Defining Biotechnology. Biotechnology is the use of biological organisms and processes to produce commercially valuable products. Many of the earliest biotech products made use of bacteria to produce recombinant proteins. That is, the bacteria produced human proteins that could be used as therapeutics in humans. This feat is possible because both humans and bacteria shared a common ancestor. Remarkably, the genetic information that human cells use to make proteins can be used by bacteria found in human feces.
Sometimes, the use of bacteria and yeast in the production of foods such as cheese and beer is placed under the umbrella of biotechnology. However, for our purposes in this class, biotechnology will be limited to the products created using modified genetic information. For example, the recombinant proteins mentioned above are the result of taking genetic information from human cells and, through the use of numerous molecular biology processes, bringing that information into bacterial cells in the context that these organisms can understand.
Central Dogma of Biology. Despite the need to go back in time a couple billion years, humans and bacteria share a common ancestor. Evolutionary theory as well as the central dogma of biology weave together to allow bacteria to read genetic information derived from human cell to make human proteins. The central dogma of molecular biology posits that genetic information flows from DNA to RNA to protein. While the “DNA to RNA” step can be reversed, the same is not true for genetic information flowing from the form of protein back to nucleic acids such as DNA and RNA.
Last Universal Common Ancestor. Of all known living organisms, DNA serves not only as the information that is both passed down from one generation of organisms to the next but also as the source code for proteins using RNA as an intermediate, or messenger, molecule. This fact implies that the last universal common ancestor (aka LUCA) had a DNA genome. All organisms since have made use of DNA genomes as well as the genetic code used to decipher the information. With DNA genomes in all living organisms and a shared used of a genetic code, biotechnology is built on the ability of scientists to use molecular biology tools to edit and modify DNA. The possible modifications are nearly endless.
Model organisms. The extent of biodiversity makes it impractical to study all organisms in a laboratory setting. Instead, representative organisms from the tree of life have been disproportionately studied. Multiple factors have guided the selection of these “model organisms” including the ease of culturing asexual organisms and breeding sexual organisms. Biological principles that are determined in model organisms are usually applicable to non-model organisms because of both the central dogma of biology and the concept of LUCA.
In a positive feedback loop, research of a model organisms incentivizes additional research of that model organism because tools to study the organism are developed in one study that could be used in follow-up studies of that organism. However, recent improvements in molecular biology and biotechnology methods are reducing the barriers of entry for studying new organisms and, thus, reducing our reliance on any particular model organism.