Project description:The diverse mixture of contaminants frequently present in estuarine wetlands complicates their assessment by routine chemical or biological analyses. We investigated the use of gene expression to assess contaminant exposure and the condition of southern California (USA) estuarine fish. Liver gene expression, plasma estradiol concentrations and gonad histopathology were used to investigate the biological condition of longjaw mudsuckers (Gillichthys mirabilis). A wide array of metals, legacy organochlorine pesticides, PCBs and contaminants of emerging concern were detected in sediments and whole fish. Overall gene expression patterns were characteristic to each of four sites investigated in this study. Differentially expressed genes belonged to several functional categories including xenobiotic metabolism, detoxification, disease and stress responses. In general, plasma estradiol concentrations were similar among fish from all areas. Some fish gonads had pathologic changes (e.g. infection, inflammation) that could indicate weakened immune systems and chronic stress. The differential expression of some genes involved in stress responses correlated with the prevalence of histologic gonad lesions. This study indicates that sentinel fish gene expression data is a promising tool for assessing the biological condition of fish exposed to environmental contaminants. Key Words: Gene expression, fish, contaminants, estuaries. This abstract belongs to a manuscript that has been submitted to Environmental Science and Technology. The manuscript has been invited as part of an especial Omics Issue which is expected to be published in 2012.
Project description:Feral organisms are affected by adverse environmental factors present in their habitat. It was hypothesized that transcript expression pattern in a suitable target organ of a sentinel feral organism compared to a reference transcript population may serve as a comprehensive biomarker of these adverse effects. This study was aimed at inquiring the applicability of such biomarker and establishing a procedure for its appropriate utilization. The examined system contains dual-labeled microarray-based evaluation of the hepatic transcript expression pattern in a sentinel fish sampled in two habitats, a polluted (Haifa Bay) and a clean (Dor) site, respectively, for two years. The hepatic expression patterns were compared to a reference RNA assumed to represent specimens that have no exposure history to pollution. The sentinel fish is Lithognathus mormyrus, which inhabits a marine coastal habitat along the Mediterranean coast of Israel. The hepatic transcript expression patterns were evaluated using a 1152-clone cDNA microarray, biased towards pollution-affected genes. The LIMMA software was used to calculate the log2 ratios of expressions (M) and to identify the differentially expressed genes in each sample (adjusted P<0.01). Keywords: Response of fish hepatic gene expression pattern to environmental conditions.
Project description:White bass (Morone chrysops) are a popular sportfish throughout the southern United States, and one parent of the commercially successful hybrid striped bass (M. chrysops x M. saxatilis). Currently, white bass are cultured using diets formulated for other carnivorous fish, such as largemouth bass (Micropterus salmoides) or hybrid striped bass and contain a significant percentage of marine fish meal. Since there are no studies regarding the utilization of alternative proteins in this species, we evaluated global gene expression of white bass fed diets in which fish meal was partially or totally replaced by various combinations of soybean meal, poultry by-product meal, canola meal, soy protein concentrate, wheat gluten, or a commercial protein blend (Pro-Cision). Significant differential expressed genes and gene ontology of pairwise comparisons between control diet and each test diet are presented and discussed.