Abstract
With the first leaf meristems of barley, two sets of experiments were undertaken with the object of understanding the radiation-induced mitotic arrest. The first of these was aimed at investigating the effect of sorne enzymes (ribonuclease and lysozyme) and basicpolymers (hexadecyl trimethyl ammonium bromide, poly-L-lysine and calf thymus histone) on the commencement of mitosis, and the second at studying radiation effect on the mitotic chromosomes. An advance of interphase cells into mitosis was inhibited with higher concentrations of the agents administered. When synchronization was made by the previous irradiation, prophase cells were decreased in the number with increasing doses reirradiated, suggesting that prophase chromosomes were unpacked and retrograded to an earlier, filamentous G2 Stage, soon after receiving γ-rays.
