title: Germline replacement by transfer of primordial germ cells into partially sterilized embryos in the chicken.
abstract: We report a novel technique for almost complete replacement of the recipient germline with donor germ cells in the chicken. Busulfan solubilized in a sustained-release emulsion was injected into the yolk of fertile eggs before incubation. A dose of 100 microg was found to provide the best outcome in terms of reducing the number of endogenous primordial germ cells (PGCs) in embryonic gonads (0.6% of control numbers) and hatchability (36.4%). This was applied for preparing partially sterilized embryos to serve as recipients for the transfer of exogenous PGCs. Immunohistochemical analysis showed that the proportion of donor PGCs in busulfan-treated embryos was significantly higher than in controls (98.6% vs. 6.4%). Genetic cross-test analysis revealed that the germline transmission rate in busulfan-treated chickens was significantly higher than in controls (99.5% vs. 6.0%). Of 11 chimeras, 7 produced only donor-derived progenies, suggesting that these produced only donor-derived gametes in the recipient's gonads. This novel germline replacement technique provides a powerful tool for studying germline differentiation, for generating transgenic individuals, and for conserving genetic resources in birds.
authors.affiliation: Faculty of Agriculture, Shinshu University, Nagano, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Fumitake
authors.initials: F
authors.lastname: Usui
authors.forename: Tamao
authors.initials: T
authors.lastname: Ono
authors.forename: Kumiko
authors.initials: K
authors.lastname: Takeda
authors.forename: Keijiro
authors.initials: K
authors.lastname: Nirasawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kagami
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tagami
mesh_terms: D000818:Animals; D002066:Busulfan / Q000494:pharmacology; D002642:Chick Embryo; D002645:Chickens; D046528:Chimerism; D047108:Embryonic Development / Q000187:drug effects; D005260:Female; D005854:Germ Cells / Q000637:transplantation*; D006066:Gonads / Q000187:drug effects / Q000196:embryology; D008297:Male; D019653:Myeloablative Agonists / Q000494:pharmacology; D013245:Sterilization, Reproductive / Q000379:methods; D018183:Transplantation Chimera
chemical_list: D019653:Myeloablative Agonists; D002066:Busulfan