宇宙科学研究所
お茶の水女子大学
東京大学
東邦大学
Virginia Polytech. Inst. State Univ.
埼玉医科大学
鶴見大学
鹿屋体育大学
神奈川歯科大学
早稲田大学
著者所属（英）
Institute of Space and Astronautical Science
Ochanomizu University
University of Tokyo
Toho University
Virginia Polytechnical Institute State University
Saitama Medical School
Tsurumi University
National Institute of Fitness and Sports in Kanoya
Kanagawa Dental College
Waseda University
出版者
宇宙開発事業団
出版者（英）
National Space Development Agency of Japan (NASDA)
The newt egg is a large single cell. The heavier vegetal hemisphere orienting downward by gravity gives a fixed reference of morphogenesis with respect to gravity. Effects of gravity on the early development of Japanese red bellied newt were studied. In this experiment (named as AstroNewt), four female newts were sent to orbit. They were treated by gonadotrophic hormone to ensure egg laying in space and fertilization with sperm stored in their body cavity. Eggs were laid during the flight. Some of eggs were at the stage of late morula, tail bud, and fore limb formation on MD (Mission elapsed time Day) 5 and 12. Morphology of embryo was normal judged by the close up video images. Early developmental process of newt undertakes without gravity. However, at a small sample size and lack of histological survey on embryo, this conclusion can not be generalized further. During the mission, two newts were lost on MD5 and MD9. In contrast to the flight group, all four ground control newts were kept quite healthy and laid many eggs. Based on AAEU (Aquatic Animal Experiment Unit) water pressure log, water circulation seemed to be blocked in the cassette after winding egg laying tape on MD4, a day before the newt in it was found lost. Microscopic examination on the two newts that were recovered in alive from orbit revealed many biological effects of space flight. Liver, stomach and lung of flight samples showed pathological changes that were not found in the ground controls.
イモリの宇宙における産卵および受精卵の発生(ASTRONEWT)
00271002.pdf
(2.74MB)
