Abstract: | The frequency of acrocentric chromosome associations (ACA) in the long-term culture of lymphocytes progressively decreases by 25% (on the average) for one mitotic cycle. As a result proliferous lymphocytes after 3-4 divisions contain either no associations or not more than 2 associating acrocentrics. The diversity of the peripheral blood lymphocytes as to the frequency of ACA in the first mitosis is connected with their different proliferative activity in the organism. |