Csaba György
Department of Genetics, Cell and Immunobiology, Semmelweis University, Budapest, Hungary.
Cell Biol Int. 2013 Apr;37(4):267-75. doi: 10.1002/cbin.10054. Epub 2013 Mar 1.
The unicellular ciliate, Tetrahymena, has been the main model for studying the hormonal system of unicellular animals. Tetrahymena produce, store, secrete and take up insulin, the hormone being similar to that of mammals, both immunocytochemically and functionally. The plasma membrane and nuclear envelope of Tetrahymena have insulin receptors, which are structurally similar to the mammalian receptor, as it their binding capacity. The cell has also second messengers and signal pathways for insulin. Insulin influences the synthesis of other hormones. The first short encounter between the cell and insulin provokes the hormonal imprinting that alters the function of the cells and is transmitted to the progeny, and can persist for over 1,000 generations, in hormone binding, hormone content, phagocytosis, cell growth and movement. Insulin has a survival function in Tetrahymena and during stress insulin production and binding are elevated. Other protozoa also react to insulin, and the evolutionary aspects are discussed in this review since it is still not appreciated that the hormones are of great antiquity in the animal kingdom.
单细胞纤毛虫四膜虫一直是研究单细胞动物激素系统的主要模型。四膜虫能产生、储存、分泌并摄取胰岛素，这种激素在免疫细胞化学和功能上都与哺乳动物的胰岛素相似。四膜虫的质膜和核膜具有胰岛素受体，其结构与哺乳动物受体相似，结合能力也相似。该细胞还具有胰岛素的第二信使和信号通路。胰岛素会影响其他激素的合成。细胞与胰岛素的首次短暂接触会引发激素印记，这种印记会改变细胞功能并传递给后代，并且在激素结合、激素含量、吞噬作用、细胞生长和运动方面可以持续超过1000代。胰岛素在四膜虫中具有生存功能，在应激期间胰岛素的产生和结合会增加。其他原生动物也会对胰岛素产生反应，本文将讨论其进化方面，因为人们仍然没有认识到激素在动物界有着悠久的历史。
