The role of gravity in chick embryogenesis.
Thirty fertilized chick eggs preincubated for 0, 7 and 10 days on earth (10 eggs each) were flown in the space shuttle 'Endeavour' and further incubated for 7 days under microgravity. Twenty out of thirty eggs (9/10 ten-day-old; 10/10 seven-day-old; 1/10 zero-day-old) were recovered alive after landing. The only living embryo of the zero-day-old group died 24 days after launch, and was comparable to a 16-day-old embryo. The high mortality of the 0-day-old eggs appeared to be related to the specific inner structure of the egg. Simulation experiments performed on earth indicated that when yolk stayed in the albumen for more than 2 days, most of the embryos died. The subtle difference in specific gravity between the yolk (1.029) and albumen (1.040) plays a critical role in early chick embryogenesis.
Suda
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T
Department of Biochemistry, School of Dentistry, Showa University, Tokyo, Japan.
Abe
E
E
Shinki
T
T
Katagiri
T
T
Yamaguchi
A
A
Yokose
S
S
Yoshiki
S
S
Horikawa
H
H
Cohen
G W
GW
Yasugi
S
S
D000818:Animals; D002642:Chick Embryo / Q000254:growth & development*; D006112:Gravitation; D016019:Survival Analysis