Evolutional study on the endocrine system of brain-pituitary interaction in amphioxus

点击翻译按钮获取中文摘要

1. EST analysis of cDNA libraries from Hatschek's pit and neural tube in amphioxus (Branchiostoma belcheri) was attempted in order to the evolutional study on brain-pituitary endocrine system. The results so far are as follows.(1) The successfully removal of he neural tube included brain part enabled the high quality of constructed cDNA library. The EST project of neural tube has been started from 2002 as the collaboration with Profs. K. Agata and S. Kuratani, Riken, Kobe. Nucleotide sequences of the 3800 clones without redundant was analyzed until March 2002. The project continues to obtain all of cDNA clones from amphioxus neural tube. A few hormone genes were obtained such as parathyroid hormone, RFamid, calcitonin, and some kinds of growth factors. In near future, the EST results in amphioxus will reveal an evolution of brain from the neural tube by the comparison of molecule structure and physiological mechanism with specific genes which exist both in amphioxus neural tube and vertebrate brain.(2) The cDNA library from Hatschek's pit includes muscle, skin and nephridium from that the small size of the pit. DNA sequences which might be specific in the pit was Insulin like growth factor binding protein, Insulin like protein, Ferritin, Amyloid, Calcium related proteins. These genes in amphioxus were phylogenetically studied. (3) These results generated from amphioxus contribute the study on mechanism and interactions of neurotransmitters in the brain of vertebrate and mammal.2. Establishment of in situ hybridization in adult amphioxus.3. First success of natural spawning of amphioxus in the laboratory in Japan. Spawning behavior was investigated by movie during reproductive period, two months, and determined the spawning conditions and estimated behavioral and environmental factors for success of spawning.