ISSN:
1615-6102
Keywords:
Isoetes
;
Megasporogenesis
;
Monoplastidy
;
Meiosis
;
Microtubules
;
Mitotic apparatus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The large megasporocytes ofIsoetes provide an exceptional system for studying microtubule dynamics in monoplastidic meiosis where plastid polarity assures coordination of plastid and nuclear division by the intimate association of MTOCs with plastids. Division and migration of the plastid in prophase establishes the tetrahedrally arranged cytoplasmic domains of the future spore tetrad and the four plastid-MTOCs serve as focal points of a unique quadripolar microtubule system (QMS). The QMS is a dynamic structure which functions in plastid deployment and contributes directly to development of both first and second division spindles. The nucleation of microtubules at discrete plastid-MTOCs is compared with centrosomal nucleation of microtubules in animal cells where growth of microtubules involves dynamic instability.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01323073
