Fluorescent transgenic fish
Biotechnology to serve the business of pets, transgenic fish that glow in the dark. The genetic manipulation competes with the traditional and artificial selection (used for centuries in goldfish) in the development of new varieties of fish, and the last, are the fluorescent fish.
Transgenesis had been used so far to create varieties of plants and animals that were bigger, more resistant to disease, or who need less food than natural varieties, but has already begun to use purely ornamental purposes, in creating new varieties of fish and other animals. The Taiwanese have been the pioneers in regard to the use of transgenic animals as new in the business of pets. Since 2002 already sold in Taiwan, Malaysia, Japan and Hong Kong, genetically modified fish.
The first transgenic fish, the TK-1:
The first, created and patented in Taiwan, was the TK-1. It is actually the Japanese medaka, A small freshwater fish with high transparency in its body, which was ideal for the intentions of the creators of TK-1. The fish in question is grafted a jellyfish gene that produces fluorescence in animals that have it. They succeeded by using a plasmid as a vector, the PGLO, which includes the gene encoding GFP (Green Fluorescence Protein).
This gene from a jellyfish, the Aequorea victoria, which produces this protein naturally. Thus, by the plasmid, introduced the GFP gene in medaka embryos, producing transgenic fish, having now the GFP gene, produced in your body fluorescent protein.
In this fish does not take long to follow the TK-2, TK-3, and the TK-4, using similar techniques in other species of fish (such as Brachydanio rerio) And again in the Japanese medaka, thus fluorescent varieties that glow when exposed to ultraviolet light, ranging from the first yellow-green, blue or fuchsia later.
Other transgenic fish
The latest achievement in this regard was the creation of two new varieties of fluorescent, this time of cichlids. The new species that have acquired fluorescence are cichlids convicts and angelfish. In both cases have had to use different techniques to graft the previous gene, due to peculiarities of these species that prevented them from using the same techniques.
In the case of the convict cichlid was chosen as direct microinjection into the eggs, but for angel fish had to be used electroporation to the cell membrane more permeable, thereby allowing the entry Plasmid.
New GM cichlids exhibit high fluorescence and transmitted the gene to offspring normally, which enabled them to produce and five generations of fluorescent fish. After a year of testing, is scheduled to begin selling in 2012. Transgenic fish are marketed sterilized to prevent possible adverse effects on the environment and at the same time ensuring monopoly. However, these methods are not entirely safe and the animals are not always sterile.
Cons and risks of transgenesis
Environmental organizations are concerned about the emergence of these new animals, and with good reason, since carry some real dangers. Species that can hybridize with their natural forms, to get to escape to nature, which could lead to dire consequences for the species in question.
Genetically engineered fish are often mating advantage over natural varieties, and because of this, the foreign genes would be easily to the normal population, mixing with it.
However, they have a disadvantage in terms of survival of eggs and larvae. Therefore, mixing with the normal population, could dramatically reduce the viability of offspring, which would entail a gradual population decline until their complete disappearance. There could also be the opposite case, where the transgenic fish is mixed with the normal population, but the moves and dies, along with many other species.
Fear is what happens to the transgenic Coho salmon, bigger and stronger than the natural variety, and is proving to be more aggressive than this. This is similar to what happens when you release any animal in an environment which does not belong, regardless of whether genetically modified or not, as with the Nile perch when released into Lake Victoria in Africa.
Perch adapted to the lake, becoming a invasive species, Destroying much of the local fauna and therefore condemned to extinction of many native species (known to have disappeared more than two hundred local fish, and many others are in serious danger.)
Furthermore, it is difficult to predict exactly how the gene behaves in the body itself which has been implemented, especially the animal be released in the medium and thus be influenced by other variables and stimuli.
Under certain circumstances transgene could affect other genes, cause changes in behavior, or even release toxins. Even in the ornamental fish industry are quiet because they fear that countries that oppose the marketing of fish to Singapore prevent the export of all kinds of tropical fish raised there, and not just GM.
In short, advantages genetic manipulation, such as obtaining resistant varieties that can live in polluted environments, is in constant touch with other applications less practical or possible negative consequences of the release of transgenic animals.
