Fig. 3

Mislocalized cone mitochondria are found in Müller glia (MG) cells PR, photoreceptor layer; IR, inner retina; OLM, outer limiting membrane. (A) In vivo imaging of fish expressing gnat2:mtBFP and GFAP:GFP shows mislocalized mitochondria both inside (filled arrow) and outside (unfilled arrow) MGs. Both images were obtained from mtKR+, LED+ fish. Scale: 5 μm. (B) 3D reconstruction of mislocalized mitochondrion encapsulated by an MG process from the first panel of (A). Scale: 3 μm. (C) Quantification of mislocalized cone mitochondria classified by colocalization with MGs. Activation of mtKR increases both MG+ and MG− mislocalized mitochondria. ∗p < 0.05 and ∗∗∗∗p < 0.0001 using a two-way ANOVA. n = 6 noKR fish, n = 7 kR+ fish. (D) Images from a 4 h, 5 min interval in vivo timelapse of a Tg(gnat2:mtBFP, GFAP:GFP,gnat2:mtKR) fish post-LED treatment. Scale: 5 μm. (E) Longitudinal micrographs from SBFEM for mtKR− and mtKR+ fish (both LED treated). The mtKR fish contains several swollen, electron-lucent mitochondria between cone cell bodies near the photoreceptor nuclear layer and synapse. Scale: 5 μm. (F) Transverse section from SBFEM stack of a mtKR+ fish at the OLM where abundant swollen/lucent mitochondria can be observed between cone cells in MG. Scale: 5 μm. (G) 3D reconstruction of MG cytosol (green) and the swollen mitochondria (multicolor) observed both at the OLM further down MG processes.