Gene expression profiles of embryonic motor neurons in the SOD1G93A mouse model of amyotrophic lateral sclerosis: insights into earliest pathogenesis

Although ALS typically presents in mid to late-life, there is increasing evidence for a protracted preclinical period of motor neuron dysfunction. The goal of this study is to identify the earliest gene expression patterns in lower motor neurons that drive selective neuronal vulnerability in a mouse model of ALS. We have implemented transgenic SOD1G93A with a lower motor neuron fluorescent reporter (HB9-GFP) mice to unambiguously isolate spinal motor neurons using FACS for gene expression profiling using RNA sequencing at embryonic day (E)12.5. Data from this transcriptomic study allowed the identification of disturbance in MN homeostasis which occur at the day of birth of spinal motor neurons in SOD1G93A mice. Pathway analysis uncovered several remarkably dysregulated pathways including RNA metabolism disturbance and excitotoxicity. Our findings have the potential to reveal insights into the incipient molecular mechanisms that confer motor neuron vulnerability and therefore may highlight relevant gene targets and pathways for effective intervention in ALS. Gene expression profile of mouse spinal motor neurons. Wild-type control with 4 biological replicates compared with mouse SOD1G93A motor neurons 4 biological replicates at embryonic day 12.5.