9631441 Hogstrand Every living organism needs minute quantities of zinc. However, female squirrelfish (Holocentridae) accumulate massive quantities of zinc in liver and ovaries. This zinc seems to be used for reproductive processes. In response to estrogen, zinc is transported from the ovaries where it may be required for egg development. Female squirrelfish liver have at least two proteins that handle zinc. One of these proteins, metallothionein, is found in the cell nucleus. Nuclear localization of metallothionein is unusual and in mammals it has been associated with rapidly dividing cells, such as tumor cells. The other major zinc-binding protein in female squirrelfish liver has not been observed anywhere else and its function is unknown. Thus, in many aspects squirrelfish present an entirely new view of zinc in biological systems and demonstrate the ability of zinc in biological systems and demonstrate the ability of some animals to handle this essential, but potentially toxic, element. The long-term goals of this project are to (1) identify novel aspects of the role of zinc in reproductive biology, to (2) determine the role of metallothionein in reproduction, and (3) characterize the novel female-specific zinc-binding protein (FZnBP).
