Cloning of a second variant of somatolactin-encoding cDNA from the gilthead seabream Sparus aurata

cDNA clones which include coding sequences of the gilthead seabream (Sparus aurata) somatolactin (SL) have been isolated from a cDNA library prepared from seabream pituitary gland poly (A)^sup +^ RNA. Flounder - SL cDNA was used as a hybridization probe. The complete nucleotide (nt) sequence of the seabream somatolactin has been determined. The clone encodes a polypeptide of 231 amino acid (aa) residues including 24 amino acid residues of signal peptide. Northern blot hybridization detected one band of approximately 1.8 kb mRNA. By comparing the sequences of this SL cDNA to the one recently published, it is suggested that two variants of the SL exist in seabream. By comparing the sequences of the aa of SL to the deduced aa sequences, it is possible that even a third variant of SL exists in this species.[PUBLICATION ABSTRACT]