The influence of simulated microgravity on the proteome of .

BACKGROUND

The waterflea is an interesting candidate for bioregenerative life support systems (BLSS). These animals are particularly promising because of their central role in the limnic food web and its mode of reproduction. However, the response of to altered gravity conditions has to be investigated, especially on the molecular level, to evaluate the suitability of for BLSS in space.

METHODS

In this study, we applied a proteomic approach to identify key proteins and pathways involved in the response of to simulated microgravity generated by a two-dimensional (2D) clinostat. We analyzed five biological replicates using 2D-difference gel electrophoresis proteomic analysis.

RESULTS

We identified 109 protein spots differing in intensity (<0.05). Substantial fractions of these proteins are involved in actin microfilament organization, indicating the disruption of cytoskeletal structures during clinorotation. Furthermore, proteins involved in protein folding were identified, suggesting altered gravity induced breakdown of protein structures in general. In addition, simulated microgravity increased the abundance of energy metabolism-related proteins, indicating an enhanced energy demand of .

CONCLUSIONS

The affected biological processes were also described in other studies using different organisms and systems either aiming to simulate microgravity conditions or providing real microgravity conditions. Moreover, most of the protein sequences are well-conserved throughout taxa, indicating that the response to altered gravity conditions in follows a general concept. Data are available via ProteomeXchange with identifier PXD002096.