WormMine: AnatomyTerm WBbt:0003734

• Definition: a section of pharynx of which muscles contract with a peristaltic motion.
• Name: isthmus
• Primary Identifier: WBbt:0003734

0 Children

0 Expression Clusters

21 Expression Patterns

• Primary Identifier: Expr4437
• Pattern: Expressed in the seam cells from L1 to adult. Expressed in the rectal epithelial cells from L1 and maintain through adulthood. Expressed in the pro- and metacorpus and isthmus.

• Primary Identifier: Expr4658
• Pattern: The antibody could detect MPS-4 expression in terminal bulb and in anterior, but not in posterior isthmus or corpus. When the head of the worm is cut, the corpus remains covered by the cuticle because the body wall muscles contract. Thus, the cuticle might have prevented the antibody to stain the corpus even after robust permeabilization. However, in intact worms permeabilized by the same freeze-crack method authors detected expression in terminal bulb and isthmus (albeit les intense) but not in corpus. Further, in the cut head preparations, metacorpus and the region of corpus immediately adjacent to it are usually not covered by the cuticle and yet the antibody failed to detect MPS-4 (n=3). This suggests that even if MPS-4 is expressed in corpus, the protein level is low. The antibody did not stain the pharynx of mps-4 KO nematodes confirming its specificity. Notably, the expression pattern of MPS-4 partially overlapped with that of EXP-2 indicating that the two proteins colocalize in specific areas of the pharynx.

• Primary Identifier: Expr9390
• Pattern: The LTD-1::GFP signal is present throughout the development of C. elegans. This signal was detected as early as the 2-fold embryo. The ltd-1 reporter is also expressed throughout the seam cell division process. Its expression is observed in the seam cells of the early embryo and in the larval stages once these cells have commenced division. The LTD-1::GFP signal is also observed in rectal epithelial cells (tentatively, U and Y cells) and in the terminal bulb (marginal cells) and isthmus of the pharynx from hatching to adulthood.
• Subcellular Localization: Sub-cellular localization within the body wall muscle: Dense bodies, Cytoplasm, +/- Nucleus The LTD-1::GFP construct is expressed in the apical regions of the dorsal and ventral hypodermis in very tightly organized circumferential filament bundles. This cytoskeletal expression pattern mirrors the intracellular distribution of actin and tubulin in C. elegans. In late embryos, the GFP signal is localized to the apical junction between hyp 5, hyp 6 and hyp 7 and between the seam cells and the P blast cells in the ventral midline. This signal highlights the cell fusion processes that take place during post-embryonic development. The ltd-1 reporter is also expressed throughout the seam cell division process. It clearly outlines the cytokinesis between posterior mother cells and anterior daughter cells and illustrates the subsequent fusion of the anterior daughter cells to the hypodermal syncitium. The GFP signal is also observed in longitudinal filaments within the cytoplasm linking both extremities of the elongating seam cells and in the alae formed by their fusion.

• Primary Identifier: Expr2252
• Pattern: The LTD-1::GFP signal is present throughout the development of C. elegans. This signal was detected as early as the 2-fold embryo. The ltd-1 reporter is also expressed throughout the seam cell division process. Its expression is observed in the seam cells of the early embryo and in the larval stages once these cells have commenced division. The LTD-1::GFP signal is also observed in rectal epithelial cells (tentatively, U and Y cells) and in the terminal bulb (marginal cells) and isthmus of the pharynx from hatching to adulthood.
• Subcellular Localization: The LTD-1::GFP construct is expressed in the apical regions of the dorsal and ventral hypodermis in very tightly organized circumferential filament bundles. This cytoskeletal expression pattern mirrors the intracellular distribution of actin and tubulin in C. elegans. In late embryos, the GFP signal is localized to the apical junction between hyp 5, hyp 6 and hyp 7 and between the seam cells and the P blast cells in the ventral midline. This signal highlights the cell fusion processes that take place during post-embryonic development. The ltd-1 reporter is also expressed throughout the seam cell division process. It clearly outlines the cytokinesis between posterior mother cells and anterior daughter cells and illustrates the subsequent fusion of the anterior daughter cells to the hypodermal syncitium. The GFP signal is also observed in longitudinal filaments within the cytoplasm linking both extremities of the elongating seam cells and in the alae formed by their fusion.

• Primary Identifier: Expr15962
• Pattern: Endogenously tagged LIN-2, LIN-7, LIN-10 and LET-23 EGFRallow for the analysis of their localization and expression patterns in other tissues. We found that all four proteins are expressed inneurons and sensory tissue in the head, and along the ventral anddorsal nerve chords. The intestine is prone to a highdegree of autofluorescence and was excluded from the initialanalysis. Whereas LET-23 EGFR and LIN-7 overlapped minimallyin the head, LIN-2 and LIN-7 colocalized strongly in theneural ring, and the ventral and dorsal nerve chords. Ofnote, we observed that LIN-2 was more strongly expressed in theisthmus of the pharynx than LIN-7. In contrast, LIN-7 wasmore strongly expressed in the gonad and uterus than LIN-2. LIN-10 overlapped minimally with LIN-2 in the neural ring and nerve chords, and shared very little overlap with LET-23 EGFR in other neural tissues in the head of the worm. LET-23::mK2 was strongly expressed in the excretory duct cell in which it signals through the LET-60 Ras/MPK-1 ERK pathway to regulate excretory duct cell development (Abdus-Saboor et al., 2011; Yochem et al., 1997).

• Primary Identifier: Expr1744
• Remark: Reporter gene fusion type not specified.
• Pattern: F42G10.2 expressed in pharyngeal muscles and several unspecified neurons. The promoter of F42G10.2 was not active in the intestine, anus, or excretory cell. Promoter activity observed throughout the pharynx. GFP observed in the corpus, isthmus and terminal bulb.

• Primary Identifier: Expr7872
• Remark: Picture: Figure 9.
• Pattern: Transgenic animals carrying the csq-1::gfp fusion constructs showed expressions of GFP in body-wall muscles beginning from the 2-fold stage embryo through to adult stages. In addition, GFP signals were observed in vulval muscles and in the isthmus and terminal bulb regions of the pharynx.

• Primary Identifier: Expr20
• Remark: Developmental expression pattern screen for genes predicted in the C.elegans genome sequencing project. Life_stage summary = post L1
• Pattern: Expression is seen from the L1 larval stage as neural processes (small nuclei in the pharynx) in the ventral and dorsal nerve cords. This expression appears to be cytoplasmic. Staining is evident in a few intestinal nuclei just anterior to the intestinal-rectal valve. A ring of stain is also present around the isthmus of the pharynx from L2 to L4. Staining is evident in small nuclei (possibly neuronal) of the pharynx, as a cytoplasmic smear down the dorso/ventral nerve cords, and in a few intestinal nuclei just anterior to the intestinal-rectal valve. A ring ofstain is also present around the isthmus of the pharynx from L2 to L4.
• Subcellular Localization: Expression is a cytoplasmic smear down the dorso/ventral nerve cords.

• Primary Identifier: Expr3055
• Pattern: The CeENT1-GFP fusion protein was produced throughout the life cycle, from late embryo stage through the larval stages to the adult, but only in a limited number of cell types. The CeENT1-GFP fusion protein was particularly abundant in the pharyngeal musculature, notably in the terminal bulb and procorpus. The fusion protein was also strongly evident in all of the intestinal cells both of larvae and adults.
• Subcellular Localization: Fluorescence was most marked at the cell surfaces, suggesting that the fusion protein was correctly inserted and targeted to the plasma membranes.

• Primary Identifier: Expr3056
• Pattern: The CeENT2 fusion protein showed a temporal and spatial pattern of expression very similar to that of ZK809.4::GFP (see Expr3055). The chief difference was that the CeENT2-GFP fusion protein was more abundant in the isthmus and metacorpus regions of the pharynx than the CeENT1-GFP fusion protein.
• Subcellular Localization: Fluorescence was most marked at the cell surfaces, suggesting that the fusion protein was correctly inserted and targeted to the plasma membranes.

• Primary Identifier: Expr11156
• Pattern: ncx-2 is expressed in pharyngeal muscle including procorpus, metacorpus, isthmus and terminal bulb, body wall muscle, enteric muscle, and vulval muscle.

• Primary Identifier: Expr11162
• Pattern: ncx-8 is strongly expressed in the pharyngeal muscle including procorpus, metacorpus, isthmus andterminal bulb, and in the intestine.

• Primary Identifier: Expr14125
• Pattern: strong pharyngeal expression (isthmus and terminal bulb), posterior gut, PVT sometimes

• Primary Identifier: Expr503
• Remark: Transgenic Marker: rol-6(su1006)
• Pattern: Expressed in intestine, pharynx, pharyngeal terminal bulb, pharyngeal isthmus, pharyngeal intestinal valve, mu_sph, and excretory cell at unspecified stage. Not observed in the nervous system or germ line, which differs from immunostaining results (see Expression pattern 504).
• Subcellular Localization: ITR-1 present in membrane preparations by Western blotting.

• Primary Identifier: Expr3025
• Pattern: The iri-1::gfp is expressed in the terminal bulb of the pharynx, amphid socket cells, pharyngeal-intestinal valve, intestine, excretory cell, rectal epithelial cells, and vulva hypodermis. In addition, iri-1::gfp is expressed in the corpus of the pharynx, the pharyngeal neuron I3, the anal sphincter and in the gonad precursor cells Z1 and Z4.

• Primary Identifier: Expr15773
• Pattern: Strong expression of TPS-1 occurred predominantly in the hypodermis, a tissue in which DAF-9 and STRM-1 are also expressed. Some expression was observed in a number of head neurons and in the isthmus of the pharynx, and no expression was seen in the intestinal cells.

• Primary Identifier: Expr828
• Remark: Authors established that itr-1 has three promoters responsible for differential tissue expression.
• Pattern: Expression of pC is observed in the intestine, pharyngeal isthmus and spermathecal (Sp) valve, uterine sheath cells and spermatheca.

• Primary Identifier: Expr1200110
• Pattern: Data from the TransgeneOme project

• Primary Identifier: Expr3717
• Pattern: Comma-stage embryos began to express the GFP-tagged protein in intestinal cells, and animals retained the intestinal expression through the adult stage, although the intestinal expression became weaker after the L1 stage. The fusion protein was also detected in the muscles of the pharyngeal isthmus from the 3-fold embryonic stage, and in a pair of head neurons, which were identified as AUA neurons, from the late L1 stage. These expression patterns were retained through the adult stage.
• Subcellular Localization: The FLR-4::GFP fusion protein accumulated at the cell membrane of intestinal cells, especially the lateral membrane intervening the intestinal cells.

• Primary Identifier: Expr1408
• Remark: late embryo (author) = fully-elongated embryo (curator)
• Pattern: AKT-1/GFP expression is first observed in late embryos and is maintained throughout the life of the animal. In postembryonic animals, AKT-1/GFP is expressed in the majority of head neurons including sensory neurons. Expression is also observed in motor neurons of the ventral and dorsal nerve cord and several other neuronal commissures throughout the body, and the tail neurons. Additional tissues that consistently express AKT-1/GFP include neurons and muscle cells of the pharynx, the rectal gland cells, and the spermatheca. AKT-1/GFP expression was observed more variably in a variety of cell types including hypodermis, intestine, muscle, some of the P-cell descendants that form the vulva, and in the excretory canal.
• Subcellular Localization: The fusion protein is localized throughout the cell body and axonal and dendritic processes of neurons but is usually excluded from the nucleus.

• Primary Identifier: Expr1409
• Remark: See Expr1408 for akt-1 expression pattern.
• Pattern: AKT-2/GFP full-length protein fusion gene is expressed at the same times as AKT-1/GFP and in the same tissues that express AKT-1/GFP although AKT-2/GFP seems to be less abundant.

0 Life Stages

1 Parents

Definition	Name	Synonym	Primary Identifier
	pharyngeal segment		WBbt:0005789