Monday, May 26, 2008
The research has provoked some interest, particularly in rice dependant countries. The International Rice Reasearch Institute in the Phillipines is interested in the technology, in the context of integrating maize genes into rice, but for the present, this scale of genetic engineering remains unfeasable.
These receptor molecules are protein structures that are components of a cell’s outer membrane. They act like receiving docks and catch specific compounds from the blood and enable the cells to engulf or interact with the compounds.
The researchers found that two receptors for cannabinoids also responded to UV light. They made the discovery during a search for the initial interaction between UV light and human skin cells.
If cannabinoid receptors are important in the initiation of skin cancer by UV light, then animals that lack the receptors should be relatively protected from the ravages of the light
Working with mouse embryos, the researchers removed the genes for the cannabinoid receptors. They found that the skin of the resulting adult mice, which lacked the receptors, was resistant to the development of UV-induced inflammation and skin tumors called papillomas.
The next question is why evolution should have produced receptors that respond to both UV light and cannabinoids?
Scientists from Michigan State University have discovered that an enzyme produced by microbes living in the stomachs of cows is the key to efficiently turning corn plants into biofuels. This enzyme is essential to the digestion of grasses by cows. It can also be utilized to turn other plant fibers into simple sugars. These simple sugars can then be used to produce ethanol to fuel trucks and cars.
Michigan State University scientists have conveniently grown corn plants that contain this enzyme by inserting the particular gene from a bacterium that live in cows' stomachs. This effectively converts the un-usable sugars, such as cellulose, which are locked up in the plant’s stalks and leaves into usable sugar without the aid of costly synthetic chemicals and processes.
Originally only the kernels of corn plants could be utilized to make ethanol, but this innovative discovery will allow the whole corn plant to be used. Consequently, more fuel can be produced at a smaller cost.
The main target for the enzyme produced in the corn plants is the vacuole as it is a safe and convenient place for the enzyme to be stored until harvest. The enzyme will accumulate in the vacuole with other cellular and metabolic waste products and will only become active when it is being used for biofuels. Since it is located only in the vacuole, the enzyme is only to be produced in the leaves and stalks of the plant where it is required and not in the seeds, roots or the pollen.
This revolutionary idea promises an effective carbon neutral and renewable energy source.
For more information visit: http://www.sciencedaily.com/releases/2008/04/080408085453.htm
Researchers in the US have created ‘living computers’ by using genetically altered bacteria. The findings of this research demonstrate that computing in living cells is feasible. It also opens the doors to a number of potential applications including data storage and as a tool in manipulating genes for genetic engineering.
The research team was from the biology and mathematics departments of Davidson College, North Carolina and Missouri Western State University, Missouri, USA. They achieved execution of DNA-based computation in living cells by engineering Escherichia coli to address a classic mathematical puzzle called the Burnt Pancake Problem (BPP).
The BPP is solved by sorting a stack of distinct objects (pancakes) into proper order and orientation using the minimum number of manipulations. The pancakes are of different sizes, each of which has a golden and a burnt side. The largest pancake must be on the bottom and all pancakes golden side up. Each manipulation reverses the order and orientation of one or more adjacent objects in the stack.
A system was designed that uses site-specific DNA recombination to mediate inversions of genetic elements that represent pancakes within plasmid DNA. Inversions (or “flips”) of the DNA fragment pancakes were driven by genes added from the Salmonella typhimurium Hin/hix DNA recombinase system. The system used sorts DNA segments by inversions to produce different permutations of a promoter and a tetracycline resistance coding region; E. coli cells become antibiotic resistant when the segments are properly sorted. The time required to reach the mathematical solution reflects the minimum number of flips needed to solve the burnt pancake problem.
It is believed the system has the potential to be scaled up to larger and more complex problems and by exploiting the infinitesimally tiny scale of DNA and bacteria, ‘living computers’ could carry out complex parallel processing problems that would otherwise utilise very large and expensive electronic computing systems. Since bacteria multiply naturally and have their own repair mechanisms, ‘living computers’ could be less expensive and require less space compared with conventional devices. Additionally, ‘living computers’ could evolve through DNA mutations to solve new problems.
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Malcolm Keth (41751819)
Thursday, May 1, 2008
MS (muscular dystrophy) is a type of disease that depletes the fatty sheaths that protect nerve fibres, causing a loss of muscle control. In the 1970s, scientists found that a specific version of a gene conferred a fourfold increase in the risk of MS. This gene encoded for an immune system protein called human leukocyte antigen DRB1.
Recently, studies in the USA and Sweden have now indicated that people with MS are 20-30% more likely than non-sufferers to have a variation of other immunity-linked genes. These genes encode the protein interleukin-2 receptor alpha, and also the receptor for the immune system messenger protein, interleukin-7.
The interleukin-7 receptor is attached to the membrane of cells, most typically immune system T-cells. When the interleukine7 binds to it, the receptor signals the cell to take part in immune response reactions.
The variant of the interleukin-7 receptor gene slightly favours production of a free-floating version of the receptor. The membrane-bound receptors compete with free-floating receptors for interleukin-7, therefore an excess of these free-floating receptors affects the fine-tuning of immune responses.
Previously, MS was believed to have a hereditary component, however the recent discovery of more MS-conducive gene variations may also indicate that MS is an autoimmune disease. This is because interleukine-2-receptor-alpha (a protein produced by one of the gene-variants) has been linked to Graves’ disease and type1 diabetes, which have autoimmune traits.
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