Developmental transcriptomics in Atlantic haddock: Illuminating pattern formation and organogenesis in non-model vertebrates.

Gadiforms such as Atlantic haddock comprise some of the world's most economically important fisheries. Understanding the early life history of these fish is a prerequisite for predicting effects of a changing environment and increased human activities. Robust assessment of the effects of environmental impacts on the embryos of non-model vertebrates is hampered by a lack of molecular resources and detailed knowledge regarding the regulation of genes and pathways in early development. Here we used mRNA sequencing to link transcriptional changes to developmental processes in haddock, specifically, pattern formation and organogenesis. Temporal expression of key developmental genes was tightly anchored to either the appearance of visible structures or cellular processes characterised in model organisms. These findings demonstrate the high potential of developmental transcriptomics as an analytical tool for improved understanding of pathophysiological mechanisms leading to abnormal development in any vertebrate.