Engineering Support of Microgravity Life Science Research: Development of an Avian Development Facility
The Avian Development Facility (ADF) is designed to provide a 'window' for the study of embryogenesis in space. It allows researchers to determine and then to mitigate or nullify the forces of altered gravity upon embryos when leaving and re-entering the Earth's gravity. The ADF design will allow investigations to begin their incubation after their experiments have achieved orbit, and shut down the experiment and fix specimens before leaving orbit. In effect, the ADF makes every attempt to minimize launch and re-entry effects in order to isolate and preserve the effects of the experimental variable(s) of the space environment.
Avian biotechnology instrumentation as a mechanism for understanding human dysfunction in space
Gravitational biologists are recognizing the advantages and convenience the avian egg offers, as a biological model for examining developmental dysfunctions under microgravity conditions. The avian egg is a self-contained, individual development package with its own life-support system, requiring no additional food, water, or waste-removal systems. Since there is no dependence on a maternal host, embryos are unaffected by maternal responses to the microgravity environment. In addition, selected embryos can he manipulated without jeopardizing other members of .I the clutch, making selective collection of avian specimens in microgravity far easier than with most species. Thus, the avian model offers many research opportunities that can be structured for understanding human diseases, as well as those problems associated with adaptation to the weightless environment of space.
Organisation of Xenopus egg cytoplasm: response to simulated microgravity.
The cytoplasm of Xenopus fertilised eggs appears to be organised into three major compartments based primarily on the uneven distribution of yolk platelets. There is a shift of these yolk compartments during the first cell cycle that is thought to be involved in the dorsal/ventral morphogenesis of the embryo. The involvement of gravity in Xenopus cytoplasmic organisation and in compartment shifts was addressed by examining, cytologically, the yolk compartments in embryos that developed under the simulated microgravity conditions of the horizontal clinostat. The cytoplasmic organisation into yolk compartments was found to be maintained, and the asymmetric movements of compartments still occurred in eggs that developed on the clinostat. It is suggested that the organisation of Xenopus egg cytoplasm into discrete compartments relies on forces other than those involving gravity (i.e., not density differences), and that the compartment shifts that take place during the first cell cycle are active movements. The variation in compartment size and composition observed from batch to batch of eggs, and to a lesser extent from egg to egg, during this study was addressed.