WHOLE-MOUNT IN-SITU HYBRIDIZATION OF CELL-TYPE-SPECIFIC MESSENGER-RNAS IN DICTYOSTELIUM

We have been able to hybridize nonradioactive probes from cell-type-sp ecific genes to fixed whole-mounts prepared at the mound, slug, and cu lminant stages of Dictyostelium development. The cellular patterns of labeling with probes from the prespore gene, cotB, and the prestalk ge nes, ecmA and ecmB, confirmed the patterns seen in strains carrying re porter constructs in which the regulatory regions of these genes drive beta-galactosidase. This technique permits the direct observation of protein synthetic capacity from characterized genes without the need o f generating transformed lines carrying specific reporter constructs. Moreover, the pattern is not complicated by a previous developmental h istory of gene expression. (C) 1995 Academic Press, Inc.