Search

Abstract Despite the observed severe effects of microgravity on mammalian cells, many astronauts have completed long term stays in space without suffering from severe health problems. This raises questions about the cellular capacity for adaptation to a new gravitational environment. The International Space Station (ISS) experiment TRIPLE LUX A, performed in the BIOLAB laboratory of the ISS COLUMBUS module, allowed for the first time the direct measurement of a cellular function in real time and on orbit. We measured the oxidative burst reaction in mammalian macrophages (NR8383 rat alveolar macrophages) exposed to a centrifuge regime of internal 0 g and 1 g controls and step-wise increase or decrease of the gravitational force in four independent experiments. Surprisingly, we found that these macrophages adapted to microgravity in an ultra-fast manner within seconds, after an immediate inhibitory effect on the oxidative burst reaction. For the first time, we provided direct evidence of cellular sensitivity to gravity, through real-time on orbit measurements and by using an experimental system, in which all factors except gravity were constant. The surprisingly ultra-fast adaptation to microgravity indicates that mammalian macrophages are equipped with a highly efficient adaptation potential to a low gravity environment. This opens new avenues for the exploration of adaptation of mammalian cells to gravitational changes.

Molecular techniques have become increasingly important for the identification of arbuscular mycorrhizal fungi (AMF). In this work Acaulospora longula and Glomus mosseae have been detected in plant roots from pastures using specific nucleotide primers for the two species. Part of the 5' end of the large subunit of the ribosomal RNA gene was amplified by nested PCR and sequenced. The distribution of the fungi within three different plant species, Plantago lanceolata, Trifolium repens, and Holcus lanatus, and two different types of grassland, have been studied. Neither the fungi nor the plants showed specific preference for their symbiotic partnership. [ABSTRACT FROM AUTHOR]