Human Motor Axons Have a Distinct Transcriptome that Overlaps with Mouse Motor Axons
(A) Immunocytochemistry of human control iPSC-derived MNs growing in a microfluidic device.
(B) PCA based on all expressed genes shows clear separation of human axonal and somatodendritic fractions along PC1.
(C) Numbers of detected genes in human bulk somas, axons, and single human Hb9-GFP+ MNs. Human axons contain >3,400 transcripts, while somas contain >15,000 transcripts at RPKM >0.1. Single cells are intermediate with approximately 10,000 transcripts detected. Data are represented as means ± SEM.
(D) Expression of selected marker genes in human soma and axon samples reveals strong axonal presence of mRNAs for cytoskeletal elements and the TF FOXP1. Glial markers are absent in axons.
(E) Comparison of the human motor axon transcriptome with the common mouse motor axon transcriptome (Figure S3A) reveals an overlap of 1,273 genes (after exclusion of non-orthologous genes). These genes enrich in GO terms for energy production, translation, and nonsense-mediated decay. Scale bar: (A) 100 μm.