Comparative endocrinology on the pituitary gland of lampreys and hagfish

七鳃鳗和盲鳗脑下垂体的比较内分泌学

基本信息

批准号：
12640648
负责人：
NOZAKI Masumi
金额：
$ 2.11万
依托单位：
Niigata University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640648/
关键词：
LAMPREY HAGFISH PITUITARY GLAND ADENOHYPOPHYSIAL HORMONES GONADOTROPIN GROWTH HORMONE ADRENOCORTICOTROPIN 個体発生

项目摘要

Lampreys and hagfish are the only two extant representatives of the oldest class of vertebrates, Agnatha (jawless fishes). The present study aimed to elucidate the pituitary system of lampreys and hagfish by means of both immunohistochemical and molecular biological techniques. 1) Adenohypophysial cell types were studied in the sea lamprey (Petromyzon marinus) pituitary gland. It was found that ACTH-like cells were distributed in most parts of the rostral pars distalis, whereas MSH-like cells in almost all parts of the pars intermedia. In the proximal pars distalis, GH-like cells occupied the dorsal half, while GTH-like cells in the ventral half. Thus, at least four types of adenohypophysial cells are present in the sea lamprey pituitary. 2) A cDNA coding conserved amino acid sequence in gnathostome GHs has been cloned from the sea lamprey pituitary, followed by the isolation of the mature protein from the sea lamprey pituitary. That protein has been identified to be lamprey GH by demonstrating an increase of expression of lamprey IGF gene in the liver. 3) Ontogeny of adenohypophysial cell types was studied in sea lampreys at several different stages of the life cycle. Results obtained were discussed in connection with the life cycle of sea lampreys. 4) Immunoreactive adenohypophysial cell types were studied in the pituitary of the Atlantic and the Pacific hagfish, Myxine glutinosa, Eptatretus burgeri and Paramyxine atami. In all three species, three different types of hormone cells were detected in the adenohypophysis. They were ACTH-like cells, GH-like cells and GTH-like cells. It is suggested that ACTH, GH and GTH are ancient hormones and maintain their original functions throughout vertebrate evolution, while the later derived hormones, such as PRL and TSH, may have contributed to the expansion of vertebrates into new environments.

七鳃鳗和盲鳗是最古老的脊椎动物无颌鱼（无颌鱼）中仅存的两种代表。本研究旨在通过免疫组织化学和分子生物学技术阐明七鳃鳗和盲鳗的垂体系统。 1) 研究了七鳃鳗 (Petromyzon marinus) 垂体的腺垂体细胞类型。结果发现ACTH样细胞分布在远端远端的大部分部位，而MSH样细胞几乎分布在中间部的所有部位。在近端远侧部，GH样细胞占据背侧一半，而GTH样细胞占据腹侧一半。因此，七鳃鳗垂体中至少存在四种类型的腺垂体细胞。 2)从海七鳃鳗垂体中克隆了编码颚口动物GHs保守氨基酸序列的cDNA，并从海七鳃鳗垂体中分离出成熟蛋白。通过证明肝脏中七鳃鳗 IGF 基因表达的增加，该蛋白质已被鉴定为七鳃鳗 GH。 3）在海七鳃鳗生命周期的几个不同阶段研究了腺垂体细胞类型的个体发育。所获得的结果与七鳃鳗的生命周期有关。 4) 研究了大西洋和太平洋盲鳗、Myxine glutinosa、Eptatretus Burgeri 和 Paramyxine atami 的垂体中的免疫反应性腺垂体细胞类型。在所有三个物种中，在腺垂体中检测到三种不同类型的激素细胞。它们是ACTH样细胞、GH样细胞和GTH样细胞。有人认为，ACTH、GH 和 GTH 是古老的激素，在整个脊椎动物进化过程中保持其原始功能，而后来衍生的激素，如 PRL 和 TSH，可能有助于脊椎动物扩展到新的环境。