To yet another blog on transgenesis. Here we will be discussing some of the most fascinating inventions of genetically modified organisms.
GLOW IN THE DARK CATS
These glow in the dark cats were created in an attempt to learn how to combat HIV and FIV.
Now HIV needs no introduction, it is Human Immunodeficiency Virus and it attacks the human immune system using the individual to suffer from various infection and ultimately succumb to death. In the same way we have FIV or Feline immunodeficiency virus which does the same thing with cats, i.e attacking their immune system . The scientists in order to create a cure for this disease ran experiments with cats to better understand how to combat AIDS.
Two types of genes were transferred to feline eggs ( oocytes). First one, a gene TRIMCyp coding for restriction factor which is found in rhesus macaques. This gene protects the rhesus macaques from infection by FIV. The second one, a gene coding for GFP(green fluroscent protein) protein from jellyfish that glows under blue light. The second gene( coding for GFP) was added as a tag to the antiviral gene from the rhesus macaques, in order to make sure if the gene was transferred to the genome of the cats and passed on to the next generation of cats. The result, a glowing cat.
Spider goat is a transgenic goat with the capability of producing spider silk proteins in their milk. These proteins could be then later isolated and purified using chromatographic techniques and used in medical, textiles fields. This recombinant silk protein was named Biosteel. This was because it was as strong as steel and also elastic at the same time, with the capability of stretching 20 times its unaltered shape without breaking.These transgenic goats were first created by a Montreal based company- Nexia biotechnologies. The company created lines of goats to produce recombinant versions of two spidroins from Nephila clavipus, the golden orb weaver, MaSp1 and MaSp2. When the female goats lactate their milk contains the recombinant silk biopolymer. Scientists have also tested its toughness and found the when the recombinant silk was woven it was tough enough to stop a bullet.So, don’t be surprised if you find spider silk in bullet proof jackets in the future.
SUDDEN DEATH MOSQUITOES
Mosquitoes act as carriers of pathogens to transmit diseases like malaria, zika fever, dengue, chikungunia. These diseases result in worldwide deaths of people affected by them. These diseases are caused by viruses transferred by female Aedes agypti mosquito when it bites humans.Therefore, scientists genetically modified the male mosquitoes in such a way that when they mate with females the progeny doesn’t survive till adulthood. Genetically modified mosquitoes where first created by a biotechnology company Oxitec.
Oxitec scientists first developed a GM mosquito line (called OX513A) in 2002, by inserting genes from other organisms into the mosquitoes’ genomes . The OX513A GM mosquito line had two important genes:
1. a “fluorescence gene” from a colored marine coral (Discosoma sp.) that causes mosquito larvae to glow red under fluorescent light; and
2. a “lethality gene” that consists of a combination of DNA sequences from the bacterium E. coli and from the herpes simplex virus, and causes mosquito larvae to die unless they receive an antidote.
The fluorescence gene is used to identify GM mosquitoes and the lethality gene, called tetracycline transcriptional activator variant (or tTAV), encodes a protein that blocks the transcription of several other genes that are essential for the development of the mosquitoes. GM mosquito larvae that produce the tTAV protein die before reaching maturity. However, the tTAV protein cannot prevent the transcription of other genes when it is bound to
the antibiotic tetracycline. Therefore, tetracycline acts as a repressor of the lethality gene. In the lab, the GM mosquito larvae reared in presence of tetracycline develop normally
into adult mosquitoes. When these adult GM mosquitoes are released into the wild and breed with wild, non-GM mosquitoes, their offspring inherit the lethality gene. Without tetracycline in the environment to protect them, the offspring will die.