Humanizing the Mouse

March 20, 2015

By Medical Discovery News

Humanizing the Mouse

In the 1986 horror movie “The Fly,” a scientist’s teleportation experiment goes awry when a fly lands in one of the teleportation pods and he undergoes a transformation into a part fly, part human monster. Today, science has given us the capability to create animal-human hybrids, although so far none of them has craved human flesh like they tend to do in the movies.

Neuroscientists at the Massachusetts Institute of Technology (MIT) have been introducing human genes into mice to study the effects on mouse brain function and capabilities. They are doing this in small steps, using genetic engineering techniques to introduce a specific, single human gene into a mouse. This will allow scientists to evaluate the impact of each human gene on the brain in another species. It’s not quite a monstrous Franken-mouse, but the results have definitely been revealing.

The human version of gene Fox2p is connected with language and speech development, a trait associated with the higher order brain function unique to humans. When this gene was introduced into mice in the experiment, they developed more complex neurons and more extensive circuits in their brains. Scientists wondered if this gene is responsible for the enhanced brain and cognitive abilities displayed in humans.

In the behavioral experiments at MIT, scientists placed mice in a maze and evaluated the reactions of mice harboring the Fox2p gene versus normal mice. The maze offered two modes of navigation to the mice: visual clues in the environment that were observable from within the maze and tactile clues in the pathways of the maze consisting of smooth or textured floor.

The hybrid mice learned to navigate the maze quickly, finishing it three times faster than normal mice. This cognitive enhancement or flexibility reflects the human capability of handling and processing information. The tactile information is handled by something called procedural or unconscious learning. However, the sight-derived clues represent declarative learning. It is the addition of the Fox2p gene that gave mice the ability to integrate both forms of learning.

Interestingly, if the visual clues or the tactile clues were removed, the hybrid mice did no better than the normal mice at navigating the maze. This might mean that the hybrid mice only performed better when they could utilize both forms of information. This ability to switch between and consider different forms of memory (procedural and declarative) is important and may explain in part why it is so important in human speech and language development.

Humanized animals are being used in a number of scientific fields to help us understand different elements of human physiology. Expect to see more of the humanization of animals in the future, but alas for you Sci-Fi fans – a Frankenmouse is not yet on the horizon.

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The Synthetic Revolution in Biology

Oct. 18, 2013

By Medical Discovery News

Synthetic biology sounds like an oxymoron. One word means artificial while the other means natural. Put together, what those two words really mean is a combination of biology and engineering that will allow scientists to harness biological processes for human use. Imagine genetic engineering and biotechnology on steroids.

In short, synthetic biology aims to manipulate cells or their components to achieve a certain result, such as advancing human health, producing energy, manufacturing products, producing food, or protecting the environment. There are plenty of applications for synthetic biology in many important fields. Scientists want to create cells with new and unique properties that are programmed to fulfill a directed purpose. For example, these engineered cells might be programmed to synthesize new biofuels.

One practical example of the promise of synthetic biology is directed at malaria, a disease caused by a single-celled parasite called Plasmodium that has been killing humans throughout our recorded history. Today, it infects 250 million people worldwide each year and is the No. 1 killer of children under five.

Malaria is currently treated by a group of drugs that are derived from artemisinin, such as artseunate, artemether, and dihydroartemisinin. Artemisinin is a compound from the sweet wormwood plant, which was used as a natural remedy for centuries in China. The downside is that this plant must grow for up to 1.5 years before it can be harvested for drug production. Of course, the normal variables of agriculture – rain, sunlight, soil content, labor – also mean that the supply of sweet wormwood fluctuates. Combined with the expensive manufacturing process, the result is that not everyone who is infected with malaria can be treated.

Synthetic biology has the power to change that. Recently, the World Health Organization gave pharmaceutical giant Sanofi approval to produce artemisinin using a genetically modified form of a yeast called Saccharomyces cervesiae. Several genes are inserted into the yeast’s genome to alter its metabolic pathways to produce a precursor to artemisinin. This has turned a simple organism into a “one-cell factory” for a new source of artemisinin.

Now, it will only take three months to produce artemisinin for antimalarial drugs. It will also insure a steady supply and greatly increases the amount that can be produced at one time. About 25 tons were produced in 2013 and that is expected to double next year. And if that weren’t good enough already, each dose of the yeast-produced artemisinin will only cost 25 cents.

Critics of synthetic biology fear a Frankensteinian world of potentially dangerous biological creations. In that regard, the United States government is drafting guidelines and regulations for this new field. With proper care and funding, synthetic biology will yield many new advances to improve lives as it reaches it potential in the future.  

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