In breeding season and non-breeding season, the effects of three kinds of progesterone plugs on estrous control in ewes were studied. Meanwhile, the advantages and the disadvantages of the progesterone plugs were anal...In breeding season and non-breeding season, the effects of three kinds of progesterone plugs on estrous control in ewes were studied. Meanwhile, the advantages and the disadvantages of the progesterone plugs were analyzed. The results showed that there were no significant difference among three progesterone plugs on modulating the ewes＇ estrus and pregnancy, and affecting estrous rate and fecundation rate （P〉0.05）. It was observed that the progesterone plug produced by Animal Husbandry Research Center of Heilongjiang Academy of Agricultural Sciences could modulate the ewes＇ estrus and pregnancy effectively, and the low cost and convenience in operation made it popularize in the reproducation of sheep widely.展开更多
In order to determine the effect of foreign genes on a transgenic parasite,the pathogenicity and development in chickens of transgenic E.tenella strain TE1,which expresses yellow fluorescent protein (YFP) and dihydrof...In order to determine the effect of foreign genes on a transgenic parasite,the pathogenicity and development in chickens of transgenic E.tenella strain TE1,which expresses yellow fluorescent protein (YFP) and dihydrofolate reductase thymidylate synthase derived from Toxoplasma gondii(TgDHFR-TS), were compared with that of the parental strain BJ.Results indicated that the fecundity of the transgenic parasite(TE1) was reduced at least 4 times relative to that of the BJ strain.Low dosage of the TE1 strain induced less pathogenesis in chickens than did the BJ strain,but chickens inoculated with a higher dosage of TE1 oocysts displayed severe pathogenicity and mortality as did the BJ strain.In addition,trophozoites, the first generation and the second generation meronts and merozoites,microgamonts and macrogamonts of the transgenic parasite TE1 were seen by fluorescence microscopy.More interestingly,not all four sporonts in the sporulating transgenic oocysts express YFP.These findings suggest that the expression of YFP and TgDHFR-TS genes to some extent reduced pathogenicity and reproductive potential of transgenic E.tenella.Recombination between homologous or non-homologous chromosomes occurred during zygotic meiosis in E.tenella strain TE1.展开更多
基金Supported by Heilongjiang Institute of Agricultural Sciences Youth Funded Projects
文摘In breeding season and non-breeding season, the effects of three kinds of progesterone plugs on estrous control in ewes were studied. Meanwhile, the advantages and the disadvantages of the progesterone plugs were analyzed. The results showed that there were no significant difference among three progesterone plugs on modulating the ewes＇ estrus and pregnancy, and affecting estrous rate and fecundation rate （P〉0.05）. It was observed that the progesterone plug produced by Animal Husbandry Research Center of Heilongjiang Academy of Agricultural Sciences could modulate the ewes＇ estrus and pregnancy effectively, and the low cost and convenience in operation made it popularize in the reproducation of sheep widely.
基金supported by the National High Technology Research and Development Program of China(Project No. 2006AA02Z458)the Doctor Startup Foundation of Henan University of Science and Technology(09001350)
文摘In order to determine the effect of foreign genes on a transgenic parasite,the pathogenicity and development in chickens of transgenic E.tenella strain TE1,which expresses yellow fluorescent protein (YFP) and dihydrofolate reductase thymidylate synthase derived from Toxoplasma gondii(TgDHFR-TS), were compared with that of the parental strain BJ.Results indicated that the fecundity of the transgenic parasite(TE1) was reduced at least 4 times relative to that of the BJ strain.Low dosage of the TE1 strain induced less pathogenesis in chickens than did the BJ strain,but chickens inoculated with a higher dosage of TE1 oocysts displayed severe pathogenicity and mortality as did the BJ strain.In addition,trophozoites, the first generation and the second generation meronts and merozoites,microgamonts and macrogamonts of the transgenic parasite TE1 were seen by fluorescence microscopy.More interestingly,not all four sporonts in the sporulating transgenic oocysts express YFP.These findings suggest that the expression of YFP and TgDHFR-TS genes to some extent reduced pathogenicity and reproductive potential of transgenic E.tenella.Recombination between homologous or non-homologous chromosomes occurred during zygotic meiosis in E.tenella strain TE1.
