. Comparison of axonal transport of TIR-1:GFP in AWC axons of worms immobilized with different concentrations of tetramisole and polystyrene microbeads:(A) Representative kymographs of moving TIR-1::GFP in AWC axons of worms immobilized with 0.5-7.5 mM tetramisole (Tet) or microbeads. The line within two blue arrowheads represents a retrograde trafficking event toward the proximal axon (P) or the ­­­­­AWC cell body; the line between two red arrowheads represents an anterograde trafficking event toward the distal (D) axon. (B) The percentage of anterograde and retrograde trafficking events. The average number of trafficking events per animal imaged is 19 (0.5 mM Tet), 24 (1 mM Tet), 21 (2 mM Tet), 19 (7.5 mM Tet), and 13 (microbeads). Z-test was used to determine p-values. Error bars, SE of proportion. ns, not significant. (C) The average velocity of anterograde and retrograde trafficking events. Red and blue lines indicate the comparison of anterograde and retrograde velocities, respectively. Student's t-test was used to determine p-values. Error bars, SEM. ns, not significant. The significance level 0.01 was adjusted to 0.0025 (0.01/4) using the Bonferroni method (Chen, Feng, & Yi, 2017) in (B) and (C).

Picture from Olahova M et al. (2008) Proc Natl Acad Sci U S A "A redox-sensitive peroxiredoxin that is important for longevity has tissue- and ...."

Fig. S7. PRDX-2 is widely expressed during embryogenesis and in multiple tissues postembryonically. Immunostaining with anti-PRDX-2 antibodies of wild-type (N2) embryos (A), an extruded gonad dissected from an adult hermaphrodite (B), and larvae (C and D) revealed that PRDX-2 is expressed during embryogenesis (A) and postembryonically in the gonad (the mitotic region is indicated) (B), neurons (C), and intestine (D). Comparisons with DAPI-stained DNA (A and D) suggest that PRDX-2 is excluded from the nucleus. Consistent with its activity as a thioredoxin peroxidase, PRDX-2-immunostaining produced a punctate staining pattern in intestinal cells similar to the localization of thioredoxin [Jee C, Vanoaica L, Lee J, Park BJ, Ahnn J (2005) Thioredoxin is related to life span regulation and oxidative stress response in Caenorhabditis elegans. Genes Cells 10:1203-1210]. Differential interference contrast light images (DIC) are also shown.

Picture from Chisnell P et al. (2018) MicroPubl Biol "Silencing the ASI gustatory neuron pair extends lifespan"

Disrupting the function of sensory neurons of C. elegans can increase their lifespan (Apeld and Kenyon 1999). This effect is not limited to large-scale disruption, as ablation of single pairs of neurons have been shown to modify lifespan (Alcedo and Kenyon 2004; Lee and Kenyon 2009; Liu and Cai 2013). We tested whether silencing the neuron pair ASI with the tetanus toxin light chain (Tetx), as opposed to ablating it, could increase lifespan. Tetanus toxin disrupts neurotransmission by blocking the release of both small clear-core vesicles and large dense-core vesicles, but should not affect communication via gap junctions (Schiavo et al. 1992; McMahon et al. 1992). We expressed GFP::Tetx using the ASI-specific promoter pgpa-4 (Figure Panel A) and conducted lifespan assays comparing animals with high fluorescence and undetectable fluorescence. Tetx in ASI extended lifespan in otherwise wild-type animals (Figure Panel B, Table 1, 14.9% average median lifespan increase across 5 replicates).

Picture from Hyun M et al. (2016) Genetics "BLIMP-1/BLMP-1 and Metastasis Associated Protein (MTA1) Regulate Stress ...."

Figure 1 The levels of BLMP-1 during development and the growth rate and lethality of blmp-1 mutants. (A and B) The levels of blmp-1 mRNA measured by qPCR (A) and BLMP-1 protein measured by Western blot analysis (B) are highest at L2 stage compared to other stages in wild-type C. elegans. In A, the values are average 6 SEM of three independent experiments. Em, embryos;YA, young adults. In B, actin is shown as a loading control. (C) The numbers of wild-type animals and blmp-1 mutants in different development stages (L2, L3, L4, and dead) were counted at 48 hr from egg hatching to yield the fraction of each stage and the death rate. blmp-1 mutants show more L2/L3 stages and dead worms compared to wildtype animals. (D) Growth rates of wild-type animals and blmp-1 mutants. Starting at 43 hr after hatching, the numbers of adult worms were counted every hour until 100% became adults (Lee et al. 2012; Wang et al. 2015). blmp-1 mutants showed grossly normal grow rate.

Picture from Kim J et al. (2017) MicroPubl Biol "A quantitative trait locus for nictation behavior on chromosome V"

Lee et al., 2017 showed that CB4856 has a lower nictation ratio (the number of nictating dauers over the number of moving dauers on a micro-dirt chip) than N2, and that a genetic locus (nict-1) on chromosome IV mediates this phenotype difference. Although this paper had no evidence of any other genetic loci for nictation behavior, we have studied other quantitative trait loci (QTL) using different linkage-based mapping strategies. Here, we report another genetic locus that was identified using introgression lines on chromosome V. N2 x CB4856 introgression lines were tested using a population nictation assay (Lee et al., 2015). We measured the nictation ratios of the ewIR65, ewIR67, ewIR68, and ewIR70 lines, which contain N2-type genome in all chromosomes except for CB4856-type chromosome V segments (Figure 1A). Among them, only ewIR70 line showed significant lower nictation ratio. Therefore, we narrowed down the chromosome V right region. We also measured nictation ratios of ysIR50, ewIR74, and ysIR51 lines (Figure 1B). ysIR50 and ysIR51 were derived from N2 x ewIR70. ysIR50, ewIR74, and ysIR51 lines showed significantly lower nictation ratios than that of N2. Because the putatively responsible QTL region is covered by another near-isogenic region, eanIR158, which was made independently by Erik Andersen's laboratory, we measured the nictation ratios of eanIR158 and jyIR3 lines and found that they did not show any significant difference from N2 (Figure 1C). eanIR158 and jyIR3 lines were built with QX1430 x N2 (personal communication) and QX217 x N2 (Balla et al., 2015), respectively, and QX1430 and QX217 were made by Leonid Kruglyak's laboratory (Andersen et al., 2015; Rockmen and Kruglyak, 2009). However, ewIR70 and ewIR74 were built by Jan Kammenga's laboratory (Doroszuk et al., 2009). Thus, we concluded that the two laboratories may have used different N2 or CB4856 strain derivatives, which may have altered genetic variations in the introgression lines. A take-home lesson is that it is important to examine NILs derived from common original strains in order to follow QTL without being affected by differences in background genotypes. Jan Kammenga kindly provided their N2 x CB4856 introgression lines for chromosome V, which include ewIR65, ewIR67, ewIR68, ewIR70, and ewIR74, and Erik Andersen also gave us many introgression lines, which include eanIR158 and jyIR3 covering 15-19 Mb of chromosome V. We appreciate their help.

Picture from Wang, Ying et al. (2020) MicroPubl Biol

(A) Photograph of the head of a transgenic animal expressing GFP under the control the promoter of delm-2(Pdelm-2::GFP) (front is to the left). (B) same as in (A) for a delm-1 mutant expressing AgTRPA1 under the control of Pdelm-2 (delm-1;Pdelm-2::AgTRPA1;Pdelm-2::GFP). delm-2 is expressed in OLQ and IL socket glia (Han et al., 2013). (C) Schematic representation of a OLQ or IL socket glia in the indicated genetic backgrounds. In animals expressing AgTRPA1 in socket glia, influx of cations is present only at temperatures above 27°C due to the temperature sensitivity of AgTRPA1. WT is N2. (D) Ratios of responses (responses/total number of trials, labelled on the Y axis as "responses/tot trials") assayed at 22°C for wild type animals (N2, 0.770 ± 0.042, n = 20), trpa-1(ok999) (0.210 ± 0.042, n = 20), delm-1(ok1226) (0.250 ± 0.035, n = 20), and delm-1 expressing mosquito TRPA1 (AgTRPA1) in OLQ and IL1 socket glia (delm-1(ok1226);Pdelm-2::AgTRPA1, 0.270 ± 0.036, n = 20). (E) Ratios of responses assayed at 28C for wild type animals (N2, 0.6480 ± 0.026, n = 50), trpa-1(ok999) (0.228 ± 0.024, n = 50), delm-1(ok1226) (0.248 ± 0.025, n = 50), and delm-1 expressing mosquito TRPA1 (AgTRPA1) in OLQ and IL1 socket glia (delm-1(ok1226);Pdelm-2::AgTRPA1, 0.624 ± 0.025, n = 50). Data are expressed as means ± SE, ****p<0.0001 by ANOVA with Bonferroni correction.

Picture from Rollins J et al. (2017) MicroPubl Biol "Loss of eif-2alpha phosphorylation on S49 (mammalian S51) associated with the ...."

The gene eif-2alpha (Y37E3.10) in C. elegans encodes for the alpha subunit of eukaryotic translation initiation factor 2 (eIF2). The eIF2 trimer is required for delivering charged tRNAMet to the ribosome in a reaction requiring the hydrolysis of GTP to GDP (Sokabe et al., 2012). The phosphorylation of eif2-alpha on its 49th serine residue (Nukazuka et al., 2008) prevents replenishing GDP with GTP and thus reduces translation initiation by preventing delivery of tRNAMet. The phosphorylation of the mammalian ortholog of eif-2alpha occurs on serine 51 in response to a variety of stresses (Taniuchi et al., 2016) including: osmotic stress, ultraviolet light, cold shock, oxidative stress, heat shock, anoxia, and serum starvation. In C. elegans, the phosphorylation of eif-2alpha has shown to increase in response to ER stress (Howard et al., 2016; Richardson et al., 2011), osmotic stress (Lee and Strange, 2012), and uncharged tRNAs (Rousakis et al., 2013). This is thought to promote survival by reducing translation in a way that also promotes longevity. Using CRISPR-cas9 genome engineering (Paix et al., 2015) we replaced serine 49 in eif-2alpha with alanine, which cannot be phosphorylated. The C. elegans line ANR165 harbors this engineered allele in the wild-type N2 background.The phosphorylation status of eif-2alpha in response to hypertonicity, heat, and oxidative stress was probed using an antibody specific to its phosphorylated form. Wild type N2 worms showed an increased in phosphorylated eif2-alpha in response to all stresses tested (Figure 1A, dotted box outlines P-eif2-alpha bands). Total protein is shown as a loading control. In comparison, phosphorylated eif-2alpha was not detectable in ANR165 treated with any of the stresses. This result confirms that serine 49 is the site of phosphorylation in eif-2alpha in response to salt stress and is a novel finding for heat and oxidative stress in C. elegans. In addition, eif2-alpha S49A mutants were viable, demonstrating that loss of eif-2alpha serine 49 phosphorylation is non-lethal. Furthermore, time to develop from egg to egg laying adult was significantly (Wilcoxon rank sum test, p < 0.01, n=15) shortened in eif2-alpha S49A mutants (Figure 1B) by a mean of 4 hours compared to N2. This result suggests that the phosphorylation status of eif2-alpha serves a role in development which may be related to its effect on translation. A role for eif2-alpha in development is not surprising as mutants expressing a phosphomemetic version of it in the ASI neurons were impaired in growth and development (Kulalert et al., 2017).

Picture from Dasgupta, Madhumanti et al. (2020) MicroPubl Biol

Figure 1. E. faecalis induces early larval arrest in C. elegans: (A) Images of C. elegans L1 larvae fed E. coli OP50 (Top) or E. faecalis OG1RF (Bottom) for 24 h, 48 h and 72 h. Scale bar, 100 um. (B) Mean +/- SEM of body length in populations of L1 larvae fed OP50 or OG1RF for 24 h, 48 h and 72 h. Reported length of L1, L2, L3 and L4 larvae is indicated on the right y axis. (C) Kaplan Meier survival curves for wild type animals fed on OG1RF and deltafsrB E. faecalis (TX5266). Also see Table 1. (D) Mean +/- SEM of body length in populations of L1 larvae fed OP50, OG1RF or TX5266 for 24 h, 48 h and 72 h. (E) Mean +/- SEM of body length in populations of 48 h starved, E. faecalis-fed and E. coli-fed larvae transferred to E. coli plates and measured at regular intervals of 12 hours. n=15-20 animals/ treatment/experiment in panels 1B, 1D and 1E where each point represents the mean of body length of a population of animals (N>3 experiments). *, p less than equal to 0.05; **, p less than equal to 0.01; ***, p less than equal to 0.001; ns-non-significant. In panel D, * indicates significance with respect to OP50-fed animals at the same time point. (F) (i) Cartoon showing vulval invariant cell lineages and morphogenesis in wild-type hermaphrodites (Burdine et al., 1998; Sulston and Horvitz, 1977; Cui and Han, 2003). At larval stage, L3, vulval precursor cells P(5-7).p adopt primary (1) or secondary (2) cell fates and undergo invariant cell divisions to produce 22 cells organized into toroids, VulA, vulB1, vulB2, vulC, vulD, vulE, and vulF, shown by A, B1, B2, C, D, E, and F cell types (Sharma-Kishore et al., 1999). Blue coloured oval cells indicate egl-17::cfp expression in specific lineages. (ii) Cartoon showing early L4 vulva, when egl-17::cfp is exclusively seen in granddaughters of P6.p (1), and mid-L4 stage, where the expression is shifted to 2 lineage cells, vulC and vulD. (iii) Merged DIC and fluorescence images showing stage specific egl-17::cfp in vulval cells. P6.p (1 cell stage/L2), P6.px (2 cell/midL3), P6.pxx (4 cell/mid to late L3), and P6.pxxx (8 cell/early L4 onwards), x denotes one round of mitotic division. Gonads are demarcated with white line. In all animals, anterior is to the left. Scale bar, 5 um. (G) Expression of egl-17::cfp in C. elegans L1 larvae fed OP50 or OG1RF for 20 h and 84 h. Duration of feeding on E. coli or E. faecalis are shown on X-axis and the bars represent % positive or negative egl-17::cfp in vulva cells. Numbers on the bars indicate the number of animals which are positive or negative for egl-17::cfp expression. Zero on top of blue bars indicate that there are no OP50-fed animals which do not show egl-17::cfp expression. (H) Confocal images of egl-17::cfp in C. elegans L1 larvae fed OP50 or OG1RF for 20 h and 84 h. White circles depict gonad primordium and yellow P6.p lineage. In all animals anterior is to the left. Scale bar, 5 um. (I) Scanning electron microscopy images of larvae fed OP50 for 4 h and fed OG1RF for 72 h. Arrow heads indicate alae. n= 25-30 animals/ treatment. Scale bar, 20 um.