PRODUCTION OF TRANSGENIC MICE FROM IN-VITRO FERTILIZED-EGGS CRYOPRESERVED BY ULTRARAPID FREEZING

In vitro fertilized mouse eggs (C57BL/6N), followed by ultrarapid free zing were used for production of transgenic mice by microinjection of the chicken beta-actin promoter-driven the firefly luciferase cDNA (be ta act-Luc). Following micromanipulation, the survival rates of the cr yopreserved eggs and of the fresh in vitro fertilized eggs (control) w ere 70.8% (131/185) and 71.9% (159/221), respectively. After transferr ing them into oviducts of psudopregnant recipients on Day 1, 13.6% (17 /125) of the cryopreserved eggs developed to live offspring and 14.1% (21/149) of fresh eggs did so. It was confirmed by Southern blotting a nalysis that each two transgenic mice were produced from the cryoprese rved eggs (12%, 2/17) and the fresh eggs (10%, 2/21). All of transgeni c mice produced from both eggs showed the expression of the luciferase gene. These results indicate that the in vitro fertilized eggs cryopr eserved by ultrarapid freezing, can be, easily and conveniently, used for generation of transgenic mice.