Research
Salmon Insulin-like Growth Factor Binding Proteins
Collaborators: M Shimizu (post-doc), A Pierce (graduate students)
Support: US Department of Agriculture
Major hormones controlling growth in fish, as in all vertebrates, include growth hormone and insulin-like growth factor-I (IGF). The action of IGF in regulating growth of mammals is enhanced or inhibited by six different IGF binding proteins (IGFBPs), which are important modifiers of growth rate of mammals. Fish have at least three to four IGFBPs, which appear to be similar to some of the mammalian IGFBPs, although very little research has been done on fish IGFBPs. One difficulty in study fish IGFBPs is that there are no sensitive, precise assays to measure changes in their concentrations in fish in fast or slow growing states. We propose to purify two salmon IGFBPs from salmon blood serum and develop sensitive radioimmunoassays to measure IGFBPs in salmon blood. This work should provide a much greater understanding of how fish growth is regulated and ultimately lead to improvements in growth efficiency of fish in public and commercial aquaculture.
California Chinook Salmon
Support: UC Davis
The winter-run chinook salmon (Oncorhynchus tshawytscha) of the Sacramento River, California, spawn from June through August and the offspring may be ready to enter sea water at various ages from 6 months to 1.5 years depending on their development rate. The proposed work will study in this stock of salmon the timing of smolting, the process that prepared the fish for seawater entry. Eggs from June and August spawning dates will be reared at low and high growth rates to determine precisely when smolting occurs. Results from these studies will help refine rearing techniques for the captive broodstock program at the University of California Bodega Bay Marine Lab. This work will aid recovery efforts for Sacramento River chinook salmon listed under the Endangered Species Act.