| 2． |
"Recessive Black": A Plumage Color Mutant in Japanese quail.
Fujiwara,A.1), Mizutani,M.1), Ono,T.2) and Kagami,H.2)
1) Nippon Institute for Biological Science, Laboratory Animal Research Station
2) Shinshu University
The Journal of Poultry Science, 2005.
Abstracts：A black plumage color mutant (BPC) was described in this paper. The BPC quail was a dark colored bird. The chick down feathers on the back and head were black ending with a brown tip. The face and throat was cream-yellow and the ventral surface is a mixture of gray and cream-yellow. The beak and shanks were darkly pigmented but some toes were yellow while other had spotted areas of pigmentation.
When the birds reached to maturity, both males and females had pigmentation, and the feather appearance of dorsal and ventral surface were basically similar. The dorsal feather pattern was similar to that of wild-type except that the wheat-straw shafting was absent. Some of BPC quail showed small areas of white feather at the junction of the upper and lower beaks and in the throat under the lower beak.Genetic analysis showed that the BPC was controlled by an autosomal recessive gene. A gene symbol "rb" has been proposed. |
| 3． |
INTRODUCTION OF GENES RELATING TO MUSCULAR DYSTROPHY INTO CHIMERIC CHICKENS BY EMBRYO ENGINEERING
Fujiwara,A.1), Mizutani,M.1), Ono,T.2) and Kagami,H.2)
1) Nippon Institute for Biological Science, Laboratory Animal Research Station,
2) Shinshu University
Cytotechnology, 2005.
Abstract：A novel system has been developed to introduce genes relating to muscular dystrophy to chimeric chickens. Fertilized eggs were obtained from New Hampshire chicken; NH-413 strain which have genes relating to Fukuyama type muscular dystrophy. Blastoderms were isolated from these embryos. Cells from the center of area pellucida were specifically isolated from the blastoderms. Excess yolk were removed by PBS and only pluripotent cells were obtained. These cells were used as donor. Recipient embryos were obtained from White Leghorn chicken; Line-M. Approximately 700 cells were removed from the center of the area pellucida of the recipient in stage X blastoderm. The donor cells were microinjected into the subgerminal cavity of the recipients' blastoderms. The manipulated embryos were cultured ex vivo until hatching.The generated chimeric chickens had the donor derived brown plumage in the down, suggesting that the cells containing muscular dystrophy were introduced into the chimeras. These chimeric chickens will be raised until sexual maturity. The chimeric chickens will be back-crossed to donor strain; the New Hampshire. In case, these individuals would be germline chimeras, the New Hampshire's offspring would be breed very rapidly. These should be one of the powerful strategies for breeding and regeneration of chickens for an experimental animal model.Key words:avian; pluripotent cells; cell culture
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| 7． |
Comparative Evaluation of Sex Reversal Effects of Naturaland Synthetic Estrogens in Sex Reversal Test Using F1(AWE x WE) Japanese Quail Embryos
Shibuya,K., Mizutani,M., Sato,K., Itabashi,M. and Nunoya,T.
Nippon Institute for Biological Science
Journal of Poultry Science, 42:119-129,2005.
Abstract：Sex reversal effects of 17 beta-estradiol (E2), diethylstilbestrol (DES) and ethynylestradiol (EE2) on male gonads in F1(AWE x WE) Japanese quail (Corturnix japonica) embryos were comparatively evaluated in a newly developed in vivo screening model called as the sex reversal test.Male and female offspring of F1(AWE x WE) Japanese quail exhibit exactly wild and albino plumage colors, respectively, ruled by a criss-cross inheritance.The natural and synthetic estrogens were injected into egg white just before the incubation.At 16 days of incubation, embryos were subjected by a complete necropsy and their gonads were grossly observed and examined histopathologically and morphometrically.Grossly, genetic sex confirmed by plumage colors coincided completely with external sex phenotype of the gonads in all embryos of the control group and E2 and DES-treated groups.However, several male embryos with wild plumage in the EE2 2000 ng group possessed an ovary-like gonad in the left side and a vestigial right gonad.Histopathologically, E2, DES and EE2 exposures induced a dose-dependent sex reversal effect, i.e. ovotestis develpment, in the left testis.The left testes showing an ovary-like morphology in the EE2 2000 ng group consisted of the most of area replaced with ovarian tissue and the small area of remaining testicular cords.The incidence and morphometric analysis of the ovotestis revealed that the order of potency of sex reversal effect in Japanese quail embryos was EE2 > DES > E2.E2, DES and EE2 exposures induced no noticeable changes in the ovaries of any embryos.The present study suggests that the sex reversal test using F1(AWE x WE) Japanese quail embryo is possible to evaluate feminization effects of endocrine disrupting chemicals with estrogenic activities in avian male embryos.
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