Group 1 LEA proteins contribute to the desiccation and freeze tolerance of Artemia franciscana embryos during diapause
- 418 Downloads
Water loss either by desiccation or freezing causes multiple forms of cellular damage. The encysted embryos (cysts) of the crustacean Artemia franciscana have several molecular mechanisms to enable anhydrobiosis—life without water—during diapause. To better understand how cysts survive reduced hydration, group 1 late embryogenesis abundant (LEA) proteins, hydrophilic unstructured proteins that accumulate in the stress-tolerant cysts of A. franciscana, were knocked down using RNA interference (RNAi). Embryos lacking group 1 LEA proteins showed significantly lower survival than control embryos after desiccation and freezing, or freezing alone, demonstrating a role for group 1 LEA proteins in A. franciscana tolerance of low water conditions. In contrast, regardless of group 1 LEA protein presence, cysts responded similarly to hydrogen peroxide (H2O2) exposure, indicating little to no function for these proteins in diapause termination. This is the first in vivo study of group 1 LEA proteins in an animal and it contributes to the fundamental understanding of these proteins. Knowing how LEA proteins protect A. franciscana cysts from desiccation and freezing may have applied significance in aquaculture, where Artemia is an important feed source, and in the cryopreservation of cells for therapeutic applications.
KeywordsLate embryogenesis abundant (LEA) proteins Intrinsically disordered proteins (IDPs) Desiccation tolerance Freeze tolerance Brine shrimp RNA interference (RNAi)
This work was supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant (RGPIN/7661-2011) to THM, and an NSERC Julie Payette Scholarship and Killam Pre-doctoral Scholarship awarded to JT.
- National Oceanic and Atmospheric Administration (2011). NOAA’s 1981-2010 Climate Normals. http://www1.ncdc.noaa.gov/pub/data/normals/1981-2010/products/station/USW00024127.normals.txt. Accessed 1 August 2013
- Clegg JS (1986) The physical properties and metabolic status of Artemia cysts at low water contents: the ‘water replacement hypothesis’. In: Leopold AC (ed) Membranes, metabolism and dry organisms. Comstock, Ithaca, pp 169–187Google Scholar
- Clegg JS, Drinkwater LE, Sorgeloos P (1996) The metabolic status of diapause embryos of Artemia franciscana (SFB). Physiol Zool 69:49–66Google Scholar
- Cornette R, Kanamori Y, Watanabe M, Nakahara Y, Gusev O, Mistumasu K, Kadono-Okuda K, Shimomura M, Mita K, Kikawada T, Okuda T (2010) Identification of anhydrobiosis-related genes from an expressed sequence tag database in the cryptobiotic midge Polypedilum vanderplanki (Diptera; Chironomidae). J Biol Chem 285:35889–35899PubMedCentralPubMedCrossRefGoogle Scholar
- Crowe JH, Crowe LM, O’Dell SJ (1981) Ice formation during freezing of Artemia cysts of variable water contents. Mol Physiol 1:145–152Google Scholar
- Förster F, Liang C, Shkumatov A, Beisser D, Engelmann JC, Schnölzer M, Frohme M, Müller T, Schill RO, Dandekar T (2009) Tardigrade workbench: comparing stress-related proteins, sequence-similar and functional protein clusters as well as RNA elements in tardigrades. BMC Genomics 10:469PubMedCentralPubMedCrossRefGoogle Scholar
- Hatanaka R, Hagiwara-Komoda Y, Furuki T, Kanamori Y, Fujita M, Cornette R, Sakurai M, Okuda T, Kikawada T (2013) An abundant LEA protein in the anhydrobiotic midge, PvLEA4, acts as a molecular shield by limiting growth of aggregating protein particles. Insect Biochem Mol Biol 43:1055–1067PubMedCrossRefGoogle Scholar
- Storey KB, Storey JM (2013) Molecular biology of freezing tolerance. Comp Physiol 3:1283–1308Google Scholar
- Van Stappen G, Lavens P, Sorgeloos P (1998) Effects of hydrogen peroxide treatment in Artemia cysts of different geographical origin. Arch Hydrobiol Spec Issues Advanc Limnol 52:281–296Google Scholar
- Warner AH, Chakrabortee S, Tunnacliffe A, Clegg JS (2012) Complexity of the heat-soluble LEA proteome in Artemia species. Comp Biochem Physiol D 7:260–267Google Scholar
- Wu G, Zhang H, Sun J, Liu F, Ge X, Chen W-H, Yu J, Wang W (2011) Diverse LEA (late embryogenesis abundant) and LEA-like genes and their responses to hypersaline stress in post-diapause embryonic development of Artemia franciscana. Comp Biochem Physiol B 160:32--39Google Scholar