Detalle de: Expression of growth hormone gene in the head kidney of gilthead sea bream (Sparus aurata)

The presence of growth hormone (GH) mRNA in the head kidney of gilthead sea bream (Sparus aurata) was assessed by reverse transcription and polymerase chain reaction (RT-PCR). Reverse transcription was made with oligo-dT primers, and a single cDNA band (435 bp) corresponding in length to the distance between two specific GH primers was obtained. No corresponding product was seen using liver and brain RNA samples. The amplified DNA hybridized specifically with a pituitary GH probe after Southern transfer to nylon membranes. The identity of this DNA fragment was further confirmed by sequencing a nested PCR product (343 bp). This finding supports the hypothesis that the immune system in both higher and lower vertebrates is an extrapituitary site for the expression of GH, which may serve as an autocrine/paracrine factor in immunomodulation. J. Exp. Zool. 283:326–330, 1999. © 1999 Wiley-Liss, Inc.