Complex Logic Circuit Made From Bacterial Genes

another random user writes "Just as electronic circuits are made from resistors, capacitors and transistors, biological circuits can be made from genes and regulatory proteins. Engineer Tae Seok Moon's dream is to design modular 'genetic parts' that can be used to build logic controllers inside microbes that will program them to make fuel, clean up pollutants, or kill infectious bacteria or cancerous cells. The circuit Moon eventually built consisted of four sensors for four different molecules that fed into three two-input AND gates. If all four molecules were present, all three AND gates turned on and the last one produced a reporter protein that fluoresced red, so that the operation of the circuit could be easily monitored."

Comments

Re:Um...

[Anonymous Coward]

Sure, but we don't know how to program life to do what we want. I'm not convinced that implementing digital logic circuits is the way to accomplish his goal, but I'm not convinced that it isn't either. This may be a dead end. Perhaps we will have a much better method later. However, this seems to be an approach that we can investigate now.

Re:Um...

[ColdWetDog]

Stop with the analogies already. That's like trying to fix a radiator leak with WD-40.

Yes, life does infinitely more complex logical operations than these simple logic circuits. But we can't control that stuff well and we have figured out how to do fairly elaborate things with simple logic gates in hardware. So if you can create such 'easy to program' devices into cells, you can hopefully use them as an interface to the more complex machinery.

Imagine a Beowulf cluster of E. coli ....

Re:List of applications sounds like funding BS ...

[pepty]

Actually, we are very likely to outperform nature when it comes to specialized jobs like eating crude oil in the gulf. We would start off with the organisms that are there naturally and optimize them for better metabolism in that specific environment, or hybridize them with other bacteria to make them more efficient in other environments. The trade off is the resulting microbes are crap at living under other conditions, but we don't care about that. Nature makes horses fast but evolution balances speed against fragility. People breeding horses make horses much faster - and then watch in horror as their legs break like matchsticks. When it comes to industrial bacteria, people turn mustangs into the equivalent of eight legged quarterhorses on steroids that keel over just after finishing their first race.

I don't see Moon's research conferring much of an advantage in industrial, remediation, or medical uses; those are best off with a single control mechanism. Most of the decision making process for those situations will continue to be most efficient if it is done outside of the bacteria. For an analogy: a factory could have four sensors hooked up to four smartphones to tell it how much it has in stock of four diffeerent parts and automatically order more when the levels get too low. Or instead a factory could have a sensor and a smart phone phone attached to each and every individual part to do that job. Each part would have to carry that sensor and phone which would inflate its cost without contributing to its final use. Ditto for distributing the control architecture to the bacteria.

I think the use for Moon's control architecture will be in research; the rest (like you said) will be hype.

Re:odd comments

[pepty]

Well if you were already used to pasting together molecular biology code snippets, you'd be impressed that someone found a way to combine that many in one system without something going wrong. You wouldn't see it as something that different from what has been going on for the past ~25 years. If you want a direct ancestor they were doing three logic gates back in 1999.

If you were interested in using this to do something industrial or medical (not just research in a research lab) you would focus on the "something close to what you want" part and realize that you would end up going with a specialized solution that gives you what you want, not something close to it.

Huge Accomplishment

[qbel]

Very interesting article.. For those that didn't read the article, I really like how Moon emphasizes the difference between what has been done before and what he has done. What was accomplished earlier was the construction of gates, circuits and complex systems from non-living material, silicon... But what he has accomplished is the intellectual breakdown of an already living system, and the use of that knowledge to manipulate and prove that he can control it by reproducing the gates and circuits we use for modern technology. I say it while biting my cheek, but hopefully this will also lead eventually to complex, controlled biological systems. Looks like there are still hurdles to go over, but definitely bravo so far.

Kind of raises a pretty important question, though: if and when complex systems start growing, and if AI and robots are created from them.. Will they still be just robots, or will they be living organisms? Man what I wouldn't give to hear Isaac Asimov talk about that for 5 minutes.

Re:Um...

[TapeCutter]

This as it stands it pretty rudimentary, but it could be the first step in allowing us to program cells in a much more defined and complex way than anything we can do yet.

It's all relative, my 1970's HS biology teacher would have viewed this as "Star Trek" science. This level of detailed understanding would have made his jaw drop in awe, as it did mine. :).