Effects of microgravity on DNA damage response in Caenorhabditis elegans during Shenzhou-8 spaceflight

Abstract

Purpose: Space radiations and microgravity both could cause DNA damage in cells, but the effects of microgravity on DNA damage response to space radiations are still controversial.

Materials and methods: A mRNA microarray and microRNA micro- array in dauer larvae of Caenorhabditis elegans (C. elegans) that endured spaceflight environment and space radiations environment during 16.5-day Shenzhou-8 space mission was performed.

Results: Twice as many transcripts significantly altered in the spaceflight environment than space radiations alone. The majority of alterations were related to protein amino acid dephosphorylation and histidine metabolic and catabolic processes. From about 900 genes related to DNA damage response, 38 differentially expressed genes were extracted; most of them differentially expressed under spaceflight environment but not space radiations, although the identical directions of alteration were observed in both cases. cel-miR-81, cel- miR-82, cel-miR-124 and cel-miR-795 were predicted to regulate DNA damage response through four different anti-correlated genes.

Conclusions: Evidence was provided that, in the presence of space radiations, microgravity probably enhanced the DNA damage response in C. elegans by integrating the transcriptome and microRNome.

Keywords::

• Space radiations
• microgravity
• DNA damage response
• Gene expression
• microRNA

Acknowledgements

This work was supported by the Fundamental Research Funds for the Central Universities (No. 3132014306) and National Natural Science Foundation of China (No. 31270903).

Declaration of interest The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Supplementary material available online

Supplementary Figures 1, 2 and Tables I, II.