We’re always learning new things about life on Earth -- from discovering new species to
learning how our cells keep us alive.
But what about making life?
Last week, researchers said they had created a tiny synthetic bacterium that could help
us understand the fundamental requirements for life.
That’s because this bacterium had the fewest genes of any known free-living thing.
Researchers wanted to create an organism with a minimal genome, to help us figure out which
genes are really essential for survival, and eventually to design more complex synthetic
organisms.
So the team, led by scientists from the J. Craig Venter Institute, started with something
nicknamed Synthia -- a bacterium that the same team had created back in 2010, and was
considered by some to be the world’s first synthetic organism.
Back then, they essentially made a copy of a bacterium’s genome from scratch and inserted
it into the empty cell of a related bacterium.
And the result -- Synthia -- fit the basic definition of life: it could make energy to
live, grow, and self-replicate.
But this time around, the team wanted to see how much of that genome Synthia really needed.
So they began deleting genes that they thought might be dispensable, based on earlier research.
They kept testing different combinations of genes in a trial-and-error sort of way, until
they arrived at a living thing that … was living… but seemed to have the fewest genes
possible.
They called the new organism Mycoplasma mycoides JCV-syn3.0 .
It has a mere 473 genes.
By comparison, the smallest free-living bacterium -- called Mycoplasma genitalium [gen-it-TAIL-ee-um]
-- has 525 genes, while humans have 20-to-25,000.
And the crazy thing is -- even after spending years building this thing, scientists still
don’t know what /149/ of the genes in the new organism actually /do/… that’s like
30% of them.
They only know that they’re vital for it to stay alive.
So we have this new living thing with a tiny genome, but there’s still a lot to learn
about the genetic foundations of life.
But bacteria aren’t the only synthetic things that scientists are working on.
In recent years, there’s also been at least some research done on electronic cigarettes.
And last week, researchers from the University of Patras [PA-truh (Greek) or puh-TRAS (English)]
in Greece published a study, in a journal called Addiction, that compared different
types of e-cigs to measure how much nicotine they deliver, and how consistent their nicotine
delivery is over time.
They did this because, well, not a lot of research has gone into e-cigarettes.
But they’re so popular that agencies are having to catch up to figure out how to regulate
and standardize them.
So the scientists set out to compare some original e-cigs that went on the market a
few years ago, to newer ones that are being used.
And they also wanted to see how both of those compared to pharmaceutical nicotine inhalers
that are sometimes used to help people quit smoking.
Now, turns out that all e-cigarettes have the same basic parts:
There’s a battery, a container for the so-called e-liquid -- which is the nicotine mixture
that turns into vapor…
And then an atomizer -- Basically, it uses a battery to power a heating element to vaporize
the liquid into a gas.
But different models of e-cigarettes have at least three different types of atomizers
to provide the nicotine fix.
The older models have a metal mesh or wick attached the atomizer, which can vaporize
the liquid that the user applies to it, one drop at a time.
Then there are cartomizers, which are atomizers attached to a cartridge full of the liquid.
They’re pretty standard in commercial e-cigs these days.
And, lastly, there are so-called clearomizers which have a clear tank full of the stuff,
connected to a replaceable wick-and-coil combo that creates the vapor. These are a slightly
newer technology.
So the team created their own custom e-liquid to load up several brands of e-cigarettes
-- 3 with cartomizers, and 4 with clearomizers -- and then used a pharmaceutical nicotine
inhaler and a pack of cigarettes as controls.
Then, they programmed a sort of “smoking machine” to puff on the different cigarettes
newer models -- delivered nicotine more consistently than the cartomizers, and about the same as
the pharmaceutical kind.
Many clearomizers also delivered more nicotine with each puff than any other e-cigarette
or even tobacco cigarettes.
So in addition to clearing the air, if you will, about what kinds of e-cigs deliver how
much of the drug, the researchers say that their study could be used to test e-cigs in
the future, so people know what they’re getting.
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