Research on the pyrenoid in Chlamydomonas

类蛋白核位于藻类叶绿体中，在低CO_2条件下，衣藻体内的蛋白核含量增加了约3倍。用HgCl2固定的类蛋白核在蔗糖密度梯度离心法中显示，在适应低CO2条件的细胞中类蛋白核相对较重。类蛋白核的平均蛋白质含量也显示出相同的结果。在对类蛋白核形成的低CO_2浓度的适应过程中，Rubisco小亚基的两个基因之一rbcS1的转录水平低于高CO_2条件下的转录水平，而另一个Rubisco基因rbcS2的转录水平与高CO_2条件下几乎相同。在氯霉素存在的情况下，仍能观察到类蛋白核的发育。

The pyrenoid, which is located in chloroplast of algae, increases under low CO_2 conditions by about 3 times in Chlamydomonas. Sucrose density gradient centrifugation of the pyrenoid fixed with HgC1_2 showed relatively heavier pyrenoid in the cells adapted to low CO_2 condition. Average protein content of the pyrenoid showed the same result. During the adaptation to low CO_2 concentration where the pyrenoid developed, rbcS1, one of two genes of small subunit of Rubisco, was transcribed less than that in high CO_2 condition, while rbcS2, the other Rubisco gene, was at almost the same level. The development of the pyrenoid was still observed in the presence of chloramphenicol.