Transcriptome Analysis on the ALAN-Induced Zebrafish Ovary: Desynchronization of Life Processes and Initiation of Diseases

Abstract

Objective: The effect of artificial light at night (ALAN) on “transcriptome” is prominent owing to its capacity for “desynchronization” of organismal physiology. Light influences the circadian rhythm. This study aims to explore the ALAN-induced ovarian transcriptome of zebrafish for desynchronization of life processes. Methods: Four experimental conditions were set up for female zebrafish: one normal 12-hour light and 12-hour dark (LD) cycle, and three continuous exposures to ALAN for one week (LLW), one month (LLM), and one year (LLY). The whole transcriptome data analysis of the ALAN-exposed samples was then compared with the normal sample using RNA-Seq, followed by exploratory analyses. Results: The analysis revealed two different patterns of expression of genes where LLW and LLM differ with LLY samples in comparison to LD. Compared to LD, downregulation of the predicted hub genes was observed in all treatments; ribosome and oxidative phosphorylation pathways were enriched. LLY vs. LD contrast depicts the enrichment of three more pathways—RNA polymerase, adhesion junction, and signaling. The gene ontology (GO) enrichment portrays more prevalent biological processes in LLW vs. LD and LLM vs. LD than in LLY vs. LD. Contrast-wise disease annotation represents neoplasms as the most prevalent; disease enrichment denotes the major class of neoplasm, carcinoma, coupled with intellectual disability, global developmental delay, and seizures. Conclusion: Our study displayed desynchronization of various genes and pathways leading to the initiation of diseases, for the first time in zebrafish. Even though, this data shows that ALAN is a serious threat, further research is needed to determine the intensity and the duration of ALAN which might cause potential repercussions.