Genomic analysis of Sparus aurata reveals the evolutionary dynamics of sex-biased genes in a sequential hermaphrodite fish

Authors: Pauletto, Marianna and Manousaki, Tereza and Ferraresso, Serena and Babbucci, Massimiliano and Tsakogiannis, Alexandros and Louro, Bruno and Vitulo, Nicola and Quoc, Viet Ha and Carraro, Roberta and Bertotto, Daniela and Franch, Rafaella and Maroso, Francesco and Aslam, Muhammad L. and Sonesson, Anna K. and Simionati, Barbara and Malacrida, Giorgio and Cestaro, Alessandro and Caberlotto, Stefano and Sarropoulou, Elena and Mylonas, Costantinos C. and Power, Deborah M. and Pararnello, Tomaso and Canario, Adelino V.M. and Tsigenopoulos, Costas and Bargelloni, Luca

Sexual dimorphism is a fascinating subject in evolutionary biology and mostly results from sex-biased expression of genes, which have been shown to evolve faster in gonochoristic species. We report here genome and sex-specific transcriptome sequencing of Sparus aurata, a sequential hermaphrodite fish. Evolutionary comparative analysis reveals that sex-biased genes in S. aurata are similar in number and function, but evolved following strikingly divergent patterns compared with gonochoristic species, showing overall slower rates because of stronger functional constraints. Fast evolution is observed only for highly ovary-biased genes due to female-specific patterns of selection that are related to the peculiar reproduction mode of S. aurata, first maturing as male, then as female. To our knowledge, these findings represent the first genome-wide analysis on sex-biased loci in a hermaphrodite vertebrate species, demonstrating how having two sexes in the same individual profoundly affects the fate of a large set of evolutionarily relevant genes.

Journal: Communications biology
DOI: 10.1038/s42003-018-0122-7
Year: 2018

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