Cell cycles and proliferation patterns in Emphasi

Authors: Chunhui Zhang Jianguo Liu Litao Zhang

Publish Date: 2016/09/29

Volume: 35, Issue: 5, Pages: 1205-1211

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Abstract

Most studies on Haematococcus pluvialis have been focused on cell growth and astaxanthin accumulation far less attention has been paid to cell cycles and proliferation patterns The purpose of this study was to clarify cell cycles and proliferation patterns in H pluvialis microscopically using a camera and video recorder system The complicated life history of H pluvialis can be divided into two stages the motile stage and the nonmotile stage All the cells can be classified into forms as follows motile cell nonmotile cell zoospore and aplanospore The main cell proliferation both in the motile phase and nonmotile phase in H pluvialis is by asexual reproduction Under normal growth conditions a motile cell usually produces two sometimes four and exceptionally eight zoospores Under unfavorable conditions the motile cell loses its flagella and transforms into a nonmotile cell and the nonmotile cell usually produces 2 4 or 8 aplanospores and occasionally 20–32 aplanospores which further develop into nonmotile cells Under suitable conditions the nonmotile cell is also able to release zoospores The larger nonmotile cells produce more than 16 zoospores and the smaller ones produce 4 or 8 zoospores Vegetative reproduction is by direct cell division in the motile phase and by occasional cell budding in the nonmotile phase There is as yet no convincing direct evidence for sexual reproduction

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