J Neurobiol 1997 Jul;33(1):11-17
Department of Biological Sciences, Columbia University, New York, New York 10027, USA.
To explore possible neurogenic functions of the genes of the Hox/HOM complexes, we injected the mRNA from the leech homeobox genes Lox1 and Lox4 into adult neurons that normally do not express them. The ectopic expression of Lox1 induced a specific tra nsformation in the electrical properties of certain identified neurons: action potential amplitude increased about threefold after the injections. This effect of Lox1 expression was restricted, among cell types examined, to the anterior pagoda neurons (AP s) and the nut neurons. This effect was also restricted to Lox1 ectopic expression; the action potentials of APs and nut neurons were not enlarged when the mRNAs of either Lox4, another leech Hox/HOM gene, or beta-galactosidase were injected. Lox1 mRNA in jection did not affect the resting potential, input resistance, or axonal morphology of the transformed APs, raising the possibility that it acts via the modification of voltage-dependent ion channels. Thus, a specific homeobox gene can transform key neur onal characteristics in a cell-specific manner. We may thus add electrophysiologic properties to other aspects of neuronal identity determined by homeobox gene expression.
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PMID: 9212066, MUID: 97355585