Modern breeding has resuscitated grocery store tomatoes with an influx of wild genes; in the past 50 years, researchers have bred back some 40 disease -
resistance genes into commercial crops.
But putting drug -
resistance genes into microbes that cause disease doesn't sound like a great idea.
The wild Asian banana Musa acuminata malaccensis — the genome of which was published last year (A. D'Hont Nature 488, 213 — 217; 2012)-- seems to be resistant, and researchers are experimenting with putting
its resistance genes into the Cavendish.
It may take as long to breed a new
resistance gene into a new cultivar as to introduce a new fungicide (± 10 years), even though this time can be shortened somewhat today with molecular tools by reducing the back - crossing cycles.
Emblematic of our goal to be a «hands - on» science center, a 32 - seat lab was the first space renovated, and in the spring of 1988 we conducted the first lab field trips during which students cut and separated viral DNA or inserted an antibiotic
resistance gene into bacteria.
Not exact matches
In terms of biodiversity, organic farming takes
into account
gene adaptation, local ecosystems and species to improve disease
resistance, soil,
gene pools and local wildlife habitats.
Specifically, they have found unnaturally high levels of antibiotic
resistance genes in sediments where the river comes
into contact with treated municipal wastewater effluent and farm irrigation runoff as it flows 126 miles from Rocky Mountain National Park through Fort Collins and across Colorado's eastern plain, home to some of the country's most densely packed livestock operations.
«When you contaminate a site with
resistance genes, those
genes can be transferred
into environmental organisms and actually increase the concentration of contamination.»
The answer is important because sludge bacteria are much more likely to thrive and spread their
resistance genes once the sludge is discharged
into rivers (in treated wastewater) and onto crop fields (as slurried fertilizer).
As a marker for successful insertion, the researchers also put a
gene encoding antibiotic
resistance into the plasmid.
Is the jump in
resistance genes coming from a population explosion in the resistant enteric, or intestinal, bacteria coming
into the sewage plant?
The researchers — James Robl, a developmental biologist and his colleagues at the University of Massachusetts at Amherst, and Steve Stice at Advanced Cell Technology in Worcester, Massachusetts — inserted a marker
gene fused with a
gene for
resistance to the chemical neomycin
into a culture of connective tissue cells called fibroblasts.
Ideally, they could insert the
resistance genes from Asian chestnuts
into American ones.
A plasmid, a simple kind of DNA - delivery vehicle, will move a
gene for antibiotic
resistance into the bacterial cells, jump - starting the Crispr - Cas9 system.
Bacteria expressing enzyme in one cell (bright green), while genetically identical cells do not, remaining protected from antibiotic onslaught; image courtesy of Yuichi Wakamoto / Neeraj Dhar / John McKinney Some strains of nasty bacterial infections, such as MRSA (methicillin - resistant Staphylococcus aureus), come loaded with
resistance to antibiotics built right
into their
genes.
The team cut and pasted a bovine
gene for NRAMP1, a protein linked to
resistance against TB and other bacterial infections,
into fetal dairy cow genomes.
When they inserted those
genes into crop genomes, through a technique called recombinant DNA, the plants were able to produce the protein for bug
resistance on their own, eliminating the need to spray insecticide.
Biotechnologist James Dale and colleagues at Queensland University of Technology in Brisbane, Australia, cloned a
resistance gene named RGA2 from a type of wild banana that's impervious to TR4 and inserted it
into the Cavendish, creating six lines with varying numbers of RGA2 copies.
Simply incorporating the
gene, known as Bt,
into a plant gives it
resistance to pests, without requiring periodic spraying by the farmer.
Hendrik is preparing the publication of the most complete woolly mammoth genome yet, and Harvard geneticist George Church's team is already working to introduce specific DNA variants —
genes for hair, tusks, subcutaneous fat and cold
resistance —
into cultured cells from Asian elephants (right).
The scientists have also detected
resistance genes for sulphonamides and another antibiotic in the treated wastewater — which will be turned
into snow at a nearby ski resort, in a relatively pristine part of a river basin, later this year.
They cloned the
resistance gene, called RB, and then inserted it
into a disease - susceptible potato variety called Katahdin.
The offspring and their descendants glow under blue light, showing that both
genes were successfully bred
into the line of cats and that the properties of the HIV
resistance gene can be tested.
Scientists inserted the jellyfish
gene for GFP along with the
gene for HIV
resistance into a cat egg before it underwent IVF treatment.
«We were happy to find that antibiotic
resistance genes from soil bacteria generally aren't poised to jump suddenly
into pathogens,» Dantas said.
Into some bacteria they inserted
genes for
resistance to particular antibiotics; the idea is that only the antibiotic - resistant bacteria are carrying the real message.
Further analysis reveals that the antibiotic
resistance genes are often lumped together
into «
resistance islands» within microbes» DNA, with up to five
genes within one island.
Scientists» initial idea was to introduce
genes conferring
resistance to human pathogens
into mosquitoes, and then enlist Wolbachia to help these traits race through the population.
Dr Melita Gordon, from the University of Liverpool's Institute of Infection and Global Health, said: «Importantly, the antibiotic
resistance genes, which have previously been carried on a separate genetic package, have now been incorporated
into the main chromosome of the bacteria itself, which is likely to make it easier for the Typhoid strain to retain these
resistance genes.»
Genetic engineers directly transferred the
gene for the toxic protein
into crops to give them built - in
resistance.
Additional experiments showed the feasibility of creating a two - layer security system for T cells by simultaneously blocking a
gene the HIV virus needs to gain entry
into cells and a
gene the virus needs to survive and reproduce within the cell, resulting in doubly secure
resistance.
If these bacteria happen to come
into contact with other microbes that carry
resistance genes, those
genes can pop over in one step.
Because disease organisms mutate quickly to overcome crop
resistance controlled by single
genes, researchers are rushing to identify new
resistance genes and to incorporate multiple
genes into high - yielding varieties, according to Ravi Singh, CIMMYT wheat scientist who participated in the reported study.
Students introduce a
gene for antibiotic
resistance into the bacterium E. coli.
Using plant biotechnology we have introduced two
resistance genes of a wild potato
into a modern potato variety.
Briefly, the
genes were cloned
into a pET24 vector with kanamycin
resistance and transformed
into Escherichia coli BL21 (DE3) cells.
For the rice plant to effectively combat blast, scientists at IRRI are combining
into the same rice type different race - specific
genes and
genes conferring quantitative
resistance.
Pyramiding of two or more effective
resistance genes / alleles
into elite rice lines enhances the durability and spectrum of
resistance.
The environmental resistome therefore constitutes a reservoir of
resistance genes that can be mobilized
into human pathogenic bacteria [13], [21].
One use of these
genes might be to insert them
into other crop plants to provide «disease
resistance, or to make them grow bigger and faster,» says Kaul.
Early insights
into the potential of the Oxford Nanopore MinION for the detection of antimicrobial
resistance genes
Antimicrobial
resistance genes can be carried on plasmids or on mobile elements integrated
into the chromosome.
Worse still is when agribusiness and geneticists change the seeds of grasses, with their genetic manipulations converting, for example, 4 - and - a-half-foot tall traditional wheat
into 18 - inch tall high - yield semidwarf strains that now comprise 99 % of all wheat grown worldwide, or insert various
genes for herbicide
resistance, as in genetically modified corn.
A
gene for green fluorescent protein from the jellyfish, Aequorea Victoria, has been inserted
into the cats» DNA and is used as a marker for cells carrying a second
gene which confers
resistance to the feline version of the AIDS virus, the Feline Immunodeficiency Virus (FIV).