AUTHOR=Jia Xiaoyu , Feng Yibo , Ma Wenju , Zhao Wei , Liu Yanan , Jing Guangyin , Tian Jing , Yang Tao , Zhang Ce 

TITLE=A fluidic platform for mobility evaluation of zebrafish with gene deficiency

JOURNAL=Frontiers in Molecular Neuroscience

VOLUME=Volume 16 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/molecular-neuroscience/articles/10.3389/fnmol.2023.1114928

DOI=10.3389/fnmol.2023.1114928

ISSN=1662-5099

ABSTRACT=Mobility of the zebrafish and the cellular behavior in vivo reflect pathological conditions, e.g., brain disorders, disrupted motor functions and insensitivity to environmental challenges. Zebrafish is, therefore, a suitable animal model for molecular genetic tests and drug discovery. However, it remains technologically challenging to quantitatively assess zebrafish’s mobility in a dynamically flowing environment, and simultaneously monitor the cellular behavior in vivo. In this work, we developed a facile fluidic device equipped with an electric motor to induce mechanical vibration, and controllably generate various flow patterns in a single droplet. The dynamically flowing environment mimics the habitat of a zebrafish in the wild. It is observed that in a droplet with four recirculating flows, there are two equilibrium positions, where the constrained zebrafish remains stagnant, i.e., the “source” position dominated by outgoing flows and the “sink” position with incoming flows. Motile wild-type zebrafish tends to swim against the flow, and fight to stay in the “sink”. Slight deviation from streamline flow leads to an increased torque, and thus pushes the zebrafish even further away. Deviation angle from the sink position can, therefore, be used to quantify the mobility of zebrafish under flowing environmental conditions. In contrast, zebrafish with motor neuron dysfunction caused by lipin-1 deficiency is forced to stay at the source position, where both the head and tail are aligned with the flow direction. Moreover, in a droplet of comparable size, single zebrafish can be effectively restrained for high resolution imaging. The proposed methodology provides opportunities to quantitatively assess zebrafish’s mobility, and directly link the cellular behavior reflecting pathological symptoms.