Ultraviolet radiation and handling medium osmolarity affect chimaerism success in zebrafish

The effects of a predefined ultraviolet radiation dose (0.529 mW/cm2 for 30s) together with two different micromanipulation medium osmolarities (30 mOsm/kg vs 300 mOsm/kg) were tested on embryo survival at different developmental stages and on the somatic (skin) and germ-line chimaerism rates. Somatic (13%, 6/47 adults) and germ-line chimaerism (50% pigmented F1 larvae) were detected only in the UV-treated recipient embryos micromanipulated in a 300 mOsm/kg medium. From the results obtained, we concluded that the conditions cited above were the most suitable to improve somatic and germ-line chimaerism rates in zebrafish.