Chicken anterior pituitary extract(CAPE) and acetone dried chicken anterior pituitary (ACAPE) were injected intraperitoneally into normal laying hens (‘ovulation suppressed’ following pretreatment with daily subcutaneous injection of PMSG) to induce multiple ovulations. The dose of PMSG, the effect of CAPE and ACAPE and the time required for induction of ovulation following injection of ovulation inducing hormone were determined. The results revealed that (1) when 75 IU PMSG was administered daily, egg laying stopped in 33% of the treated hens within 6 days after the first injection. However, the percentage of hens showing the same effects changed significantly (over 95%) within 3 to 6 days when the amount of PMSG was increased to 100 IU; (2) the number of ovulated ova was 1 00±0 00, 2 33±0 26,2 20±0 20 respectively after receiving 100 mg, 200 mg and 300 mg; the number of ovulated ova was 2 00±0 00, 2 86±0 48, 3 00±1 50 respectively after receiving 10 mg, 15 mg and 20 mg ACAPE; (3) The time from injection to ovulation in almost all hens was about 7 5 h except one hen ovulated about 6 5 h after receiving ACAPE .
Blood samples were collected from chicken embryos at stage 11～15, and labeled with fluorescent dye PKH26. Primordial germ cells (PGCs) were then isolated from blood samples by nycodenz density gradient centrifugation. After PGCs were labeled and isolated, about 200 PGCs in one microliter were injected into the subgerminal cavity of quail blastoderm at stageⅩ. After 48 hours incubation, chicken PGCs were identified by fluorescent microscopy. Red fluorescence emitted from PKH26 labeled chicken PGCs was observed in the head, the heart and the developing gonadal anlage of quail embryos. The result suggests that chicken PGCs still keep migration ability after 56 hours.
