2. Design the DNA of the bacterial pets

Context

After learning about microorganisms, we tell the participants that nowadays we are able to give instructions to bacteria in their own language. The language of bacteria is DNA. Did you know that most of medicines we take when we are sick are made by microorganisms with modifies DNA? Following the example of the vinegar fermentation, we teach the kids that we can instruct microbes to make medicines instead of vinegar for example, or just a flower smell!

At Center Pompidou, we invited the kids to go on and play on the computers the game, in which they are able to design a DNA sequence and modify their own microorganism, to then bring it home in a sticker.

Description of the game

The game is made with the interactive novel python engine RenPy. This is a simple software that allows people to create a story consisting on messages and some basic interaction with the player. The game, which you can download below for MacOS or Windows, teaches you step by step about the basis of DNA design. The game is supported by a glossary sheet on the table, which is available below.

Scientific basis of the DNA design game

In the game, you will be require to give 4 different inputs: promoter, gene, terminator, and microorganism. The game follows scientific vocabulary and correct terms which can be expanded if you want to develop it further.

The microorganisms available are: Lactobacillus (a genus of bacteria known as probiotics which are specially known to ferment yogurt), baker's yeast or levure de boulanger (Sacchharomyces cerevisiae which is used to ferment bread or beer), microalgae (this is a broader term, which includes photosynthetic bacteria or microscopic plants), black mold or champignon noir (Aspergillus niger used for the industrial production of vitamin C) and kombucha. Kombucha is a ferment that ferments sugared tea, and includes a symbiosis of a yeast such as Saccharomyces cerevisiae, along with a bacterial species such as Gluconacetobacter xylinus to oxidize yeast-produced alcohols to acetic acid (and other acids). All these microorganisms are often used in biotechnology, and can be found in many industrial applications. For example, researchers have used microalgae to produce biofuels, or baker's yeast to produce complex molecules such as drugs against cancer.

The way the DNA parts fit together in the game also has a scientific basis. For example, the promoter is specific for each microorganism. In fact, promoters are often specific for groups of organisms which are related. That means that a promoter that works in a plant would hardly work in yeasts. The structure of promoters in prokaryotes (bacteria) is very different from those in eukaryotes (yeast or plants or mammals). We reflected this in the game making the promoters specific for each microorganism. Promoters often span 100-1000 DNA letters but we have made the examples shorter in the game, like for all the other sequences.

Genes code for a specific function, and can generally be transferred between organisms. We have reflected this in the game making one function per gene, and making all genes available for all the microorganisms. These are the 5 genes available and the inspiration from real genes used in the biotechnology industry:

1. Blue gene:

Inspired by the many blue reporting proteins such as this enzyme that produces indigo from tryptophan. Indigo is the pigment used to stain jeans blue. Link here for a DNA part example.

2. Medicine gene: 

The most remarkable example of a gene modification product used for medicine is insulin. In 1978, biotechnology firm Genentech used recombinant DNA techniques to produce synthetic “human” insulin in bacteria. Insulin is the first human protein to be manufactured through biotechnology, allowing mass treatment of diabetes. Link here for a DNA part example.

3. Flower parfum gene:

Many genes from flowers are known and can be cloned in yeast or bacteria. Some scents are very expensive and rare, and biotechnology companies are trying to produce some of this rare molecules in microorganisms to reduce the cost. For example this DNA part on the link here sequences for the enzyme R-Linalool Synthase, responsible for lavender scent.

4. Green fluorescent gene:

This gene was inspired on GFP (the green fluorescent protein) is perhaps the most used protein in genetic engineering and cell biology. It comes from the jellyfish Aequorea victoria and can be fluorescent under blue light. This allows us to see better extracellular structures and processes that otherwise would be impossible to analyze. Find in this link the DNA sequence for the original jellyfish green fluorescent protein.

5. Violet gene:

The inspiration from this gene comes from the operon (group of genes) VioABCDE (link to the sequence of DNA here). This produces a purple pigment (violacein) from L-tryptophane ( an aminoacid). Violacein is a pigment naturally produced by the bacteria Chromobacterium violaceumto defect itself from protozoa trying to eat it while living together in the soil.

The final result will only depend from the choice of gene (5 available) and the choice of microorganism (5 available). That means we have 25 possible combinations (5 times 5). However, the experiment will only succeed if the regulatory sequences before (promoter) and after the gene (terminator) are present and correct. The last sequence included in the DNA part is the terminator. Terminators are less specific than promoters, so we have reflected this fact allowing to use any of the 5 available promoter for any gene and microorganism. However, the terminator must be present for the experiment to succeed.

 

Download here the game for PC here

Download here the game for Mac here