Cooperation of kinetochores and pole in the establishment of monopolar mitotic apparatus.

AUTOR(ES)

Mazia, D

RESUMO

Monopolar mitotic apparatus can be produced in sea urchin eggs by a manoeuvre that distributes the four poles of the second mitosis into four separate blastomeres. The pole of the monopolar mitotic apparatus generates a half-spindle that is similar in structural details to the half-spindle of a normal bipolar mitotic apparatus, although the chromosomes are not as well aligned as in a normal metaphase plate. The chromosomes are oriented; one kinetochore faces the pole while its sister kinetochore faces away from the pole. The poleward kinetochore is connected to the pole by bundles of microtubules. No microtubules are seen on the sister kinetochore that faces away from the pole. Therefore, a single pole can direct most of the events in the establishment of a mitotic apparatus. Our interpretation examines the cooperation of kinetochores and poles in the formation of microtubules between them, stressing the half-spindle as the medium of cooperation and leaving open the question whether the kinetochores are origins or terminations of microtubules.

Documentos Relacionados

• The nuclear-mitotic apparatus protein is important in the establishment and maintenance of the bipolar mitotic spindle apparatus.
• Simple ultrafiltration apparatus.
• Asymmetric acetylcholinesterase is assembled in the Golgi apparatus.
• Developmental Regulation of the Plastid Protein Import Apparatus.
• Biomechanics of the Locomotor Apparatus. Contributions on the Functional Anatomy of the Locomotor Apparatus