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Effects of spaceflight conditions on fertilization and embryogenesis in the sea urchin Lytechinus pictusCalcium loss and muscle atrophy are two of the main metabolic changes experienced by astronauts and crew members during exposure to microgravity in space. Calcium and cytoskeletal events were investigated within sea urchin embryos which were cultured in space under both microgravity and 1 g conditions. Embryos were fixed at time-points ranging from 3 h to 8 days after fertilization. Investigative emphasis was placed upon: (1) sperm-induced calcium-dependent exocytosis and cortical granule secretion, (2) membrane fusion of cortical granule and plasma membranes; (3) microfilament polymerization and microvilli elongation; and (5) embryonic development into morula, blastula, gastrula, and pluteus stages. For embryos cultured under microgravity conditions, the processes of cortical granule discharge, fusion of cortical granule membranes with the plasma membrane, elongation of microvilli and elevation of the fertilization coat were reduced in comparison with embryos cultured at 1 g in space and under normal conditions on Earth. Also, 4% of all cells undergoing division in microgravity showed abnormalities in the centrosome-centriole complex. These abnormalities were not observed within the 1 g flight and ground control specimens, indicating that significant alterations in sea urchin development processes occur under microgravity conditions. Copyright 1999 Academic Press.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Schatten, H. (University of Missouri-Columbia MO 65211, United States)
Chakrabarti, A.
Taylor, M.
Sommer, L.
Levine, H.
Anderson, K.
Runco, M.
Kemp, R.
Date Acquired
August 22, 2013
Publication Date
January 1, 1999
Publication Information
Publication: Cell biology international
Volume: 23
Issue: 6
ISSN: 1065-6995
Subject Category
Life Sciences (General)
Distribution Limits
STS-77 Shuttle Project
short duration
Flight Experiment
NASA Experiment Number 95010376
NASA Discipline Developmental Biology
Non-NASA Center