In Vivo Modeling of Zebrafish Zinc Finger,MIZ-Type Containing 1 Expression and Its Effect on Pigmentation

Objective:The zinc finger,MIZ-type containing 1(ZMIZ1)gene has been identified as a possible susceptibility gene associated with vitiligo,therefore we conducted this study to investigate the role ofZMIZ1 in pigmentation.Methods:We generate a zebrafish loss-of-function model using morpholino oligonucleotides(MOs),and two orthologs of humanZMIZ1 have been annotated(ZMIZ1a andZMIZ1b).The expression profiles of ZMIZ1a and ZMIZ1b and their effects on the pigmentation in zebrafish were evaluated by using whole-mount in situ hybridization and melanin quantification.Statistical analysis was performed using the unpaired Studentt-test or one-way analysis.Results:Investigation of the temporal and spatial expressions of these two transcripts suggested that the expressions ofZMIZ1a andZMIZ1b 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 thatZMIZ1a andZMIZ1b MOs caused embryonic developmental delays and malformations in zebrafish.Further analysis of the melanin content in the morphants revealed thatZMIZ1a significantly(49.1%for 0.667 mmol/L inZMIZI1a group,P=0.03)reduced the melanin content in a dose-dependent manner,but only the highest concentration of injectedZMIZ1b MOs significantly(50%for 0.667 mmol/L inZMIZ1b group,P=0.02)reduced the melanin content.A tyrosinase inhibition assay indicated no significant difference between the morphants and wild-type zebrafish.Conclusion: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.