Zebrafish Cyp1b1 knockout alters eye and brain metabolomic profiles, affecting ocular and neurobehavioral function

Cytochrome P450 1B1 (CYP1B1) is an enzyme that metabolizes endogenous and xenobiotic compounds. CYP1B1 is thought to be involved in the metabolism of compounds vital to the proper development of the eye. Studies have identified CYP1B1 as a causative gene in the ocular disease primary congenital glaucoma (PCG), however CYP1B1’s role in PCG development and related eye disorders is poorly understood. To explore CYP1B1’s role an in vivo zebrafish (Danio rerio) model was used. This study sought to determine if knocking out CYP1B1 produced an ocular defect similar to PCG and whether this could be distinguished from other neurobehavioral effects. To do this a new CYP1B1 knockout line (wh5) was generated using CRISPR/Cas9 induced deletions truncating the protein before the catalytic domain. Behavior assays, untargeted metabolomics, and RNA sequencing was used to determine the phenotype of the wh5 line. RNA sequencing based transcriptomics was performed on adult eye and brain samples. 95 genes in the eye and 45 genes in the brain were found to be differentially expressed between the genotypes. Untargeted metabolomics analysis was performed on the same tissue type and pathway analysis was performed on the separate data sets. KEGG pathways involved in lipid, steroid, amino acid, and nitrogen metabolism were found to be significantly perturbed. A joint pathway multi-omics analysis was performed introducing gene interactions into the metabolomics pathway analysis. wh5 zebrafish performed significantly different in multiple larval and adult behavior assays, however an ocular defect could not be distinguished from other neurobehavioral phenotypes due to large metabolic and transcriptomic changes in both organs. To investigate the role of CYP1B1 in the eye and and brain a CYP1B1 knockout zebrafish line (wh5) was used. Adult zebrafish whole eyes and brains were dissected. Five replicates of each sample type were sequenced: sex, genotype (WT or KO (wh5)), and organ for a total of 40 samples.