Licensed to Clone

Ian Wilmut, the scientist who produced the first cloned sheep, received approval to inject nuclei from the cells of people with motor neuron disease, into embryonic stem cells (derived from discarded fetuses). The idea is apparently to make an ES cell line, that can be differentiated into neurons, whose properties can be studied in the lab.

This is an unusual approach to studying a genetic disorder. The normal strategy would be to identify the genetic lesion causing ALS, engineer a mouse with that mutation and then study the characteristics of neurons in that mouse at leisure. However in the case of ALS, its tricky. Only one gene underlying ALS (SOD1) has been identified with certainty, and mutations in SOD1 are only responsible for a small fraction of ALS cases. Engineered mice are a valuable tool for studying the role of SOD1 in producing ALS, but the concensus now is that the disease progression in those mice is a complex process.

So studying how motor neurons degenerate in the other 98% of ALS cases, might yield novel insights. For example, it might be obvious that all ALS neurons produced in this manner have similar cellular defects. The advantage of using cloning techniques, is that its not necessary to know what the mutations are. This is a good example of the power of cloning as a research tool, although it should be acknowledged that the disease in question is an unusual one.