INVESTIGADORES
SOMOZA Gustavo Manuel
artículos
Título:
Insulin-like growth factor I of pejerrey, Odontesthes bonariensis: cDNA characterization, tissue distribution and expression profiles after growth hormone administration.
Autor/es:
ANDRÉS SCIARA; GUSTAVO M. SOMOZA; SILVIA ARRANZ
Revista:
Journal of Experimental Zoology Part A.
Editorial:
Wiley Interscience
Referencias:
Año: 2008 vol. 309 p. 407 - 418
ISSN:
1548-8969
Resumen:
The insulin-like growth factor (IGF) system plays a central role in the neuroendocrine regulation of growth in all vertebrates. The liver production of IGF-I is a key factor in the control of body growth by GH. Since pejerrey Odontesthes bonariensis has been reported as a fish fish with low growth rates in captivity basic research on this respect is needed in order to understand it. In this context, the pejerrey IGF-I cDNA was cloned and its hepatic expression was examined in fish after recombinant pejerrey growth hormone (pjGHr) administration as an attempt to understand the GH dependency and temporal pattern of its expression. The rapid amplification of cDNA ends (RACE) was used to obtain the full-length of IFG-I transcript. This transcript was showed a high sequence similarity to other teleosts sequences. The tissue distribution analysis by RT-PCR in adult fish revealed that IGF-I expressed ubiquitously with the highest mRNA levels in the liver, posterior intestine and brain. No alternative IGF-I mRNA was found in the liver, as it was reported for other teleosts. IGF-I transcript was measured in the liver after pjGHr in vivo stimulation by means of quantitative real-time PCR assays. A dose-dependent response of IGF-I mRNA was observed after pjGHr administration, and reached a 6 fold IGF-I maximum increase over control group when 2,5 ìg pjGH /g-body weight (bw) were injected. Temporal analysis of transcriptional induction of hepatic IGF-I showed that administration of a single dose of pjGHr (1 ìg/g-bw) into juvenile pejerrey resulted in a 4,5 fold increase (P<0,02) 9 hours post injection (hpi), that returned to control levels at 15 hpi. These results add novel information on the nucleotide sequence of IGF-I in Atheriniformes. Furthermore, this study demonstrates that pejerrey recombinant growth hormone could promote a dramatic response in liver, increasing the IGF-I mRNA level.