observation of the collective behavior and optogenetic experimentation of nematode dauer worms

Investigando comportamentos coletivos em nematóides usando meio de ágar ração para cães

Both nonscientists and scientists are fascinated with animals&#39; collective behaviors, as in flocks of birds and schools of fish. Collective behaviors have been analyzed in a broad range of fields, including physics, biology, mathematics, and robotics. In particular, active matter physics is a growing research field that focuses on systems composed of self-propelled elements, that is, dissipative systems, such as flocks of birds, schools of fish, biofilms of motile bacteria, cytoskeletons composed of active molecules, and groups of self-propelled colloids. The theory of active matter physics maintains that however complex the behaviors of individuals are, the collective motions of enormous numbers of living things are governed by a small number of simple rules. For example, the Vicsek model, a candidate for a unified description of the collective motion of self-propelled particles, predicts that short-range alignment interaction of moving objects is required to form a long-range ordered phase with eccentric fluctuation in 2D, as in herds of animals1. Top-down experimental approaches pertaining to the physics of active matter are developing rapidly. Previous experiments confirmed the formation of a long-range ordered phase in Escherichia coli2. Other recent works&#160;employed cells3,4, bacteria5, motile colloids6, or moving proteins7,8. Simple minimal models such as the Vicsek model successfully described these real phenomena. In contrast with these unicellular experimental systems, collective behaviors by animals are usually observed in the wild, as no one could hope to perform controlled experiments with 10,000 real birds or fish.
Biologists share the same interest as physicists: how individuals interact with each other and functionally behave as a group. One of the traditional research fields for analyzing individual behavior is neuroscience, in which the mechanisms underlying behavior have been examined at the neuronal and molecular levels. Many neuroscientific bottom-up approaches have been developed thus far. Top-down approaches in physics and bottom-up approaches in biology can be facilitated using model animals such as the fruit fly, the worm Caenorhabditis elegans, and the mouse9. However, there have been few findings on the large-scale collective behavior of these model animals in the laboratory10; it is still difficult to prepare genetically tractable model animals on a large scale in the laboratory. Therefore, in current research on collective behaviors in biology and physics, it has been difficult for scientists who usually do research in the laboratory to study animals&#39; collective behaviors.
In this study, we established a method for the large-scale cultivation of nematodes to study their collective behaviors. This system allows us to change environmental conditions and examine the effect of individual-level locomotion on collective behaviors using mutants10. In active matter physics, the parameters of the mathematical model can be controlled in both experiments and simulations, which enables verification of that model for identifying unified descriptions. Genetics is used to understand the neural circuit mechanism underlying collective behavior11.

Autor em destaque: Análise comportamental coletiva do Nematóide, Caenorhabditis elegans

O cultivo em larga escala de nematoides para estudar seus comportamentos coletivos

Observação do comportamento coletivo e experimentação optogenética de vermes do nematoide dauer

Comece colocando uma nova placa NGM desprovida de E.coli e DFA em uma placa de alumínio no palco de um microscópio macro zoom. Use uma unidade controladora de temperatura Peltier para manter o fundo da placa a 23 graus Celsius de temperatura por pelo menos cinco minutos. Em seguida, substitua a placa pela tampa de uma placa em que os vermes nematoides subiram.Aumente a temperatura do fundo da placa para 26 graus Celsius para alterar a umidade interior. Agora, capture imagens da superfície interna da tampa da placa a 20 quadros por segundo usando a câmera do microscópio, mantenha os vermes ZX899 no DFA, mantendo essa condição por cinco minutos antes da iluminação. Agora ilumine os vermes ZX899 presos a uma tampa de placa de Petri, mantida a 23 graus Celsius.Capture as imagens da superfície interna da placa a 20 quadros por segundo. O aumento da umidade exibiu tamanhos de compartimento maiores dos padrões da rede de vermes antes de finalmente entrar em colapso, deixando aglomerados de vermes dormentes na superfície interna da tampa.

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Research

JoVE Journal

Biology

Observation of the Collective Behavior and Optogenetic Experimentation of Nematode Dauer Worms

54 visualizações. Comece colocando uma nova placa NGM desprovida de E.coli e DFA em uma placa de alumínio no palco de um microscópio macro zoom. Use uma unidade controladora de temperatura Peltier para manter o fundo da placa a 23 graus Celsius de temperatura por pelo menos cinco minutos. Em seguida, substitua a placa pela tampa de uma placa em que os vermes nematoides subiram.Aumente a temperatura do fundo da placa para 26 graus Celsius para alterar a umidade interior. Agora, capture imagens da super...

Vídeo: Observação do comportamento coletivo e experimentação optogenética de vermes do nematoide dauer

The Large-Scale Cultivation of Nematodes to Study Their Collective Behaviors

Animals exhibit dynamic collective behaviors, as observed in flocks of birds, schools of fish, and crowds of humans. The collective behaviors of animals have been investigated in the fields of both biology and physics. In the laboratory, researchers have used various model animals such as the fruit fly and zebrafish for approximately a century, but it has remained a major challenge to study large-scale complex collective behavior orchestrated by these genetically tractable model animals. This paper presents a protocol to create an experimental system of collective behaviors in Caenorhabditis elegans. The propagated worms climb on the lid of the Petri plate and show collective swarming behavior. The system also controls worm interactions and behaviors by changing the humidity and light stimulation. This system allows us to examine the mechanisms underlying collective behaviors by changing environmental conditions and examining the effects of individual-level locomotion on collective behaviors using mutants. Thus, the system is useful for future research in both physics and biology.

Here, a system is reported for studying the collective behaviors of nematodes by culturing them in bulk using dog food agar medium. This system allows researchers to propagate large numbers of dauer worms and can be applied to Caenorhabditis elegans and other related species.

Animals exhibit dynamic collective behaviors, as observed in flocks of birds, schools of fish, and crowds of humans. The collective behaviors of animals ...