Synthetic Biology Circuits: Logic Functions and Memory

Researchers at MIT have made significant advancements in synthetic biology by developing genetic circuits within bacterial cells that not only execute logic functions but also retain memory of their operations. These circuits, detailed in a recent publication in Nature Biotechnology, can encode results in the cell’s DNA and transmit this information across multiple generations, potentially enhancing applications in environmental monitoring, biomanufacturing, and stem cell programming.

Key Developments and Milestones

• 1961: Discovery of the Lac Operon by Jacob and Monod, marking the first recognized gene regulation pattern.
• 1970: Discovery of restriction enzymes, pivotal for DNA manipulation.
• 1983: Development of the Polymerase Chain Reaction (PCR) technique by Kary Mullis, revolutionizing DNA amplification.
• 2000: Design of the first synthetic gene circuits, including a genetic toggle switch and a biological clock.
• 2003: Invention of BioBrick plasmids by Tom Knight, foundational for the International Genetically Engineered Machine (iGEM) competition established at MIT in 2004.
• 2004: The first international conference for synthetic biology, Synthetic Biology 1.0 (SB1.0), is held at MIT.
• 2005: Development of a light-sensing circuit in *E. coli*.
• 2010: Publication of the first synthetic bacterial genome, *M. mycoides* JCVI-syn1.0.
• 2011: Engineering of functional synthetic chromosome arms in yeast.
• 2012: Introduction of CRISPR-Cas9 for targeted DNA cleavage by Charpentier and Doudna labs.
• 2019: Creation of the first bacterial genome entirely designed by a computer, named *Caulobacter ethensis-2.0*.
• 2020: Development of the first xenobot, a programmable synthetic organism derived from frog cells and designed by AI.
• February 10, 2023: MIT publishes findings on new genetic circuits that perform logic functions and remember results encoded in DNA, potentially used for long-term environmental sensors and stem cell programming.

Future Implications

The ability to remember results could lead to innovative uses such as long-term environmental sensors that can monitor changes over time or more efficient controls for biomanufacturing processes. Additionally, this technology could aid in programming stem cells to differentiate into various cell types based on historical data. This development marks a significant step forward in the field of synthetic biology, paving the way for smarter biological systems capable of complex decision-making and adaptive responses based on their historical data.

Read More
[1] https://en.wikipedia.org/wiki/Synthetic_life?oldformat=true
[2] https://hudsonrobotics.com/a-brief-history-of-synthetic-biology/
[3] https://bis.zju.edu.cn/binfo/lecture/synbio/nrmicro3239.pdf
[4] https://www.nature.com/articles/s41467-020-19092-2
[5] https://news.mit.edu/2013/cell-circuits-remember-their-history-0210
[6] https://innovationtoronto.com/mit-engineers-design-new-synthetic-biology-circuits-that-combine-memory-and-logic/
[7] https://pubmed.ncbi.nlm.nih.gov/29915814/
[8] https://www.fiercebiotech.com/research/mit-team-employs-synthetic-biology-to-create-circuits-could-detect-signs-disease