The relationship between the frequency of participation of acrocentric chromosomes in formation of satellite associations and the duration of human lymphocyte cultivation with phytohemmaglutinin]

All acrocentrics were shown to take part in the formation of satellite association at the 52nd, 72nd and 90th hr of human lymphocytes culturing, in the first mitosis with equal frequency but having different associative capacity in further mitoses. It seems likely that a single nucleolus in the lymphocytes at initial stage of activation, the high frequency of satellite associations, and a random participation of acrocentrics in the associations in first mitosis are due to that all acrocentrics form association in small lymphocytes which are sensitive to PHA.