Cell size for commitment to cell division and number of successive cell divisions in cyanidialean red algae
Cell size for commitment to cell division and number of successive cell divisions in cyanidialean red algae
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DOI：
10.1007/s00709-021-01628-y
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发表时间：
2021-03-06
期刊：
影响因子：
2.9
通讯作者：
Miyagishima, Shin-ya
中科院分区：
文献类型：
--
作者：
Jong, Lin Wei;Fujiwara, Takayuki;Miyagishima, Shin-ya
几种真核细胞谱系通过多个分裂细胞周期增殖，在此期间细胞生长到其原始大小的许多倍，然后经历几轮细胞分裂而没有干预生长。对单细胞和多细胞volvocine绿色藻类的研究（群体）物种的细胞分裂的最小数目与第一轮连续细胞分裂定型的阈值细胞大小之间存在相关性：单细胞莱茵衣藻的平均新生子细胞体积是其两倍，四细胞四叶虫的平均新生子细胞体积是其四倍，其中殖民地中的每个细胞通过两次连续的细胞分裂产生子蜂群，并且对于八细胞的胸卵囊，每个细胞通过三次连续的细胞分裂产生子蜂群，共八次。为了评估这种现象是否也适用于其他谱系，我们的特点cyanidialean红藻，即，Cyanidioschyzon merolae，通过二分裂增殖，以及Cyanidium caldarium和Galdieria sulphuraria，形成多达4个和32个子细胞（自孢子），分别在孵化前的母细胞。结果表明，细胞连续分裂的次数与细胞分裂阈值或第一轮细胞连续分裂的细胞大小也有相关性。在两个C. merolae和C.在高温藻中，细胞分裂的细胞大小检查点存在于G1期，如先前在volvocine绿色藻类中所示。当C. merolae细胞在CDKA的条件性消耗下被阻滞在G1期并异常增大，在CDKA恢复后，细胞经历两次或更多次连续的细胞分裂而不干预细胞生长，类似于C. caldarium和G.硫磺。这些结果表明，细胞分裂的阈值大小是一个主要因素，在确定连续的细胞分裂的数量和进化的变化，在真核藻类的细胞大小监测机制导致了多分裂细胞周期的变化。
Several eukaryotic cell lineages proliferate by multiple fission cell cycles, during which cells grow to manyfold of their original size, then undergo several rounds of cell division without intervening growth. A previous study on volvocine green algae, including both unicellular and multicellular (colonial) species, showed a correlation between the minimum number of successive cell divisions without intervening cellular growth, and the threshold cell size for commitment to the first round of successive cell divisions: two times the average newly born daughter cell volume for unicellular Chlamydomonas reinhardtii, four times for four-celled Tetrabaena socialis, in which each cell in the colony produces a daughter colony by two successive cell divisions, and eight times for the eight-celled Gonium pectorale, in which each cell produces a daughter colony by three successive cell divisions. To assess whether this phenomenon is also applicable to other lineages, we have characterized cyanidialean red algae, namely, Cyanidioschyzon merolae, which proliferates by binary fission, as well as Cyanidium caldarium and Galdieria sulphuraria, which form up to four and 32 daughter cells (autospores), respectively, in a mother cell before hatching out. The result shows that there is also a correlation between the number of successive cell divisions and the threshold cell size for cell division or the first round of the successive cell divisions. In both C. merolae and C. caldarium, the cell size checkpoint for cell division(s) exists in the G1-phase, as previously shown in volvocine green algae. When C. merolae cells were arrested in the G1-phase and abnormally enlarged by conditional depletion of CDKA, the cells underwent two or more successive cell divisions without intervening cellular growth after recovery of CDKA, similarly to C. caldarium and G. sulphuraria. These results suggest that the threshold size for cell division is a major factor in determining the number of successive cell divisions and that evolutionary changes in the mechanism of cell size monitoring resulted in a variation of multiple fission cell cycle in eukaryotic algae.