Transient effects of microgravity on early embryos of Xenopus laevis

• Published in: Advances in space research 1996, Vol.17 (6), p.219-223
• Main Authors: De Mazière, A, Gonzalez-Jurado, J, Reijnen, M, Narraway, J, Ubbels, G.A
• Format: Article
• Language: English
• Subjects: Animals; Cell Polarity; Centrifugation; DNA - analysis; Embryo, Nonmammalian; Female; Fertilization - physiology; Gastrula - chemistry; Gastrula - cytology; Gene Expression Regulation; Larva; Male; Space Flight; Space life sciences; Spacecraft - instrumentation; Weightlessness; Xenopus laevis - embryology; Xenopus laevis - growth & development; Xenopus laevis - physiology
• ISSN: 0273-1177; 1879-1948
• DOI: 10.1016/0273-1177(95)00638-U

In order to study the role of gravity on the early development of the clawed toad Xenopus laevis, we performed an experiment on the Maser-6 sounding rocket launched from Kiruna (Sweden) on 4 Nov 1993. The aim was to find out whether a short period of microgravity (μg) during fertilization and the first few minutes of development does indeed result in abnormal axis formation as was suggested by a pilot experiment on the Maser 3 in 1989. On the Maser 6 we used two new technical additions in the Fokker CIS unit, viz. a 1-g control centrifuge and a video recording unit which both worked successfully. The 1-g control centrifuge was used to discriminate between the influences of flight perturbations and μg. After fertilization shortly before launch, one of the first indications of successful egg activation, the cortical contraction, was registered in μg and on earth. Analysis of the video tapes revealed that the cortical contraction in μg starts earlier than at 1 g on earth. After recovery of the eggs fertilized in μg and culture of the embryos on earth, the morphology of the blastocoel has some consistent differences from blastulae from eggs fertilized in the 1-g centrifuge of the rocket. However from the gastrula stage onward, the μg embryos apparently recover and resume normal development: the XBra gene is normally expressed, and histological examination shows normal axis formation.