Analysis of mechanisms of maternal inheritance using laser fluorescence fluorimetory

从莱茵梭子蟹受精卵中分离核酸酶的尝试表明，提取的核酸酶需要钙离子的存在才能完全激活，因此称为核酸酶C。核酸酶C具有多态性，由六个分子组成，分子质量分别为16K、18K、21K、22K和26K。在其他藻类中也发现了具有类似性质的核酸酶。因为EGTA抑制了对男性来源的cp核的优先破坏。核酸酶C可能是体内cpDNA优先消化的原因。我提出了一种调节年轻受精卵中cpDNA母系遗传的机制，称为主动消化假说。在配子发生过程中，雌配子通过改变雌cpDNA周围的结构域来保护其cpDNA免受核酸酶C的攻击。雄配子和雌配子交配后不久，在新形成的受精卵中，特定的mRNAs在雌性起源的细胞核中合成。然后，由mRNAs编码的蛋白质在细胞质中从头合成，并直接或间接激活核酸酶C。核酸酶C优先消化雄性起源的叶绿体中的cpDNA。由于女性起源的cpDNA保留下来，并传递给后代，因此发生了母系遗传。

Attempts to isolate nucleases from young zygotes of C. reinhardtii showed that extracted nucleases required the presence of Ca++ for full activation and are thus call Nuclease C. They show polymorphism and are composed of six molecules with molecular masses of 16K,18K,21K,22K,and 26K. Nucleases with similar properties have been found in other algae. Since preferentail destruction of cp-nuclei of male origin is inhibited by EGTA. Nuclease C may be responsible for the preferential digestion of cpDNA in vivo. I proposed a mechanism for the regulation of maternal inhericance of cpDNA in young zygotes called as the active digestion hypothesis. Female gametes have the ability to protect their cpDNA against Nuclease C during gametogenesis by changing the domains surrounding female cpDNA. Soon after mating of male and female gametes, specific mRNAs are synthesized in a cell nucleus of female origin in the newly formed zygote. Then proteins which are coded by the mRNAs are synthesized de novo in the cytoplasm and directly or indirectly activated Nuclease C. Nuclease C preferentially digests cpDNA in the chloroplast of male origin. Since cpDNA of female origin remains, and is transmitted into progeny, maternal inheritance occurs.