Calorie restriction in the rotifer Brachionus plicatilis enhances hypoxia tolerance in association with the increased mRNA levels of glycolytic enzymes
- 238 Downloads
The rotifer Brachionus plicatilis shows a typical sigmoid growth curve, where calorie restriction (CR) and hypoxia are thought to be introduced at high population density in the stationary phase. CR may induce a shift from aerobic to anaerobic metabolism in this stationary phase, possibly contributing to an increased hypoxia tolerance. This study was undertaken to investigate the effect of CR on hypoxia tolerance at the molecular level. When rotifers were cultured under CR (fed every second day) or fed ad libitum (AL), and subsequently exposed to hypoxia, those in the CR group had a higher survival rate than their AL counterparts. We then cloned cDNAs encoding three glycolytic enzymes, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), enolase (ENO), and phosphoglycerate mutase (PGM) and compared their accumulated mRNA levels between CR and AL rotifers at ages of 1–8 days by quantitative real-time PCR. The CR group showed significantly higher mRNA levels of GAPDH and ENO than their AL counterparts. Furthermore, rotifers in the stationary phase showed higher mRNA levels of these enzymes than those in the exponential growth phase. These results suggest that CR induces anaerobic metabolism, which possibly contributes to population stability under hypoxia in the stationary phase.
KeywordsBrachionus plicatilis Calorie restriction Glycolysis Hypoxia Rotifer
We are grateful to Professor A. Hagiwara, Graduate School of Science and Technology, Nagasaki University, Japan for providing Brachionus plicatilis Ishikawa strain. This work was partly supported by a Grant-in-Aid from the Ministry of Education, Culture, Sports, Science and Technology of Japan. Y. O. was supported by Research Fellowships for Young Scientist from the Japan Society for the Promotion of Science.
- Donati, A., G. Recchia, G. Cavallini & E. Bergamini, 2008. Effect of aging and anti-aging caloric restriction on the endocrine regulation of rat liver autophagy. Journals of Gerontology Series A: Biological Sciences and Medical Sciences 63: 550–555.Google Scholar
- Gracey, A. Y., J. V. Troll, & G. N. Somero, 2001. Hypoxia-induced gene expression profiling in the euryoxic fish Gillichthys mirabilis. Proceedings of the National Academy of Sciences of the United States of America 98: 1993-1998.Google Scholar
- Houthoofd, K., B. P. Braeckman, A. De Vreese, S. Van Eygen, I. Lenaerts, K. Brys, F. Matthijssens & J. R. Vanfleteren, 2004. Caloric restriction, Ins/IGF-1 signalling and longevity in the nematode Caenorhabditis elegans. Belgian Journal of Zoology 134: 79–84.Google Scholar
- Hulbert, A. J., D. J. Clancy, W. Mair, B. P. Braeckman, D. Gems & L. Partridge, 2004. Metabolic rate is not reduced by dietary-restriction or by lowered insulin/IGF-1 signalling and is not correlated with individual lifespan in Drosophila melanogaster. Experimental Gerontology 39: 1137–1143.CrossRefPubMedGoogle Scholar
- Yoshinaga, T., Y. Minegishi, I. F. M. Rumengan, G. Kaneko, S. Furukawa, Y. Yanagawa, K. Tsukamoto & S. Watabe, 2004. Molecular phylogeny of the rotifers with two Indonesian Brachionus lineages. Coastal Marine Science 29: 45–56.Google Scholar