Mitochondria as key responders of metabolic and hormonal disturbances in fish. Meta-analysis flowchart of transcriptomic data in gilthead sea bream (Sparus aurata)

Abstract

Trabajo presentado en el 17th International Congress of Comparative Endocrinology celebrado en Barcelona del 15 al 19 de julio de 2013The application of genomic technologies in aquaculture is providing a growing number of valuable information about the metabolic mechanisms controlling key traits for optimal performance in cultured fish. For instance, development of fish-specific microarrays has allowed researchers to monitor the simultaneous expression of thousands of genes on a vast diversity of experimental conditions. Nevertheless, an integration of the heterogeneous data generated to detect common patterns of gene activity for particular traits is still far to be achieved. On this issue, the integrated meta-analyses of functional genomics data have enormous potential for identifying phenotype-associated genes. To achieve this goal, the bioinformatic tool Fish and Chips (http://fishandchips.genouest.org), specifically designed for the meta-analysis of fish-related microarray experiments, has been constructed. It involves an automatic re-normalization and re-analysis of the included datasets from fish species of interest in aquaculture and in basic research (355 stored to date, from public repositories and private experiments) to identify clusters of co-expressed genes that are functionally annotated. Meta-analysis of a group of differentially expressed genes in white skeletal muscle samples of gilthead sea bream from a feed restriction trial showed a close relationship with other clusters from aerobic muscles (heart and red skeletal muscle) derived from the same experience, and many gene ontology (GO) terms related to mitochondria function appeared as common links among clusters. More interestingly, a second round of cluster profile comparison revealed that mitochondria-related GOs were also linking differentially expressed genes from heart samples of the feed restriction trial with liver samples of gilthead sea bream with cortisol-treated fish. These results evidence that mitochondria are among the first responders to various stress challenging homeostasis of the cell and organism, and further characterization in fish of this cellular organelle is desirable in order to obtain reliable markers of optimal growth and performance in aquaculture.Peer Reviewe