title: Deep Brain Photoreceptor (val-opsin) Gene Knockout Using CRISPR/Cas Affects Chorion Formation and Embryonic Hatching in the Zebrafish.
abstract: Non-rod non-cone photopigments in the eyes and the brain can directly mediate non-visual functions of light in non-mammals. This was supported by our recent findings on vertebrate ancient long (VAL)-opsin photopigments encoded by the val-opsinA (valopa) and val-opsinB (valopb) genes in zebrafish. However, the physiological functions of valop isoforms remain unknown. Here, we generated valop-mutant zebrafish using CRISPR/Cas genome editing, and examined the phenotypes of loss-of-function mutants. F0 mosaic mutations and germline transmission were confirmed via targeted insertions and/or deletions in the valopa or valopb gene in F1 mutants. Based on in silico analysis, frameshift mutations converted VAL-opsin proteins to non-functional truncated forms with pre-mature stop codons. Most F1 eggs or embryos from F0 female valopa/b mutants showed either no or only partial chorion elevation, and the eggs or embryos died within 26 hour-post-fertilization. However, most F1 embryos from F0 male valopa mutant developed but hatched late compared to wild-type embryos, which hatched at 4 day-post-fertilization. Late-hatched F1 offspring included wild-type and mutants, indicating the parental effects of valop knockout. This study shows valop gene knockout affects chorion formation and embryonic hatching in the zebrafish.
authors: Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia.
authors: Chong Yee
authors: CY
authors: Hang
authors: Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia.
authors: Shogo
authors: S
authors: Moriya
authors: Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia.
authors: Satoshi
authors: S
authors: Ogawa
authors: Brain Research Institute, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia.
authors: Ishwar S
authors: IS
authors: Parhar
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000196:embryology / Q000378:metabolism*; D064113:CRISPR-Cas Systems / Q000235:genetics*; D002823:Chorion / Q000254:growth & development*; D005260:Female; D055786:Gene Knockout Techniques; D008297:Male; D009154:Mutation; D055355:Opsins / Q000737:chemistry / Q000172:deficiency / Q000235:genetics*; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry / Q000172:deficiency / Q000235:genetics*; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics*
chemical_list: D055355:Opsins; D043562:Receptors, G-Protein-Coupled; C000601498:vertebrate ancient long opsin A, zebrafish