Effects of Busulfan Sustained-release Emulsion on Depletion and Repopulation of Primordial Germ Cells in Early Chicken Embryos

The current study aimed to determine the optimal time of busulfan (1,4-butanediol dimethanesulfonate) administration for the preparation of suitable recipient embryos to generate germline chimeras in chickens. We compared two different administration times, with regards to the degree of endogenous primordial germ cell (PGC) depletion and donor PGC incorporation in recipient embryos. A dose of 75μg busulfan in 50μL sustained-release emulsion was injected into the yolk of chicken embryos incubated for 0h or 24h. Both busulfan treatments resulted in significant reduction in the number of PGCs compared with that of controls (P