Reoto Tani, Tetsuro Morita, Christophe Klopp, Yann Guiguen, Ryosuke Yazawa, Marine Milhes, Wataru Kawamura, Goro Yoshizaki, Tokyo University of Marine Science and Technology (TUMSAT), Plateforme Bio-Informatique - Génotoul, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Système d'Information des GENomes des Animaux d'Elevage (SIGENAE), Génome et Transcriptome - Plateforme Génomique ( GeT-PlaGe), Plateforme Génome & Transcriptome (GET), Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Génopole Toulouse Midi-Pyrénées [Auzeville] (GENOTOUL), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire de Physiologie et Génomique des Poissons (LPGP), Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique )-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)
International audience; Chub mackerel Scomber japonicus and blue mackerel S. australasicus have become important aquaculture target species in Japan. For an efficient and stable aquaculture production of mackerels, it is desirable to work with a female-biased broodstock and thus to be able to manage precisely their sex ratio. As these two mackerel species do not have any external sexual dimorphism, direct biopsy of the gonads or measurement of sex hormone plasma levels is used in research to determine their phenotypic sex. However, these methods are associated with handling stress that results in gonadal atresia. Besides, it is difficult to identify sex using these methods in immature individuals. Therefore, genetic sexing would be desirable in these species to overcome these problems. In this study, we developed molecular sex identification tools for both chub and blue mackerels using sex-specific single-nucleotide variations (SNVs) identified by pool-sequencing (pool-seq) analyses. Genomic DNA was isolated from 30 males and females, in each species, and sequenced as pooled samples. Results of these pool-seq analyses identified a clear XX/XY male heterogametic sex-determination system in blue mackerel and a ZZ/ZW female heterogametic system in chub mackerel. Using this pool-seq information, we designed primer sets for genetic sex identification in both species. Results demonstrated that these primer sets are robust and accurate in assessing the genotypic sex of both blue and chub mackerels (accuracy > 99.5% in the chub, and > 94.5% in the blue mackerel) in various geographical samples of different ages. This method can now be applied for the efficient management of sex ratios in both mackerel aquaculture populations and wild-caught animals for fisheries management.