Kanamycin marker

E. coli plasmid containing a cloned DNA constract with spinach psbC up to a conserved Sph I site and a kanamycin marker in the downstream region... 

In aminoglycoside-treated animals, the cells can be led to canonical apop-totic death through activation of caspases. Caspase-9 forms an apoptosome complex with cytochrome c and APAF-1 and leads to apoptosis through activation of caspase-3. Aminoglycosides activate caspases in auditory structures conversely, inhibition of caspase activity successfully blocks neomycin-induced vestibulotoxicity. In contrast, apoptotic markers were essentially absent in a mouse model of chronic kanamycin ototoxicity where death of auditory sensory cells ensued via cathepsins. The activation of cathepsin D was accompanied by the nuclear translocation of endonuclease G, necrotic cleavage of PARP, and activation of p,-calpain, all facets of necrotic cell death. 

Once the desired plant variety has been selected, the marker gene serves no useful purpose in the new plant, but it does continue to produce the gene product, APH(.V)I1 in the case of kanamycin resistance. This enzy me is present at very low concentrations in food. 

The use of marker genes that encode resistance lo clinically important antibiotics raises questions regarding whether the enzyme in the foot could inactivate oral doses of the antibiotic or whether die gene present in the plant DNA could be transferred lo pathogenic microbes in the GI tract or in soil rendering them resistant to treatment with the antibiotic, FDA evaluated these questions for the use of kanamycin resistance in tomato, cotton, canola,... 

There is no known mechanism by which a gene can be transferred from a plant chromosome to a microbe. Thus, the possibility of that such transfer would generate new resistant organisms is very small, especially when compared to the high rate of spread of resistance through known mechanisms of microbe to microbe transfer to antibiotic resistance. FDA believes that the use of marker genes that encode resistance 10 other clinically useful antibiotics can be evaluated by similar criteria that were used for kanamycin resistance. 

FIGURE 2 Depiction of the strategy used for the creation of the genomic deletion set of strains for S. cerevisiae. Each disruption contains a selectable marker, kanamycin (G418) resistance, and a tag or specific sequence unique to each construct. The PCR primers flanking the unique tag or bar code can be used to quantify the persistence of that tag and therefore of that specific mutation in a population of cells. 

Hoseki,Yano, T., Koyama, Y., Kuramitsu, S., and Kagamiyama, H. (1999) Directed evolution of thermostable kanamycin-resistance gene a convenient selection marker for Ther-mus thermophilus. J. Biochem., 126, 951-956. 

Lipscomb, G.L., Conway, J.M., Blumer-Schuette, S.E., Kelly, R.M., and Adams, M.W.W, (2016) Thermostable kanamycin resistance marker expands the toolkit for genetic manipulation of Caldicellulosiruptor bescii. Appl Environ. Microbiol doi 10.1128/AEM.00570-16. 

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