Molecular characterization, tissue distribution patterns and nutritional regulation of IGFBP-1, -2, -3 and -5 in yellowtail, Seriola quinqueradiata.
Insulin-like growth factor-binding proteins (IGFBPs) play a vital role in regulating the biological activities of IGFs. In this study, we cloned and determined full-length cDNA sequences of yellowtail IGFBP-1, -2, -3 and -5. Their tissue distribution was determined by real-time quantitative RT-PCR, which revealed that IGFBP-1, -2, -3 and -5 are widely distributed in yellowtail tissues. In yellowtail, both IGFBP-1 and -2 are highly expressed in the liver, IGFBP-3 is predominantly expressed in the heart and skin, with the lowest expression in the liver, and IGFBP-5 is highly expressed in the liver and kidneys. The widespread tissue expression of the yellowtail IGFBPs suggests that they may act in an autocrine and/or paracrine manner in the regulation of IGF activity. The effects of nutritional deprivation on yellowtail IGFBPs and IGF-I were also examined. During a 15-day starvation period, significant elevation was observed in hepatic yellowtail IGFBP-1. Refeeding restored its level to that of the control. No significant change was observed in the hepatic yellowtail IGFBP-2 mRNA levels in starved fish compared with control fish during the starvation period. Interestingly, during the early period of food deprivation, a significant increase was observed in hepatic yellowtail IGFBP-3 and -5 mRNA levels, concomitant to the significant elevation in hepatic IGF-I mRNA from day 3 to day 9. The unexpected increase in growth stimulatory IGFBPs and IGF-I during nutritional deprivation may represent a species-specific response to changes in nutritional condition.
Pedroso
Fiona L
FL
United Graduate School of Agricultural Sciences, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime, Japan.
Fukada
Haruhisa
H
Masumoto
Toshiro
T
D000818:Animals; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000235:genetics / Q000378:metabolism; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000235:genetics / Q000378:metabolism; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics / Q000378:metabolism; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000235:genetics / Q000378:metabolism; D018969:Insulin-Like Growth Factor Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D010473:Perciformes / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012867:Skin / Q000378:metabolism
D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D018972:Insulin-Like Growth Factor Binding Protein 3; D018975:Insulin-Like Growth Factor Binding Protein 5; D018969:Insulin-Like Growth Factor Binding Proteins; D012333:RNA, Messenger