The enteric nervous system of the C. elegans pharynx is specified by the Sine oculis-like homeobox gene ceh-34
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, United States
Figures
Figure 1
The pharyngeal nervous system of Caenorhabditis elegans.
(A) Overview of the C. elegans alimentary system from Wormbook (Hall and Altun, 2007), with neuronal cell bodies in the pharynx added in red. (B) Projection patterns of pharyngeal neurons within the …
Figure 2 with 2 supplements
ceh-34 is expressed in all pharyngeal neurons.
(A) ceh-33 and ceh-34 loci showing different alleles and fosmid reporters used in this study. (B) Expression of the ceh-34 CRISPR/Cas-9-engineered reporter allele ot903 over the course of …
Figure 2—figure supplement 1
Evolution of Sine oculis orthologs in nematodes.
(A) Phylogeny of ceh-33/34 gene duplication in nematodes. Phylogeny based on homeodomains. (B) Synteny of the ceh-33/ceh-34 locus across several Caenorhabditis species.
Figure 2—figure supplement 2
Expression of the organ selector pha-4.
(A) pha-4 expression (stIs10077) is not affected in ceh-34(tm3733) mutants. Animals were scored at the L1 stage. Statistical analysis was performed using unpaired t-test. (B) pha-4 is continuously …
Figure 3
Pharyngeal neurons are generated in ceh-34 mutants but lose their neurotransmitter identity.
(A) Pictures at the L1 stage showing expression of pan-neuronal reporter transgenes that monitor ric-4 (otIs350), ric-19 (otIs380), unc-11 (otIs620), and rab-3 (otIs291) expression. A single focal …
Figure 4
ceh-34 affects the expression of receptors for neurotransmitters and neuropeptides.
(A) Representative pictures and quantification showing neurotransmitter receptor expression loss in ceh-34 mutants. Reporter genes used are transgenes glr-2 (ivIs26), mgl-1 (otIs341), and a …
Figure 5
ceh-34 affects neuropeptidergic identity of pharyngeal neurons.
(A) Representative pictures and quantification showing expression of 10 different neuropeptides is affected in ceh-34 mutants. Reporter genes used are transgenic reporters for flp-2 (ynIs57), flp-4 …
Figure 6 with 2 supplements
ceh-34 affects other identity features of pharyngeal neurons.
(A) Representative pictures and quantification showing sensory receptor expression loss in ceh-34 mutants. Reporter transgenes used are glr-7 (otIs809), gur-3 (nIs780), and str-97 (otIs716). str-97 …
Figure 6—figure supplement 1
Summary of previous single cell transcriptomic analysis of genes broadly expressed in pharyngeal neurons.
scRNA data was extracted from the Cengen App and displayed in a heatmap format, as previously described (Taylor et al., 2021). The F13H10.6 gene was included here as well because of its striking …
Figure 6—figure supplement 2
ceh-34 affects ceh-28 expression.
Representative pictures and quantification are shown. Reporter gene used is ceh-28 (nIs175). Twenty percent of worms show a cell outside the pharynx ectopically expressing ceh-28. Animals were …
Figure 7
ceh-34 is continuously required to maintain gene expression and function of pharyngeal neurons.
(A) Schematic of the AIDv2 system (Hills-Muckey et al., 2022). Skp1, Cul1, Rbx1, and E2 are phylogenetically conserved components of the E3 ligase complex. TIR1F79G is a modified plant-specific …
Figure 8 with 2 supplements
ceh-34 affects the assembly of pharyngeal circuitry.
(A) ceh-34 null mutants display disorganized axodendritic projections. Axodendritic projections were scored as a whole rather than by individual neuron because with all the pharyngeal neurons being …
Figure 8—figure supplement 1
ceh-34 is required to maintain synapse organization in the pharyngeal nervous system.
Synchronized population of worms at the L1 or young adult stage were transferred onto ethanol or 5-Ph-IAA-coated plates and scored 48 hr later. Worms were expressing TIR1F79G ubiquitously under the r…
Figure 8—figure supplement 2
Axonal defects in slt-1 mutants.
(A) Effects of slt-1 on the I2/I4 neurons. Orange arrows indicate position of pharyngeal nerve ring. Blue arrow indicates ectopic projection. The gur-3 reporter array is nIs780. (B) Effects of slt-1 …
Figure 9
Limited involvement of eya-1 in pharyngeal neuron identity specification.
(A) eya-1 is expressed in all pharyngeal neurons throughout the life of the worm. Images of L1 and adult worms showing co-localization of eya-1 expression (nIs352) with the pan-neuronal gene rab-3 (o…
Figure 10
ceh-34 cooperates with homeobox genes to specify distinct pharyngeal neuron types.
(A) unc-86 and ceh-34 synergistically affect NSM differentiation. Representative images and quantification are shown. Reporter gene used is cat-1 (otIs224). Animals were scored at the L4 stage. …
Figure 11 with 2 supplements
Other homeobox genes involved in specifying distinct pharyngeal neuron types.
(A) ceh-2 affects M3 neuron differentiation. Representative images and quantification are shown. Reporter gene is eat-4 (otIs388). Animals scored at the L4 stage. Statistical analysis was performed …
Figure 11—figure supplement 1
Homeobox mutant alleles.
(A) Homeobox mutant alleles generated in this study. Numbers indicating beginning and end of deletion are relative to the start codon of the gene of interest. See Materials and methods for detail. (B…
Figure 11—figure supplement 2
Homeobox misexpression experiments.
We misexpressed genomic copies of the unc-86 and ttx-3 locus, driven by the pan-pharyngeal neuron promoter ehs-1 in several independent transgenic lines to generate the normally NSM-specific …
Figure 12
Summary of homeobox gene codes involved in pharyngeal neuron identity specification.
Shown here are homeobox genes for which an involvement in pharyngeal neuron differentiation has been shown, as well as the 8 (of a total of 14) pharyngeal neuron classes for which a homeobox …
Additional files
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Supplementary file 1
Strain list.
This file provides a list of all Caenorhabditis elegans strains used in this study.
- https://cdn.elifesciences.org/articles/76003/elife-76003-supp1-v2.docx
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Transparent reporting form
- https://cdn.elifesciences.org/articles/76003/elife-76003-transrepform1-v2.docx
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Source data 1
This file provides all the primary animal scoring data.
- https://cdn.elifesciences.org/articles/76003/elife-76003-data1-v2.xlsx
