AP Biology class blog for discussing current research in Biology

Tag: Worms

Worms Infused with Spider Genes Spin Silk Tougher Than Kevlar

Researchers have achieved a significant milestone in biotechnology by genetically modifying silkworms to produce spider silk. Spider silk is renowned for its exceptional strength and durability, surpassing even the toughness of Kevlar. Justin Jones, a biologist specializing in engineered spider silks at Utah State University, described the material as “a truly high-performance fiber.” This breakthrough has the potential to revolutionize various industries. It could be employed in the production of lightweight yet incredibly strong structural components, thereby enhancing the fuel efficiency of planes and cars. Additionally, this innovation could lead to the development of wound dressings for faster healing and sutures for surgical procedures.

Silkworm cultivation has been practiced for thousands of years, providing raw material for textiles. However, their silks tend to be fragile. On the other hand, spiders face the opposite issue – their silks are remarkably strong and a greener alternative to synthetic fibers, which are produced by using fossil fuels. However, their silks are challenging to cultivate. Silkworms coexist peacefully, while spiders are territorial and tend to be aggressive when in close proximity.

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Over the years, researchers have endeavored to genetically engineer silkworms to produce spider fibers, aiming to harness the desirable qualities of both organisms. The primary challenge has been the size of spider silk proteins, which are significantly larger. Inserting these large genes into the genomes of other animals has proven to be a complex task.

In a recent study, Junpeng Mi, a biotechnologist at Donghua University in Shanghai, China, opted to work with smaller spider silk proteins. Mi and his fellow scientists focused on MiSp, a protein found in Araneus ventricosus, an orb-weaving spider native to East Asia. They utilized CRISPR (clustered regularly interspaced short palindromic repeats), a gene editing tool, to replace the gene in silkworms responsible for their primary silk protein with MiSp. During this process, the scientists retained some silkworm sequences in their MiSp gene construct to ensure compatibility with the worm’s internal machinery.

The MiSp gene itself is 5440 base pairs in size and encodes 1766 amino acids. The protein features repetitive amino acid sequences, which contribute to the unique mechanical properties of spider silk. MiSp also possesses N and C terminal domains, which play specific roles in the assembly and characteristics of the silk protein. The protein exhibits a predominant beta-sheet structure, as opposed to an alpha-helix structure. Beta-sheets are a secondary structure in proteins, characterized by the arrangement of beta-strands connected by hydrogen bonds, resulting in a sheet-like structure.

The beta-sheet structure is a pivotal factor in the exceptional strength and toughness of spider silk. This structure facilitates the formation of crystalline regions within the silk fibers, providing both mechanical stability and properties that render spider silk one of the strongest natural materials known.

The genetically modified silkworms carrying the spider genes produced fibers with remarkable tensile strength and toughness. The resulting fibers were nearly as tough as the strongest natural spider silk and nearly six times stronger than Kevlar.

The flexibility of the MiSp-based fibers surprised the researchers. Typically, this protein produces strong but not stretchy fibers. “But it does make a flexible fiber when you put it in a silkworm,” says Jones.

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Mi and his team aim to scale up the production of spider silk fibers for commercial use. This involves crossbreeding their specialized silkworms with commercially viable strains commonly used in large-scale silk farming. The resulting biodegradable fibers may initially find application in surgical sutures.

Jones raises concerns regarding safeguarding intellectual property rights during the commercialization process. This is likely to involve the distribution of transgenic silkworm eggs to numerous farmers. There is also uncertainty about whether the introduced genes will persist through subsequent generations of silkworm breeding.

The researchers plan to continue pushing the boundaries of spider silk engineering. They are currently exploring the possibility of modifying silkworms to produce spider silks with enhanced strength and elasticity. Mi and his team envision creating silk proteins that incorporate non-natural amino acids. This offers great potential for producing silks with unique properties. This could allow scientists to create silks that surpass the strength and toughness of materials like Kevlar.

When I first heard about CRISPR and the idea of genetically modifying living organisms, it raised many concerns for me. The notion of creating a material stronger than Kevlar in an organism smaller than my hand heightens my apprehensions. What if foreign countries exploit this technology for military purposes? What if it’s used as a biological weapon by enhancing the virulence or resistance of pathogens? What if terrorist organizations like Hamas employ this technology to further their destructive aims against the Israeli people?

Genetic modification prompts contemplation of numerous ethical concerns it may bring. If I were in a position of governance, I would impose stricter regulations, conduct more extensive long-term studies, and implement transparent labeling for genetically modified organisms. It is imperative to acknowledge that discussions about the ethics of genetic modification are ongoing and may evolve as the technology advances, along with society’s deepening understanding of genetics. Decisions in this realm should consider all potential applications that gene editing offers. Now, I ask you, what are your concerns with this technology? What problems do you think it brings? Personally, I am against this technology, and I believe there should be many legislative laws against it because of its potential impacts in the future.

Genetic modification is a powerful innovation with the potential to revolutionize and, potentially, disrupt our society. It is a tool that demands judicious use, taking into account its ethical and societal implications. Gene editing can be a catalyst for positive transformation in our world, cultivating a future that balances scientific progress with ethical responsibility. Spiders and silkworms represent just the beginning of this new frontier in scientific research.







Meeting Your Great Great Great… Grandchildren

The MDI Biological Lab along with the Buck Institute of Research on Aging have discovered cell pathways that could increase the human lifespan by 400-500%. “The increase in lifespan would be the equivalent of a human living for 400 or 500 years.” The implications this would have are immense along with some potential drawbacks, but let’s get into the science first.

The research was conducted on C. elegans, a nematode, because “it shares many of its genes with humans and because its short lifespan of only three to four weeks.” The short lifespan allows scientists to quickly see the effects of their efforts to extend the healthy lifespan. The keyword here is “healthy” because prolonging life means nothing unless you can extend the quality as well. The scientists used a double mutant in the insulin signaling and TOR pathways. The alteration in the insulin pathway yields a 100% increase in lifespan and the TOR pathway yields a 30% increase. The incredible discovery though was that when combined the new lifespan was amplified by 500%!! The expected yield was 130%.

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Here depicted is a diagram showing the meaning of a double mutant.

Researchers still say “the discovery in C. elegans of cellular pathways that govern aging, it hasn’t been clear how these pathways interact.” This discovery does lead to the mindset that the important methods of anti-aging are in the interactions between cellular pathways rather than singular pathways. This newly found interaction could also explain why scientists have had trouble discovering “the gene” the governs aging. The combinations of these treatments are described as being similar to the “way that combination therapies are used to treat cancer and HIV.”

It’s odd to picture a world where this treatment could be considered “cosmetic” in a way. Eventually, the human lifespan could expand to hundreds of years with some even living to 1000. The implications that this could have are a current problem we have of overpopulation. It is farfetched, but this would help immensely with the mission to expand into space. The ability to survive with hundreds of years on a potential “colony ship” allows humans to expand to other planets where we would be able to expand greatly. I’ll end with a question: If this treatment was 100% safe and affordable, would you get it? Why or why not?

Discovery in Worms Could Save Human Lives in the Future

A germline is the ancestry of one generation of cells to the next ones. But, scientists for a long time did not know how this has not been destroyed. Over time cell’s proteins become deformed and clump together, and this damage gets passed down to the next generation. So, in theory the germline should have already been destroyed, but it is still producing new and healthy life to this day. The question is: how?

Scientists have recently found the answer to this through studying a tiny worm called Caenorhabditis elegans. Similar to humans, these worms rely on certain genes to control their cellular division. In fact, they have a gene called daf-2 which has the ability to more than double their lifespan. After seeing this gene, scientists have realized that there are genes that are involved in repairing cells so that they do not become deformed or clumped.

Photo Source

Caenorhabditis elegans are hermaphrodites where once eggs are mature they travel to the sperm. But, the eggs have a lot of damaged proteins, only not the ones near the sperm. This led scientists to hypothesize that the sperm send out a signal to tell the egg to get rid of its damaged proteins. This signal triggers the lysosomes in the egg cells to become acidic and break down the clumps.

Even though this discovery was found on worms it could have seriously beneficial implications for humans. Stem cells also use lysosomes to get rid of damaged proteins. So this discovery could lead into learning how to treat diseases, such as Alzheimer’s Disease, to clean their aging tissue. A discovery found by studying tiny worms could lead to the answer to how to cure diseases that come with old age.

“What Does Light Taste Like?” I Don’t Know, Ask A Nematode.


by Entomology on

The vision of light is a beautiful blessing brought to us by our sight receptor cells. Since the sight of light is so great, the taste of it must be even better. Though we don’t know the taste of light, there may be a very tiny someone who does, the nematode. In the article Tasting Light: New type of photoreceptor is 50 times more efficient than the human eye, published on, it states that, at the University of Michigan, researchers have discovered a new photoreceptor amidst a bunch of taste receptor cells in nematodes and other invertebrates. This new receptor is called, LITE-1. Because of the receptor’s unusual location, it is believed that these animals have an ability to taste light. New studies have also shown that LITE-1 is no average photoreceptor.

LITR-1 was discovered in nematodes, which are eyeless roundworms only measuring about a millimeter in length. You might be thinking, “Nematodes don’t have eyes. So why would they need photoreceptors?” Shawn Xu, a senior study author who has a lab at University of Michigan Life Sciences Institute, where he is also a faculty member, demonstrated in his lab that even though nematodes are  eyeless, they still move away from flashes of light. The purpose of photoreceptors is to transform light into a signal that is usable for the body. This fact leads scientists to believe that it’s possible for that the roundworm uses this photoreceptor, located among its taste receptors, so that it can convert light into something that the worm can taste in order to perceive it. Xu also says that “LITE-1 actually comes from a family of taste receptor proteins first discovered in insects.”

Though these nematodes are extremely tiny, their peculiar LITE-1 photoreceptors are nothing to be looked over. Something that makes LITE-1 strange is that it has the astounding ability to absorb UVA and UVB light. Another unusual trait of LITE-1 is that it is unlike other photoreceptor proteins. Photoreceptors consist of two parts: a base protein and a chromophore. Breaking these two sections apart does not destroy all of their ability to function. However, LITE-1, when broken apart loses its ability to absorb light entirely.

LITE-1 also has a range possible future uses, such as being applied as a sunscreen that can absorb harmful rays or being used to promote the development light sensitivity in new types of cells. The future of LITE-1 shows great promise  and could open doors for the potential of other animals, besides invertebrates, to have a new and possibly delicious way of sensing light.



Fat Worms Show Signs of Biofuel Advancements


Image by bramblejungle on Flickr

Scientists from Michigan State University appear to have made a significant advancement in biofuel research, at least if some chubby worms are to be believed. The scientists are attempting to use a gene found in Algae involved in oil production to engineer plants that can store oil not just in their seeds but in the stem and leaves also. Biofuel production has typically focused on plant’s seeds because that is where oil occurs naturally, but plants that can be engineered to store oil throughout the entire plant could hold significantly more oil than plants that can’t.

The scientists tested their new plants by using them to feed Caterpillar Larvae. The Caterpillars fed with the oily leaves from the enhanced plants gained more weight than those fed with regular plant leaves. Christopher Benning, a professor of biochemistry and molecular biology at MSU, said “If oil can be extracted from leaves, stems and seeds, the potential energy capacity of plants may double. Further, if algae can be engineered to continuously produce high levels of oil, rather than only when they are under stress, they can become a viable alternative to traditional agricultural crops.”

With these advancements in biofuel production, how much longer do you think it will be until Biofuels finally catch up with Fossil Fuels?

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