In this Lab, you will take the fragment of DNA that causes a unique trait in one organism such as the DNA that makes a firefly glow and splice that DNA into a different organism, so that the second organism takes on the trait of the first organism. At least, that's what you will attempt to do. The results may not always be what you expect. In the controversial field of genetic engineering, heated claims and passionate counterclaims are everywhere. And as technology advances, both the promises and the objections are rapidly multiplying.

We have designed a gene splicing simulator that follows many of the same steps that bioengineers use when they create transgenic organisms. By using the simulator, you will increase your understanding of what is involved in gene splicing, you will learn the major technical problems that must be solved, you will master the different procedures used, and you will study some of the potential dangers and ethical questions associated with bioengineering.

All of the genetic traits that appear in the gene attribute list on this screen have been spliced into one of the listed host organisms by bioengineers. Each has resulted in the creation of a viable transgenic organism. Not every transgenic animal you engineer will be able to survive in the real world, but if you keep trying, you will soon end up with a unique creature, one that was produced from the DNA of two completely different organisms.

Directions:
The red, green, yellow and blue cylinders that form the DNA are called base sequences. Each color represents a different nucleotide: Thymine, Cytosine, Adenine, and Guanine.

It is okay to include some extra base sequences when you cut out the sequence you are looking for. But be careful not to cut off part of the base sequence you are trying to remove.

Only one of the restriction enzymes in the enzyme list will properly cleave the highlighted DNA. Each of the enzymes is followed by a description of that particular enzyme's action.

For more information, click on the Diagram icon. Review THE CLEAVING PROCESS diagram and the MATCHING RESTRICTION ENZYMES TO CLEAVAGE SITES diagram.

Once you have chosen an enzyme, enter the letter name of the RESTRICTION ENZYME in the data window located in the upper right-hand section of this screen.

After you have entered the Restriction Enzyme, click CONTINUE to see if you have chosen the correct enzyme.

In ethical questions such as this one, ; there is no 'right' or 'wrong' answer. : Make your decision baud on what you % believe

The DNA segment sour organism can rarely be spliced directly into .e host DNA. Instead, the DNA segment is introduced into the host organism in one of a number of ways, including biological vectors, such as bacteria, a. mechanical vectors, such as gene guns a. micropipettes. In ths simulation, we are going to use biological vectors exclusively. Specifically, we are going to use bacteria.

The DNA of a bacterium is arranged in small rings of DNA called Plasmids. A representation of a plasmid is shown on this screen. (An actual plasmid has , many more nucleotides than are shown here.) Two different representations of the DNA segment , you isolated in STEP 3 are also shown: a color-coded representation a. a standard text representation.

To successfully splice the source , organism, DNA segment in. the I plasrnid DNA, you must choose the I proper enzyme from the Restriction I Enzyme oniy tne proper enzyme will cut the plasmid open in a way that will allow it to join with the sticky ends of the source organism, gene. Remember, to ensure that the two DNA types can be spliced together, the dangling (or sticky) ends of the source organism DNA fragment must be the mirror-image of the poi. on the plasmic! where the splice takes place. This means that both ends of the DNA fragment must have the exact same base sequence, but with the pattern reversed. For more information, click on the Diagram icon. Review THE CLEAVING PROCESS diagram and the MATCHING RESTRICTION ENZYMES TO CLEAVAGE SITES diagram.

Once you have decided which restriction enzyme should be used, enter its name in the data window, and click on CONTINUE to see if you chose the proper enzyme.

Ether push RESET to return to the start of Ibis VR lab, or push the RETURN icon to ex,t this lab.

While the actual process of engineering a transgenic organism has been greatly simplified in this Lab, as have the ways of introducing the recombinant DNA to the host organism, the steps you have followed are identical to the ones used by scientists when they create a transgenic organism. In fact, scientists have used all the source organism gene traits listed in this Lab to create viable, healthy transgenic organisms.

But in many cases, what initially appears be a normal, healMy transgenic organism, turns out to exhibit unexpected flaws in its internal make-up a. immune system or develops dangerous diseases. Sometimes these flaws do not appear until years after the organism is created.

In worst-case scenaHos, bioengineering results in an organism that cannot survive in the real world. Such an organism is termed "non-viable, Even worse, sometimes an organism could be created that passes dangerous traits on to other organisms.

Scientists have learned that while genetic engineering is full of potential to change the world for the better, it is also a complex, unpredictable discipline. It is not unusual for scientists to repeat the same gene-splicing operation hundreds of times . before Mey achieve a successful result. Even then, bioengineers are . often unsure as to why a specific splice attempt succeeded, while other similar attempts did not.

Even if your attempt at engineering a . transgenic organism did not succeed, or ended in a way you did not expect, we encourage you to try again. Use a different combination of DNA or a repetition of the same mmbination. It is only through persistent, careful experimentation, tempered by constant ethical supervision that we can come to understand -- a. utilize bio-engineering for the benefit of the world.