共查询到20条相似文献,搜索用时 0 毫秒
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Bacci ML 《Veterinary research communications》2007,31(Z1):9-14
Transgenesis offers new possibilities to rapidly modify the genome of living organisms. The application of transgenesis to farm animals faces many problems, more than those observed in the transgenesis of laboratory animals, as there are currently many different techniques available to obtain transgenic animals, which all have problems regarding low efficiency and high costs. When these techniques are applied to farm animals the problems concerning transgenesis are multiplied. Two main techniques, male pronuclear microinjection and sperm mediated gene transfer, utilised in farm animal transgenesis, are briefly presented. The improvement of these techniques and the employment of other biotechnologies such as cloning, could expand the uses of transgenic farm animals for human health. 相似文献
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胚胎干细胞的研究是当前生物技术领域研究的热点之一,尤其是在生产转基因动物方面具有极大的科研及应用价值。本文就动物胚胎干细胞的研究概况、生物学特性、在生产转基因动物中的应用现状作了阐述,同时对尚需解决的学术及技术关键问题进行了研究与探讨。 相似文献
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Honscha W 《DTW. Deutsche tier?rztliche Wochenschrift》1999,106(10):425-432
A modern pharmacotherapy without the use of proteins as drugs is not more practicable. In the clinic blood coagulation factors (factor VIII and IX), growth hormones (human growth hormone), enzymes (1-antitrysin, insulin), and cytokines are currently used. At the beginning, the proteins were isolated from biological sources or expressed in vitro by the use of E. coli or eukaryotic cell lines. At the moment efforts were undertaken to express these proteins in the milk of transgenic animals. This review article describes the methods for the generation of transgenic animals, the benefits and drawbacks of this new technique in comparison to established methods for the production of proteins as pharmaceuticals. At the end of the review possible improvements of the method are described. 相似文献
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Wheeler MB 《Journal of animal science》2003,81(Z3):32-37
The introduction of specific genes into the genome of farm animals and its stable incorporation into the germ line has been a major technological advance in agriculture. Transgenic technology provides a method to rapidly introduce "new" genes into cattle, swine, sheep, and goats without crossbreeding. It is a more extreme methodology, but in essence, not really different from crossbreeding or genetic selection in its result. Methods to produce transgenic animals have been available for more than 20 yr, yet recently lines of transgenic livestock have been developed that have the potential to improve animal agriculture and benefit producers and/or consumers. There are a number of methods that can be used to produce transgenic animals. However, the primary method to date has been the microinjection of genes into the pronuclei of zygotes. This method is one of an array of rapidly developing transgenic methodologies. Another method that has enjoyed recent success is that of nuclear transfer or "cloning." The use of this technique to produce transgenic livestock will profoundly affect the use of transgenic technology in livestock production. Cell-based, nuclear transfer or cloning strategies have several distinct advantages for use in the production of transgenic livestock that cannot be attained using pronuclear injection of DNA. Practical applications of transgenesis in livestock production include enhanced prolificacy and reproductive performance, increased feed utilization and growth rate, improved carcass composition, improved milk production and/or composition, and increased disease resistance. One practical application of transgenics in swine production is to improve milk production and/or composition. To address the problem of low milk production, transgenic swine over-expressing the milk protein bovine alpha-lactalbumin were developed and characterized. The outcomes assessed were milk composition, milk yield, and piglet growth. Our results indicate that transgenic overexpression of milk proteins may provide a means to improve swine lactation performance. 相似文献
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Hirabayashi M Hirao M Takahashi R Kimura K Hirasawa K Ueda M Hochi S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(10):1047-1052
Superovulation of female rabbits was induced by subcutaneous injection(s) of porcine FSH. Zygotes were recovered 17 to 19 hr after hCG injection and were classified into two categories under a microscope equipped with Nomarski interference-contrast optics at x 200 magnification: (A) zygotes with clearly visible pronuclei, or (B) zygotes with visualized pronuclei after 10 min centrifugation at 12,000 x g. No significant difference between strains was found in the proportion of category-A zygotes (JW 72.6% vs NZW 79.3%). Pronuclei of category-A zygotes were located in the center of the cytoplasm, and the pronuclei of category-B zygotes were slightly moved by centrifugation toward the mass of cytoplasmic lipid droplets. Exogenous DNA solution (5 microg/ml of fusion gene composed of bovine alphaS1-casein promoter and human growth hormone structural gene) was microinjected into the pronucleus of the JW zygotes. The pronucleus of category-A zygotes with a mean volume of 7.4 pl swelled up to 16.6 pl (132% increase), while that of category-B zygotes with a mean volume of 6.1 pl swelled up to 15.9 pl (148% increase). Nevertheless, similar proportions of category-A and category-B zygotes developed into offspring after transfer to recipient females (11.1 and 11.2%, respectively). The efficiency to produce hGH-carrying transgenic rabbits was 0.9% (2/235) from category-A zygotes and 0.5% (1/215) from category-B zygotes (P>0.05). To date, transgenic rabbits have been produced without centrifugation of pronuclear zygotes. However approximately 25% of fertilized rabbit zygotes can be used for DNA microinjection after they have been centrifuged to visualize their pronuclei. 相似文献
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Moisyadi S Kaminski JM Yanagimachi R 《Comparative immunology, microbiology and infectious diseases》2009,32(2):47-60
Even though intracytoplasmic sperm injection (ICSI) has been widely used for the production of offspring in human infertility clinics and in reproductive research laboratories using mice, many researchers engaged in animal transgenesis still consider it somewhat cumbersome. The greatest advantage of ICSI-mediated transgenesis is that it allows introduction of very large DNA transgenes (e.g., yeast artificial chromosomes), with relatively high efficiency into the genomes of hosts, as compared to pronuclear injection. Recently, we have developed an active form of intracytoplasmic sperm injection-mediated transgenesis (ICSI-Tr) with fresh sperm utilizing transposons. The transgenic efficiencies rival all transgenic techniques except that of lentiviral methods. 相似文献
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The electrophoretic pattern of serum proteins in normal animals 总被引:1,自引:0,他引:1
M Irfan 《Research in veterinary science》1967,8(2):137-142
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Production of transgenic and non-transgenic clones in miniature pigs by somatic cell nuclear transfer 总被引:1,自引:0,他引:1
Kurome M Ishikawa T Tomii R Ueno S Shimada A Yazawa H Nagashima H 《The Journal of reproduction and development》2008,54(3):156-163
Miniature pigs have been recognized as valuable experimental animals in various fields such as medical and pharmaceutical research. However, the amount of information on somatic cell cloning in miniature pigs, as well as genetically modified miniature pigs, is much less than that available for common domestic pigs. The objective of the present study was to establish an efficient technique of cloning miniature pigs by somatic cell nuclear transfer. A high pregnancy rate was achieved following transfer of parthenogenetic (3/3) and cloned (5/6) embryos using female miniature pigs in the early pregnancy period as recipients after estrus synchronization with prostaglandin F2 alpha analog and gonadotrophins. The production efficiency of the cloned miniature pigs using male and female fetal fibroblasts as nucleus donors was 0.9% (2/215 and 3/331, respectively). Cloned miniature pigs were also produced efficiently (7.8%, 5/64) by transferring reconstructed embryos into the uteri of common domestic pigs. When donor cells transfected with the green fluorescent protein (GFP) gene were used in nuclear transfer, the production efficiency of the reconstructed embryos and rate of blastocyst development were comparable to those obtained by non-transfected cells. When transfected cell-derived reconstructed embryos were transferred to three common domestic pig recipients, all became pregnant, and a total of ten transgenic cloned miniature pigs were obtained (piglet production efficiency: 2.7%, 10/365). Hence, we were able to establish a practical system for producing cloned and transgenic-cloned miniature pigs with a syngeneic background. 相似文献
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Kim S Saadeldin IM Choi WJ Lee SJ Lee WW Kim BH Han HJ Bang du H Lee BC Jang G 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(11):1453-1457
Transgenic research on cattle embryos has been developed to date using viral or plasmid DNA delivery systems. In this study, a different gene delivery system, piggybac transposition, was employed to investigate if it can be applied for producing transgenic cattle embryos. Green or red fluorescent proteins (GFP or RFP) were transfected into donor fibroblasts, and then transfected donor cells were reprogrammed in enucleated oocytes through SCNT and developed into pre-implantation stage embryos. GFP was expressed in donor cells and in cloned embryos without any mosaicism. Induction of RFP expression was regulated by doxycycline treatment in donor fibroblasts and pre-implantational stage embryos. In conclusion, this study demonstrated that piggybac transposition could be a mean to deliver genes into bovine somatic cells or embryos for transgenic research. 相似文献
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