Anomalous diffusion and search behavior in Caenorhabditis elegans
[eng] In this thesis, our focus was on unraveling how Caenorhabditis elegans samples its environment in the absence of gradients and food resources. We analyzed data from a relocation experiment in which individual worms, including wild-type isolates and defective mutants, were displaced from a food...
| Autor: | |
|---|---|
| Tipo de documento: | tese |
| Estado: | Versão publicada |
| Data de publicação: | 2024 |
| País: | España |
| Recursos: | Universidad de Barcelona |
| Repositório: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/215394 |
| Acesso em linha: | https://hdl.handle.net/2445/215394 http://hdl.handle.net/10803/692238 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Biocenosis Nematodes Biocenoses |
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Anomalous diffusion and search behavior in Caenorhabditis elegans |
| title |
Anomalous diffusion and search behavior in Caenorhabditis elegans |
| spellingShingle |
Anomalous diffusion and search behavior in Caenorhabditis elegans Lloret Cabot, Roger Biocenosis Nematodes Biocenoses |
| title_short |
Anomalous diffusion and search behavior in Caenorhabditis elegans |
| title_full |
Anomalous diffusion and search behavior in Caenorhabditis elegans |
| title_fullStr |
Anomalous diffusion and search behavior in Caenorhabditis elegans |
| title_full_unstemmed |
Anomalous diffusion and search behavior in Caenorhabditis elegans |
| title_sort |
Anomalous diffusion and search behavior in Caenorhabditis elegans |
| dc.creator.none.fl_str_mv |
Lloret Cabot, Roger |
| author |
Lloret Cabot, Roger |
| author_facet |
Lloret Cabot, Roger |
| author_role |
author |
| dc.contributor.none.fl_str_mv |
Bartumeus Ferré, Frederic Universitat de Barcelona. Facultat de Biologia |
| dc.subject.none.fl_str_mv |
Biocenosis Nematodes Biocenoses |
| topic |
Biocenosis Nematodes Biocenoses |
| description |
[eng] In this thesis, our focus was on unraveling how Caenorhabditis elegans samples its environment in the absence of gradients and food resources. We analyzed data from a relocation experiment in which individual worms, including wild-type isolates and defective mutants, were displaced from a food patch to an empty arena in tightly controlled environmental conditions. We characterized the spreading patterns of the worms and analyzed their movement dynamics at various temporal scales, ranging from milliseconds to hours. Our findings revealed an intricate, time-dependent spreading process, likely driven by internal states and memory relaxation due to the absence of clear external stimuli. Notably, C. elegans exhibited superdiffusive spreading behavior, prompting us to investigate the mechanisms behind this phenomenon and its adaptive significance in search contexts. To this end, we devised a classification algorithm that enabled us to characterize C. elegans trajectories into its elementary motor behaviors: sharp turns and crawls. Leveraging these insights, we developed a mechanistic model of movement that reproduces C. elegans search trajectories in great detail, shedding light on the emergence of superdiffusion. Additionally, we evaluated the search performance of various C. elegans-inspired movement models across multiple spatial scales, assuming two distinct search conditions: symmetric (all targets distant) and asymmetric (near and far targets) scenarios. Through this exercise, we quantitatively assessed the contribution of both superdiffusion and turning dynamics to the search performance of C. elegans. Finally, in an effort to reinforce our theoretical results with a real case study, we conducted a series of experiments with C. elegans individuals foraging in patchy landscapes with bacteria. In these experiments, we employed both homogeneous (regular) and heterogeneous (aggregate) landscapes, mirroring the search conditions evaluated in the synthetic simulations. Our findings confirmed that turning dynamics and superdiffusion are key elements of search behavior in C. elegans, fundamentally shaping its search performance in all landscape configurations analyzed. Furthermore, our results suggest that these two mechanisms have the potential to influence the ecological fitness of the species in the natural environment. While our conclusions are primarily based on the specific experimental conditions analyzed, which involve a sharp transition from resource-plentiful to empty arenas, we believe that the findings we present offer valuable insights into both the understanding of C. elegans search behavior and the adaptive value of superdiffusion and turning dynamics in search processes. |
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2024 |
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2024 |
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info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/publishedVersion |
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doctoralThesis |
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publishedVersion |
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https://hdl.handle.net/2445/215394 http://hdl.handle.net/10803/692238 |
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https://hdl.handle.net/2445/215394 http://hdl.handle.net/10803/692238 |
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Inglés |
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Inglés |
| dc.rights.none.fl_str_mv |
cc by-nc-sa (c) Lloret Cabot, Roger, 2024 http://creativecommons.org/licenses/by-nc-sa/3.0/es/ info:eu-repo/semantics/openAccess |
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cc by-nc-sa (c) Lloret Cabot, Roger, 2024 http://creativecommons.org/licenses/by-nc-sa/3.0/es/ |
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openAccess |
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application/pdf |
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Universitat de Barcelona |
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Universitat de Barcelona |
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Tesis Doctorals - Facultat - Biologia reponame:Dipòsit Digital de la UB instname:Universidad de Barcelona |
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Universidad de Barcelona |
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Dipòsit Digital de la UB |
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Dipòsit Digital de la UB |
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1869422062738604032 |
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Anomalous diffusion and search behavior in Caenorhabditis elegansLloret Cabot, RogerBiocenosisNematodesBiocenoses[eng] In this thesis, our focus was on unraveling how Caenorhabditis elegans samples its environment in the absence of gradients and food resources. We analyzed data from a relocation experiment in which individual worms, including wild-type isolates and defective mutants, were displaced from a food patch to an empty arena in tightly controlled environmental conditions. We characterized the spreading patterns of the worms and analyzed their movement dynamics at various temporal scales, ranging from milliseconds to hours. Our findings revealed an intricate, time-dependent spreading process, likely driven by internal states and memory relaxation due to the absence of clear external stimuli. Notably, C. elegans exhibited superdiffusive spreading behavior, prompting us to investigate the mechanisms behind this phenomenon and its adaptive significance in search contexts. To this end, we devised a classification algorithm that enabled us to characterize C. elegans trajectories into its elementary motor behaviors: sharp turns and crawls. Leveraging these insights, we developed a mechanistic model of movement that reproduces C. elegans search trajectories in great detail, shedding light on the emergence of superdiffusion. Additionally, we evaluated the search performance of various C. elegans-inspired movement models across multiple spatial scales, assuming two distinct search conditions: symmetric (all targets distant) and asymmetric (near and far targets) scenarios. Through this exercise, we quantitatively assessed the contribution of both superdiffusion and turning dynamics to the search performance of C. elegans. Finally, in an effort to reinforce our theoretical results with a real case study, we conducted a series of experiments with C. elegans individuals foraging in patchy landscapes with bacteria. In these experiments, we employed both homogeneous (regular) and heterogeneous (aggregate) landscapes, mirroring the search conditions evaluated in the synthetic simulations. Our findings confirmed that turning dynamics and superdiffusion are key elements of search behavior in C. elegans, fundamentally shaping its search performance in all landscape configurations analyzed. Furthermore, our results suggest that these two mechanisms have the potential to influence the ecological fitness of the species in the natural environment. While our conclusions are primarily based on the specific experimental conditions analyzed, which involve a sharp transition from resource-plentiful to empty arenas, we believe that the findings we present offer valuable insights into both the understanding of C. elegans search behavior and the adaptive value of superdiffusion and turning dynamics in search processes.[cat] En aquesta tesi ens hem centrat a entendre com Caenorhabditis elegans explora un entorn sense menjar ni gradients ambientals. Hem analitzat el moviment d’aquest animal en un experiment de reubicació, en el qual vàrem traslladar individus de diverses soques tant salvatges com mutants, des d’una placa de petri amb menjar, a un espai sense menjar i amb condicions de temperatura i humitat molt controlades. Per desenvolupar la nostra recerca hem caracteritzat detalladament els patrons de dispersi´o de C. elegans, basant-nos en les trajectòries obtingudes i també en la dinàmica del seu moviment mesurat a diverses escales de temps, des dels milisegons fins a l’hora. Els nostres resultats indiquen que C. elegans dispersa segons un procés no estacionari, probablement modulat pels seus estats interns i no pas per estímuls externs com per exemple gradients ambientals. Cal destacar que els indi- vidus de C. elegans estudiats varen exhibir un patró de dispersió superdifusiu, fet que va motivar-nos a investigar en profunditat els mecanismes físics que expliquen l’emergència d’aquest fenomen i també quina és la seva rellevància adaptativa en contextos de cerca. Per fer-ho, vàrem desenvolupar un algoritme de classificació per caracteritzar les trajectòries de C. elegans en els seus comportaments motrius elementals. Basant-nos en els resultats obtinguts, vàrem desenvolupar un model mecanicista del moviment de C. elegans que ens ha permès entendre quins mecanismes físics generen superdiffusió Seguidament, ens vàrem centrar a caracteritzar la seva eficiència en condicions de cerca simètriques, on tots els recursos es troben lluny, i en condicions de cerca asimètrica, on es poden trobar recursos tant a prop com lluny. A través de simulacions virtuals, vàrem quantificar la contribució de la superdifusió de la dinàmica de girs en l’eficiència de cerca de C. elegans. Finalment i amb la intenció de reforçar les nostres conclusions teòriques vàrem fer una sèrie d’experiments de cerca on individus de C. elegans podien buscar, trobar i consumir menjar distribuït segons un paisatge homogeni (regular), utilitzat per estudiar la condició simètrica, o un paisatge heterogeni (agregat), utilitzat per estudiar la condició asimètrica. Els resultats obtinguts varen confirmar que tant la dinàmica de girs com la superdifusió són dos elements clau en el comportament de cerca de C. elegans, ja que determinen la seva eficiència de cerca. Més encara, els nostres resultats suggereixen que aquests dos mecanismes podrien arribar a influir l’èxit reproductiu de l’espècie a la naturalesa. Tot i que les conclusions obtingudes en aquesta tesi són relatives a condicions experimentals específiques, creiem que els resultats presentats i les seves interpretacions, ofereixen un coneixement valuós per entendre el comportament de cerca de C. elegans i el valor adaptatiu de la superdifusió en els processos de cerca.Universitat de BarcelonaBartumeus Ferré, FredericUniversitat de Barcelona. Facultat de Biologia2024info:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/215394http://hdl.handle.net/10803/692238Tesis Doctorals - Facultat - Biologiareponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaIngléscc by-nc-sa (c) Lloret Cabot, Roger, 2024http://creativecommons.org/licenses/by-nc-sa/3.0/es/info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/2153942026-05-27T06:46:51Z |
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15.812455 |