Extended Data Fig. 1: Distribution of endosomal and TGN markers is not affected in BORC-KO i3Neurons.

a-c, WT, BORCS5-KO and BORCS7-KO i3Neurons grown for 25 days on glass coverslips were fixed, permeabilized and co-stained with antibodies to endogenous MAP2 (soma and dendrites) (magenta) (all three panels) and cation-independent mannose 6-phosphate receptor (CI-MPR) (endosomes and TGN) (a), early endosomal antigen 1 (EEA1) (early endosomes) (b), or TGN46 (TGN) (c) (all in grayscale). Nuclear DNA was stained with DAPI (blue). Scale bars: 10 μm. Notice the presence of CI-MPR in all neuronal domains including axons (a), EEA1 only in the soma and dendrites (b) and TGN46 only in the soma (c), and how the distribution of all these markers does not change upon BORCS5 KO or BORCS7 KO. All the experiments shown in a-c were repeated three times.