Search for the genes responsible for adaptation to marine environments: osmoregulatory hormone genes

寻找负责适应海洋环境的基因：渗透调节激素基因

基本信息

批准号：
16207004
负责人：
TAKEI Yoshio
金额：
$ 30.95万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

项目摘要

The sea, from which the life originates, is generally a comfortable environment for living organism. However, high osmotic pressure of seawater poses a heavy burden to marine teleosts that have plasma osmotic pressure only one third of seawater. Hormones play central roles in body fluid regulation in such hyperosmotic environmental. However, major hormones that play key roles in seawater adaptation have not been identified thus far, although vasopressin/vasotocin is identified as an essential hormone to adapt to the terrestrial environment. Therefore, we search for Na-extruding hormones in the genome database of pufferfish and medaka, and they are much diversified in teleost fish. For instance, natriuretic peptides (NPs) have 7 paralogs in teleost, much more than 3 in mammals, and one of the NPs, atrial NP (ANP), is found to be a major seawater-adapting hormone in teleost fish. ANP decreases plasma Na concentration in seawater eels by inhibiting drinking and subsequent absorption of Na … More Cl by the intestine, thereby promoting seawater adaptation. Adrenomedullin is a water and Na-extruding hormone in mammals, but it forms an independent subfamily of 5 paralogs (AM1, 2, 3, 4 and 5) in teleost fish. Further, we discovered AM2 and AM5 in mammals. AM2 has potent central actions for body fluid regulation such as inhibition of drinking and oxytocin secretion in mammals, while AM5 may be related to regulation of immune system. AM2 and AM5 have a potent dipsogenic and antidiuretic effects, so that these hormones may promoter seawater adaptation in teleost fish. Guanylin, an intestinal hormone, causes diarrhea in mammals by secreting Cl ions into the lumen of the intestine, with which water moves in parallel. In teleost fish, guanylin also stimulates Cl secretion in the intestine. However, the secreted Cl ions are absorbed with Na and K through Na-K-2Cl co-transporter, two more osmolytes moves from the lumen into the body, resulting in absorption of water. Therefore, guanylin may promote seawater adaptation by acquiring more water to cope with dehydration. In summary, we could identify major hormones that promote seawater adaptation through the three-year project supported by JSPS. Less

海洋是生命的发源地，通常为生物体提供舒适的环境，然而，海水的高渗透压给海洋硬骨鱼带来了沉重的负担，因为血浆的渗透压只有海水的三分之一，而激素在体液中起着核心作用。然而，尽管加压素/加压素被认为是适应海水的必需激素，但迄今为止，尚未确定在海水适应中发挥关键作用的主要激素。因此，我们在河豚和青鳉的基因组数据库中寻找钠排泄激素，它们在硬骨鱼中具有丰富的多样性，例如，利钠肽（NP）在硬骨鱼中有7种旁系同源物，远多于哺乳动物中的3种。，其中一种 NP，心房 NP (ANP)，被发现是硬骨鱼的主要海水适应激素，ANP 会降低血浆 Na。肾上腺髓质素是哺乳动物中的一种水和钠排出激素，但它形成了一个由 5 个旁系同源物组成的独立亚家族（AM1、2、 3、4 和 5) 在硬骨鱼中此外，我们发现 AM2 和 AM5 在哺乳动物中具有有效的体液调节作用，例如抑制饮水和催产素。 AM5 可能与免疫系统的调节有关，AM2 和 AM5 具有强效的促利尿作用，因此这些激素可能促进硬骨鱼的海水适应，鸟苷素是一种肠道激素，通过分泌引起哺乳动物腹泻。 Cl 离子进入肠腔，与水平行移动，在硬骨鱼中，鸟苷酸也刺激肠内的 Cl 分泌。离子通过 Na-K-2Cl 协同转运蛋白与 Na 和 K 一起吸收，另外两种渗透剂从管腔移动到体内，导致水的吸收。因此，鸟苷酸可以通过获取更多的水来应对脱水，从而促进海水适应。总之，我们可以通过 JSPS Less 支持的三年项目确定促进海水适应的主要激素。