title: Germline transmission of genetically modified primordial germ cells.
abstract: Primordial germ cells (PGCs) are the precursors of sperm and eggs. In most animals, segregation of the germ line from the somatic lineages is one of the earliest events in development; in avian embryos, PGCs are first identified in an extra-embryonic region, the germinal crescent, after approximately 18 h of incubation. After 50-55 h of development, PGCs migrate to the gonad and subsequently produce functional sperm and oocytes. So far, cultures of PGCs that remain restricted to the germ line have not been reported in any species. Here we show that chicken PGCs can be isolated, cultured and genetically modified while maintaining their commitment to the germ line. Furthermore, we show that chicken PGCs can be induced in vitro to differentiate into embryonic germ cells that contribute to somatic tissues. Retention of the commitment of PGCs to the germ line after extended periods in culture and after genetic modification combined with their capacity to acquire somatic competence in vitro provides a new model for developmental biology. The utility of the model is enhanced by the accessibility of the avian embryo, which facilitates access to the earliest stages of development and supplies a facile route for the reintroduction of PGCs into the embryonic vasculature. In addition, these attributes create new opportunities to manipulate the genome of chickens for agricultural and pharmaceutical applications.
authors.affiliation: Origen Therapeutics, 1450 Rollins Road, Burlingame, California 94010, USA.
authors.forename: Marie-Cecile
authors.initials: MC
authors.lastname: van de Lavoir
authors.forename: Jennifer H
authors.initials: JH
authors.lastname: Diamond
authors.forename: Philip A
authors.initials: PA
authors.lastname: Leighton
authors.forename: Christine
authors.initials: C
authors.lastname: Mather-Love
authors.forename: Babette S
authors.initials: BS
authors.lastname: Heyer
authors.forename: Renee
authors.initials: R
authors.lastname: Bradshaw
authors.forename: Allyn
authors.initials: A
authors.lastname: Kerchner
authors.forename: Lisa T
authors.initials: LT
authors.lastname: Hooi
authors.forename: Terri M
authors.initials: TM
authors.lastname: Gessaro
authors.forename: Susan E
authors.initials: SE
authors.lastname: Swanberg
authors.forename: Mary E
authors.initials: ME
authors.lastname: Delany
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Etches
mesh_terms: D000818:Animals; D002460:Cell Line; D019070:Cell Lineage; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics*; D005260:Female; D005434:Flow Cytometry; D005818:Genetic Engineering / Q000379:methods; D016678:Genome / Q000235:genetics; D005854:Germ Cells / Q000166:cytology* / Q000378:metabolism* / Q000637:transplantation; D018095:Germ-Line Mutation / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D010063:Ovum / Q000166:cytology / Q000378:metabolism; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism*