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.
Designer babies have been discussed as a possibility for decades. With the recent advancement to genome editing technology referred to as “CRISPR”, the discussions about the ethics of have been amplified. This is because CRISPR has reduced hurdles to human genome editing in terms of cost and technical ease. Three days ago, the following video was posted to YouTube:
This unorthodox reveal of the existence of genetically modified humans was shocking to the world at large, yet predictions of rogue scientists “skipping over ethical concerns and going for it” have been floating around for years. More than one TED Talk has addressed the ethical concerns of designer babies. Here is one for our last Amazon Review assignment of the year.
For more thoughts on this subject, try out any of the following movies:
“At the Senkwekwe Center for mountain gorilla orphans in Congo, a handful of Virunga National Park rangers live around the clock with four juveniles whose parents were killed. The rangers see their families only every few weeks and are very close to their charges. Chief caretaker André Bauma along with his team have hand-raised the gorillas since they were first brought to the center. The first gorilla, Ndakasi, was found when she was just two months old, near the body of her murdered mother. Bauma cared for her like a human child—letting her sleep on his chest for warmth and bottle-feeding her to help build her strength. After that, three more orphaned gorillas joined “the family” at the center. Since no mountain gorilla orphan has ever been successfully returned to the wild, they will always depend on humans.”
Chapter 8 of The Tangled Bank discusses evolutionary adaptations that came about due to different types of mutation. First, if genes are duplicated within a genome, the copies might come under the control of a new promoter. This could change the rules about when and how much a gene is expressed. Second, gene recruitment can occur if mutations lead to a different protein function. The protein could acquire a second function while maintaining the first function or the old function could be lost and a new function takes its place as the purpose of that gene.
Together, these examples drive home the idea that gene expression control (example: promoter properties) and gene coding information (example: protein function) can be thought of as separate “parts”. Synthetic biology is based on the idea that the parts could be mixed and matched to intentionally lead to a specified function. Genetic engineers can build ever increasingly complex processes by connecting more parts together. As an introduction to this, we will watch “Synthetic Biology: Programming Living Bacteria” by Christopher Voigt.