Using global genome approaches to address problems in cod mariculture1

Abstract

AbstractA number of techniques, including expressed sequence tag (EST) analysis, serial analysis of gene expression, and micro-arrays, are available to study the global expression and regulation of genes. Many of these techniques are being used for intensively reared fish such as trout, salmon, and catfish to study genes involved in growth, reproduction, and health. In contrast, relatively little is known about the composition and regulation of transcriptomes in gadids. However, several bottlenecks in cod mariculture might benefit from the discovery and analysis of genes involved in reproduction, growth, and disease. As a result, we have begun EST analysis of genes in the cod ovary. Complimentary DNA (cDNA) libraries of cod ovaries taken from females at oocyte final maturation and ovulation have been constructed, and 1361 ESTs have been analysed. As expected, several oocyte-related genes were observed, including various zona pellucida egg membrane proteins. However, pivotal cell cycle regulators such as cyclins, genes involved in the regulation of apoptosis such as the Bcl-2-related ovarian killer protein, and hormone receptor components were also observed. Finally, a cDNA for a potential novel cod antifreeze protein was observed 12 times, suggesting the existence of a cod egg-specific antifreeze protein.