Today's Science publication explains the mechanism for how widely-expressed genes can cause selective death of motor neurons, resulting in MND. By identifying two specific mutations in the same gene, the combined research group has produced a precise mammalian model of MND and described the pathogenetic link between specific gene mutations and selective, progressive degeneration of motor neurons. The research groups initially began their research with two distinct mouse models of late-onset MND and traced the genetic cause of the symptoms to specific point mutations in one gene, Dnchc1. Based on that discovery, the combined research team defined that the mutations in the Dnchc1 gene impaired axonal transport in the nerve cell, which specifically caused cell-death in motor neurons without affecting other cell types. This type of selective motor neuron degeneration is clinically similar on a cellular and organismal level to the human disease state seen in ALS and other motor neuron diseases.