concerns with trangenesis Flashcards
discuss 2 biological issues with transgenesis and 5 public concerns relating to transgenesis, as well as actions taken and reasons these issues shouldnt be concerns. 14 marks
biological issues
1)Gene disruption may lead to unintended effects (difference in phenotype which wasnt predicted) because often theres to way to choose where the trangene is inserted
action taken: if a vital gene has been disrupted the transformant is thrown out
counter: this process occurs through selective breeding
pants can rejoin non homologous ends of DNA when a dsDNA break occurs; DNA wont cause disruption
2)somoclonal variation are variations in plants which are caused by going through the tissue culture stage; this is very common in plant sregenerated from calluses
action taken: use pollen transfer which avoid the callus stage
public concerns
1) concern about foreign DNA entering plant genomes
counter: this occurs with selective breeding; frost resistance in wheat
2)novel gene products may be toxin to non target organisms such as consumers
action taken:
a)carry out feeding trials
b)ensure the gene isint expressed in edible parts of plant
3) transposone events (genes jumping)
counter: these are natually occuring events
4) marker genes involving antibiotic resistance genes may have effects on antibiotic resistance in consumers, or gene transfer to bacteria may occur
action taken: use other marker genes like enzymes to break down sugars, and if antibiotic resistanc egenes are used, make sure they arent for the antibiotics used by the pharmacutical industry
counter: risk of gene transfer is low compared to other routes such as antiobiotics in animal feed
5)ecological impacts due to disrupted composition or gene transfer to weeds.
action taken: perform field studies and ecological modelling
conclusion; there is concern of unintended effects but this is just the same as with conventionally bred crops
discuss the two types of unintended effects; 4 marks
how can unintended effects be measured; 6 marks
predictable; introduce a gene for antifungal properties and the dlower colour changes because a flower colour gene was disrupted
unpredictable; change in phenotype cant be explained by current biological understanding; a gene for a growth hormone is disrupted but flower colour changes
target approach; statistically show that all aspects of offspring are similar to parent apart from the effect that the GOI was intended to have
problem; no EU guidlines on whcih chemical levels should be screened for. common knowledge of toxins present has to be used
non target aproach; use omics such as metabolomics, proteomics etc to show investiagte different webs of molecules in the plant offspring.
problem; the proteome is in constant flux so multiple checks at multiple times must be done
