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Effects of Sub-Gravity on Cellular Phenomena of Developing Frog Eggs (P-1047)
Principal Investigator
Research Area:
Developmental biology
Species Studied
Scientific Name: Rana pipiens Species: Frog, leopard


Developing frog eggs exhibit a marked sensitivity to disorientation with respect to the normal gravity vector. This study investigated the effect of weightlessness on the ability of the fertilized frog eggs to divide, differentiate, and develop normally. Although the original experiment plan called for fertilization of the eggs in space, the experiment was redesigned with fertilization occurring just before launch, due to difficulties in obtaining an acceptable degree of reliability in sustaining egg fertilizability over the expected launch pad hold-time by "freezing." Instead, maintenance at 43 °F would adequately inhibit the first division for fourteen to fifteen hours.

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Young, R.S. and J.W. Tremor: The Effect of Weightlessness on the Dividing Egg of Rana pipiens. Bioscience, vol. 18, 1968, pp. 609-615.

Young, R.S. and J.W. Tremor: Weightlessness and the Developing Frog Egg. Life Sciences and Space Research: Proceedings of the 10th Plenary Meeting of COSPAR, London, England, July 27-28, 1967, North Holland Publishing, 1968, pp. 87-93.

Young, R.S. et al.: The Effect of Weightlessness on the Dividing Eggs of Rana pipiens. BIOSPEX: Biological Space Experiments, NASA TM-58217, 1979, p. 137.

Young, R.S. et al.: The Effect of Weightlessness on the Dividing Eggs of Rana pipiens. The Experiments of Biosatellite II, NASA SP-204, 1971, pp. 251-271.

Young, R.S.: Gravity and Embryonic Development. Life Sciences and Space Research: Symposium on Gravitational Physiology, Varna, Bulgaria, May 30-31, 1975, Pergamon Press, 1976, pp. 69-75.

Cell differentiation
Cell division
Embryo growth & development
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Data Information
Data Availability
Archive is complete. No data sets are available for this experiment. Please Contact LSDA if you know of available data for this investigation.

Behavior, Locomotion
Behavior, Swimming, tadpoles, Observation
Cell division
Damage, Developmental abnormalities, frog, Microscopy
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
Biosatellite II 09/07/1967 09/09/1967 2 days

Additional Information
Managing NASA Center
Ames Research Center (ARC)
Responsible NASA Representative
Ames Research Center LSDA Level 3
Project Manager: Helen Stewart
Institutional Support
National Aeronautics and Space Administration (NASA)
Alternate Experiment Name
Protocol / Approach