Site of pcd gene action and Purkinje cell mosaicism in cerebella of chimaeric mice.

Abstract

PURKINJE cell degeneration, pcd, is a new autosomal recessive mutation in mice. Affected animals are characterised by a moderate ataxia that results from the postnatal loss of virtually all cerebellar Purkinje cells1. We describe here experiments to determine whether the pcd gene acts intrinsically within the Purkinje cell or whether the degeneration is secondary to a primary lesion in some other cell type. In this study, experimental chimaeras were made which contained mixtures of mutant (pcd/pcd) and genotypically normal (+/+) cells (these chimaeras are denoted pcd/pcd←→+/+). The results indicate that the pcd gene does act within the Purkinje cell. The chimaeras have also been used to examine the surviving population of +/+ Purkinje cells for evidence of clonal development. Surprisingly, these preliminary studies reveal no evidence of clones; the distribution of cells derived from the +/+ component seems random.