1
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Theska T, Renahan T, Sommer RJ. Starvation resistance in the nematode Pristionchus pacificus requires a conserved supplementary nuclear receptor. ZOOLOGICAL LETTERS 2024; 10:7. [PMID: 38481284 PMCID: PMC10938818 DOI: 10.1186/s40851-024-00227-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 01/18/2024] [Indexed: 03/17/2024]
Abstract
Nuclear hormone receptors (NHRs) are a deeply-conserved superfamily of metazoan transcription factors, which fine-tune the expression of their regulatory target genes in response to a plethora of sensory inputs. In nematodes, NHRs underwent an explosive expansion and many species have hundreds of nhr genes, most of which remain functionally uncharacterized. However, recent studies have reported that two sister receptors, Ppa-NHR-1 and Ppa-NHR-40, are crucial regulators of feeding-structure morphogenesis in the diplogastrid model nematode Pristionchus pacificus. In the present study, we functionally characterize Ppa-NHR-10, the sister paralog of Ppa-NHR-1 and Ppa-NHR-40, aiming to reveal whether it too regulates aspects of feeding-structure development. We used CRISPR/CAS9-mediated mutagenesis to create small frameshift mutations of this nuclear receptor gene and applied a combination of geometric morphometrics and unsupervised clustering to characterize potential mutant phenotypes. However, we found that Ppa-nhr-10 mutants do not show aberrant feeding-structure morphologies. Instead, multiple RNA-seq experiments revealed that many of the target genes of this receptor are involved in lipid catabolic processes. We hypothesized that their mis-regulation could affect the survival of mutant worms during starvation, where lipid catabolism is often essential. Indeed, using novel survival assays, we found that mutant worms show drastically decreased starvation resistance, both as young adults and as dauer larvae. We also characterized genome-wide changes to the transcriptional landscape in P. pacificus when exposed to 24 h of acute starvation, and found that Ppa-NHR-10 partially regulates some of these responses. Taken together, these results demonstrate that Ppa-NHR-10 is broadly required for starvation resistance and regulates different biological processes than its closest paralogs Ppa-NHR-1 and Ppa-NHR-40.
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Affiliation(s)
- Tobias Theska
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology, Tübingen, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Tess Renahan
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology, Tübingen, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Ralf J Sommer
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology, Tübingen, Max-Planck-Ring 9, 72076, Tübingen, Germany.
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2
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Hiramatsu F, Lightfoot JW. Kin-recognition and predation shape collective behaviors in the cannibalistic nematode Pristionchus pacificus. PLoS Genet 2023; 19:e1011056. [PMID: 38096160 PMCID: PMC10721034 DOI: 10.1371/journal.pgen.1011056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 11/08/2023] [Indexed: 12/17/2023] Open
Abstract
Kin-recognition is observed across diverse species forming an important behavioral adaptation influencing organismal interactions. In many species, the molecular mechanisms involved are difficult to characterize, but in the nematode Pristionchus pacificus molecular components regulating its kin-recognition system have been identified. These determine its predatory behaviors towards other con-specifics which prevents the killing and cannibalization of kin. Importantly, their impact on other interactions including collective behaviors is unknown. Here, we explored a high altitude adapted clade of this species which aggregates abundantly under laboratory conditions, to investigate the influence of the kin-recognition system on their group behaviours. By utilizing pairwise aggregation assays between distinct strains of P. pacificus with differing degrees of genetic relatedness, we observe aggregation between kin but not distantly related strains. In assays between distantly related strains, the aggregation ratio is frequently reduced. Furthermore, abolishing predation behaviors through CRISPR/Cas9 induced mutations in Ppa-nhr-40 result in rival strains successfully aggregating together. Finally, as Caenorhabditis elegans are found naturally occurring with P. pacificus, we also explored aggregation events between these species. Here, aggregates were dominated by P. pacificus with the presence of only a small number of predators proving sufficient to disrupt C. elegans aggregation dynamics. Thus, aggregating strains of P. pacificus preferentially group with kin, revealing competition and nepotism as previously unknown components influencing collective behaviors in nematodes.
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Affiliation(s)
- Fumie Hiramatsu
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior–caesar, Bonn, Germany
- International Max Planck Research School for Brain and Behavior, Bonn, Germany
| | - James W. Lightfoot
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior–caesar, Bonn, Germany
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3
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Lenuzzi M, Witte H, Riebesell M, Rödelsperger C, Hong RL, Sommer RJ. Influence of environmental temperature on mouth-form plasticity in Pristionchus pacificus acts through daf-11-dependent cGMP signaling. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2023; 340:214-224. [PMID: 34379868 DOI: 10.1002/jez.b.23094] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/14/2021] [Accepted: 07/30/2021] [Indexed: 12/16/2022]
Abstract
Mouth-form plasticity in the nematode Pristionchus pacificus has become a powerful system to identify the genetic and molecular mechanisms associated with developmental (phenotypic) plasticity. In particular, the identification of developmental switch genes that can sense environmental stimuli and reprogram developmental processes has confirmed long-standing evolutionary theory. However, how these genes are involved in the direct sensing of the environment, or if the switch genes act downstream of another, primary environmental sensing mechanism, remains currently unknown. Here, we study the influence of environmental temperature on mouth-form plasticity. We find that environmental temperature does influence mouth-form plasticity in most of the 10 wild isolates of P. pacificus tested in this study. We used one of these strains, P. pacificus RSA635, for detailed molecular analysis. Using forward and reverse genetic technology including CRISPR/Cas9, we show that mutations in the guanylyl cyclase Ppa-daf-11, the Ppa-daf-25/AnkMy2, and the cyclic nucleotide-gated channel Ppa-tax-2 eliminate the response to elevated temperatures. Together, our study indicates that DAF-11, DAF-25, and TAX-2 have been co-opted for environmental sensing during mouth-form plasticity regulation in P. pacificus.
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Affiliation(s)
- Maša Lenuzzi
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Developmental Biology, Tübingen, Germany
| | - Hanh Witte
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Developmental Biology, Tübingen, Germany
| | - Metta Riebesell
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Developmental Biology, Tübingen, Germany
| | - Christian Rödelsperger
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Developmental Biology, Tübingen, Germany
| | - Ray L Hong
- Department of Biology, California State University, Northridge, California, USA
| | - Ralf J Sommer
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Developmental Biology, Tübingen, Germany
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4
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Lo WS, Roca M, Dardiry M, Mackie M, Eberhardt G, Witte H, Hong R, Sommer RJ, Lightfoot JW. Evolution and Diversity of TGF-β Pathways are Linked with Novel Developmental and Behavioral Traits. Mol Biol Evol 2022; 39:msac252. [PMID: 36469861 PMCID: PMC9733428 DOI: 10.1093/molbev/msac252] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 10/19/2022] [Accepted: 11/07/2022] [Indexed: 12/12/2022] Open
Abstract
Transforming growth factor-β (TGF-β) signaling is essential for numerous biologic functions. It is a highly conserved pathway found in all metazoans including the nematode Caenorhabditis elegans, which has also been pivotal in identifying many components. Utilizing a comparative evolutionary approach, we explored TGF-β signaling in nine nematode species and revealed striking variability in TGF-β gene frequency across the lineage. Of the species analyzed, gene duplications in the DAF-7 pathway appear common with the greatest disparity observed in Pristionchus pacificus. Specifically, multiple paralogues of daf-3, daf-4 and daf-7 were detected. To investigate this additional diversity, we induced mutations in 22 TGF-β components and generated corresponding double, triple, and quadruple mutants revealing both conservation and diversification in function. Although the DBL-1 pathway regulating body morphology appears highly conserved, the DAF-7 pathway exhibits functional divergence, notably in some aspects of dauer formation. Furthermore, the formation of the phenotypically plastic mouth in P. pacificus is partially influenced through TGF-β with the strongest effect in Ppa-tag-68. This appears important for numerous processes in P. pacificus but has no known function in C. elegans. Finally, we observe behavioral differences in TGF-β mutants including in chemosensation and the establishment of the P. pacificus kin-recognition signal. Thus, TGF-β signaling in nematodes represents a stochastic genetic network capable of generating novel functions through the duplication and deletion of associated genes.
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Affiliation(s)
- Wen-Sui Lo
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Marianne Roca
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior—Caesar, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - Mohannad Dardiry
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Marisa Mackie
- Department of Biology, California State University, Northridge, CA
| | - Gabi Eberhardt
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Hanh Witte
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Ray Hong
- Department of Biology, California State University, Northridge, CA
| | - Ralf J Sommer
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - James W Lightfoot
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior—Caesar, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
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5
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Eren GG, Roca M, Han Z, Lightfoot JW. Genomic integration of transgenes using UV irradiation in Pristionchus pacificus. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000576. [PMID: 35693893 PMCID: PMC9187223 DOI: 10.17912/micropub.biology.000576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 05/22/2022] [Accepted: 05/26/2022] [Indexed: 11/30/2022]
Abstract
Transgenes are widely used throughout molecular biology for numerous applications. In Caenorhabditis elegans, stable transgenes are usually generated by microinjection into the germline establishing extrachromosomal arrays. Furthermore, numerous technologies exist to integrate transgenes into the C. elegans genome. In the nematode Pristionchus pacificus, transgenes are possible, however, their establishment is less efficient and dependent on the formation of complex arrays containing the transgene of interest and host carrier DNA. Additionally, genomic integration has only been reported via biolistic methods. Here we describe a simple technique using UV irradiation to facilitate the integration of transgenes into the P. pacificus genome.
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Affiliation(s)
- Güniz Göze Eren
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior – caesar, Bonn, Germany
| | - Marianne Roca
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior – caesar, Bonn, Germany
| | - Ziduan Han
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology, Tuebingen, Germany
| | - James W Lightfoot
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior – caesar, Bonn, Germany.
,
Correspondence to: James W Lightfoot (
)
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6
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Quach KT, Chalasani SH. Flexible reprogramming of Pristionchus pacificus motivation for attacking Caenorhabditis elegans in predator-prey competition. Curr Biol 2022; 32:1675-1688.e7. [PMID: 35259340 PMCID: PMC9050875 DOI: 10.1016/j.cub.2022.02.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/18/2021] [Accepted: 02/09/2022] [Indexed: 12/16/2022]
Abstract
Animals with diverse diets must adapt their food priorities to a wide variety of environmental conditions. This diet optimization problem is especially complex for predators that compete with prey for food. Although predator-prey competition is widespread and ecologically critical, it remains difficult to disentangle predatory and competitive motivations for attacking competing prey. Here, we dissect the foraging decisions of the omnivorous nematode Pristionchus pacificus to reveal that its seemingly failed predatory attempts against Caenorhabditis elegans are actually motivated acts of efficacious territorial aggression. While P. pacificus easily kills and eats larval C. elegans with a single bite, adult C. elegans typically survives and escapes bites. However, non-fatal biting can provide competitive benefits by reducing access of adult C. elegans and its progeny to bacterial food that P. pacificus also eats. We show that the costs and benefits of both predatory and territorial outcomes influence how P. pacificus decides which food goal, prey or bacteria, should guide its motivation for biting. These predatory and territorial motivations impose different sets of rules for adjusting willingness to bite in response to changes in bacterial abundance. In addition to biting, predatory and territorial motivations also influence which search tactic P. pacificus uses to increase encounters with C. elegans. When treated with an octopamine receptor antagonist, P. pacificus switches from territorial to predatory motivation for both biting and search. Overall, we demonstrate that P. pacificus assesses alternate outcomes of attacking C. elegans and flexibly reprograms its foraging strategy to prioritize either prey or bacterial food.
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Affiliation(s)
- Kathleen T. Quach
- Neurosciences Graduate Program, University of California San Diego, Gilman Drive, La Jolla, CA 92037, USA.,Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Sreekanth H. Chalasani
- Neurosciences Graduate Program, University of California San Diego, Gilman Drive, La Jolla, CA 92037, USA.,Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, North Torrey Pines Road, La Jolla, CA 92037, USA.,Lead Contact,Correspondence: , Twitter: @shreklab
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7
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Hiraga H, Ishita Y, Chihara T, Okumura M. Efficient visual screening of CRISPR/Cas9 genome editing in the nematode Pristionchus pacificus. Dev Growth Differ 2021; 63:488-500. [PMID: 34813661 DOI: 10.1111/dgd.12761] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/17/2021] [Accepted: 09/30/2021] [Indexed: 12/22/2022]
Abstract
CRISPR/Cas9 genome editing has been applied to a wide variety of organisms, including nematodes such as Caenorhabditis elegans and Pristionchus pacificus. In these nematodes, genome editing is achieved by microinjection of Cas9 protein and guide RNA into the hermaphrodite gonads. However, P. pacificus is less efficient in CRISPR/Cas9 genome editing and exogenous gene expression. Therefore, it takes considerable time and effort to screen for target mutants if there are no visual markers that indicate successful injection. To overcome this problem, co-injection markers (gRNA for Ppa-prl-1, which induces the roller phenotype, and Ppa-egl-20p::turboRFP, a plasmid expressing a fluorescent protein) have been developed in P. pacificus. By selecting worms with the roller phenotype or turboRFP expression, screening efficiency is substantially increased to obtain worms with desired mutations. Here, we describe a step-by-step protocol for the visual screening system for CRISPR/Cas9 genome editing in P. pacificus. We also describe technical tips for microinjection, which is difficult for beginners. This protocol will facilitate genome editing in P. pacificus and may be applied to other nematode species.
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Affiliation(s)
- Hirokuni Hiraga
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Yuuki Ishita
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Takahiro Chihara
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan.,Program of Basic Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Misako Okumura
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan.,Program of Basic Biology, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
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8
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Rödelsperger C, Ebbing A, Sharma DR, Okumura M, Sommer RJ, Korswagen HC. Spatial Transcriptomics of Nematodes Identifies Sperm Cells as a Source of Genomic Novelty and Rapid Evolution. Mol Biol Evol 2021; 38:229-243. [PMID: 32785688 PMCID: PMC8480184 DOI: 10.1093/molbev/msaa207] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Divergence of gene function and expression during development can give rise to phenotypic differences at the level of cells, tissues, organs, and ultimately whole organisms. To gain insights into the evolution of gene expression and novel genes at spatial resolution, we compared the spatially resolved transcriptomes of two distantly related nematodes, Caenorhabditis elegans and Pristionchus pacificus, that diverged 60-90 Ma. The spatial transcriptomes of adult worms show little evidence for strong conservation at the level of single genes. Instead, regional expression is largely driven by recent duplication and emergence of novel genes. Estimation of gene ages across anatomical structures revealed an enrichment of novel genes in sperm-related regions. This provides first evidence in nematodes for the "out of testis" hypothesis that has been previously postulated based on studies in Drosophila and mammals. "Out of testis" genes represent a mix of products of pervasive transcription as well as fast evolving members of ancient gene families. Strikingly, numerous novel genes have known functions during meiosis in Caenorhabditis elegans indicating that even universal processes such as meiosis may be targets of rapid evolution. Our study highlights the importance of novel genes in generating phenotypic diversity and explicitly characterizes gene origination in sperm-related regions. Furthermore, it proposes new functions for previously uncharacterized genes and establishes the spatial transcriptome of Pristionchus pacificus as a catalog for future studies on the evolution of gene expression and function.
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Affiliation(s)
- Christian Rödelsperger
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Annabel Ebbing
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Utrecht,
The Netherlands
| | - Devansh Raj Sharma
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Misako Okumura
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
| | - Ralf J Sommer
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Hendrik C Korswagen
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Utrecht,
The Netherlands
- Developmental Biology, Department of Biology, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht,
The Netherlands
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9
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Han Z, Lo WS, Lightfoot JW, Witte H, Sun S, Sommer RJ. Improving Transgenesis Efficiency and CRISPR-Associated Tools Through Codon Optimization and Native Intron Addition in Pristionchus Nematodes. Genetics 2020; 216:947-956. [PMID: 33060138 PMCID: PMC7768246 DOI: 10.1534/genetics.120.303785] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 10/14/2020] [Indexed: 12/12/2022] Open
Abstract
A lack of appropriate molecular tools is one obstacle that prevents in-depth mechanistic studies in many organisms. Transgenesis, clustered regularly interspaced short palindromic repeats (CRISPR)-associated engineering, and related tools are fundamental in the modern life sciences, but their applications are still limited to a few model organisms. In the phylum Nematoda, transgenesis can only be performed in a handful of species other than Caenorhabditis elegans, and additionally, other species suffer from significantly lower transgenesis efficiencies. We hypothesized that this may in part be due to incompatibilities of transgenes in the recipient organisms. Therefore, we investigated the genomic features of 10 nematode species from three of the major clades representing all different lifestyles. We found that these species show drastically different codon usage bias and intron composition. With these findings, we used the species Pristionchus pacificus as a proof of concept for codon optimization and native intron addition. Indeed, we were able to significantly improve transgenesis efficiency, a principle that may be usable in other nematode species. In addition, with the improved transgenes, we developed a fluorescent co-injection marker in P. pacificus for the detection of CRISPR-edited individuals, which helps considerably to reduce associated time and costs.
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Affiliation(s)
- Ziduan Han
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
| | - Wen-Sui Lo
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
| | - James W Lightfoot
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
| | - Hanh Witte
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
| | - Shuai Sun
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
| | - Ralf J Sommer
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
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10
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Athanasouli M, Witte H, Weiler C, Loschko T, Eberhardt G, Sommer RJ, Rödelsperger C. Comparative genomics and community curation further improve gene annotations in the nematode Pristionchus pacificus. BMC Genomics 2020; 21:708. [PMID: 33045985 PMCID: PMC7552371 DOI: 10.1186/s12864-020-07100-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 09/23/2020] [Indexed: 02/07/2023] Open
Abstract
Background Nematode model organisms such as Caenorhabditis elegans and Pristionchus pacificus are powerful systems for studying the evolution of gene function at a mechanistic level. However, the identification of P. pacificus orthologs of candidate genes known from C. elegans is complicated by the discrepancy in the quality of gene annotations, a common problem in nematode and invertebrate genomics. Results Here, we combine comparative genomic screens for suspicious gene models with community-based curation to further improve the quality of gene annotations in P. pacificus. We extend previous curations of one-to-one orthologs to larger gene families and also orphan genes. Cross-species comparisons of protein lengths, screens for atypical domain combinations and species-specific orphan genes resulted in 4311 candidate genes that were subject to community-based curation. Corrections for 2946 gene models were implemented in a new version of the P. pacificus gene annotations. The new set of gene annotations contains 28,896 genes and has a single copy ortholog completeness level of 97.6%. Conclusions Our work demonstrates the effectiveness of comparative genomic screens to identify suspicious gene models and the scalability of community-based approaches to improve the quality of thousands of gene models. Similar community-based approaches can help to improve the quality of gene annotations in other invertebrate species, including parasitic nematodes.
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Affiliation(s)
- Marina Athanasouli
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Hanh Witte
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Christian Weiler
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Tobias Loschko
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Gabi Eberhardt
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Ralf J Sommer
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Christian Rödelsperger
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany.
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11
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Sensory cilia as the Achilles heel of nematodes when attacked by carnivorous mushrooms. Proc Natl Acad Sci U S A 2020; 117:6014-6022. [PMID: 32123065 DOI: 10.1073/pnas.1918473117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Fungal predatory behavior on nematodes has evolved independently in all major fungal lineages. The basidiomycete oyster mushroom Pleurotus ostreatus is a carnivorous fungus that preys on nematodes to supplement its nitrogen intake under nutrient-limiting conditions. Its hyphae can paralyze nematodes within a few minutes of contact, but the mechanism had remained unclear. We demonstrate that the predator-prey relationship is highly conserved between multiple Pleurotus species and a diversity of nematodes. To further investigate the cellular and molecular mechanisms underlying rapid nematode paralysis, we conducted genetic screens in Caenorhabditis elegans and isolated mutants that became resistant to P. ostreatus We found that paralysis-resistant mutants all harbored loss-of-function mutations in genes required for ciliogenesis, demonstrating that the fungus induced paralysis via the cilia of nematode sensory neurons. Furthermore, we observed that P. ostreatus caused excess calcium influx and hypercontraction of the head and pharyngeal muscle cells, ultimately resulting in rapid necrosis of the entire nervous system and muscle cells throughout the entire organism. This cilia-dependent predatory mechanism is evolutionarily conserved in Pristionchus pacificus, a nematode species estimated to have diverged from C. elegans 280 to 430 million y ago. Thus, P. ostreatus exploits a nematode-killing mechanism that is distinct from widely used anthelmintic drugs such as ivermectin, levamisole, and aldicarb, representing a potential route for targeting parasitic nematodes in plants, animals, and humans.
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12
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Rödelsperger C, Athanasouli M, Lenuzzi M, Theska T, Sun S, Dardiry M, Wighard S, Hu W, Sharma DR, Han Z. Crowdsourcing and the feasibility of manual gene annotation: A pilot study in the nematode Pristionchus pacificus. Sci Rep 2019; 9:18789. [PMID: 31827189 PMCID: PMC6906410 DOI: 10.1038/s41598-019-55359-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 11/20/2019] [Indexed: 01/15/2023] Open
Abstract
Nematodes such as Caenorhabditis elegans are powerful systems to study basically all aspects of biology. Their species richness together with tremendous genetic knowledge from C. elegans facilitate the evolutionary study of biological functions using reverse genetics. However, the ability to identify orthologs of candidate genes in other species can be hampered by erroneous gene annotations. To improve gene annotation in the nematode model organism Pristionchus pacificus, we performed a genome-wide screen for C. elegans genes with potentially incorrectly annotated P. pacificus orthologs. We initiated a community-based project to manually inspect more than two thousand candidate loci and to propose new gene models based on recently generated Iso-seq and RNA-seq data. In most cases, misannotation of C. elegans orthologs was due to artificially fused gene predictions and completely missing gene models. The community-based curation raised the gene count from 25,517 to 28,036 and increased the single copy ortholog completeness level from 86% to 97%. This pilot study demonstrates how even small-scale crowdsourcing can drastically improve gene annotations. In future, similar approaches can be used for other species, gene sets, and even larger communities thus making manual annotation of large parts of the genome feasible.
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Affiliation(s)
- Christian Rödelsperger
- Max Planck Institute for Developmental Biology, Department for Integrative Evolutionary Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany.
| | - Marina Athanasouli
- Max Planck Institute for Developmental Biology, Department for Integrative Evolutionary Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Maša Lenuzzi
- Max Planck Institute for Developmental Biology, Department for Integrative Evolutionary Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Tobias Theska
- Max Planck Institute for Developmental Biology, Department for Integrative Evolutionary Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Shuai Sun
- Max Planck Institute for Developmental Biology, Department for Integrative Evolutionary Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Mohannad Dardiry
- Max Planck Institute for Developmental Biology, Department for Integrative Evolutionary Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Sara Wighard
- Max Planck Institute for Developmental Biology, Department for Integrative Evolutionary Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Wen Hu
- Max Planck Institute for Developmental Biology, Department for Integrative Evolutionary Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Devansh Raj Sharma
- Max Planck Institute for Developmental Biology, Department for Integrative Evolutionary Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
| | - Ziduan Han
- Max Planck Institute for Developmental Biology, Department for Integrative Evolutionary Biology, Max-Planck-Ring 9, 72076, Tübingen, Germany
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Moreno E, Lightfoot JW, Lenuzzi M, Sommer RJ. Cilia drive developmental plasticity and are essential for efficient prey detection in predatory nematodes. Proc Biol Sci 2019; 286:20191089. [PMID: 31575374 PMCID: PMC6790756 DOI: 10.1098/rspb.2019.1089] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 09/16/2019] [Indexed: 01/08/2023] Open
Abstract
Cilia are complex organelles involved in a broad array of functions in eukaryotic organisms. Nematodes employ cilia for environmental sensing, which shapes developmental decisions and influences morphologically plastic traits and adaptive behaviours. Here, we assess the role of cilia in the nematode Pristionchus pacificus, and determine their importance in regulating the developmentally plastic mouth-form decision in addition to predatory feeding and self-recognition behaviours, all of which are not present in Caenorhabditis elegans. An analysis of a multitude of cilia-related mutants including representatives of the six protein subcomplexes required in intraflagellar transport (IFT) plus the regulatory factor X transcription factor daf-19 revealed that cilia are essential for processing the external cues influencing the mouth-form decision and for the efficient detection of prey. Surprisingly, we observed that loss-of-function mutations in the different IFT components resulted in contrasting mouth-form phenotypes and different degrees of predation deficiencies. This observation supports the idea that perturbing different IFT subcomplexes has different effects on signalling downstream of the cilium. Finally, self-recognition was maintained in the cilia deficient mutants tested, indicating that the mechanisms triggering self-recognition in P. pacificus may not require the presence of fully functional cilia.
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Affiliation(s)
| | | | | | - Ralf J. Sommer
- Department of Evolutionary Biology, Max Planck Institute for Developmental Biology, Max-Planck-Ring 9, 72076 Tübingen, Germany
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14
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Angilletta MJ, Youngblood JP, Neel LK, VandenBrooks JM. The neuroscience of adaptive thermoregulation. Neurosci Lett 2019; 692:127-136. [DOI: 10.1016/j.neulet.2018.10.046] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 10/17/2018] [Accepted: 10/21/2018] [Indexed: 01/05/2023]
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15
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Moreno E, Lenuzzi M, Rödelsperger C, Prabh N, Witte H, Roeseler W, Riebesell M, Sommer RJ. DAF‐19/RFX controls ciliogenesis and influences oxygen‐induced social behaviors in
Pristionchus pacificus. Evol Dev 2018; 20:233-243. [DOI: 10.1111/ede.12271] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Eduardo Moreno
- Max Planck Institute for Developmental BiologyDepartment of Evolutionary BiologyTübingenGermany
| | - Maša Lenuzzi
- Max Planck Institute for Developmental BiologyDepartment of Evolutionary BiologyTübingenGermany
| | - Christian Rödelsperger
- Max Planck Institute for Developmental BiologyDepartment of Evolutionary BiologyTübingenGermany
| | - Neel Prabh
- Max Planck Institute for Developmental BiologyDepartment of Evolutionary BiologyTübingenGermany
| | - Hanh Witte
- Max Planck Institute for Developmental BiologyDepartment of Evolutionary BiologyTübingenGermany
| | - Waltraud Roeseler
- Max Planck Institute for Developmental BiologyDepartment of Evolutionary BiologyTübingenGermany
| | - Metta Riebesell
- Max Planck Institute for Developmental BiologyDepartment of Evolutionary BiologyTübingenGermany
| | - Ralf J. Sommer
- Max Planck Institute for Developmental BiologyDepartment of Evolutionary BiologyTübingenGermany
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16
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Moreno E, Sommer RJ. A cilia-mediated environmental input induces solitary behaviour in Caenorhabditis elegans and Pristionchus pacificus nematodes. NEMATOLOGY 2018. [DOI: 10.1163/15685411-00003159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Nematodes respond to a multitude of environmental cues. For example, the social behaviours clumping and bordering were described as a mechanism of hyperoxia avoidance in Caenorhabditis elegans and Pristionchus pacificus. A recent study in P. pacificus revealed a novel regulatory pathway that inhibits social behaviour in a response to an as yet unknown environmental cue. This environmental signal is recognised by ciliated neurons, as mutants defective in intraflagellar transport (IFT) proteins display social behaviours. The IFT machinery represents a large protein complex and many mutants in genes encoding IFT proteins are available in C. elegans. However, social phenotypes in C. elegans IFT mutants have never been reported. Here, we examined 15 previously isolated C. elegans IFT mutants and found that most of them showed strong social behaviour. These findings indicate conservation in the inhibitory mechanism of social behaviour between P. pacificus and C. elegans.
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Affiliation(s)
- Eduardo Moreno
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Ralf J. Sommer
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Max-Planck Ring 9, 72076 Tübingen, Germany
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