Abstract：
This study analyzed the effects of Ca2+ metal ions among culture medium components on the Chlorella sorokiniana strain DSCG150 strain cell growth. The C. sorokiniana strain DSCG150 strain grew based on a multiple fission cell cycle and growth became stagnant in the absence of metal ions in the medium, particularly Ca2+. Flow cytometry and confocal microscopic image analysis results showed that in the absence of Ca2+, cell growth became stagnant as the cells accumulated into four autospores and could not transform into daughter cells. Genetic analysis showed that the absence of Ca2+ caused upregulation of calmodulin (calA) and cell division control protein 2 (CDC2_1) genes, and downregulation of origin of replication complex subunit 6 (ORC6) and dual specificity protein phosphatase CDC14A (CDC14A) genes. Analysis of gene expression patterns by qRT-PCR showed that the absence of Ca2+ did not affect cell cycle progression up to 4n autospore, but it inhibited Chlorella cell fission (liberation of autospores). The addition of Ca2+ to cells cultivated in the absence of Ca2+ resulted in an increase in n cell population, leading to the resumption of C. sorokiniana growth. These findings suggest that Ca2+ plays a crucial role in the fission process in Chlorella.
摘要：
本研究分析了培养基成分中Ca2金属离子对小球藻DSCG150菌株细胞生长的影响。C.sorokiniana菌株DSCG150菌株基于多个裂变细胞周期生长，并且在培养基中没有金属离子的情况下生长停滞，特别是Ca2+。流式细胞术和共聚焦显微图像分析结果表明,在无Ca2+,细胞生长停滞，因为细胞积累成四个自孢子，不能转化为子细胞。遗传分析表明,Ca2+缺失导致钙调蛋白(calA)和细胞分裂控制蛋白2(CDC2_1)基因上调,以及复制起点复合物亚基6（ORC6）和双特异性蛋白磷酸酶CDC14A（CDC14A）基因的下调。通过qRT-PCR对基因表达模式的分析显示，Ca2+的缺乏不会影响细胞周期进程高达4n的自孢子，但它抑制了小球藻细胞的裂变（自孢子的释放）。在不存在Ca2+的情况下培养的细胞中添加Ca2+导致n细胞群增加，导致C.sorokiniana恢复生长。这些发现表明，Ca2在小球藻的裂变过程中起着至关重要的作用。
