New approaches for analyzing the proteome and stress response mechanisms of euryhaline desert fishes

Authors: Dietmar Kültz

Year: 2009 (xli)

Abstract

Most fish species are limited in their distribution to either the marine or freshwater habitats because they cannot tolerate large salinity fluctuations. Their mechanisms of osmoregulation and transepithelial ion transport are optimized such that they only work efficiently in either the ocean or freshwater. However, a number of fish species are capable of tolerating extremely wide salinity fluctuations. Interestingly, most of these fish species also have increased tolerance towards many other types of environmental stress, including heat stress and hypoxia. Among those fish species are many desert fishes that frequently face severe changes in salinity as a result of evaporation and droughts. We have studied the underlying molecular mechanisms of environmental (in particular salinity) stress tolerance in tilapia (Oreochromis mossambicus), which occur in California’s Salton Sea. To study environmental implications and the evolutionary conservation of such environmental stress tolerance mechanisms we are poised to apply a new proteomics approach for revealing such mechanisms in desert pupfish (Cyprinodon macularius) and Salt creek pupfish (C. salinus). This presentation provides a brief overview of my laboratory’s proteomics approaches, which utilize sophisticated protein fractionation technologies followed by mass spectrometry using the identification of proteins involved in osmotic stress signaling in tilapia as an example. An outline of our plan for applying this technology to the study of environmental stress tolerance mechanisms in pupfish is discussed.