Ref ID : 4668
Jean Cachon, Monique Cachon, and Paule Salvano; The Nuclear Division of Oxyrrhis marina: an Example of the Role Played by the Nuclear Envelope in Chromosome Segregation. Arch.Protistenk 122:43-54, 1979
Reprint
In File
Notes
Oxyrrhis marina is a marine Protozoa which has up-to-now no clear position among the Dinoflagellates though its mitosis was considered by Grasse (1952) as typical of the group. The electron microscopical observations show that this mitosis is singular. The nucleus is deeply hollowed by a furrow as it is usual in Dinoflagellates but no microtubules are observed in it in spite of all our attempts. The chromosomes are rod-shaped and made of longitudinal fibrils. They are attached by one end on the nuclear envelope and at these levels no kinetochore is seen. The separation of the daughter-chromosomes and their distribution in two sets seem to be realized by an elongation of the nuclear envelope. Cytophotometrical studies have been made and they are in agreement with our interpretation: there is a progressive and continuous DNA synthesis during the resting-stage and an equal distribution of DNA among the two telophasic daughter-nuclei.