The first thing we are going to need is a gene that makes things glow. One commonly used gene is the gene for the green fluorescent protein from jellyfish. This protein wouldn't be of use for us though, because it only glows under ultraviolet light. The luciferase gene from fireflies generates its own light, but it requires energy to do so. We will use the luciferase gene for our experiment.

The next step is to consider regulation. The luciferase gene requires energy so we don't want it expressed everywhere, because it might result in stunted plants. For our project, we will use a light-sensitive repressor and a leaf-specific promoter so that the leaves will light up only when the plant is in the dark. This will conserve how much energy the plant needs to use to glow.

One nice thing about working with plants is that you can grow a complete plant from any cell, bypassing the complications of dealing with germline cells. If we introduce our luciferase gene under the control of a light-sensitive repressor and leaf-specific promoter into mature plants, there are methods to isolate the "transformed" cells and regenerate them into complete plants.

This outline simplifies many of the required procedures. Finding light-sensitive repressors and leaf specific promoters is a feat in itself. The process of introducing DNA into plants and recovering the "transformed" plants is also cumbersome. Additionally, plants don't like to make proteins that they don't need to, and may find ways to stop production of luciferase. The same general problems apply to humans and other animals as well. Thus, genetic engineers must develop efficient DNA delivery techniques and find appropriate promoters and modify genes/promoters so that they won't be rejected.

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