As top level predators, bottlenose dolphins (Tursiops truncatus), are particularly sensitive to chemical and biological toxins that accumulate and biomagnify in the marine food chain. A dolphin’s exposure to such toxins can be assessed using standard analytical methods, but it is costly and requires the collection of multiple tissue samples. We are currently investigating the potential of screening for multiple contaminant and/or algal toxin exposure through their associated immunological and/or endocrine perturbations in bottlenose dolphins using microarray technology and gene expression profile analysis. If successful, the gene expression profile analysis could provide a cost- 45 effective means to screen for indicators of chemical and biological toxin exposure as well as disease status in dolphins, and potentially other cetaceans. A newly developed dolphin oligo microarray representing 24,418 unigene sequences was used to analyze blood samples from 74 dolphins collected from 4 geographic locations in the South East USA (Beaufort, NC, Sarasota Bay, FL, Saint Joseph Bay, FL, Sapelo Island, GA and Brunswick, GA). The Georgia samples were selected due to the measured high concentrations of persistent organochlorine contaminants in their blubber. Genes involved in xenobiotic metabolism, in development/differentiation and oncogenic pathways were found to be differentially expressed in GA dolphins compared to the other locations. Hypothyroidism has been previously described in GA dolphins and, interestingly, a few of the genes that we identified are involved in the proper function of the thyroid. The analysis of GA animals alone, correlated with contaminant load measured, showed the activation of genes involved in stress response, DNA repair and skin damages, UV and/or viral infection-induced. The transcriptomic data analysis will be a first step towards identification of markers/patterns indicative of exposure to chemical contaminants as well as marine toxins and will promote an understanding of toxic mechanisms and/or pathways that are currently not well understood in marine mammals.

Wild dolphin transcriptomes: identification of the immune response to environmental contaminants through gene expression information

MANCIA, Annalaura;
2012

Abstract

As top level predators, bottlenose dolphins (Tursiops truncatus), are particularly sensitive to chemical and biological toxins that accumulate and biomagnify in the marine food chain. A dolphin’s exposure to such toxins can be assessed using standard analytical methods, but it is costly and requires the collection of multiple tissue samples. We are currently investigating the potential of screening for multiple contaminant and/or algal toxin exposure through their associated immunological and/or endocrine perturbations in bottlenose dolphins using microarray technology and gene expression profile analysis. If successful, the gene expression profile analysis could provide a cost- 45 effective means to screen for indicators of chemical and biological toxin exposure as well as disease status in dolphins, and potentially other cetaceans. A newly developed dolphin oligo microarray representing 24,418 unigene sequences was used to analyze blood samples from 74 dolphins collected from 4 geographic locations in the South East USA (Beaufort, NC, Sarasota Bay, FL, Saint Joseph Bay, FL, Sapelo Island, GA and Brunswick, GA). The Georgia samples were selected due to the measured high concentrations of persistent organochlorine contaminants in their blubber. Genes involved in xenobiotic metabolism, in development/differentiation and oncogenic pathways were found to be differentially expressed in GA dolphins compared to the other locations. Hypothyroidism has been previously described in GA dolphins and, interestingly, a few of the genes that we identified are involved in the proper function of the thyroid. The analysis of GA animals alone, correlated with contaminant load measured, showed the activation of genes involved in stress response, DNA repair and skin damages, UV and/or viral infection-induced. The transcriptomic data analysis will be a first step towards identification of markers/patterns indicative of exposure to chemical contaminants as well as marine toxins and will promote an understanding of toxic mechanisms and/or pathways that are currently not well understood in marine mammals.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/1958217
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