The visual pigment xenopsin is widespread in protostome eyes and impacts the view on eye evolution
- Sars International Centre for Marine Molecular Biology, University of Bergen, Norway
Figures
Figure 1 with 1 supplement
Conservation of functionally important motifs and residues in different opsin types.
Alignment of parts of the transmembrane domain VII and the cytosolic helix VIII of selected opsin sequences showing the conserved lysine 296 (K296) chromophore binding site and other conserved …
Figure 1—figure supplement 1
Conservation of functionally important motifs and residues in xenopsins.
Alignment of parts of the transmembrane domain VII and the cytosolic helix VIII of selected opsin sequences showing the conserved lysine 296 (K296) chromophore binding site and other motifs …
Figure 2 with 8 supplements
C-opsins and xenopsins display type-specific conserved gene structures.
Maximum Likelihood tree of opsin protein sequences (IQ-TREE, LG+F+R8). Labeled nodes have support values of SH-like approximate likelihood ratio test (blue dot) and ultrafast bootstrap ≥0.9 (purple …
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Figure 2—source data 1
Accession numbers of the genes used for gene tree inference.
- https://cdn.elifesciences.org/articles/55193/elife-55193-fig2-data1-v2.xlsx
Figure 2—figure supplement 1
Un-collapsed tree of phylogeny shown in Figure 2.
Maximum Likelihood tree (IQ-TREE, LG+F+R8). Labeled nodes have support values of approximate Bayes test ≥0.98 (yellow dot), SH-like approximate likelihood ratio test ≥90 (blue dot) and ultrafast …
Figure 2—figure supplement 2
Bayesian analysis (Phylobayes) of sequence alignment used in Figure 2.
Parametric Γ modeling of the dataset specific substitution matrix (DS-GTR) generated by Vöcking et al., 2017. Consensus tree of two out three chains (90.000 cycles, burn-in 18.000, mean difference …
Figure 2—figure supplement 3
Gene structures of all sequences, which were used for gene tree calculation and for which genomic information was available or generated in this study, mapped on the un-curated protein sequence alignment.
The sequences investigated in this study are highlighted in blue.
Figure 2—figure supplement 4
Intron phase and position of all sequences, which were used for gene tree calculation and for which genomic information was available or generated in this study, mapped on the un-curated protein sequence.
The sequences investigated in this study are highlighted in blue.
Figure 2—figure supplement 5
Unrooted xenopsin tree.
Maximum Likelihood analysis (IQ-TREE, LG+F+I+G4). Labeled nodes have support values of approximate Bayes test ≥0.98 (yellow dot), SH-like approximate likelihood ratio test ≥90 (blue dot), and …
Figure 2—figure supplement 6
Xenopsin tree rooted with few c-opsins.
Maximum Likelihood analysis (IQ-TREE, LG+F+I+G4). Labeled nodes have support values of approximate Bayes test ≥0.98 (yellow dot), SH-like approximate likelihood ratio test ≥90 (blue dot), and …
Figure 2—figure supplement 7
Xenopsin tree rooted with few cnidops.
Maximum Likelihood analysis (IQ-TREE, LG+F+I+G4). Labeled nodes have support values of approximate Bayes test ≥0.98 (yellow dot), SH-like approximate likelihood ratio test ≥90 (blue dot), and …
Figure 2—figure supplement 8
Xenopsin tree rooted with few c-opsins and cnidops.
Labeled nodes have support values of approximate Bayes test ≥0.98 (yellow dot), SH-like approximate likelihood ratio test ≥90 (blue dot), and ultrafast bootstrap ≥90 (purple dot). The sequences …
Figure 3 with 1 supplement
Xenopsin expression in Tricellaria inopinata.
(A) Anterior view of a larva showing the pigment spots of the paired lateral eyes (filled arrowheads) and the single median eye (outlined arrowheads). (B,C) WMISH of Tin-xenopsin. Maximum …
Figure 3—figure supplement 1
Expression of Tin-xenopsin in cells not associated with shielding pigment (asterisks).
FISH combined with antibody staining against acetylated alpha-tubulin (atub) and DAPI nuclear dye. (A) Close to the apical organ. (B) At the edge of the anterior ciliary groove. (C) At the opening …
Figure 4 with 3 supplements
Subcellular localization of xenopsin in the lateral eye of Tricellaria inopinata.
(A,B) Electron microscopic images (cryofixation) showing the photoreceptor cell (PRC) sending numerous cilia (ciPRC) into the eye invagination. The cilia possess basal bodies (white asterisks) and …
Figure 4—figure supplement 1
Subcellular localization of xenopsin in the median eye of Tricellaria inopinata.
(A) Electron microscopic images (chemical fixation) showing two photoreceptor cell1 (PRC1, PRC2) on the lateral sides of the eye invagination. Two pigmented coronal cells (PCC1, PCC2) line the …
Figure 4—figure supplement 2
Organization of the lateral larval eye of Tricellaria inopinata.
Serial sections (apical view) from apical (A) to abapical (F). The two pigmented coronal cells (PCC1, PCC2) do not bear cilia in the region of the eye invagination and line the apical and lateral …
Figure 4—figure supplement 3
Appearance of shielding pigment granules in the lateral eye of Tricellaria inopinata.
Shielding pigment granules (white arrowheads) appear electron-dense after chemical (A,C) and rather electron-lucent after cryofixation (B,D) in both the photoreceptor cell (PRC) and the pigmented …
Figure 5 with 1 supplement
Spectral response of Tricellaria inopinata larvae.
(A) One-dimensional displacement of larvae during stimulation with blue (454 nm) light. Each recording started with no stimulus for 30 s. Afterwards, the light stimulus was activated for 15 s, …
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Figure 5—source data 1
Raw data of behavioral experiment on larval displacement during stimulation with blue light.
- https://cdn.elifesciences.org/articles/55193/elife-55193-fig5-data1-v2.xlsx
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Figure 5—source data 2
Raw data of behavioral experiments on the spectral response of the larva.
- https://cdn.elifesciences.org/articles/55193/elife-55193-fig5-data2-v2.xlsx
Figure 5—figure supplement 1
Spectral response of the larvae.
Violin plots of all individual experiments.
Figure 6 with 1 supplement
Xenopsin in the dorsal and ventral eyes of Malacoceros fuliginosus.
(A,B) Light micrographs of ventral (arrowhead) and dorsal (asterisk) microvillar eyes at 48 hpf. (C,D) WMISH of Mfu-xenopsin in the ventral (arrowhead) and dorsal (black asterisk) eyes. (E–F’’’) …
Figure 6—figure supplement 1
The first (PRC1) and third (PRC3) photoreceptor cell of the ventral eye of Malacoceros fuliginosus bear no cilia, but exhibit basal bodies (bb) close to the apical surface.
(A) First photoreceptor cell. An accessory centriole (ac in inlet) lies close to the basal body in another layer (B) Third photoreceptor cell. mvPRC1: sensory microvilli of PRC1. mvPRC2: sensory …
Figure 7
Scenarios on eye PRC evolution in Bilateria.
The bilaterian ancestor had extraocular c-opsin+ ciliary PRCs. These became integrated into the eyes in the lineage leading to vertebrates and were lost in many protostomes along with secondary loss …
Tables
Key resources table
| Reagent type (species) or resource | Designation | Source or reference | Identifiers | Additional information |
|---|---|---|---|---|
| Gene (Tricellaria inopinata) | Xenopsin | Genbank | MT901641 | |
| Gene (Malacoceros fuliginosus) | Xenopsin | Genbank | MT901639 | |
| Gene (Malacoceros fuliginosus) | Ciliary opsin | Genbank | MT901640 | |
| Strain, strain background (Malacoceros fuliginosus) | Wild type | University of Bergen, Sars Centre for Marine Molecular Biology | NCBITaxon: 271776 | |
| Antibody | mouse monoclonal anti-acetylated α-tubulin IgG1 | Sigma-Aldrich | RRID:AB_609894 | Dilution 1:300 (Mfu) 1:50 (Tin) |
| Antibody | Rat polyclonal anti-Mfu-r-opsin3 IgG | University of Bergen, Sars Centre for Marine Molecular Biology | 1:100 | |
| Antibody | Rabit polyclonal anti-Tin-xenopsin IgG | University of Bergen, Sars Centre for Marine Molecular Biology | 1:500 | |
| Antibody | Alexa Fluor 633 goat monoclonal anti-rat IgG | ThermoFisher Scientific | RRID:AB_2535749 | 1:500 |
| Antibody | Alexa Fluor 488 goat momoclonal anti-mouse IgG | ThermoFisher Scientific | RRID:AB_2535764 | 1:500 |
| Recombinant DNA reagent | PGem-T-Tin-xenops (plasmid) | University of Bergen, Sars Centre for Marine Molecular Biology | Used for synthesizing WMISH probes | |
| Recombinant DNA reagent | PGem-T-Mfu-xenops (plasmid) | University of Bergen, Sars Centre for Marine Molecular Biology | Used for synthesizing WMISH probes | |
| Recombinant DNA reagent | PGem-T-Mfu-cops (plasmid) | University of Bergen, Sars Centre for Marine Molecular Biology | Used for synthesizing WMISH probes | |
| Sequence-based reagent | Mfu-xenops-WMISH forward primer (5’- > 3’) | University of Bergen, Sars Centre for Marine Molecular Biology | 5’-CACCATCATGTTGAATAATGACTCCTACTC-3’ | |
| Sequence-based reagent | Mfu-xenops-WMISH reverse primer (5’- > 3’) | University of Bergen, Sars Centre for Marine Molecular Biology | 5’-GATTCGTGGAATGCTGATTTGTGAC-3’ | |
| Sequence-based reagent | Mfu-cops-WMISH forward primer (5’- > 3’) | University of Bergen, Sars Centre for Marine Molecular Biology | 5’-ATCACACAGGATATCACAAATGCCTCAG-3’ | |
| Sequence-based reagent | Mfu-cops-WMISH reverse primer (5’- > 3’) | University of Bergen, Sars Centre for Marine Molecular Biology | 5’-GCAATAACGATGTCACCTGGACATTG-3’ | |
| Sequence-based reagent | Tin_xenopsin-WMISH forward primer (5’- > 3’) | University of Bergen, Sars Centre for Marine Molecular Biology | 5’-CTTATGGTCATTGCTGT-3’ | |
| Sequence-based reagent | Tin_xenopsin-WMISH reverse primer (5’- > 3’) | University of Bergen, Sars Centre for Marine Molecular Biology | 5’-CACCCTGCCATTAGTC-3’ | |
| Sequence-based reagent | Tin_xenopsin-WMISH forward nested primer (5’- > 3’) | University of Bergen, Sars Centre for Marine Molecular Biology | 5’-TGGGGGTTGTTTTGGTCGT-3’ | |
| Sequence-based reagent | Tin_xenopsin-WMISH reverse nested primer (5’- > 3’) | University of Bergen, Sars Centre for Marine Molecular Biology | 5’-CTGTTGCCTTCTTCTCTCGT-3’ | |
| Commercial assay or kit | Superscript III First-Strand Synthesis System | ThermoFisher Scientific | Catalog number: 18080051 | |
| Commercial assay or kit | RNeasy Mini Kit | Qiagen | Catalog number: 74104 | |
| Software, algorithm | IQ-TREE | http://www.iqtree.org/ | RRID:SCR_017254 | |
| Software, algorithm | Phylobayes-MPI | https://github.com/bayesiancook/pbmpi | RRID:SCR_006402 | |
| Software, algorithm | MAFFT 7 | https://mafft.cbrc.jp/alignment/server/ | RRID:SCR_011811 | |
| Software, algorithm | CLC Main Workstation | Qiagen | RRID:SCR_000354 | |
| Software, algorithm | ImageJ | NIH | RRID:SCR_003070 | |
| Software, algorithm | Imaris 8.41 | Bitplane | RRID:SCR_007370 |
