Cloning and Characterization of Rainbow Trout (Oncorhynchus mykiss) Somatolactin cDNA and Its Expression in Pituitary and Nonpituitary Tissues

doi:10.1006/gcen.1996.6880

General and Comparative Endocrinology

Volume 106, Issue 2, May 1997, Pages 271-280

https://doi.org/10.1006/gcen.1996.6880 Get rights and content

Abstract

A cDNA clone encoding rainbow trout (Oncorhynchus mykiss) somatolactin (rtSL) has been isolated from a rainbow trout pituitary cDNA library. This 2329-bp cDNA clone includes a very short 7-bp 5′-untranslated region, a coding region of 702 bp, and a long 3′-untranslated region of 1620 bp. The deduced amino acid sequence of rtSL shows a polypeptide of 233 amino acid residues which consists of a 24-amino-acid putative signal peptide followed by a 209-amino-acid mature polypeptide. This mature polypeptide has a molecular weight of 24 kDa. The rtSL shares 99% amino acid identity with chum salmon SL (csSL) and approximately 53–77% amino acid identity with SLs in other fishes, including the 7 conserved cysteine residues. Although a glycosylation site has been identified in SL of other fish species, none is observed in rtSL polypeptide. The level of rtSL mRNA in a single pituitary gland was determined by RNA blot hybridization. Results showed that levels of SL mRNA in pituitary glands of 2-year-old fish were 4- to 7-fold higher than those of 1-year-old fish. The tissue distribution of SL gene expression in adult fish was determined by reverse transcription–polymerase chain reaction (RT-PCR) and DNA blot hybridization. In addition to the pituitary gland, SL mRNA was detected in all tissues examined including brain, gill, heart, kidney, liver, skeleton muscle, spleen, ovary, testis, and immature oocytes. The extrapituitary expression of the SL gene was also detected in embryos and fry. The PCR products which contained the region coding for mature SL from heart and kidney were cloned and characterized. Nucleotide sequence analysis showed that the SL mRNAs in heart and kidney were identical to that in the pituitary gland. These results suggest that, although the pituitary gland is the predominant tissue for producing SL, it is not the only tissue that SL gene is expressed in, and the extrapituitary expression of rtSL gene starts from very early developmental stages.

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Regular ArticleCloning and Characterization of Rainbow Trout (Oncorhynchus mykiss) Somatolactin cDNA and Its Expression in Pituitary and Nonpituitary Tissues☆

Abstract

Anal. Biochem.

J. Biol. Chem.

Mol. Cell. Endocrinol.

Gen. Comp. Endocrinol.

Gen. Comp. Endocrinol.

Gene

Gen. Comp. Endocrinol.

Biochem. Biophys. Res. Commun.

Gen. Comp. Endocrinol.

J. Immunol. Methods

Gen. Comp. Endocrinol.

Rainbow trout has two genes for growth hormone

Mol. Reprod. Dev.

Development of a rainbow trout pituitary cell line that expresses growth hormone, prolactin, and somatolactin

Mol. Mar. Biol. Biotechnol.

Somatolactin, a novel pituitary protein: Isolation and characterization fromSparus aurata

Mol. Mar. Biol. Biotechnol.

A human B-lymphoblastoid cell line produces prolactin

Endocrinology

The rat prolactin gene is expressed in brain tissue: Detection of normal and alternatively spliced prolactin messenger RNA

Mol. Endocrinol.

A technique for radiolabeling DNA restriction endonuclease fragments to high specific activity

Anal. Biochem.

Detection of prolactin messenger RNA in mammary and other normal and neoplastic tissues by polymerase chain reaction

Lab. Invest.

Decidual-type prolactin expression by the human myometrium

Endocrinology

Nonpituitary human prolactin gene transcription is independent of Pit-1 and differentially controlled in lymphocytes and in endometrial stroma

Mol. Endocrinol.

A placenta-specific 5′ non-coding exon of human prolactin

Mol. Cell Endocrinol.

Constructing and screening cDNA libraries in λgt10 and λgt11

DNA Cloning: A Practical Approach

Isolation and characterization of somatolactin genes from two cold water marine teleosts, lumpfish (Cyclopterus lumpusHippoglossus hippoglossus

Mol. Mar. Biol. Biotechnol.

Effects of feeding, fasting, background adaptation, acute stress, and exhaustive exercise on the plasma somatolactin concentrations in rainbow trout

Gen. Comp. Endocrinol.

Role of prolactin and somatolactin in calcium regulation in fish

J. Exp. Biol.

Regular Article
Cloning and Characterization of Rainbow Trout (Oncorhynchus mykiss) Somatolactin cDNA and Its Expression in Pituitary and Nonpituitary Tissues☆