In Vivo Modeling of Zebrafish Zinc Finger, MIZ-Type Containing 1 (ZMIZ1) Expression and its Effect on Pigmentation

Objective: We conducted this study to investigate the role of Zinc Finger MIZ-Type Containing 1 (ZMIZ1) in pigmentation remains unclear. Methods: We generate a zebrafish loss-of-function model using morpholino oligonucleotides (MOs), and two orthologs of human ZMIZ1 have been annotated (ZMIZ1a and ZMIZ1b). The expression profiles of ZMIZ1a and ZMIZ1b and their effect on the pigmentation in zebrafish were evaluated. Results: Investigation of the temporal and spatial expressions of these two transcripts suggested that the expressions of ZMIZ1a and ZMIZ1b in the brain start to emerge in a ubiquitous fashion from 2 days post-fertilization onwards. After the successful design and validation of MOs, we observed that ZMIZ1a and ZMIZ1b MOs caused embryonic developmental delays and malformations in zebrafish. Further analysis of the melanin content in the morphants revealed that ZMIZ1a significantly (P < 0.05) reduced the melanin content in a dose-dependent manner, but only the highest concentration of injected ZMIZ1b MOs significantly (P < 0.05) reduced the melanin content. A tyrosinase inhibition assay indicated no significant difference (P > 0.05) between the morphants and wild-type zebrafish. Conclusions: This study successfully modeled a susceptibility gene identified by genome-wide association studies in a zebrafish loss-of-function model and provides insights into the biological mechanism of pigmentation.