Molecular endocrinological study on reproduction in amphioxus

L。自然条件下文昌鱼栖息地的环境与生态研究(L)1997年8月至2000.2年7月在潭西丸进行的调查包括生长、分裂和环境因素的分析，以及利用ROV观测栖息地。(1)1999年秋季至2000年夏季在实验室饲养的文昌鱼雌雄生殖腺发育情况。(2)2000年7月产卵受精成功，仔鱼生长3周。(3)除了对黑暗条件的要求外，产卵期与环境条件无关。(4)雌雄之间产生开始产卵的生理信号的可能性，这是通过分开保持的雌雄生殖活动的松散来实验的。(5)光、聚光灯、振动、触摸等刺激引起的逃逸反应方向不同。触摸尾巴导致逃逸方向为尾巴，触摸头部导致逃逸方向为尾巴或头部。哈茨克窝和基因(L)发现了神经索向哈茨克窝的延长，这似乎对应于下丘脑或正中隆起。(2)文昌鱼存在脑-下丘脑-垂体系统的可能性。(3)从哈茨克氏凹陷和肌肉之间的差减构建的cDNA文库中克隆了大约50种克隆，在cDNA序列数据库中搜索到同源序列。与内分泌系统有关的功能蛋白有胰岛素样肽、胰岛素样生长因子结合蛋白、抑制素等，而编码垂体激素基因的多克隆。(4)获得的克隆在成虫和幼虫上的表达始于原位杂交。

l. Environmental and ecological study on amphioxus habitat for understanding reproductive phenomena under natural condition(l) Investigations including analysis of growth, division and environmental factors, and observation of habitat by using ROV in Tansei-Maru from August, 1997 to July, 2000.2. Success of breeding and spawning in laboratories and analysis of swimming and reproductive behaviors.(1) Gonadal developments in a female and a male amphioxi bred from autumn in 1999 to summer in 2000 in lab. (2) Success of spawning and fertilization in July in 2000 and growth of larva for three weeks. (3) No correlation between spawning date and environmental conditions except for the requirement of dark condition. (4) A possibility of physiological signal between female and male for starting spawning which is experimented by a loose of a reproductive activity in each sex which kept separately. (5) Different escape reaction in the direction that caused by stimulation of light, spot light, vibration or touch. Touch at tail causes an escape direction to tail, and touch at head causes to either tail or head.3. Hatschek's pit and the gene(l) Discover of the elongation of nerve cord toward Hatscheck's pit which seems to correspond to hypothalamus or median eminence. (2) Possibility of an existence of brain-hypothalamus-pituitary system in amphioxus. (3) cDNA clones from cDNA library constructed from subtraction between Hatsceck's pit and muscle contained approximately 50 kinds of clones which homologous sequences are searched in data base of cDNA sequence. Functional protein concerned with endocrine system areinsulin-like peptide, IGF binding protein, inhibin and so on but mo clones encoded pituitary hormone genes. (4) Expression of obtained clones start by using in situ hybridization on adult and larva.