Fig. 6.

Fig. 6. NELO as part of a larger lymphoid network.

(A) Scheme illustrating the localization of the branchial cavity images acquired from 30-μm whole adult zebrafish head cryosections labeled with anti-ZAP70 antibody (orange hot) to reveal T/NK cells (B and C). NELO (red arrowheads) is part of the lymphoid network propagated by the ZAP70-positive cell–rich cavo-branchial epithelium (cyan arrowheads) and which connects all the lymphoid structures of the branchial cavity. (D) Scheme describing the different anatomical regions displayed by the coronal cryosection presented in (B). (E) Scheme describing the different anatomical regions displayed by the transversal cryosection presented in (C). Annotations: Aaa, afferent arch artery; dILT, distal interbranchial lymphoid tissue; Eaa, efferent arch artery; Ft, fat tissue; Op, operculum; pILT, proximal interbranchial lymphoid tissue; Tc, thymus cortex; Tm, thymus medulla. Scale bars, 200 (B) and 100 μm (C).