Biochinlica et Biophysica Acta, 1130 (1992) 345-348 345 © 1992 Elsevier Science Publishers B.V. All rights reserved 0167-4781/92/$05.0(~ BBAEXP 90344 Short Sequence-Paper The complete nucleotide sequence of the Atlantic salmon growth hormone I gene Rune Male, Audun H. Nerland ~, James B. Lorens, Wenche Telle 2 Ivar Lossius 3 and Geir K. Totland 4 Center of Biotechnology, Unirersityof Bergen, HIB, Bergen (Norway) (Received 14 February 1992) Key words: Growth hormone; Genomic sequence: (Atlantic salmon) Two closely related genes encoding growth hormone were isolated from Atlantic salmon by genomic cloning. From one of these genes a total of 6500 nucleotides were determined including 3900 nucleotides in exons and introns and about 6(10 and 2000 nucleotides in 5' and 3' flanking regions. The genc is organized in six exons and encodes a polypeptide of 210 amino acids including a 22 amino acids signal sequence. The promoter region contains a typical TATA box 21 nucleotides upstream from the transcription start site. At the 3' end, three putative poly(A) signal sequences are present. The last two are within a 121 nt inverted repeat. Growth hormone (GH) is a major determinant of somatic growth in all vertebrates and stimulates lipid mobilization and possibly has diabetogenic properties [1,2]. In salmon, GH may participate together with thyroid hormones in seawater adaptation which in- volves enhanced growth, body silvering and tolerance of increased osmolarity [2,3]. GH cDNAs have been isolated from a wide range of species, including at least 15 teleosts. In this communication we report the struc- ture of one of the two genes encoding growth hormone in Atlantic salmon (saIGH 1). DNA was extracted from Atlantic salmon (Salmo salar) liver (one individual) using standard methods [4] and further purified by isopycnic centrifugation in CsCI. Sau3A1 digested DNA, average length 15 kb, was ligated to purified AEMBL3 arms (EMBL, Heidelberg), and packaged in vitro (Promega), yielding 3.8.10 7 pfu//zg DNA. A total of 4.10 5 clones (i.e., four genome equivalents) were screened with the following The sequence reported in this communication will appear in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accessionnumber X61938. Present addresses: i Norbio A/S, H1B, Bergen, Norway: 2 Depart- ment of Biochemistry and 3 Department of Research Management, Universityof Bergen, Bergen, Norway;and 4 Richer and S~n A/S, Bergen, Norway. Correspondence: R. Male, Center of Biotechnology, University of Bergen, HIB, N-5020, Bergen, Norway. oligonucleotide probes obtained from the chum salmon growth hormone (chumGH) eDNA sequences [5]: 5' GTAGGTCTCGACCTTGTGCATGTCCTTCTTGA- A (exon V/VI), 5' GATGG(ATXGC)TC(AT)GAGT- T(GA)CAGAA (exon lid and 5' AGCCAATAGGTG- GAG(AG)TG(TC)TG (exon II). Plaque lifts were hy- bridized to end labelled oligonucleotides (5. l0 s cpm/#g) using a standard hybridization solution [4] supplemented with 10% formamide at 42°C. The filters were stringently washed at 50°C in 0.5 × SSPE/0.1% SDS. The salGH I cDNA probe [6] was labelled by random priming [7] to a specific activity of (2-5)" 109 cpm/~g. Southern blot analysis was performed using standard procedures [4]. The most stringent wash of the filters was performed at 65°C in 0.2 x SSPE/0.1% SDS. Both rainbow trout and salmon apparently possess two GH genes [5,8,9]. In agreement with these observa- tions, we obtained clones representing two different salGH genes upon screening of a genomic library from Atlantic salmon. Four clones hybridized with all three oligonucleotide probes. Rescreening at high stringency with an Atlantic salmon eDNA probe [6] confirmed that these clones contained DNA sequences deriving from the growth hormone gene. Restriction enzyme mapping showed that three of the clones possessed a similar pattern to the chumGH gene transcript de- scribed by Sekine et al. [5], whereas one clone ap- peared to correspond to a second chumGH transcript briefly described in the same report, and to the salGH