One of the major challenges in the aquaculture industry is precocious maturation. Fish that mature too early will invest energy in developing gonads instead of growing in size, and at the same time, the filet quality deteriorates. In order to overcome these challenges there is a need for an increased understanding of the mechanisms controlling sexual maturation in fish.
In this project, the transcriptome (the total expression of genes) of the pituitary of two different fish species; salmon (Salmo salar) and medaka (Oryzias latipes), has been compared. We have focused on male fish from different developmental stages, from immature fish (before sexual maturation starts) to pubertal fish. The study has identified genes assumed to play an important role for the regulation of early sexual maturation in both species. These genes are good candidates for further functional studies to unravel genes that play a key role in the onset and regulation of puberty in fish.
Dette prosjektet er en komparativ studie av hypofysen i ulike utviklingsstadier av hannfisk til de to artene laks (Salmo salar) og medaka (Oryzias latipes). Gener som er spiller en viktig rolle i reguleringen av tidlig kjønnsmodning hos fisk er identifisert og kan benyttes i videre funksjonelle studier for å løse viktige utfordringer som akvakulturnæringen står ovenfor knyttet til for tidlig kjønnsmodning.
To prevent the recurring problem of early puberty in the salmon industry, understanding the underlying molecular mechanisms is essential. The recently completed salmon genome has enabled a global approach to understand how cells or tissues regulate all prospective proteins (transcripts). In this project I will use a transcriptomics approach (RNA-seq) in combination with functional genomic tools to identify which genes are instrumental in deciding when an individual fish will enter pubertal development. The primary aim of this project is to identify (novel) genes that are important for pubertal activation of the pituitary, using male salmon as model. State-of-the-art genomic, bioinformatic and biotechnological methods will be implemented to elucidate pituitary mechanisms contributing to puberty. The transcriptome of male salmon pituitary will be characterized at the pre-, mid- and post-pubertal stage. Candidate genes identified through bioinformatics analyses will be investigated for functionality both in vivo and in vitro. The proposed project fits very well with my experience, having spent most of my PhD developing tools to investigate differentially expressed genes in eel and medaka pituitary cells using RNA-seq and functional studies of candidate genes. It is also complimentary to ongoing activities in my host groups at the Norwegian University of Life Sciences and Institute of Marine Research, thus complementing and strengthening the results obtained, and thereby enhancing the available tools and knowledge platform for improved salmon farming. The information acquired in this project should be very useful as direct targets for improved breeding and farming protocols in the salmon industry.