title: Zebrafish Jak2a plays a crucial role in definitive hematopoiesis and blood vessel formation.
abstract: We examined the role of zebrafish (Danio rerio) Jak2a, a homolog of mammalian Jak2, in the developing embryo by injecting in vitro synthesized Jak2a shRNA into zebrafish zygotes. Blood circulation was suppressed in Jak2a shRNA-injected embryos from 24hours post fertilization (hpf) and all embryos died with enlarged pericardium, shortened body lengths, and defects in some vasculature within 8 days post fertilization. O-dianisidine staining of red blood cells revealed normal blood island formation with no circulating red blood cells. As in Jak2(-/-) transgenic mice, expression of definitive Ba1 globin was significantly reduced in Jak2a knockdown embryos at 36hpf, whereas expression of other hematopoietic markers, primitive be1 globin, gata-1, and scl, were unaffected. More importantly, blood vessel formation was disturbed in Jak2a knockdown embryos as revealed by alkaline phosphatase staining at 72hpf. Thus, our data indicate that zebrafish Jak2a is important in both definitive hematopoiesis and blood vessel formation.
authors.affiliation: Department of Life Science, College of Natural Sciences, Hanyang University, Haengdang 17, Sungdong-gu, Seoul 133-791, Republic of Korea.
authors.forename: Jin Jea
authors.initials: JJ
authors.lastname: Sung
authors.forename: Jinseon
authors.initials: J
authors.lastname: Jeon
authors.forename: Jong Joo
authors.initials: JJ
authors.lastname: Lee
authors.forename: Chul Geun
authors.initials: CG
authors.lastname: Kim
mesh_terms: D000818:Animals; D001775:Blood Circulation / Q000235:genetics; D001808:Blood Vessels / Q000196:embryology*; D004625:Embryo, Nonmammalian / Q000201:enzymology; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D006410:Hematopoiesis / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D018919:Neovascularization, Physiologic / Q000235:genetics; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000502:physiology*; D034741:RNA, Small Interfering / Q000235:genetics; D019076:Transgenes; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics / Q000502:physiology*
chemical_list: D034741:RNA, Small Interfering; D029961:Zebrafish Proteins; D011505:Protein-Tyrosine Kinases; C534485:Jak2a protein, zebrafish