Zebrafish Embryos Display Characteristic Bioelectric Signals during Early Development

Area of Science:

• Developmental Biology
• Bioelectricity
• Cellular Electrophysiology

Background:

• Bioelectricity, involving endogenous electrical signaling via charged molecules, is crucial for embryonic development, regeneration, and congenital diseases.
• Previous research faced limitations in real-time in vivo monitoring of whole-organism electrical activity due to inadequate model systems and tools.

Purpose of the Study:

• To address the gap in in vivo bioelectric monitoring by developing and utilizing a suitable model system and voltage measurement tools.
• To systematically investigate cell membrane potential (Vm) signals in zebrafish embryos across different embryonic stages.

Main Methods:

• Utilized a genetically stable zebrafish line, Tg (ubiquitin: ASAP1).
• Employed ASAP1 (Accelerated sensor of action potentials 1), a genetically encoded voltage indicator (GEVI).
• Conducted systematic investigation of Vm signals using light-sheet microscopy.

Main Results:

• Observed local membrane hyperpolarization at cleavage furrows during zebrafish embryogenesis' cleavage period, preceding cytokinesis.
• Detected whole-cell transient hyperpolarization during blastula and gastrula stages, primarily in superficial blastomeres but also in deeper cells during gastrulation.
• Identified tissue-level Vm signals during the segmentation period, with dynamic fluctuations in somites starting around the 12-somite stage.

Conclusions:

• Zebrafish embryos display distinct, stage-specific cellular bioelectric signals throughout embryogenesis.
• These characteristic electrical activities suggest diverse roles in zebrafish development.
• The findings may provide insights into the mechanisms underlying human congenital diseases.