by By David McKalip, M.D......
Risk: The OX513A bugs could establish a new subspecies and actually survive in nature.
Implications: The FDA thinks the risk of this is low, but bases their conclusions on some assumptions that are not entirely accurate. However if the survival rate, percentage of females released or genetic assumptions are wrong, then the GMO mosquito could establish itself permanently.
Introduction to Part II.
The FDA has approved a genetic experiment on humanity and the ecosystem in Key West Florida. They propose to release genetically Modified Organisms (GMO), mosquitos, into the wild to see if they can control the Aedes mosquito population and decrease transmission of disease. The Sunbeam Times continues its series on the GMO Mosquito, known as OX513A by evaluating the risk of the new mosquito establishing itself in nature and the potential consequences. The FDA believes this risk is low, but they have based it on faulty assumptions and some deceptive statistics used by Oxitec to obtain FDA approval. In Particular, Oxitec claims that the GMO mosquito offspring will die quickly, when in fact a large percent can live weeks and breed more than once.
The Genetics of the GMO Mosquito – Ox 513A
The Oxitec Mosquito was made in a lab and modified the genes of the Aedes subspecies it created so that the offspring of the mosquito would die quickly. The Aedes aegyptii mosquito transmits multiple diseases (Zika, Dengue, Yellow Fever and Chikungunya) and the Zika scare is renewing dramatic efforts to kill the mosquitos. Oxitec owns the OX513A Mosquito that has been modified in two major ways using multiple genes. First, the GMO mosquito has a red fluorescence gene inserted in it so it can be identified under special lights in the laboratory for further study after recovery from the wild. Secondly it contains a so-called “lethal trait”, which is a gene for a protein called a TAV (Transcription Activator Variant). The DNA inserted into the mosquito will cause the offspring to produce the TAV protein which shuts off reading of the DNA by the cells of the mosquitos. That means the mosquito will not produce the other proteins it needs to develop and will die. The TAV gene was cut out of a Herpes Simplex Virus by scientists in 1992 (a gene called VP16 – Virion Protein 16). Transcription activators are normally occurring proteins that allow our DNA to be decoded (transcribed) into RNA which is then read by the cell (translated) to make proteins. However the TAV in the Oxitec mosquito is designed to overproduce itself and take up all the other sites for transcription of proteins so that the needed proteins are not produced, leading to death. To keep the mosquitoes alive in the lab so that they can be released into the wild, the gene also includes a tetracycline sequence. Thus Oxitec can feed tetracycline to the mosquitoes during production in the lab and keep them alive long enough to be introduced into the wild. Thus the lethal trait is called tTAV (Tetracycline Responsive Transcription Activator Variant).
The genetic engineering was done by injecting the mosquito embryos under a microscope with two different tools used to alter DNA in living organisms. Known as plasmids, these tools are circles of DNA that contain sequences allowing them to integrate into the native DNA of organisms. The embryos are injected very soon after fertilization in what is called the pre-blastoderm phase, as shown in this video. One plasmid contains a very powerful set of modifiers called Transposons, specifically known as “piggyBac”. Transposons allow genetic material to insert – often randomly – into genomes and can cause massive damage to the DNA. That means most injected embryos will die before producing a successfully transformed organism, in this case the OX513A. This sort of transposon can be very dangerous if artificially inserted into nature without control, which is why the OX513A uses what are called “non-autonomous” transposons. The piggyback transposon requires a helper protein – called transposase – which is contained in the second plasmid injected into the embryos and not present on the plasmid containing the lethal trait called “tTAV”. Theoretically, that should prevent any runaway activity of these transposons which now exist in the GMO mosquito. However, nature and genetic evolution being what they are, there is always a chance that over hundreds, thousands or more generations the GMO mosquitos or their offspring could change. That means these transposons could somehow become autonomous or find another organism with transposase that will allow them to leap all over a gene causing major man-made mutations in nature that would not happen naturally.
In summary, Oxitec intends to release male GMO mosquitos into the wild that contain a fluorescence gene and a lethal trait designed to kill the offspring that will occur between the OX513A and wild type (WT) mosquitoes. The idea will be that eggs from the pairing (GMO/WT) will die due to interference in the protein production of the embryos, leading to early death before they emerge from the water. The GMO mosquito will contain new genes not present in the rapidly and voluminously breeding mosquito population that also contain other elements designed to cause integration and mutation of their DNA if man-made control mechanisms fail. The mosquitos are also intended to survive if they access tetracycline as a food source, which can happen.
Read the entire article at SunBeamTime.com
*Dr. McKalip is a private practice neurological surgeon with firsthand experience in genetically engineering. While a researcher and academic neurosurgeon, he ran a laboratory that created viruses to alter the DNA of brain and spinal cord cells to produce proteins to promote regrowth of neurons after spinal cord injury. Dr. McKalip was awarded an NIH grant to pursue this research. Dr. McKalip is also a clinical researcher familiar with the science of clinical trials and statistical analysis of results.