논우렁이[Cipangopaludina chinensis malleata (Reeve)]의 精蟲形成 過程에 관한 電子顯微鏡的 硏究

Electron Microscopic Study on the Spermiogenesis of Cipangopaludina chinensis malleata (Reeve)

논우렁이(Cipangopaludina chinensis malleata (Reeve))의 精蟲形成 過程은 核과 細胞質의 變化로부터 시작한다. 核內의 染色質은 stacking 되기 시작하였으며 細胞質에서는 mitochondria의 모임과 軸絲의 出現이 되었다. 그런後에 細胞質은 突出되기 시작하였고, 核은 突部分으로 移動되었다. 精蟲形成過程中에 全 細胞質에서 나타나는 電子密度가 높은 物質들은 分解되거나 細胞間隙으로 exocytosis 되었다. 특히, mitochondria가 軸絲사이에 存在하며, 차츰 頭部쪽으로 移動되어지기 시작하였다. 그리고 exocytosis後에 電子密度가 높은 物質이 軸絲를 둘러싸기 시작했다. 이들 物質이 release되어 顆粒狀態로 微細小管이나 axonemal doublet 微細小管들을 通해서 각 部位로 移動되어졌다. 이러한 顆粒들은 glycogen을 함유하고 있으며 尾部의 바깥층을 이루고 있었다. 終局에 가서는 凝縮된 核은 螺旋形으로 變化하며 頸部는 cylinderical shape로 되고 中片의 mitochondria가 規則的인 lamellar屬으로 變化하여 완전히 成熟된 精蟲으로 되었다. 그러므로, 이러한 現象은 精蟲形成 過程의 特異한 過程을 나타낸다. 頭部의 染色質의 濃縮, 頭部의 螺旋狀 形態로 變化하는 것과 細胞性 物質이 mitochondria와 微細小管에 의하여 尾部의 각 部分으로 移動과 轉移되는 것이다.

The spermiogenesis of Cipangopaludina chinensis malleata began with the changes of nucleus and cytoplasm. The chromatin in the nucleus began to stack and condense around perinuclear envelope. Axonema (doublet microtubules of 9+2) appeared in the cytoplasm. After this process, the cytoplasm was protruded and the bell-shaped nucleus was located on protruding part of it. The electron dense masses were distributed throughout cytoplasm and lysed or secreted by exocytosis of lysosomal vacuoles. Especially, some mitochondria were migrated by the doublet microtubules of axonema toward nucleus. The axoneme was enclosed by electron dense materials after exocytosis of unnecessary materials for the tail formation. The electron dense masses were released and migrated into the each part through microtubules or axonemal doublet microtubules as the granular particles. These granular particles were containing glycogen. Ultimately, the condensed head developed into helical and neck region into cylindrical shape respectively. The mitochondria which have regular lamellar layers at cross axis became to middle piece, and then spermatozoon was completely matured. Thus, these phenomena showed special processes in spermiogenesis, those were as follows; chromatin in the head was condensed, the head was changed into helical shape, and cytoplasmic materials are migrated and transferred into the each part in the tail by mitochondria and microtubules.