Proper regulation of Citrine expression in TgBAC(runx1P2:Citrine) embryos (a) Multiple sequence alignment between the 5’ most bases of the runx1 alternative promoter products from human (hRUNX1) and zebrafish (zRunx1). P1 specific sequences are shown in red. The zebrafish 2a specific sequence is shown in grey. The in-exon splice site for the human transcript is highlighted in yellow. (b) Schematic representation of the zebrafish runx1 locus and regions covered by each of the previously identified zebrafish BACs1. (c) ISH for runx1 and Citrine in early TgBAC(runx1P2:Citrine) embryos depicting the region of the posterior lateral mesoderm (PLM). (d) Microscopic images of Citrine fluorescence focusing on the PLM region. Orange arrows indicate region shown in the top view panel. (e) ISH for runx1 in WT and early TgBAC(runx1P2:Citrine) embryos at 29 hpf. (f) Fluorescent microscopy image of a 50 hpf double transgenic TgBAC(runx1P2:Citrine);Tg(kdrl:mCherry) embryo focusing on the trunk region. (g) Representative microscopic image of a 6 dpf TgBAC(runx1P2:Citrine) embryo. The region of the thymus (Th), kidney (Ki) and caudal haematopoietic tissue (CHT) are indicated. (h) ISH for Citrine or runx1 in the trunk region of embryos injected with MOs targeting tal1b or gata2b. ISH for kdrl controls for integrity of vascular structures.