scholarly journals The Structure of T-DNA Insertions in Transgenic Tobacco Plants Producing Bovine Interferon-Gamma

2022 ◽  
Vol 12 (2) ◽  
pp. 761
Author(s):  
Mikhail Burlakovskiy ◽  
Natalia Saveleva ◽  
Andrey M. Rumyantsev ◽  
Vladislav V. Yemelyanov ◽  
Marina V. Padkina ◽  
...  

Many of the most modern drugs are of a protein nature and are synthesized by transgenic producer organisms. Bacteria, yeast, or animal cell cultures are commonly used, but plants have a number of advantages—minimal biomass unit cost, animal safety (plants are not attacked by mammalian pathogens), the agricultural scale of production, and the ability to produce complex proteins. A disadvantage of plants may be an unstable level of transgene expression, which depends on the transgene structure and its insertion site. We analyzed the structure of T-DNA inserts in transgenic tobacco plants (Nicotiana tabacum L.) belonging to two lines obtained using the same genetic construct but demonstrating different biological activities of the recombinant protein (bovine interferon-gamma). We found that, in one case, T-DNA was integrated into genomic DNA in the region of centromeric repeats, and in the other, into a transcriptionally active region of the genome. It was also found that in one case, the insert has a clustered structure and consists of three copies. Thus, the structure of T-DNA inserts in both lines is not optimal (the optimal structure includes a single copy of the insert located in the active region of the genome). It is desirable to carry out such studies at the early stages of transgenic plants selection.

1997 ◽  
Vol 17 (11) ◽  
pp. 6294-6302 ◽  
Author(s):  
E Rubin ◽  
A A Levy

The mechanism by which the maize autonomous Ac transposable element gives rise to nonautonomous Ds elements is largely unknown. Sequence analysis of native maize Ds elements indicates a complex chimeric structure formed through deletions of Ac sequences with or without insertions of Ac-unrelated sequence blocks. These blocks are often flanked by short stretches of reshuffled and duplicated Ac sequences. To better understand the mechanism leading to Ds formation, we designed an assay for detecting alterations in Ac using transgenic tobacco plants carrying a single copy of Ac. We found frequent de novo alterations in Ac which were excision rather than sequence dependent, occurring within Ac but not within an almost identical Ds element and not within a stable transposase-producing gene. The de novo DNA rearrangements consisted of internal deletions with breakpoints usually occurring at short repeats and, in some cases, of duplication of Ac sequences or insertion of Ac-unrelated fragments. The ancient maize Ds elements and the young Ds elements in transgenic tobacco showed similar rearrangements, suggesting that Ac-Ds elements evolve rapidly, more so than stable genes, through deletions, duplications, and reshuffling of their own sequences and through capturing of unrelated sequences. The data presented here suggest that abortive Ac-induced gap repair, through the synthesis-dependent strand-annealing pathway, is the underlying mechanism for Ds element formation.


2015 ◽  
Vol 122 (3) ◽  
pp. 685-697 ◽  
Author(s):  
M. S. Burlakovskiy ◽  
N. V. Saveleva ◽  
V. V. Yemelyanov ◽  
M. V. Padkina ◽  
L. A. Lutova

2005 ◽  
Vol 14 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Helga Schinkel ◽  
Andreas Schiermeyer ◽  
Raphael Soeur ◽  
Rainer Fischer ◽  
Stefan Schillberg

Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.


2015 ◽  
Vol 24 (6) ◽  
pp. 945-953 ◽  
Author(s):  
Selcuk Aslan ◽  
Per Hofvander ◽  
Paresh Dutta ◽  
Chuanxin Sun ◽  
Folke Sitbon

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