Stem cells made without new genes
Human pluripotent cells have been created using a virus alone
Nature News: Published online 21 June 2010
TechNyou note
This research presents more questions than answers and highlights how much we don’t know. The fact that the viral vector can potentially have such an effect on the cell might raise interesting questions and implications for gene therapy and other research, regardless of whether the vector actually produced a true pluripotent cell or just a cancerous one.
Self-Assembling Nanodevices Move and Change Shape on Demand
Self assembled nanodevices made of DNA could lead to medical devices, drug delivery systems and reprogram human stem cells to regenerate injured organs.
Science Daily 21 June 2010
Carbon nanotubes enhance battery power
Using carbon nanotubes in a battery’s electrode produced up to a 10-fold increase in the amount of power a battery could deliver.
Massachusetts Institute of Technology (MIT) News: 18 June 2010
Reference
“High-power lithium batteries from functionalized carbon nanotube electrodes.” Seung Woo Lee, Naoaki Yabuuchi, Betar M. Gallant, Shuo Chen, Byeong-Su Kim, Paula T. Hammond, & Yang Shao-Horn. Nature Nanotechnology. 19 June 2010.
Death revives warnings about rogue stem-cell clinics
The death of a woman after she was treated with stem cells at a private clinic in Thailand has reinforced warnings for desperate sick people to avoid “stem-cell tourism”.
New Scientist: 17 June 2010
See previous TechNyou posts on stem cell tourism
Stem cell offers new hope for lung disease patients
Australian researchers have found a type of stem cell that could prove crucial in reducing injury and scarring in the lung and even generate new lung cells.
University of Western Australia: media release 16 June 2010
Triple-punch gene therapy targets HIV
A combination gene therapy that endows human stem cells with three ways to resist HIV has passed its first safety test in humans.
Nature News: 16 June 2010
Reference
DiGiusto, D. L. et al. Science Translational Medicine 2, 36ra43 (2010).
Teachers: how to use jelly to teach microfluidics
It is US-based, but this article presents a quick, simple, safe, and inexpensive method for teaching microfluidics (eg, lab-on-a-chip stuff) to younger students and the general public.
American Chemical Society:
Using Inexpensive Jell-O Chips for Hands-On Microfluidics Education, Analytical Chemistry
DOI: 10.1021/ac902926x
Publication Date (Web): May 25, 2010
Download report with full instructions from here
Cisgenics: same same, but different from GM food technology
Cisgenics is being held up as a plant breeding technology distinct from the techniques that produce GM food. I think not.
Cisgenics has been given an airing around the web recently thanks to research from Oregon State University that used the plant breeding technique to create Poplar trees with varying growth traits.
The same researchers, and in the recent past a few others, have called for cisgenics to be regulated the same way non-transgenic food/crops are as they claim cisgenics is different from transgenics. Transgenics is the technique used to produce GM (genetically modified) foods.
There has also been the anticipated comment from the opposing camp that the term cisgenics is just playing semantics and that it is essentially transgenics.
Now I dismiss many of the comments about GM food that I see sprinkled liberally throughout the web, simply because they are too often based on misinformation and misunderstanding of the realities of food production. I have to dismiss them because I am becoming less tolerant of people prepared to accept without question stuff they read because (I assume) it fits their natural bias. I would love to add my two-bob’s worth to this, but I am one bloke and I type slow.
This case is an exception as I generally agree with many of the anti-cis comments. From a risk perspective, I fail to see how cisgenics is significantly different to transgenics.
Confused? The following will hopefully enlighten you somewhat about cisgenics. But I hope those more expert than me can enlighten us all a lot more and hopefully add more meat to the topic.
-genics 101
We are talking about molecular plant breeding technologies. In all methods we refer to it involves taking a gene from one individual and inserting in into another. It is the source of the gene and how that gene is constructed that differs.
Transgenics is taking a gene from an organism that is a different species or one that is not sexually compatible with the organism that you intend to insert your gene (transgene) into. This involves making a copy of the important protein coding parts of the gene, sticking them together and attaching an extra bit of DNA code to one end (called the promoter) that regulates the function of the gene, that is, where and when the gene will switch on and how active it will be. This is the controversial method behind GM food.
Cisgenics is transferring genes between the same or sexually compatible species. It involves using intact native genes (cisgenes) that include all existing regulatory (promoter) sequences and extra DNA unnecessary for protein coding. An example is one research group’s success in transferring one or more genes that confer resistance to potato blight from one potato variety to another potato variety.
A third version is called ‘intragenic’, which is a combination of the above two. It uses modified versions of native genes.
Why cisgenics
Genetic diversity among a single species is the key reason. Often among a genetically diverse species there will be individuals that will have one or more genes that are responsible for traits you desire in your crop of the same or sexually compatible species. It could be genes for resistance to fungal or pathogen attack, growth traits, fatty acid profiles and so on.
Your bog-standard cross breeding can easily ensure you get your wanted gene into your lovely crop variety, but you will also get a bunch of unwanted, often deleterious (toxic, allergenic, or disruptive), genes as well. Backcrossing can sometimes get rid of the bad genes and leave just the desirable ones, but often the bad genes are so close or tightly connected to the gene you want that you can never get rid of them no matter how many backcrosses you do. And backcrossing is a time consuming process, especially if the species you are playing with is long-lived, for example, forestry trees.
So, the answer is to make of copy of the native (cis)gene you want and transfer it into your crop variety. You get the trait you want without any of the deleterious traits hanging on for the ride, and it is done quickly – no backcrossing required.
Should cisgenic plants have less stringent regulation?
This is where the fun starts. The following are views taken from a Letter to the Editor in Nature Biotechnology – marked as NB. Where appropriate you get my disagreement.
NB:
“Cisgenic plants are fundamentally different from transgenic plants. In transgenesis, a foreign gene is introduced into a plant. A transgenic plant may have a phenotypic trait that did not occur before in that species and its crossable relatives. Such a novel trait can affect fitness in ways new to the species. Gene flow to wild relatives could potentially extend this fitness effect. This may lead to increased invasiveness of the transgenic crop or its relatives.”
TechNyou:
Forestry trees may be an exception here – though I need to think about this some more. For agricultural crops, however, this is a lame argument. Any existing agricultural crop has had any traits that would allow it to survive outside a well-tended, weed-free, paddock eliminated by selective breeding. By suggesting that the addition of a transgene could affect fitness is true. It is also true that gene flow to wild relatives can occur. But if this gene serves to make an individual less fit it is hardly going to survive in a non-agricultural environment. Gene flow can occur to wild relatives from conventionally-bred crops and these genes are equally likely to reduce the fitness of the wild relatives. Should the trans- or cis gene being introduced confer tolerance to an abiotic stress such as frost, drought or salinity then there is a real risk that if this crossed to a wild relative it might enable the wild relative to encroach on new environments. The thing is we are also using conventional breeding methods to try and introduce similar trait. Any such genes from conventional crops can equally cross to wild relatives with the same issues. It is a risk that needs to be managed regardless of the technology behind the breeding.
NB:
“In cisgenesis, the introduced gene of interest with its native promoter has already been present in the species or in crossable relatives for centuries. Therefore, cisgenesis does not add an extra trait. It does not invoke a fitness change that could not also occur through traditional breeding or in nature. The same holds true for other environmental risks, such as effects on nontarget organisms or soil ecosystems, and for usage in food or feed. As a result, deliberate release of cisgenic plants into the environment is as safe as the deliberate release of traditionally bred plants.
TechNyou:
I would argue that it does potentially induce a fitness change and that it is possible that such a change may not occur in nature becasue when does just one gene make it across in a natural fertilisation event. You are also inserting that gene in a random manner that has unpredictable consequences all of which can affect fitness.
NB:
“As the process of genetic modification itself may lead to mutations and rearrangements, cisgenic plants should be screened for unwanted changes in a similar way as plants derived from mutagenesis are screened and selected. Mutation breeding has led over the past 70 years worldwide to more than 2,250 plant varieties… Mutagenesis has led to undirected mutations and translocations. Release of mutation-derived varieties does not require molecular characterization of the mutations involved [ that is, no safety testing of what the mutation produced is required]. Although these numerous mutation-derived plant varieties have been produced and used for food, feed or as ornamentals in more than 30 countries for several decennia, we are not aware of indications that the underlying but unknown mutations, after selection of the variety, have caused damage to the environment or have caused adverse effects on consumers or livestock. This provides circumstantial evidence that the phenotypic screening and selection, which are the rule in plant breeding programs, in combination with other conventional selection procedures before introduction of varieties onto the market, have been sufficient to reduce risks of unknown mutations in plants to an acceptable low level. The same process of screening and selection will be the rule for development of cisgenic varieties.”
TechNyou:
I would tend to agree with this paragraph, but argue that on the above rationale transgenics has a risk profile similar enough to warrant it being treated equally to mutagenesis and cisgenics.
Wait, there is more
Whatever the –enics (cis-, trans, or intra-) they all require one of several laboratory techniques to insert a gene into the genome of your crop.
Bacterial taxi
Some opponents of GM foods argue among other things that bacterial or viral vectors used to transport the gene into the crop can remain in transgenic plants (and cisgenic plants as well one would assume) and may be a vehicle for gene escape and help transfer genes widely to many bacteria as well as into human cells. Real, perceived, or highly improbable, whatever the risk it is equal between cis- and transgenic plants.
Random, uncontrolled
Whatever the gene’s origin, the insertion of that gene into a new genome is a random event. That is, we cannot control where it ends up in the genome. The new position of a gene in the genome, native or otherwise, can modify the expression of that gene, a concept known as ‘position effect’. The location of the gene might also influence the regulation of surrounding genes or RNA, which may be involved in the natural production of toxins, allergens or other deleterious trait. Again this is regardless of whether it is a cis- or transgene.
Perception V reality
There seems to be considerable emphasis on the fact that because the genes in question are cis genes that it makes things OK. The public perception may align with this concept as I continually encounter the intuitive or yuck factor response to inter-species gene crosses. People have a great revulsion of placing human genes into any plant; a marginally reduced revulsion for animal genes in plants, less again for bacteria genes and a close-to-acceptance for plant genes into plants. I suspect that the acceptance will be greater again if the genes were cisgenes.
But this is a perception rather than any scientific reality and shouldn’t have any bearing on how these things are regulated, though the cynic in me might say that politicians will ignore scientific reality if there are votes in it.
The summation
So, as I see it, we need to either include many of the modern plant breeding techniques such as mutagenesis in the legislative framework that regulates GM foods and cisgenic foods, which will get howls of alarm from industry and breeders, and a few others.
Or scrap the existing regulatory framework that governs transgenic crops and food and make transgenes, cisgenes and all other biotech-related plant breeding come under the same regulations as conventional foods do now. This proposal is already producing howls of alarm and outrage, from some groups anyway.
But I can’t see how you can make cisgenics an exception and excise it from the transgenic technologies.
Feel free to correct me.
References
http://www.cisgenesis.com/content/view/2/25/lang,english/
Schouten, H, et al. Do cisgenic plants warrant less stringent oversight?
Nature Biotechnology 24, 753 (2006)
Jacobsen, E et al. Review: Cisgenesis strongly improves introgression breeding and induced translocation breeding of plants. Trends in Biotechnology, Vol 25 (5) pp. 219-223 May 2007
MacKenzie, D. How the humble potato could feed the world. New Scientist
1 August 2008
Wikipedia – http://en.wikipedia.org/wiki/Plant_breeding
Institute of Science in Society – bacterial vectors
Jason
TechNyou
A closer look at stem cell treatments
The International Society for Stem Cell Research has launched a web site to arm patients, their families and doctors with information they need to make decisions about stem cell treatments.
ISSCR media release: 8 June 2010
Web site: A closer look at stem cell treatments
Heritage Toowoomba Agshow
TechNyou will be in the Wine, food and leisure expo. Our booth will focus on sustainable food production and the science of yummy stuff