title: Detection and characterization of primordial germ cells in pheasant (Phasianus colchicus) embryos.
abstract: The developmental similarity between the chicken and pheasant (Phasianus colchicus) allows the novel biotechnologies developed in the chicken to be applied to the production of transgenic pheasants and interspecies germline chimeras. To detect pheasant primordial germ cells (PGCs) efficiently, which is important for inducing germline transmission, the ultrastructure of PGCs and their reactivity to several antibodies (2C9, QB2, anti-SSEA-1, and QCR1) and periodic acid-Schiff's solution (PAS) were examined. To obtain PGCs, blood was taken from embryos incubated for 62-72 h or from gonads from embryos incubated for 156-216 h. The PGCs collected from both sources had the typical ultrastructure of pluripotent cells: a large nucleus with a distinct nucleolus, a high ratio of nuclear to cytoplasmic volume, and a distinct cytoplasmic membrane. In comparing the morphology of PGCs collected from different sites, more mitochondria and better-developed membrane microvilli were found in gonadal PGCs than in circulating PGCs. The nucleus of gonadal PGCs was flattened and had a large eccentrically positioned nucleolus. Of the antibodies tested, only QCR1 antibody reacted with an epitope in pheasant PGCs, and no specific signal was detected to other antibodies. The temporal change in the PGC populations in the blood and gonads of embryos was examined. In blood, the population was greater (P < 0.0001) in embryos incubated for 64 h than in embryos incubated for 62 or 66-72 h (31.4 versus 5.6-16.2 microL(-1)). In embryonic gonads, the number of PGCs increased continuously from 156 to 216 h of incubation (193-2,718 cells/embryo), although the ratio of PGCs to total gonadal cells did not change significantly (0.50-0.61%). In conclusion, pheasant PGCs have typical germ cell morphology and possess the QCR1 epitope. Circulating blood and the gonads of embryos incubated for 64 and 216 h, respectively, are good sources of PGCs.
authors.affiliation: Division of Animal Genetic Engineering, School of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Korea.
authors.forename: Jin Nam
authors.initials: JN
authors.lastname: Kim
authors.forename: Young Mok
authors.initials: YM
authors.lastname: Lee
authors.forename: Tae Sub
authors.initials: TS
authors.lastname: Park
authors.forename: Jin Gyoung
authors.initials: JG
authors.lastname: Jung
authors.forename: Byeong Wook
authors.initials: BW
authors.lastname: Cho
authors.forename: Jeong Mook
authors.initials: JM
authors.lastname: Lim
authors.forename: Jae Yong
authors.initials: JY
authors.lastname: Han
mesh_terms: D000818:Animals; D002452:Cell Count; D002466:Cell Nucleolus / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D000939:Epitopes / Q000032:analysis; D046094:Galliformes / Q000196:embryology*; D005854:Germ Cells / Q000276:immunology / Q000648:ultrastructure*; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D008928:Mitochondria / Q000648:ultrastructure
chemical_list: D000939:Epitopes