Figure 4. Immuno-analyses using anti-thrombospondin show evidence of TSRs in symbiotic anemone host tissues.
(A) Immunoblots of symbiotic (SYM) and aposymbiotic (APO) A. pallida label bands at 40 and 47 kDa in symbiotic anemones and a single band at 40 kDa in aposymbiotic anemones. (B, C) Confocal images of dinoflagellate cells taken from (B) culture or (C) freshly isolated cells taken from A. pallida homogenates. A fluorescent probe conjugated to anti-human thrombospondin does not label cells from culture (B) but strongly labels host cell debris and/or membranes associated with freshly isolated cells (C). (D, E) Confocal images of cryosections from symbiotic A. pallida gastrodermal tissue stained with anti-thrombospondin at lower (D) and higher (E) magnification. Anti-thrombospondin labelling is evident in host tissues surrounding symbionts. (F) Confocal image of control anemone cryosections incubated with secondary antibody only. No anti-thrombospondin labeling is evident. Green = anti-thrombospondin, Red = algal autofluorescence, blue = DAPI stain of host and symbiont nuclei.
Figure 4—figure supplement 1. A: Actin control for immunoblot blot in Figure 4.
Figure 4—figure supplement 2. Lipophilic membrane staining of dinoflagellate cells using Dil.
