Relationship between nuclear and cytoplasmic RNA.

Abstract

Singh and Koppelman have subjected to mathematical analysis1,2 some of the experiments carried out by my colleagues and myself on the relationship between nuclear and cytoplasmic RNA3,4. I have already demonstrated the inadequacy of the model presented by Singh and Koppelman in their first communication1 by showing that a relationship defined by them as a constant (λ in my report) was in fact not a constant5. In their second communication2, Singh and Koppelman accept this point and present a modified version of the same exercise. As before, they seek to give the impression that they have taken the results of some of our experiments and shown that these results fit the particular mathematical model which they propose. Once again this is not so. In neither of the graphs produced by Singh and Koppelman have our results been accurately transcribed. In both instances, several points given in our original curves have been omitted from the graphs, and the curves have been truncated by deletion of early and late experimental points. This is well illustrated in the data for cytoplasmic RNA adenine shown in Fig. 1 of their communication. In our original report this curve is unequivocally sigmoid, but it appears in their communication as a straight line, an approximation which involves the omission of several of our experimental points, the insertion of points which do not correspond to our experimental points and the deletion of the end of the curve. In order that readers may assess the extent of the transformation, I have reproduced in Fig. 1 the original experimental curve and in Fig. 2 the same curve as re-plotted by Singh and Koppelman.