Fig. 5

The Trunk DA-PCV Joint Contains Precursors that Will Seed the Caudal Hematopoietic Tissue, Thymus, and Pronephros(A) DIC video image of a live 2 dpf embryo at the posterior trunk level, focused on the sagittal plane; arrows point at the DA-PCV joint targeted with the laser in (B). (B) Fluorescence of fluorescein just laser-uncaged all along the DA-PCV joint. The overlying diffuse labeling is due to marginal uncaging in the somite muscle overlying the target followed by diffusion within the somite muscle fibers. (C–J) Anti-fluorescein immunostaining performed 3 days later (5 dpf). (D) Ventral view of the head, showing the two thymi (arrows); arrowheads point at labeled leukocytes outside the thymi. (E) Magnified ventral view of the right thymus, showing individual labeled thymocytes among unlabeled ones. (F) Pronephros (ventral view, rostral up), with genuinely labeled cells (red arrows) around the glomerulus (g) and vesicular labeling of distal tubules (dt); two labeled cells (asterisk) are shown magnified in (F′). (G–J) Caudal hematopoietic tissue, lateral view, rostral left; areas bracketed in (G) are shown magnified in (H)–(J). Note that none of the hundreds of primitive erythrocytes fixed in the CA is labeled. pt, proximal pronephric tubule; e, erythrocyte. Scale bars represent 200 μm in (C); 100 μm in (D) and (G); 50 μm in (F); 20 μm in (E), (H)–(J); 10 μm in (F2).