Further Studies on Mitosis of Bi- and Multinucleate HeLa Cells

Abstract

Mitosis of 37 binucleate, 15 trinucleate, 5 tetranucleate, 1 pentanucleate, 1 hexanucleate and 2 9-nucleate HeLa cells was studied by means of time lapse phase contrast microcinematography of living material. When 37 cases of mitosis of binucleate cells were grouped according to the number and nuclearity of daughter cells, 12 different groups were found. The number of nuclei produced in most cases was 4 (21 cases), but examples of 3 nuclei (8 cases), 2 (3 cases), 5 (3 cases), and 6 (1 case) were also found. The number of cells produced was 3 in 16 cases, 2 in 14 cases, 4 in 5 cases, and 1 in 1 case. One cell burst in metaphase. In 25 of the 37 experiments at least 1 daughter cell had more than one nucleus. When the 15 cases of mitosis of trinucleate cells were grouped according to the number and nuclearity of daughter cells, 10 different groups were found. The number of nuclei produced was 3 in 3 cases, 4 in 3 cases, 5 in 1 case, and 6 in 2 cases. The number of cells produced was 4 in 5 cases, 3 in 2 cases, and 2 in 1 case. In 3 cases uninucleate cells exclusively were produced. For cells containing more than 3 nuclei, multinucleate daughter cells were frequently seen. Most of the bi- and multinucleate daughter cells were apparently produced by fusion a short time after cytokinesis. Metaphase, telophase, and to some extent prophase were on an average of longer duration in bi- and multinucleate cells than in uninucleate cells. A great variation in the duration of metaphase and telophase was found. In all experiments the nuclei of a bi-or multinucleate cell entered prophase and metaphase simultaneously, but in many cases the restitution after mitosis varied greatly amongst telophase parts.

Key Words:

• Binucleate cells
• duration of mitotic stages
• fusion
• HeLa cells
• mitosis
• multinucleate cells
• trinucleate cells