• 제목/요약/키워드: transgenics

검색결과 25건 처리시간 0.019초

Transgene chgH-rfp expression at developmental stages and reproductive status in marine medaka (Oryzias dancena)

  • Cho, Young Sun;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
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    • 제19권9호
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    • pp.41.1-41.7
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    • 2016
  • Background: The transgenic approach using estrogen-responsive regulator in fish has been given much attention as a potential means to detect and/or address estrogen-related aquatic pollutions. In order to address the development stage- and reproduction status-dependent expression patterns of the chgH-rfp transgene (red fluorescent protein transgene driven by choriogenin H promoter) in marine medaka Oryzias dancena, naturally occurring red fluorescent protein (RFP) signals under non-exposed conditions as well as the transgenically induced RFP signals under estrogen-exposed conditions were assayed. Results: Female transgenics begun to show naturally occurring RFP signals from the age of 7 weeks post hatching (WPH) without experimental estrogen exposure. Afterward, these RFP signals in female transgenics became robust with the progress of ovarian maturation. On the other hand, male transgenics did not show any naturally occurring RFP signal under non-exposed conditions irrespective of developmental stages and maturation statue. Upon exposures using estradiol-$17{\beta}$ (E2) and $17{\alpha}$-ethinylestradiol (EE2), RFP signals were significantly induced specifically in the livers of transgenic males. Conclusions: Male chgH-rfp transgenics were able to keep the "off" state of RFP expression during their entire life cycle unless exposed to exogenous estrogens. Owing to their tight regulation capability of estrogen-responsive transgene, transgenesis of chgH-rfp in male marine medaka could offer a useful model system for future ecotoxicogenomic studies regarding estrogenicity-related issues in aquatic and marine environments.

Agrobacterium tumefaciens Mediated Genetic Transformation of Pigeonpea [Cajanus cajan (L.) Millsp.]

  • Kumar, S.Manoj;Syamala, D.;Sharma, Kiran K.;Devi, Prathibha
    • Journal of Plant Biotechnology
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    • 제6권2호
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    • pp.69-75
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    • 2004
  • Optimal protocol for efficient genetic transformation has been defined to aid future strategies of genetic engineering in pigeon pea with agronomically important genes. Transgenic pigeonpea plants were successfully produced through Agrobacterium tumefaciens-mediated genetic transformation method using cotyledonary node explants by employing defined culture media. The explants were co-cultivated with A. tumefaciens strain C-58 harboring the binary plasmid, pCAMBIA-1301 [con-ferring $\beta$-glucuronidase(GUS) activity and resistance to hygromycin] and cultured on selection medium (regeneration medium supplemented with hygromycin) to select putatively transformed shoots. The shoots were then rooted on root induction medium and transferred to pots containing sand and soil mixture in the ratio of 1:1. About 22 putative TO transgenic plants have been produced. Stable expression and integration of the transgenes in the putative transgenics were confirmed by GUS assay, PCR and Southern blot hybridization with a transformation efficiency of over 45%. Stable integration and expression of the marker gene has been confirmed in the TO and T1 transgenics through PCR, and Southern hybridization.

Transgenesis in Fish: Indian Endeavour and Achievement

  • Pandian, T.J
    • 한국양식학회지
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    • 제16권1호
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    • pp.51-58
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    • 2003
  • The first Indian transgenic fish was generated in 1991 using borrowed constructs from foreign sources. To construct transformation vectors for the indigenous fishes, growth hormone genes of rohu (r-CH), Labeo rohita and catfish, Heteropneustes fossilis were isolated, cloned and sequenced; their fidelity was confirmed in prokaryotic and eukaryotic systems. A vector was constructed with grass carp b-actin promoter driving the expression of r-GH. Rohu eggs are large. fragile and swell 2~3 times. when fertilized. Hence they were amenable only for electroporated sperm-mediated gene transfer. Accordingly, the sperm electroporation technique was standardized to ensure 25% hatchling survival and 37% Presumptive transgenics without suffering any deformity. Southern analysis confirmed genomic integration in 15% of the tested individuals (Ti) belonging to family lines 2 and 3: another 25% of the Juveniles (Te) were also proved transgenic but with the transgene persisting extrachromosomally for longer than 1 to 2 years. perhaps due to the presence of replicon in the vector. Transgenics belonging to different family lines grew 6~8 times faster than the respective controls. Difference in growth trends of Ti and Te within a family line was not significant. In the Ti family 3 remarkable growth acceleration was sustained for a period longer than 36 weeks but in those of family 2, it gradually decreased. All transgenic fishes including the rohu converted the food at a significantly higher efficiency. Barring the transgenic mudloach, all the other transgenic fishes consumed food at significantly reduced rate.

A simple model for selection and rapid advancement of transgenic progeny in sorghum

  • Visarada, K.B.R.S.;Saikishore, N.;Kuriakose, S.V.;Rani, V. Shobha;Royer, M.;Rao, S.V.;Seetharama, N.
    • Plant Biotechnology Reports
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    • 제2권1호
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    • pp.47-58
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    • 2008
  • To select agronomically useful transgenic plants, a large number of transgenic events are initially produced, gene transfer confirmed, and advanced to obtain homozygous lines for testing in field trials. Direct in planta assays for identifying the transgene carriers in the segregating progeny are based on the activity of selectable marker gene and are easy, simple and inexpensive. For this purpose, expression of bar gene as measured by tolerance to damage by glufosinate ammonium, the active ingredient in the herbicide BASTA, was investigated. Dose damage curves were generated by leaf paint tests with BASTA on four genotypes of sorghum. Transgenic plants were characterized in terms of sensitivity to the concentration of glufosinate ammonium. In transgenics, symptoms of BASTA swab tests at different growth stages and PCR analysis for cry1B were carried out and correlated. Germination tests could not be employed for large scale evaluation of transgenic progeny because of mortality of tolerant seedlings after transplantation to soil. Based on the above findings, a simple, inexpensive, time-saving, two-step scheme for effective evaluation of transgenics and their progeny containing bar gene as selection marker using BASTA swab tests is described.

Genomic and Transgenic Approaches to Modified Plants: Disease Resistance in the Brassica as a Model System.

  • Ekuere, Usukuma;Good, Allen G.;Mayerhofer, Reinhold
    • 식물조직배양학회지
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    • 제27권4호
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    • pp.317-323
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    • 2000
  • Molecular genetic techniques can now be applied to the development of advanced plant genotypes, either through genetic transformation or genomic approaches which allow researchers to transfer specific traits using molecular markers. In this paper, we discuss the use of these techniques towards understanding the genetics of blackleg resistance in Brassica. In a comparative mapping study between Arabidopsis thaliana and Brassica napus, 6 R-ESTs, 7 B. napus RFLP markers and a B. napus EST were located in a collinear region of N7 (B. napus) and chromosome 1 (A. thaliana). One of the A. thaliana R-ESTs and 4 of the B. napus RFLPs co-segregated and mapped to the LmRl locus for blackleg resistance. Introgression of blackleg resistance from wild relatives is also investigated with the possibility of accelerating the introgression process via marker assisted selection.

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Recent Advances in Biotechnology Applications to Aquaculture

  • Lakra, W.S.;Ayyappan, S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제16권3호
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    • pp.455-462
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    • 2003
  • Biotechnological research and development are moving at a very fast rate. The subject has assumed greatest importance in recent years in the development of agriculture and human health. The science of biotechnology has endowed us with new tools and tremendous power to create novel genes and genotypes of plants, animals and fish. The application of biotechnology in the fisheries sector is a relatively recent practice. Nevertheless, it is a promising area to enhance fish production. The increased application of biotechnological tools can certainly revolutionise our fish farming besides its role in biodiversity conservation. The paper briefly reports the current progress and thrust areas in the use of synthetic hormones in fish breeding, production of monosex, uniparental and polyploid individuals, molecular biology and transgenesis, biotechnology in aquaculture nutrition and health management, gene banking and the marine natural products.

Engineering lacZ Reporter Gene into an ephA8 Bacterial Artificial Chromosome Using a Highly Efficient Bacterial Recombination System

  • Kim, Yu-Jin;Song, Eun-Sook;Choi, Soon-Young;Park, Soo-Chul
    • BMB Reports
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    • 제40권5호
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    • pp.656-661
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    • 2007
  • In this report, we describe an optimized method for generation of ephA8 BAC transgenic mice expressing the lacZ reporter gene under ephA8 regulatory sequences. First, we constructed a targeting vector that carries a 1.2 kb ephA8 DNA upstream of its first exon, a lacZ expression cassette, a kanamycin cassette, and a 0.7 kb ephA8 DNA downstream of its first exon. Second, the targeting vector was electroporated into cells containing the ephA8 BAC and pKOBEGA, in which recombinases induce a homologous recombination between the ephA8 BAC DNA and the targeting vector. Third, the FLP plasmid expressing the Flipase was electroporated into these bacteria to eliminate a kanamycin cassette from the recombinant BAC DNA. The appropriate structures of the modified ephA8 BAC DNA were confirmed by Southern analysis. Finally, BAC transgenic mouse embryos were generated by pronuclear injection of the recombinant BAC DNA. Whole mount X-gal staining revealed that the lacZ reporter expression is restricted to the anterior region of the developing midbrain in each transgenic embryo. These results indicate that the ephA8 BAC DNA contains most, if not all, regulatory sequences to direct temporal and spatial expression of the lacZ gene in vivo.

Triploid hybridization as a reproductive containment method of genetically modified fish, exemplified by fast-growing transgenic mud loach

  • Nam, Yoon-Kwon;Park, In-Seok;Kim, Dong-Soo
    • 한국양식학회:학술대회논문집
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    • 한국양식학회 2003년도 추계학술발표대회 논문요약집
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    • pp.41-41
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    • 2003
  • Transgenic triploid hybrid between fast-growingtransgenic mud loach (Misgurnus mizolepis) males and cyprinid loach (M. anguillicaudatus) females were generated and their performance on growth, feed conversion ability and reproduction were evaluated. Although the growth accelerations of diploid and triploid transgenic hybrids were not as much as those of original transgenic mud loaches, they still represented persistent growth stimulation ranging 11 to 28 fold when compared to their non-transgenic counterparts, with significantly improved feed conversion efficiency up to 2-fold (compared to non-transgenic hybrid) and 1.5-fold (compared to non-transgenic mud loach) in maximum. The gonad development of diploid hybrids was fertile in histological views regardless of transgenic genotypes but the extent of developmentin hybrid fish were less than mud loach diploids at the same age. On the other hands, very stringent sterility was obtained in both sexes of the triploid hybrid transgenics: ovary and testis from transgenic triploid hybrids were significantly depressed and any notable sign for maturation to ovum or spermatids was not detected. No viable embryo was obtained in a fertilization trial using the suspension prepared from the minced testes of transgenic triploid hybrids. This study may indicate the potential usefulness of triploid hybridization as a mean for reproductive containment of transgenic mud loach.

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Use of Transgenic and Mutant Animal Models in the Study of Heterocyclic Amine-induced Mutagenesis and Carcinogenesis

  • Dashwood, Roderick H.
    • BMB Reports
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    • 제36권1호
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    • pp.35-42
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    • 2003
  • Heterocyclic amines (HCAs) are potent mutagens generated during the cooking of meat and fish, and several of these compounds produce tumors in conventional experimental animals. During the past 5 years or so, HCAs have been tested in a number of novel in vivo murine models, including the following: lacZ, lacI, cII, c-myc/lacZ, rpsL, and $gpt{\Delta}$ transgenics, $XPA^{-/-}$, $XPC^{-/-}$, $Msh2^{+/-}$, $Msh2^{-/-}$ and $p53^{+/-}$ knock-outs, Apc mutant mice ($Apc^{{\Delta}716}$, $Apc^{1638N}$, $Apc^{min}$), and $A33^{{\Delta}N{\beta}-cat}$ knock-in mice. Several of these models have provided insights into the mutation spectra induced in vivo by HCAs in target and non-target organs for tumorigenesis, as well as demonstrating enhanced susceptibility to HCA-induced tumors and preneoplastic lesions. This review describes several of the more recent reports in which novel animal models were used to examine HCA-induced mutagenesis and carcinogenesis in vivo, including a number of studies which assessed the inhibitory activities of chemopreventive agents such as 1,2-dithiole-3-thione, conjugated linoleic acids, tea, curcumin, chlorophyllin-chitosan, and sulindac.