Plasma insulin-like growth factor-1 is unrelated to female reproductive development in a wild population of Dolly Varden charr Salvelinus malma (Walbaum, 1792)
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Insulin-like growth factors (IGFs) are endocrine agents that signal growth in fishes. Because of the interplay between growth and reproduction, endocrine control of the growth axis is thought to have a connection to the reproductive axis. Seasonal patterns and relationships between IGF-1, fish condition, and gonadal development were investigated in a wild population of female Dolly Varden charr Salvelinus malma (Walbaum, 1792) during the summer growing season prior to spawning. Fish were sampled from Florence Lake, Alaska on five sequential sampling trips during April–October 2006. Body and gonad morphometric measurements, and blood plasma samples were obtained for IGF-I quantification. IGF-I increased during summer with fish condition. The gonadosomatic index indicated a pattern of advancing reproductive development in one cohort of fish by August, which indicated impending spawning compared to an immature (non-reproductive) cohort. However, plasma IGF-I levels were not predictive of the sexually maturing cohort. We conclude that IGF-I is not a useful endocrine marker of advancing reproductive state in female Dolly Varden charr but does relate to fish condition during the summer growth period.
KeywordsFish IGF-1 Endocrine Ovary Sex
This study was supported in part by the Columbia River Inter-Tribal Fish Commission.
- Campbell, B., J. Dickey, B. Beckman, G. Young, A. Pierce, H. Fukada & P. Swanson, 2006. Previtellogenic oocyte growth in salmon: relationships among body growth, plasma insulin-like growth factor I, estradiol-17beta, follicle-stimulating hormone and expression of ovarian genes for insulin-like growth factors, steroidogenic-acute regulatory protein and receptors for gonadotropins, growth hormone, and somatolactin. Biology of Reproduction 75: 34–44.CrossRefGoogle Scholar
- Duan, C., 1997. The insulin-like growth factor system and its biological actions in fish. Integrative and Comparative Biology 37: 491–503.Google Scholar
- Frantzen, M., B. Damsgård, H. Tveiten, S. Moriyama, M. Iwata & H. K. Johnsen, 2004. Effects of fasting on temporal changes in plasma concentrations of sex steroids, growth hormone and insulin-like growth factor I, and reproductive investment in Arctic charr. Journal of Fish Biology 65: 1526–1542.CrossRefGoogle Scholar
- Hevroy, E. M., C. Hunskar, S. de Gelder, M. Shimizu, R. Waagbo, O. Breck, H. Takle, S. Sussort & T. Hansen, 2013. GH-IGF system regulation of attenuated muscle growth and lipolysis in Atlantic salmon reared at elevated sea temperatures. Journal of Comparative Physiology, Part B 183: 243–259.CrossRefGoogle Scholar
- Onuma, T. A., K. Makino, H. Katsumata, B. R. Beckman, M. Ban, H. Ando, M. Fukuwaka, T. Azumaya, P. Swanson & A. Urano, 2010. Changes in the plasma levels of insulin-like growth factor-I from the onset of spawning migration through upstream migration in chum salmon. General and Comparative Endocrinology 165: 237–243.CrossRefGoogle Scholar
- Small, B. C. & B. C. Peterson, 2005. Establishment of a time-resolved fluoroimmunoassay for measuring plasma insulin-like growth factor I (IGF-I) in fish: effect of fasting on plasma concentrations and tissue mRNA expression of IGF-I and growth hormone (GH) in channel catfish (Ictalurus punctatus). Domestic Animal Endocrinology 28: 202–215.CrossRefGoogle Scholar