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Expr13209
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Because the fluorescence signal for the endogenously tagged GFP::TSP-12 in somatic cells is faint (Expr13208), we also generated integrated transgenic lines over-expressing a functional, C-terminally tagged TSP-12::GFP transgene. In these animals, we detected TSP-12::GFP in the pharynx, intestine, neurons and M lineage cells. |
The cell surface TSP-12::GFP in the intestinal cells appears to be restricted to the basolateral membrane but absent in the apical membrane. |
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Expr11887
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At the comma stage, during larval development, and in adult animals, mig-14 is mainly expressed in the posterior part of the animal. The expression of mig-14 overlaps with the known expression patterns of C. elegans Wnt genes. Thus, mig-14 is expressed in the tail hypodermis, which expresses the Wnt gene lin-44 (Herman and Horvitz, 1994); in cells in the anal region that express egl-20/Wnt (Whangbo and Kenyon, 1999); and in posterior body wall muscle cells that express cwn-1/Wnt (Gleason et al., 2006; Pan et al., 2006). In addition, mig-14 is strongly expressed in the stomatointestinal muscle, the mesoblast cell M and its descendants, the CAN neurons, the developing vulva, the pharynx, and the pharyngeal intestinal valve. mig-14 is also weakly expressed in a small subset of head neurons, the ventral nerve cord, and the seam cells, but is undetectable in the main body hypodermis and the intestine. |
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Expr12377
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TSP-21::GFP is plasma membrane-localized and is expressed in a wide variety of somatic cell types, including the pharynx, intestine and hypodermis starting in embryos after the 100 cell stage and peaking in L1 and L2 larvae. The TSP-21::GFP signal in these tissues decreases in late larval and adult stage animals. TSP-21::GFP is also present at the surface of M lineage cells from the 1-M stage to the 16-M stage. TSP-21::GFP is enriched in the basolateral side of intestinal cells while being absent from their apical sides. In addition, while TSP-21::GFP in the M lineage cells is primarily plasma membrane localized, there is also a significant intracellular distribution of TSP-21::GFP in the M mesoblast. |
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Expr9973
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Expression of gfp::sem-2 was first detectable in a subset of cells of the E and MS lineages in early gastrulating-stage embryos. The gfp::sem-2 expression persisted through embryonic and larval development in many cell types, including vulval, hypodermal and intestinal cells. gfp::sem-2 expression in the M lineage was first detectable at the 16-M stage in the SM mother cells, M.v(l/r)pa, and remained in both of their daughter cells, M.v(l/r)paa and M.v(l/r)pap. The presence of GFP::SEM-2 in M.v(l/r)pap was transient: GFP::SEM-2 was not detectable after M.v(l/r)pap differentiated into BWMs. However, GFP::SEM-2 persisted in the nuclei of the SM cells and all their descendants until the 8-SM stage, and became undetectable at the 16-SM stage. |
The GFP::SEM-2 protein was nuclear localized, consistent with its predicted role as a transcription factor. |
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Expr13210
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SUP-17::GFP is widely expressed from the early embryo through larval development to adults. Cells expressing SUP- 17::GFP include the germline, developing vulva, hypodermis, M lineage cells, and intestinal cells. |
SUP-17::GFP is localized both at the cell surface and in the cytoplasm in small puncta. In the early embryo, cell surface localized SUP-17::GFP is enriched in the basolateral, but not the apical, surfaces. |
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Temporal description |
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Expr11524
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By antibody staining, MCM-4 was found to be expressed in dividing cells during all stages of development in wild-type animals. Embryos showed the highest levels of MCM-4 expression, in agreement with the fact that more than half of the somatic cells are formed during embryogenesis. Even dauer larvae that had been arrested in cell division for 2 weeks still contained detectable MCM-4 protein levels. These results suggest that a pool of MCM-4 is retained during prolonged periods of quiescence, so that MCM-4 might function in the re-initiation of DNA synthesis when conditions improve. Immunostaining of wild-type animals for MCM-4 showed strong nuclear staining in the gonad, embryos and postembryonic lineages. MCM-4 was detectable in sperm and accumulated during oocyte maturation in the nucleus but did not show overlap with the condensed chromosomes in diakinesis of meiotic prophase. MCM-4 was not chromatin-associated during MeiosisI of the fertilized oocyte, and the first polar body did not contain MCM-4. This finding is consistent with the absence of S phase between Meiosis I and -II. The second polar body and maternal pronucleus received some MCM-4. Subsequently, embryonic cells in interphase showed strong nuclear staining. In prophase, MCM-4 localization did not overlap with the condensing chromosomes. Upon nuclear envelope degradation, MCM-4 became diffusely localized throughout the cell and clearly did not co-localize with the metaphase-aligned chromosomes. MCM-4 remained cytoplasmic at the onset of anaphase; however, chromatin association became apparent in late anaphase. These data show that chromosome association of MCM-4 is tightly controlled, consistent with origin licensing taking place at the end of mitosis and disappearing during S phase. Similar observations were made during larval divisions. Matching the MCM-4::mCherry reporter, endogenous MCM-4 expression was detectable prior to and during mitosis. Staining of synchronized L1 animals revealed the timing of MCM-4 expression, which in general preceded mitosis by 1-2 h. After 5 h of L1 development at 20 C, MCM-4 immunostaining was predominantly detected in the epithelial seam cells, Q neuroblast daughters and gonad primordium. The somatic gonad precursor cells Z1 and Z4 showed nuclear staining, while the mitotically arrested germline precursor cells Z2 and Z3 showed diffuse cytoplasmic staining. At 6 hours of L1 development, the mesoblast (M) also stained strongly as well as the most anterior ventral cord precursors cells (W, P1 and P2). Subsequently at 7 h, additional P cells showed nuclear MCM-4 expression, which became apparent prior to migration of the nucleus into the ventral nerve cord. At 8 h of L1 development, the intestinal nuclei showed MCM-4 expression, which preceded nuclear division by at least 4 h. At subsequent time points, daughter cells that continued division, such as the Pn.a and M descendants, retained strong nuclear staining. L2 animals stained at 16 h of larval development showed strong MCM-4 expression in the gonad, the H1.a, H2.p, V1-6.p and T.ap seam cells and, weakly, the intestinal nuclei (data not shown). Importantly, MCM-4 staining did not overlap with DNA in prophase and metaphase, while in late anaphase co-localization with the chromosomes was clearly detectable. Similar to our observations with the MCM-4::mCherry reporter, we could not detect any asymmetry in MCM-4 segregation. Thus, even if only one daughter cell continued cell division, both daughters received a similar amount of MCM-4in mitosis. Furthermore, the MCM-4protein became undetectable during quiescence, i.e. the P3.p-P8.p daughter cells that resume DNA replication in the L3 stage did not show detectable expression in the L2 stage. Altogether, our reporter gene and antibody staining analysis show that MCM-4 is dynamically expressed and localized during larval development as well as during different phases of the cell cycle. Expression of MCM-4::mCherry was specifically induced in all postembryonic blast cell lineages well before mitotic entry, at the expected time of S-phase induction. The fusion protein localized to the cell nucleus until degradation of the nuclear envelope in prometaphase, at which point MCM-4 became diffusely localized through the cell. This diffuse localization indicates that MCM-4 is not chromatin-associated in mitosis. MCM-4::mCherry did not disappear upon completion of mitosis but was segregated to both daughter cells. Even cells that permanently withdrew from cell division, such as the motor neurons of the ventral nerve cord, initially retained MCM-4::mCherry expression. However, this expression subsequently disappeared in differentiated cells as well as in cells that temporarily arrested cell division, such as the Pn.p vulval precursor cells in the ventral cord. These experiments indicate that mcm-4 is transcriptionally activated at approximately the time of G1/S transition and that MCM-4 protein is segregated to both daughter cells in mitosis. |
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Expr16149
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Focusing on larval development, we found that LIN-12::mNG::3xFlag was expressed in all postembryonic mesoderm progenitor cells at the 4M and 8M stages, but was only localized to the nucleus in ventral M-lineage cells, consistent with functions in dorsoventral patterning of the M lineage (Foehr & Liu, 2008). LIN-12::mNG::3xFlag was subsequently visible in somatic gonad cells and in several PN.p cells where lin-12 regulates cell fates (reviewed by Sternberg, 2005). LIN-12::mNG::3xFlag was visible at the cell membrane and in internalized punctae in the P3.p - P8.p cells but localized to the nucleus only in P5.p and P7.p. Following vulval precursor cell patterning, LIN-12::mNG::3xFlag was highly expressed in numerous somatic gonad cells, with nuclear localization in several spermatheca and uterine precursor cells. |
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Expr11254
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cwn-1 is predominantly expressed in the posterior body wall muscle (BWM) and in the M cell/SM lineage. On average, the wild-type SMs each express 50 transcripts of cwn-1 prior to the polarity choice of P7.p. |
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Expr13403
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sem-4::GFP is expressed throughout the M lineage from the 1-M stage to the 18-M stage, and in the SM sub-lineage from the 2-SM stage to the 16-SM stage, before the cells differentiate. When these cells terminally differentiate, sem-4::GFP becomes undetectable in the differentiated coelomocytes and vulval muscles, but remains expressed in the differentiated BWMs. |
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Expr13745
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Consistent with previously reported bed-3::gfp reporter expression, bed-3 mRNA (smFISH) was predominantly expressed in hypodermal cells and vulval cells. We next examined whether bed-3 is expressed earlier in the M lineage using ayIs6[hlh-8::gfp]. We found that bed-3 is expressed in M daughters and descendants as well as SM cells. In L1 and L2 stages, the bed-3 smFISH signal appeared stronger in 2 M and 4 M stages compared to 8 M, 16 M and 18 M stages. In the L3 stage, bed-3 is expressed in SM cells near the vulval region of the animal. |
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Expr11250
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In addition to the previously reported neuronal and muscle cell expression (Chan et al., 1996; Alexanderet al., 2009), the functional UNC-40::GFP transgene is expressed in both hypodermal cells and M lineage cells.Thus, unc-40 is expressed in the signal-receiving cells of the Sma/Mab pathway. |
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Expr12808
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lin-12::gfp expression was not detected in M lineage cells at the 1-M and 2-M stages. However, at the 4-M to 8-M stages, lin-12::gfp expression was observed in all M-derived cells, with the same intensity in both the dorsal and the ventral sides. At the 10-M stage and later, lin-12::gfp is still detected in both dorsal and ventral M-derived cells, but become more restricted along the anteroposterior axis. lin-12::gfp appears to be gradually lost in the anterior M lineage cells, but retained in the posterior M lineage cells that are the precursors of CCs (M.dlpa and M.drpa) and BWMs (M.dlpp and M.drpp) on the dorsal side and precursors of SM/BWMs (M.vlpa and M.vrpa) and BWMs (M.vlpp and M.vrpp) on the ventral side. |
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