A muscle-epidermis-glia signaling axis sustains synaptic specificity during allometric growth in Caenorhabditis elegans
- Department of Neurosurgery, the State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, the Institutes of Brain Science, and Zhongshan Hospital, Fudan University Shanghai, China
- State Key Laboratory of Genetic Engineering, Department of Biochemistry, School of Life Sciences, Fudan University, China
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, United States
- Instituto de Neurobiología, Recinto de Ciencias Médicas, Universidad de Puerto Rico, Puerto Rico
Figures
Figure 1 with 1 supplement
Synaptic allometry in AIY neurons.
(A–C) Distribution of AIY synapses in wild-type animals, and model. (A–B) Confocal micrograph images of AIY presynaptic sites labeled with the synaptic vesicle marker mCherry::RAB-3 (pseudo-colored …
Figure 1—figure supplement 1
Model of CIMA-1 site of action.
(A–B) Confocal micrographs of AIY cytoplasmic GFP (green) and VCSC glia cytoplasmic mCherry (red) merged with bright field (with pharynx visible for reference) in wild type (A) and cima-1(wy84) (B) …
Figure 2 with 1 supplement
Mutant allele ola226 suppresses cima-1 (wy84) synaptic allometry defects in AIY.
(A) Cartoon diagram of the distribution of presynaptic sites in the AIY interneurons of the nematode C. elegans. The head of C. elegans (solid black lines) and the pharynx (dashed grey line) are …
Figure 2—figure supplement 1
Relationship between body size and synaptic allometry in cima-1(wy84) mutants and the ola226 allele.
(A–B’) Confocal micrographs of GFP::RAB-3 in cima-1(wy84) (A, A’) and cima-1(wy84);ola226 (B, B’) with bright field (A,B) displaying the position of the pharynx second bulb for reference, or without …
Figure 3 with 1 supplement
Glia morphology is affected in ola226 mutants.
(A) Cartoon diagram of the ventral and dorsal cephalic sheath cell glia (red) in the C. elegans head. The ventral cephalic sheath cell (VCSC) glia, located at the bottom half in the schematic, …
Figure 3—figure supplement 1
ola226 affects AIY neurite and cell body position.
(A) A cartoon diagram of AIY (red) in the C. elegans head. The blue arrow indicates the cell body, bracket indicates the Zone 1 region, asterisk indicates the Zone 2 region, and vertical dashed line …
Figure 4 with 2 supplements
ola226 is a lesion in the mig-17 gene.
(A) Schematic diagram of the mig-17 gene and corresponding protein domains coded by the exons (colored) and genetic lesions for the alleles used in this study. (B–G) Confocal micrographs of the AIY …
Figure 4—figure supplement 1
Synaptic phenotypes in mig-17 alleles.
(A–E) Confocal micrographs of the AIY synaptic vesicle marker GFP::RAB-3 (green) in the wild type (A), mig-17(ola226) (B), mig-17(k113) (C), mig-17(k174) (D) and mig-17 overexpression in wild-type …
Figure 4—figure supplement 2
mig-17(ola226) and cima-1(wy84) phenotypes in pharyngeal length.
(A) A cartoon diagram of the pharynx in the C. elegans head. The pharynx is outlined with a dashed grey line, and the length quantified in (B) is shown. (B) Quantification of pharyngeal length of …
Figure 5 with 1 supplement
MIG-17 is a secreted molecule that regulates synaptic allometry.
(A–D”’) Confocal micrographs of adult animals expressing the transcriptional reporter mig-17(genomic)::SL2::GFP (green) with reporters that co-label body wall muscles (Pmyo-3::mCherry (A–A”’)), …
Figure 5—figure supplement 1
Cell-specific expression of mig-17 in multiple tissues rescues the mig-17 suppression in mig-17(ola226);cima-1(wy84) mutants.
Quantification of the percentage of adult animals with ectopic synapses in the AIY Zone 1 region in the indicated genotypes. The body wall muscle rescue and the pan-neuronal rescue are the same as …
Figure 6 with 1 supplement
The metalloprotease activity of MIG-17 is required to suppress the formation of ectopic synapses in cima-1(wy84) mutants.
(A) Schematic diagram of the MIG-17 protein, corresponding conserved protein domains (colored) and genetic lesions for the alleles used in this study. (B–G) Confocal micrographs of the AIY …
Figure 6—figure supplement 1
CRISPR strategies to generate the mig-17(shc8) allele and the endogenous MIG-17::mNeonGreen.
(A) Schematic of the strategy used to change E303 at MIG-17 and generate the mig-17(shc8) allele. The location for the two sgRNAs used (black bolded and blue) and the shc8 (E303A) repair template …
Figure 7 with 1 supplement
MIG-17 modulates synaptic allometry through the regulation of the basement membrane.
(A) List of basement membrane components upregulated in the mass spectrometry analyses (see also Supplementary file 1), and alleles tested with cima-1 for their capacity to suppress the synaptic …
Figure 7—figure supplement 1
Phenotypes in AIY synapses of alleles affecting basement membrane proteins.
Quantification of the percentage of adult animals with ectopic synapses in the AIY Zone 1 region in wild type (WT), cima-1(wy84), emb-9(xd51), emb-9(b189), fbl-1(k201), unc-52(gk3) and unc-52(e1421) …
Figure 8
MIG-17 genetically interacts with EGL-15/Fibroblast Growth Factor Receptor to regulate synaptic allometry.
(A–C) Confocal micrographs of the AIY synaptic vesicle marker GFP::RAB-3 (green) in adult wild type (A), cima-1(wy84) (B), cima-1(wy84);egl-15(n484) (C). (D) Quantification of percentage of animals …
Figure 9 with 1 supplement
Glia maintain synaptic allometry by bridging epidermal-derived growth signals with the muscle-secreted basement membrane.
(A) Schematic of the head of C. elegans, as in Figure 1C, with indicated tissues pseudocolored. Box corresponds to cross sections examined in (B–D). (B) Segmented electron micrograph from a wild …
Figure 9—figure supplement 1
Localization of basement membrane near the nerve ring.
(A–C’’) Confocal micrographs of the basement membrane marker EMB-9 (red) (A, B and C) with VCSC glia (green) (A’–A’’), AIY neuron (green) (B’–B’’) and body wall muscle (green) (C’–C’’). Panels on …
Additional files
-
Supplementary file 1
Protein levels altered in mig-17(ola226) as detected by LS/MS proteomic analyses.
Proteins upregulated (>1.2 fold) or downregulated (<0.8 fold) are listed in the spreadsheet. Note that mig-17(ola226) was isolated from forward genetic screen, which would introduce other background mutations. Further analyses are required to determine if the protein level changes are due specifically to the mig-17(ola226) mutation.
- https://cdn.elifesciences.org/articles/55890/elife-55890-supp1-v2.pdf
-
Supplementary file 2
Strains used in this study List of strains and the corresponding genotypes used in this study.
- https://cdn.elifesciences.org/articles/55890/elife-55890-supp2-v2.pdf
-
Supplementary file 3
Constructs used in this study.
The name of constructs, the primers and the vectors (for building the constructs). Detailed cloning information is available upon request.
- https://cdn.elifesciences.org/articles/55890/elife-55890-supp3-v2.xlsx
-
Supplementary file 4
Key Resources Table.
- https://cdn.elifesciences.org/articles/55890/elife-55890-supp4-v2.docx
-
Transparent reporting form
- https://cdn.elifesciences.org/articles/55890/elife-55890-transrepform-v2.docx
