transgenics

The practical applications of transgenics, the act of splicing genetic material from one animal or plant to another, are incredible, sometimes to the level of morbidity. In addition to the use of jellyfish bioluminescent genes in potato plants, research labs led by Nexia CEO Jeffrey Turner have successfully produced two goats, Mille and Mucasade, whose mammary glands are capable of producing the silk of the orb weaver spider.

The silk of this spider has such incredible tensile strength that reportedly, a strand just three microns thick would be three times as tough as kevlar, the material used to create most bullet-proof vests. A woven cable less than an inch thick could theoretically bear the weight of a jumbo jet. The practical applications of such a material are self-explanatory.

This is not so seemingly infeasible an act, however, to mean that we can now create any protein from any animal in any other animal. The catch is that there is simply an incredible coincidence, physically, between the glands used to produce spider silk and mammary glands. And even now, the silk doesn't come out as it would from a spider--instead, a sort of milk is produced with the protein within it, which must be filtered and purified and spun. Nonetheless, the implications are remarkable. Rumor has it that if an actual demand exists for the silk, which everything indicates that it should, silk-milked cows will be the next logical step.

Turner, a geneticist himself, believes that the future of transgenics seems to lie largely in medicine. He claims that genetically bred animals will be eventually be able to mass-produce many medicines, allowing them to be provided at lower costs to the public. All indications seem to suggest that this will, in many cases, be entirely feasible. Only time will tell.

The word transgenic refers to the translocation or relocation of genetic material i.e. genes. A past, practical example of this was the translocation of genes taken from a human and inserted in to the genome of a female sheep. This is a form of genetic engineering, which is a term used to describe the skills which have been developed enabling molecular biologists to move genes from one chromosome to another. Genetic engineering involves locating a desirable gene, isolating it and then inserting it in to the genome of another organism. The proteins produced in response to the new piece of DNA by the new host cell will either have a useful effect in the host cell or may be harvested for use elsewhere.

The techniques used in genetic engineering are complex. Special enzymes called restriction endonucleases or restriction enzymes chop up DNA strands, cutting them at very specific sites. Other enzymes known as DNA ligases act as "genetic glue" and join pieces of DNA together. The required fragment of DNA cut from the chromosome of one organism is pasted in to another piece of DNA which will carry it into the host cell. Plasmids, the circular strands of DNA found in bacteria, are frequently used as these vectors. Once the plasmid is incorporated in to the host nucleus it becomes part of the new recombinant DNA of the engineered genome.

These techniques have made possible the creation of new genomes resulting in the production of altered organisms such as Polly. Polly was the next step from Dolly the sheep; Dolly was the first cloned animal, Polly was cloned latter, but was also transgenically altered. This was the first breakthrough showing the combination of two very complex and powerful techniques.