P0 protein in normal, trembler heterozygous/homozygous mice during active PNS myelination.

The quantification of P0 protein has been currently used to measure the myelination of the peripheral nervous system (PNS). Using immunological techniques, we show that, as early as postnatal day 8, the P0 content of mice homozygous and heterozygous for the Trembler mutation, represent respectively one tenth and half of the normal values. Thus, although the Trembler mutation is dominant, the myelination defect observed in heterozygous Trembler mice is more pronounced in the homozygous Trembler mice. This gene dosage effect should be taken into account when a molecular model of the Trembler mutation will be proposed.