|Davis Jr, Kenneth|
Submitted to: Annual Meeting of Society of Integrative and Comparative Biology
Publication Type: Abstract Only
Publication Acceptance Date: 7/2/2003
Publication Date: 1/5/2004
Citation: Davis Jr, K.B., Peterson, B.C. 2004. Insulin-like growth factor and igf binding proteins in sunshine bass [abstract]. In: Annual Meeting of Society of Integrative and Comparative Biology. p. 312.
Technical Abstract: Growth of fish is regulated by components of the pituitary-liver-somatic tissue axis. The influence of growth hormone from the pituitary is, in part, to stimulate the liver to synthesize and release insulin-like growth factors (IGF1 and IGF-II). IGF-I is now thought to have the direct effects on somatic tissues that result in growth. Plasma IGF-I is bound in the plasma to IGF-I binding proteins (IGFBP) and the role of the IGFBPs as growth regulators has only recently been appreciated. Sunshine bass is a hybrid between a white bass and striped bass and is widely used in aquaculture. Females grow to be larger than males, however the reason for the size difference is not known. Plasma IGF-I and IGFBPs were measured in sunshine bass of both sexes before and after a low-water confinement stress. IGF-I concentrations were 78.9+ 4.8 ng/ml in undisturbed fish and were not statistically different between males and females. Two hours after a 15 minute low-water stress, concentration were 82.2 + 4.7 and were not statistically different between males and females. Plasma concentrations of a 33-kDa IGFBP were96.6 + 16.6 arbitrary density units in undisturbed fish, were not significantly different between the sexes, and were not affected by low-water confinement. The growth difference between males and females in sunshine bass cannot be explained by concentrations of IGF-I or the 33 kDa IGFBP.