What's the truth about Glow Danios?

[Devilishturtles]

Dyed or genetically altered?

I always thought dyed, and when I found out they were my new fish for August at work, I questioned the vendor. He said "no way, we don't deal with those cheap fish that lose color in a few month. These are bred that way and will stay stunningly bright all the time". They are an extremely bright red/pink color...very pretty. The info sheet I got on them says the same thing, about being altered with a bioluminescent gene.

Did I get fooled or is the guy telling the truth?

 

[rich311k]

Yes they are gentically altered. The government did it for some reason, I just can't remember what the reason was.

 

[fishfairy]

I researched these one day and what I found out is that they take jellyfish DNA and inject it into zebra danio eggs to create the fish. This was originally done to detect pollutants in water. They are now being sold for the home aquarium and I believe a portion of the profits go towards the funding for the research (or at least it did originally, not sure if it still does or not). This page has some pretty good Q&A's about them: http://www.glofish.com/about.asp

 

[MSU Fan]

I was told the reason that these fish are not being used for the pollutant testing (original purpose) is that once the color "turns on" to detect pollutants, it won't "turn off". Therefore, populating an area with these fish would only tell you once if the water is polluted, and then never give you any more useful data without adding more fish. So they are sold as pets now. I have heard that by the end of 2006, there should be a green and blue version, with purple out early next year.

 

[joannde]

how do they get the color to "turn on" with the fish offered for public sale ? do they get exposed to pollutants ???

 

[fishfairy]

I think (could be wrong) that the glowing turns "off" when they are exposed to pollutants, not turns "on". That is why they glow when they are born.

 

[Devilishturtles]

Thanks guys. My info sheet said that they were brightly colored like so to detect pollutants. I think they lose the color when pollutants detected....I guess. Thanks guys, saved me a phone call accusing them of lying tommorow. (The company irks me to no end, I'm not really mean all the time)

 

[joannde]

Ah ! Thanks for explaining the turn off / on coloration. I feel better now also

 

[QTOFFER]

how do they get the color to "turn on" with the fish offered for public sale ? do they get exposed to pollutants ???

As a biochemist, I'll try to explain this.

First of all, all genes have two parts: the part that codes the protein product, and a part that regulates when and where the protein will be made or expressed. The regulatory element of the gene is called the promoter, and it can be responsive to environmental cues like heavy metal pollutants and to tissue-specific stimulants like hormones.

Through the miracle of genetic engineering, it is possible to mix and match these two parts between genes and between species. For instance, I have taken the protein coding part for an insect enzyme and spliced it to the promoter of a harmless human virus. When I inserted this artificial gene into cultured rat nerve cells, they started making the insect protein all the time.

The people who made glofish spliced the promoter of zebrafish myosin to the coding region of a sea anemone fluorescent protein. When inserted into zebrafish embryos, this artificial gene is turned on only in tissues that make myosin - muscle. This was done to prove that the sea anemone gene could be successfully transferred to a fish embryo, where it would be expressed and function properly. The result of this experiment is the glofish that are available in lfs.

The next step of the project is to splice the sea anemone coding region to promoters (probably from bacteria) that are responsive to heavy metals and other pollutants. These animals will eventually be used to monitor water quality - fluorescing fish will indicate the presence of a pollutant.

The expression of the sea anamone protein is not harmful to the glofish and won't affect their lifespans. The fish were not subjected to any painful procedures - the DNA was injected into them when they were one celled embryos. Because it is now part of their DNA, glofish will pass the fluorescent gene to their offspring.

 

[joannde]

QTOFFER that is FASCINATING. Thanks for explaining it ! I love natural sciences so I found this very interesting and understandable. I do much better with these topics then with the mathematics on the planted tank forum LOL

 

[Reechard]

My LFS gets these in all the time, can't keep em in stock, sell em for 7 bucks a pop. Once my GF lets me spend more money on the tank I might get a school, lol.

 

[CHBGator]

Take a look at the note at the bottom of the discription.

https://www2.carolina.com/webapp/wcs/stores/servlet/ProductDisplay?jdeAddressId=&catalogId=10101&storeId=10151&productId=48368&langId=-1&parent_category_rn=1285|83|1009|547

 

[Devilishturtles]

Wow...very interesting.

That is why I'm studying marine bio. This stuff rocks.

Thanks alot guys!