Combined structural and molecular zebrafish embryonic imaging on ethanol exposure effects during vasculature development

Mothers who consume ethanol during pregnancy expose their fetus to ethanol, leading to a range of birth defects. These include craniofacial defects, intellectual impairments, sensorimotor disabilities, and organ deformations, which are collectively known as fetal alcohol spectrum disorder (FASD). Zebrafish are a popular animal model for the study of FASD due to their external embryo development, optical transparency, and large number of embryos. Fluorescence techniques are often used to map molecular and genetic changes but cannot provide direct structural imaging. Our previously reported multimodal optical coherence tomography (OCT) and light-sheet fluorescence microscopy (LSFM) system has the unique ability to provide simultaneous 3D structural and molecular information. In this study, we exposed zebrafish embryos to different concentrations of ethanol (0.0%, 1.0%, 1.5%, and 2.0%) from 6 hours post fertilization (hpf) to 24 hpf and observed the structural and molecular effects at 48 hpf and 72 hpf using the multimodal OCT and LSFM system. The samples were a transgenic line, Tg(kdrl:GFP), where the vasculature endothelial cells express GFP. Our results clearly show that increased ethanol exposure led to a reduction of body size along with vasculature deformations, particularly in the aortic arches and caudal vessels, including the caudal aorta and vein.