title: Perturbation of cytosolic calcium by 2-aminoethoxydiphenyl borate and caffeine affects zebrafish myofibril alignment.
abstract: The objective of the current study was to investigate the effects of Ca(2+) levels on myofibril alignment during zebrafish embryogenesis. To investigate how altered cytoplasmic Ca(2+) levels affect myofibril alignment, we exposed zebrafish embryos to 2-aminothoxyldiphenyl borate (2-APB; an inositol 1,4,5-trisphosphate receptor inhibitor that reduces cytosolic Ca(2+) levels) and caffeine (a ryanodine receptor activator that enhances cytosolic Ca(2+) levels). The results demonstrated that the most evident changes in zebrafish embryos treated with 2-APB were shorter body length, curved trunk and malformed somite boundary. In contrast, such malformed phenotypes were evident neither in untreated controls nor in caffeine-treated embryos. Subtle morphological changes, including changes in muscle fibers, F-actin and ultrastructures were easily observed by staining with specific monoclonal antibodies (F59 and α-laminin), fluorescent probes (phalloidin) and by transmission electron microscopy. Our data suggested that: (1) the exposure to 2-APB and/or caffeine led to myofibril misalignment; (2) 2-APB-treated embryos displayed split and short myofibril phenotypes, whereas muscle fibers from caffeine-treated embryos were twisted and wavy; and (3) zebrafish embryos co-exposed to 2-APB and caffeine resulted in normal myofibril alignment. In conclusion, we proposed that cytosolic Ca(2+) is important for myogenesis, particularly for myofibril alignment.
authors.affiliation: Department of Chemistry, Tamkang University, No. 151, Ying-chuan Road, Tamsui, New Taipei City, Taiwan.
authors.forename: Hsin-Ju
authors.initials: HJ
authors.lastname: Wu
authors.forename: Tsorng-Harn
authors.initials: TH
authors.lastname: Fong
authors.forename: Shen-Liang
authors.initials: SL
authors.lastname: Chen
authors.forename: Jen-Cheng
authors.initials: JC
authors.lastname: Wei
authors.forename: I-Jong
authors.initials: IJ
authors.lastname: Wang
authors.forename: Chi-Chung
authors.initials: CC
authors.lastname: Wen
authors.forename: Chao-Yuan
authors.initials: CY
authors.lastname: Chang
authors.forename: Xing-Guang
authors.initials: XG
authors.lastname: Chen
authors.forename: Wei-Yu
authors.initials: WY
authors.lastname: Chen
authors.forename: Hui-Min
authors.initials: HM
authors.lastname: Chen
authors.forename: Juin-Lin
authors.initials: JL
authors.lastname: Horng
authors.forename: Yun-Hsin
authors.initials: YH
authors.lastname: Wang
authors.forename: Yau-Hung
authors.initials: YH
authors.lastname: Chen
mesh_terms: D000818:Animals; D001896:Boron Compounds / Q000633:toxicity*; D002110:Caffeine / Q000633:toxicity*; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000187:drug effects* / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D024510:Muscle Development / Q000187:drug effects*; D009210:Myofibrils / Q000187:drug effects* / Q000648:ultrastructure; D015027:Zebrafish / Q000196:embryology*
chemical_list: D001896:Boron Compounds; D002110:Caffeine; C109986:2-aminoethoxydiphenyl borate; D002118:Calcium
keywords: caffeine; calcium; embryogenesis; myogenesis; zebrafish