Restriction of proliferation of primordial germ cells by the irradiation of Japanese quail embryos with soft X-rays.
Primordial germ cells (PGCs) are the progenitor cells for the gametes. Avian PGCs are located in the central region of the area pellucida at the blastoderm stage. Shortly after further incubation, they migrate to the extra-embryonic germinal crescent, and then as soon as the blood vessels form, they enter the circulation and finally settle in the gonadal primordium. We have developed a simple method using soft X-ray irradiation (18 kV power, 20 cm distance) to reduce the number of PGCs in Japanese quail embryos, which should be useful in preparing recipient embryos for PGC-transfer studies. When embryos were exposed to the soft X-rays for 40 s before incubation, the concentration of circulating PGCs was less than one-fifth that in controls after 2 days of incubation. Embryos at day 6 of incubation contained approximately half the number of PGCs compared to controls when they were exposed before or at day 2 of incubation. Irradiation for 40 s is recommended taking into consideration the restriction of proliferation of PGCs, and viability and hatchability.
Li
H C
HC
United Graduate School of Agricultural Science, Gifu University, Gifu 501-1193, Japan.
Kagami
H
H
Matsui
K
K
Ono
T
T
D000818:Animals; D001756:Blastoderm / Q000166:cytology / Q000528:radiation effects; D002455:Cell Division / Q000528:radiation effects; D002642:Chick Embryo; D003370:Coturnix; D004912:Erythrocytes / Q000166:cytology; D005854:Germ Cells / Q000166:cytology* / Q000528:radiation effects*; D011828:Radiation Chimera; D014965:X-Rays