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EFFECTS OF SPACEFLIGHT CONDITIONS ON FERTILIZATION AND EMBRYOGENESIS IN THE SEA URCHIN LYTECHINUS PICTUS
Author(s) -
Schatten Heide,
Chakrabarti Amitabha,
Taylor Meghan,
Sommer Laurel,
Levine Howard,
Anderson Ken,
Runco Mario,
Kemp Raelynn
Publication year - 1999
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1006/cbir.1999.0371
Subject(s) - sea urchin , microbiology and biotechnology , biology , blastula , spaceflight , embryogenesis , human fertilization , granule (geology) , cortical granule , embryo , gastrulation , anatomy , lytechinus variegatus , oocyte , paleontology , aerospace engineering , engineering
Calcium 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 3h 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.