USING OVAPRIM TO ENHANCE REPRODUCTIVE PERFORMANCE IN LABORATORY REARED ZEBRAFISH Danio rerio  

Over the past two decades zebrafish have become a mainstream laboratory animal model for many fields of biomedical and basic scientific research.  Developmental biologists first selected zebrafish because larvae are clear during early stages of development, and the adults are hearty and spawn easily.  Researchers now conduct a myriad of experiments on zebrafish including forward and reverse genetic screening, and genome editing.  These experiments often lead to researchers having a single fish carrying a mutation or transgenic insertion of interest.  Under these circumstances it is critical that these individuals are successfully spawned, with frequent spawning events and large clutches being preferred.  The aim of this study is to evaluate the use of Ovaprim to enhance reproductive performance in zebrafish.

Ovaprim is a commercially available injectable hormone (Salmon Gonadotropin Releasing Hormone Analog and Domperidone) that is commonly used by commercial ornimnetal fish producers to induce spawning and enhance reproductive performance.  Ovaprim has been shown to be successful in other Cyprinid species so we believe it could be effective in zebrafish as well.  

A preliminary experiment was done to evaluate the efficacy of Ovaprim in zebrafish.  Due to the small size of zebrafish adults (avg wt 0.5g) a microinjector with a pulled glass capillary needle was used to deliver Ovaprim into the intraperitoneal cavity of male and female zebrafish (n = 6 pairs).  Pairs were then set up to spawn naturally.  Ovaprim injections didn't affect spawning success rate or fertilization, however injected fish did spawn earlier than uninjected fish and there was a trend toward larger clutch sizes.

Ongoing experiments will focus on adjusting Ovaprim concentration, injection timing, and increasing sample size to determine if Ovaprim is a viable option to improve reproductive performance in zebrafish.