Precellys®24 homogenizer has been tested to perform polysomes immunoprecipitation (IP) and translating RNA extraction from IP. In our system, polysomes of some specific cell types of the cerebellum are immunoprecipitated, by expressing a GFP tagged ribosomal protein in these specific cell types with CRE mediated recombination. As these cell types represent a few percent of the whole cerebellum, we should observe an enrichment of specific genes in the IP fraction compared to the input fraction (whole cerebellum lysate before IP).
In the IP fraction, we could obtain an enrichment of RNA from our specific cell types (i.e. Purkinje cells and GABAergic interneurons), compared to RNA obtained from whole cerebellum (RNA from input fraction). Genes only expressed by Purkinje cells (Pcp2, Calb1, Fgf7) or genes expressed by both Purkinje cells and GABAergic interneurons (Parv, Gad65) are enriched in the IP fraction, whereas genes that are not expressed in these cell types (Gfap, Mbp, Glast, NeuroD1) are depleted in the IP fraction (Figure 1).