The use of Xenopus egg cells to assay the mRNA of single cells

Abstract

TRANSLATION of mRNA in egg cells and oocytes of Xenopus laevis Daudin has been shown to be very efficient for mRN As from a variety of cells1–7 and has uses in developmental biology, molecular biology and immunology8. We have also reported its use in cancer research9. One of the main disadvantages of this tool, however, is the fact that fairly extensive RNA extraction and purification procedures are required. In particular, in cases when different cell types are mixed, as in the case with immunologically active cells, it is almost impossible to obtain information about the activity of the separate cell types. Studies in this field are always dealing with, at best, highly enriched cell populations. Therefore we have looked for a method which avoids RNA extraction and purification, with the aim of being able to work with separate cells. We have tried to inject cell homogenates directly into egg cells of Xenopus, and in the experiments reported here, we chose myeloma cells (LOU/M/WS1 rats with myeloma IR2 synthesising immunoglobulin E), because we could analyse the translation products easily and we could start with a relatively homogeneous cell population. Our results suggest that it is possible to study the translation products of single myeloma cells using this technique.