Genetic background of enhanced radioresistance in an anhydrobiotic insect: transcriptional response to ionizing radiations and desiccation

Abstract

It is assumed that resistance to ionizing radiation, as well as cross-resistance to other abiotic stresses, is a side effect of the evolutionary-based adaptation of anhydrobiotic animals to dehydration stress. Larvae of Polypedilum vanderplanki can withstand prolonged desiccation as well as high doses of ionizing radiation exposure. For a further understanding of the mechanisms of cross-tolerance to both types of stress exposure, we profiled genome-wide mRNA expression patterns using microarray techniques on the chironomid larvae collected at different stages of desiccation and after exposure to two types of ionizing radiation-70 Gy of high-linear energy transfer (LET) ions (He) and the same dose of low-LET radiation (gamma rays). In expression profiles, a wide transcriptional response to desiccation stress that much exceeded the amount of up-regulated transcripts to irradiation exposure was observed. An extensive group of coincidently up-regulated overlapped transcripts in response to desiccation and ionizing radiation was found. Among this, overlapped set of transcripts was indicated anhydrobiosis-related genes: antioxidants, late embryogenesis abundant (LEA) proteins, and heat-shock proteins. The most overexpressed group was that of protein-L-isoaspartate/D-aspartate O-methyltransferase (PIMT), while probes, corresponding to LEA proteins, were the most represented. Performed functional analysis showed strongly enriched gene ontology terms associated with protein methylation. In addition, active processes of DNA repair were detected. We assume that the cross-tolerance of the sleeping chironomid to both desiccation and irradiation exposure comes from a complex mechanism of adaptation to anhydrobiosis.

Cooption of heat shock regulatory system for anhydrobiosis in the sleeping chironomid Polypedilum vanderplanki

“…In P. vanderplanki , cross-tolerance is observed for a large variety of abiotic stresses. Salt stress and ionizing radiation have been shown to induce the expression of desiccation tolerance-related genes ( 20 , 31 ). Thus, it would not be surprising to find that heat stress enhances desiccation tolerance in P. vanderplanki , as in other anhydrobiotes ( 30 ).…”

Multiple genes contribute to anhydrobiosis (tolerance to extreme desiccation) in the nematode Panagrolaimus superbus

“…Although anhydrobiosis in animals was first described more than three centuries ago ( Van Leeuwenhoek, 1702 ), its molecular basis is poorly understood. Transcriptome and proteome analyses in tardigrades ( Milnesium tardigradum , Richtersius coronifer and Hypsibius dujardini ), bdelloid rotifers ( Adineta ricciae ), nematodes ( Aphelenchus avenae , Ditylenchus africanus , Plectus murrayi and Panagrolaimus superbus ), insects ( Polypedilum vanderplanki ), algae and plants ( Pyropia orbicularis, Myrothamnus flabellifolia and Boea hygrometrica ) identified several genes and proteins that were up- or down-regulated by water loss ( Adhikari et al , 2009 ; Haegeman et al , 2009 ; Mali et al , 2010 ; Schokraie et al , 2010 , 2012 ; Boschetti et al , 2011 ; Tyson et al , 2012 ; Yamaguchi et al , 2012 , Wang et al , 2014 ; López-Cristoffanini et al , 2015 ; Ma et al , 2015 ; Zhu et al , 2015 ; Ryabova et al , 2017 ). Such studies are, by their nature, correlative, and do not provide evidence for a functional role of the genes or proteins concerned.…”

Curcumin increases efficiency of γ-irradiation in gliomas by inhibiting Hedgehog signaling pathway

“…22,23 As known, g-irradiation and other ionizing radiation work by damaging the DNA double strand of cancer cells leading to cellular death. 24,25 After that, DNA damage repair has been launched and genes associated with DNA repair will be activated, such as p53, ATM and ATR. Cells with mutant type of these genes would be resistant to irradiation.…”