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.