Modification of regulatory elements of marker genes
The concern about antibiotic resistance marker genes is predominantly about their transfer and expression in bacterial cells and a technology which would prevent such expression might have to be considered. Already the genes used for selection in plants are controlled by plant promoter sequences which render them unlikely to be sufficiently expressed in bacteria. The introduction of an intron sequence in the marker gene would restrict its expression to plant cells and definitively prevent any expression in bacteria. Introns are sequences of DNA that naturally interrupt the coding sequences of animal and plant cells. These are equipped with mechanisms allowing their removal during the transcription process while bacteria are not equipped to do this and therefore would be unable to read a gene containing introns.
Antibiotic resistance marker genes such as the NPTII gene which provides resistance towards kanamycin are very well researched in all the relevant aspects such as their functioning, biochemical properties and prevalence in the bacterial community. Their safety has been well examined and assessed. Under these conditions it is likely that achieving the same level of confidence as has been established for NPTII with another selection system may be long and difficult. Any remaining concerns attached to such genes could be removed by the addition of an intron.
Copyright © 2018-2020 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.