Genetic engineering is a method which has existed since the dawn of time; as time elapsed selective breeding has been a main source of genetic manipulation. But over the past half century newer technologies have emerged allowing humans to dictate and more tightly regulate animal and plant genetic flow. The development of transgenesis in plants is a well-established field and is readily accepted and consumed by humans but in the case of transgenic animals they have yet to be publically available to consumers. The process of transgenesis involves the introduction of exogenous genes from one species and incorporating it into the genome of another species. As a result the characteristics of the incorporated gene will be expressed in the new species. The most common methods facilitating transgenesis involve plasmid vectors, pronuclear injection and viral vectors.
Transgenic salmon are currently being reviewed by the FDA as being the first approved transgenic animal to be publicly available for consumption. Reasons why transgenic salmon are on the cusp of approval is to address over fishing issues and due to the main current source of salmon (Atlantic salmon) being classified as an endangered species. Genetically modified salmon have been modified by integrating the growth hormone regulating gene from Atlantic Chinook salmon in conjunction with an antifreeze promoter gene from ocean pout(Du, Gong et al. 1992; Saunders, Fletcher et al. 1998).
Conventionally salmon only grow during the spring and summer seasons when warm temperatures are present, but during the colder climates growth rates plateaus. In the event of transgenic when climatic conditions falls below a certain temperature the promoter gene from the ocean pout is switched on, thus the production of growth hormone. The antifreeze (AFP) gene is taken from the ocean pout which inhabit the waters close to the poles. In these areas water temperatures can reach below freezing, transgenic salmon will