Embryogenesis of a calanoid copepod analyzed by transcriptomics

The calanoid copepod Acartia tonsa (Dana) has attracted interest because of its use as a copepod model organism as well as its potential economic role as live fish larval feed. While the adult genome and transcriptome of A. tonsa has been investigated, no studies have been performed investigating the genome-wide transcriptional changes during the normal subitaneous embryogenesis. Thus, the aim of the current study was to investigate said transcriptional changes throughout A. tonsa embryonic development. RNA extraction and de novo transcriptome assembly for the subitaneous embryogenesis of the copepod was conducted. The assembly includes for the first-time samples describing quiescent development and overall helps establishing a framework for future studies on the molecular biology of our species of interest. Among the findings reported, sequences annotated to well-known developmental genes, were identified. At the same time are described the molecular changes and gene expression levels throughout the entire 42 h the embryonic development lasts. In conclusion, here we present the most complete genome-wide transcriptional map of early copepod em-bryonic development to date, enabling further use of A. tonsa as a model organism for crustacean development. Keywords: enrichment of pathways; subitaneous embryogenesis, comparative genomics; transcriptome assembly; invertebrate genomics.