Cell Division in Diatoms
1991; Elsevier BV; Linguagem: Inglês
10.1016/s0074-7696(08)60497-0
ISSN2163-5854
Autores Tópico(s)Photosynthetic Processes and Mechanisms
ResumoThis chapter describes mitosis in diatoms and explores how the observations and inferences from these cells relate to mitotic mechanisms in general. Diatoms are among the most widespread, prolific organisms on the planet and they are significantly important in global ecology. There are two major groups of diatoms—the centrics and the pennates, both diploid in the vegetative state. The centrics are oogamous, differentiating uniflagellate sperm that fertilize a large, inert oogonium. In contrast, pennates usually have isogamous amoeboid gametes. Most diatoms studied possess a prominent granule tightly associated with the interphase nucleus. In some larger diatoms, the microtubule center (MC) is very conspicuous in vivo. MC is usually spherical during interphase but may change during the cell cycle. As the primorial spindle grows, the microtubule (MT) cytoskeleton associated with the MC becomes particularly striking. Then the nucleus moves to a predetermined position in the cell for mitosis, a movement orchestrated by the MT cytoskeleton enlarging around the MC. The MC is intimately involved with the creation of the spindle, after which it dissolves. In turn, new MCs arise close to the spindle poles.
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