Intracellular pH Regulates Transitions Between Dormancy and Development of Brine Shrimp (Artemia salina) Embryos

Science  22 Jul 1983:
Vol. 221, Issue 4608, pp. 366-368
DOI: 10.1126/science.221.4608.366


The intracellular pH (pHi)of encysted gastrula-stage embryos of the brine shrip, Artemia, as previously shown by in vivo phosphorus-31 nuclear magnetic resonance spectroscopy, increases by more than 1 unit during arousal from cryptobiotic dormancy and decreases by the same amount during reinduction of dormancy. These changes in pHi are now shown to be a fundamental regulator of the transitions between dormancy and metabolism: acidification of activated embryo pHi by more than 1 unit with carbon dioxide induced a state comparable to natural dormancy, while alkalinization of dormant embryo pHi with the weak base ammonia terminated natural dormancy. This demonstration of pHi-mediated regulation of cryptobiotic dormancy extends the known scope for pHi as a regulator of development to include multicellular stages of the metazoan life cycle.