Micro Life Zone
Asked by shadycactus6 to Chris on 19 May 2012.
Keywords: elaborate, fluorescent, green, mice
The fluorescence you see, known as green fluorescence protein, was first isolated from a jellyfish. The gene that codes for this green fluorescent protein can be manipulated and inserted into the DNA of an organism allowing us to see this fluorescence under certain sources of light. The fluorescence you see in the mice appears only in cells that have a specific protein present called actin. This included skin, most organs and some cells in the blood. The hair does not “glow green”. We used to use a type of torch that when shone on the mouse, the mouse glowed green. We called it our light saber!
These mice are completely fertile and live a normal, healthy life.
One question to think about is “Can the offspring glow in the dark?”
The answer to this is both yes and no. We need to think of the genetics behind all this.
An allele is one of two or more forms of a gene. Most multicellular organisms, ie. Us, have two sets of chromosomes, that is, we are “diploid”. Diploid organisms have one copy of each gene (and therefore one allele) on each chromosome. If both alleles are the same, they are called homozygotes. If the alleles are different, they are heterozygotes.
In the case of green fluorescent protein (GFP) mice:
- If the offspring are homozygous (express copies of the gene on both alleles), they do not survive as too much GFP is expressed/made and it is too toxic to the embryo.
- If the offspring are heterozygous (express the gene on one allele only), the mice fluoresce under a specific wavelength of ultra violet light (488nm). They survive and are quite healthy and happy and lead a normal life. These are the mice we use in research.
- If the offspring don’t have any functional copies on either allele, they do not glow at all, but are still healthy and happy.
Litters of GFP mice can be checked using the torch described in my earlier answer. If they glow, then they are heterozygous and are used in certain experiments. If they don’t glow, they are GFP “null” and are not used in research.
By BRIDGE8 under license from Mangorolla CIC 2023