Tine Mbaye auteur aut IRD Lorgeril de J. auteur aut IRD Panfili Jacques auteur aut IRD Diop Khady auteur aut IRD Bonhomme F. auteur aut IRD Durand Jean-Dominique auteur aut IRD text journalArticle eng text/pdf born digital access The effects of salinity on the expression of genes coding for growth hormone (GH) and prolactin-1 (PRL1) were studied in various natural populations of the black-chinned tilapia Sarotherodon melanotheron from West Africa. Individuals were sampled in June 2005 in six locations in Senegal and the Gambia, at various salinities between 0 and 101. The poorest condition factors were recorded in the most saline sampling site and the best growth in the fish from a marine environment. The pituitary GH mRNA levels were significantly higher in fish adapted to seawater, whereas the PRL1 mRNA levels were highest in fish adapted to fresh- and brackish water. These results show that the PRL1 mRNA levels seem to reflect relatively well the differences in environmental salinity, in contrast to those of GH, which would tend instead to reflect the individual growth in each environment. However, no relation could be found between growth in the hypersaline areas and the expression profile of GH. Although the fish analysed were morphologically identical, the expression of genes coding for GH and PRL1 showed large differences between individuals. This inter-individual variation in gene expression remains poorly understood. specialized adaptation estuaries gambia growth osmoregulation mRNA expression saloum variation SENEGAL GAMBIE 034 147 3 541-549 2007 1096-4959 https://www.documentation.ird.fr/hor/fdi:010040666 10.1016/j.cbpb.2007.03.010 1096-4959 [F B010040666] https://www.documentation.ird.fr/hor/fdi:010040666 https://www.documentation.ird.fr/intranet/publi/2007/09/010040666.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2007-10-11 2022-05-28 fdi:010040666 fre