Ability Of Primordial Germ Cells Research Articles

Effect of soft X-ray irradiation on the migratory ability of primordial germ cells in chickens

1. The present study was conducted to elucidate the effect of soft X-ray irradiation on the migratory ability of primordial germ cells (PGCs) to the germinal ridges of chicken embryos. 2. PGCs (Barred Plymouth Rock, BPR) were isolated from embryonic blood and irradiated with soft X-rays for 1–10 min. Then, the PGCs were transfected in vitro with GFP gene by lipofection. The manipulated PGCs were transferred to recipient embryos (White Leghorn, WL) and migration to the germinal ridges was analysed by examining GFP gene expression in the gonads of recipient embryos under UV light at ×40 magnifications. The expression of GFP gene was detected in all the gonads of recipient embryos examined up to 10·5 d of culture. 3. Migration of PGCs irradiated with soft X-rays to the germinal ridges was also confirmed by detecting a single nucleotide polymorphism in the D-loop region of the mitochondrial DNA of BPR and WL chickens. Freshly collected PGCs (BPR) were transferred to the bloodstream of recipient embryos (WL). The fate of the transferred donor PGCs was traced by detecting the single nucleotide polymorphism in the D-loop region of the mitochondrial DNA in BPR and WL used in this study. Transferred donor PGC-derived cells were detected in all the gonads of 17-d cultured embryos by PCR. 4. The results suggest that PGCs irradiated with soft X-rays still retain the ability to migrate to the germinal ridges of recipient embryos.

Effects of Ultraviolet Irradiation on the Migratory Ability of Primordial Germ Cells (PGCs) in the Domestic Chicken

The effect of ultraviolet (UV) irradiation on the ability of primordial germ cells (PGCs) to migrate toward the gonadal ridge was investigated in the domestic chicken. When PGCs were irradiated with UV (254nm, 0.9±0.1μW/cm2) the extent of nuclear damage, as determined by the comet assay, was positively correlated with the duration of UV irradiation in the range from 0 to 60 seconds. However, no further increase in nuclear damage was detected when the duration of UV irradiation was extended from 60 to 120 seconds. To evaluate the migratory ability of PGCs after UV irradiation, 15 fluorescent-labeled PGCs were transferred into the vascular system of 2-day-old embryos and the fluorescent-labeled PGCs present in the gonads of recipient embryos were counted 5 days later. When the duration of UV irradiation was less than 60 seconds, the number of fluorescent-labeled PGCs found in the gonads of the recipient embryos exceeded the number of transferred PGCs. In conclusion, the ability of PGCs to migrate toward the developing gonad is retained after exposure to UV irradiation that causes apparent damage to the nucleus.

Assessment of functional gametes in chickens after transfer of primordial germ cells

The ability of primordial germ cells (PGCs) transferred from donor to recipient embryos to form functional gametes was assessed using feather colour as a phenotypic marker. Donor primordial germ cells were obtained in blood samples taken from Dwarf White Leghorn embryos, homozygous for the dominant allele at the locus for 'dominant white' plumage (I), which had been incubated for 52 h. Blood samples containing PGCs were transferred by intravascular injection to Barred Plymouth Rock embryos (ii) incubated for 53, 72 and 96 h. Of the embryos which hatched, 28 were male and 31 were female. All chicks were raised to sexual maturity and test mated with Barred Plymouth Rock fowl. All of the 3117 offspring exhibited the typical Barred Plymouth Rock phenotype; no Barred Plymouth Rock x Dwarf White Leghorn chicks were obtained. The results of this study suggest that the frequency of transmission of the donor line genotype after PGC transfer must be improved for this technique to be useful for the routine development of transgenic poultry.