Tag Archives: Chapter 10: DNA

Nanotechnology and gene therapy

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Nanoinjector

The nano-scale ceramic marble represents a cell. This nano machine is a hundred times thinner than a single human hair.

The XXIst century promises great technological leaps in the fields of biotechnology and genetic engineering—possibly bringing us the dystopies we’ve seen in films like GATTACA (Niccol, 1997). That’s the worst case scenario, of course. Best case scenario, cancer research—one example of many—will greatly benefit from tools such as the one described in this blog post:

Nanoinjectors provide scientists with unprecedented ways of manipulating genetic material, thus getting us closer to the promise of Biotechnology, which was first hinted at with the mapping of the Human Genome, during the last decade of the XXth Century: 

The ability to transfer a gene or DNA sequence from one animal into the genome of another plays a critical role in the medical research of diseases such as cancer, Alzheimer’s and diabetes.

But the traditional method of transferring genetic material into a new cell, microinjection, has a serious downside. This method uses a hollow needle to pump a DNA-filled liquid into an egg cell nucleus, but that extra fluid causes the cell to swell and die 40 percent of the time.

Now a multidisciplinary team of Brigham Young University scientists has developed a way to significantly reduce cell death when introducing DNA into egg cells. The researchers have created a microscopic lance that delivers DNA to the cells through electrical forces.—Via

DNA is fragile. This means that scientists need ways to very carefully handle these molecules. The following images, taken from the primary source of this blog post, show how the lance works. You can also watch a video of the process below:

Nano injector III

More information about these types of technologies can be found here.

5 point bonus question for AP and 10H Bio students*:

Knowing what we know about the structure of DNA, explain the following passage:

“”Because DNA is naturally negatively charged, it is attracted to the outside of the lance using positive voltage,” said Brian Jensen, BYU professor of mechanical engineering.””

What part of the DNA molecule accounts for its “negatively charged” feature?

*To receive full credit, you have to answer the bonus question below.

The Molecular Basis of Inheritance

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"The key to Ion Torrent's Personal Genome Machine is a semiconductor chip that holds 1.5 million sensors, each of which can hold a single strand DNA fragment. The chip electronically detects the DNA sequence, unlike other sequencing machines that optically detect DNA with pricey lasers, microscopes, and cameras. It can sequence a DNA sample in a few hours, while other machines can take at least a week. And it can scale up fast."

“The key to Ion Torrent’s Personal Genome Machine is a semiconductor chip that holds 1.5 million sensors, each of which can hold a single strand DNA fragment. The chip electronically detects the DNA sequence, unlike other sequencing machines that optically detect DNA with pricey lasers, microscopes, and cameras. It can sequence a DNA sample in a few hours, while other machines can take at least a week. And it can scale up fast.” Via DIY DNA on a Chip: Introducing the Personal Genome Machine

The following videos account for the mayor topics discussed for our tests on March 18 (10H) and March 19 (AP Bio).

Anyone can benefit from any video, but keep in mind that the AP Bio course addresses more details of the DNA molecule. The first two videos are from Crash Course Biology, and account for DNA Structure, DNA Replication, mRNA transcription, and Protein Synthesis. These videos cover the specifics of 10th grade Bio:

DNA Structure and Replication

DNA Transcription & Translation

The next three videos are from Craig Savage. They discuss the same topics of the Molecular Basis of Inheritance, but with a closer look. AP Bio students will benefit more from these videos:

Introduction to Protein Synthesis

Transcription

Translation

Memes as Genes, Genes as Memes: a Strange Loop of Information

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"A diagram showing the spread of the "No one should" meme on Facebook. Each node represents a different version, and each edge connects a version to the most likely ancestor variant. Nodes are colored by timing prompt: rest of the day (blue), next 24 hours (red), or other (purple), showing that mutations in the timing prompt are preserved along the branches of the tree. Credit: Lada Adamic."--Via physorg.com

“A diagram showing the spread of the “No one should” meme on Facebook. Each node represents a different version, and each edge connects a version to the most likely ancestor variant. Nodes are colored by timing prompt: rest of the day (blue), next 24 hours (red), or other (purple), showing that mutations in the timing prompt are preserved along the branches of the tree. Credit: Lada Adamic.”–Via physorg.com

Consider the following statement: We are human beings, product of emergent mutations and natural selection. We’ve asked & answered questions about the cosmos; using animism, magic, religion, philosophy, and, more recently, science–

we are the universe aware of itself.

The patterns that resemble networks in our brains–galaxies are organized, as long as they are close enough, as networks; neurons are organized in networks; the Internet is one huge network–, are a big part of what makes us human. If we want to get a better grasp on what makes us human, to account for the relationship we have with the current technological context is a good way to start. Thus, nowadays, subjects as neuroscience, information theory, and consciousness research (a very tricky subject), are powerful tools when dealing with questions that have been with us for millennia…

How is humanity dealing with these questions in the 21st Century?

If you thought about heredity and the Internet as possible approaches to these questions, you are correct. Genetics and information theory (via biotechnology and infographics) can be put to use in interesting and interdisciplinary ways. Richard Dawkins–biologist–came up with the idea that cultural units (music, art, words, etc.) behave in ways that resemble genetic variation:

“Dawkins made his own jump from the evolution of genes to the evolution of ideas. For him the starring role belongs to the replicator (a DNA molecule, human consciousness), and it scarcely matters whether replicators were made of nucleic acid. His rule is “All life evolves by the differential survival of replicating entities.” Wherever there is life, there must be replicators. Perhaps on other worlds replicators could arise in a silicon-based chemistry—or in no chemistry at all.

What would it mean for a replicator to exist without chemistry? “I think that a new kind of replicator has recently emerged on this very planet,” Dawkins proclaimed near the end of his first book, The Selfish Gene, in 1976. “It is staring us in the face. It is still in its infancy, still drifting clumsily about in its primeval soup, but already it is achieving evolutionary change at a rate that leaves the old gene panting far behind.” That “soup” is human culture; the vector of transmission is language, and the spawning ground is the brain.

For this bodiless replicator itself, Dawkins proposed a name. He called it the meme, and it became his most memorable invention, far more influential than his selfish genes or his later proselytizing against religiosity. Memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation,” he wrote. They compete with one another for limited resources: brain time or bandwidth. They compete most of all for attention.”

Mutations are a common occurrence in both scenarios: the digital and the organic (for more information on what memes are, you can click here). The following quote, taken from the article Facebook memes can evolve like genes, gives us some insight into what parallels are drawn between genes and memes:

“In many ways memes shape the culture and communities through which they move,” said Eytan Adar, an assistant professor in the U-M School of Information and the Department of Electrical Engineering and Computer Science. “The thing we really wanted to understand was how the cultures shaped the memes. This work has implications for understanding how people communicate and influence each other, and let’s us measure people’s beliefs, desires, values, and even what entertains and amuses them.”

Tools like the Yule-Simon distribution were used in this interdisciplinary research. Knowing this, do you think that concepts discussed in class, such as allele, mutation, selection, etc., are applicable to their findings? What examples taken from the article could you give that resemble concepts related to genetics and evolution?*

*If you answer these questions, you’ll be awarded a 5 point bonus in the Genetics exam (Feb 25, 10H; Feb 26, AP Bio).