Predominance of Alphaproteobacteria in Cladonia arbuscula as detected by simultaneous use of EUB338MIX-Cy3 and ALF968-Cy5 FISH probes (CLSM images). (a) Transversal and (b) tangential sections. Pink, Alphaproteobacteria (resulting from a positive signal with both probes); red, other bacteria (stained by EUB338MIX-Cy3 only); green, chlorophyll autofluorescence; yellow/brown, fungal autofluorescence; A, algal cells; F, fungal hyphae. Scale bars are 10 μm. (c, d) 3D reconstructions (formed by spots and isosurfaces) of the images in (a) and (b), respectively. Red/blue spots, Alphaproteobacteria; red spot, other bacteria; yellowish isosurface, fungi; green isosurface, algal cells.