Correlated failure of synthetic activities in a wheat chromosome

Abstract

The process of chromosome condensation during meiotic prophase, with its uniformity and synchronization of all parts of the nucleus, provides evidence in support of the genotypic control of chromosome behaviour. So characteristic is this co-ordinated development that any exceptions to it have been considered as due to a basic differentiation of chromosome material into euchromatin and heterochromatin. I have, however, shown recently that the normal synchronized condensation of chromatin threads in the pollen mother cells of perennial ryegrass can be induced to break down by experimental means. This and the other induced changes which affect nucleolus organization have provided evidence pointing to a common control of metabolic activities in chromosomes. In the present experiment, the uniformity characterizing the behaviour of chromosomes in bread wheat has been observed to break down, though the techniques involved here are of a very different nature.