The Great Green Jellyfish

So two weeks ago we looked at an aquatic salamander that had the incredible ability to regenerate lost limbs and even other parts of its body.  This week we will be taking a look at another aquatic animal, but this one chooses to make its home among the salty ocean waves rather than the tranquil freshwater lakes that the Axolotl loved.

This Jellyfish’s Life is Crystal Clear

The Crystal Jellyfish.  Image from David A. Hoffman (flickr.com)

The Crystal Jellyfish. Image from David A. Hoffman (flickr.com)

The Crystal jellyfish (Aequorea victoria) makes its home in the ocean waters along the coast of the Northwest United States and has a rather important role to modern biological science.  But before I delve into the explanation of this organisms’ importance to science, let’s take some time to learn about it first.

As I stated before, this animal is a jellyfish and is found in the ocean waters along the coast of California all the way north to British Columbia, Canada.  These little jellyfish range from 3-10 inches in diameter and comes, like most jellyfish, with a set of stinging tentacles.  These tentacles are used to paralyze and capture its prey, which include copepods (small crustaceans), plankton and other kinds of jellyfish.  If you know anything about jellyfish, then this is all fairly standard.  So what is it about the Crystal Jellyfish that sets it apart and makes it helpful to scientists?  Well, it has to do with a little thing called bioluminescence.

Biolumi-What?

I know that bioluminescence is a big word, but essentially all it means is that the organism can produce its own light.  Think of the fireflies that you might see in the summertime; the yellow-green light that they produce is an example of bioluminescence.  The Crystal Jellyfish produces two kinds of light, blue light and green light, which are created by an intricate reaction between Calcium ions, and two proteins called aequorin and green fluorescent protein (GFP).

When the jellyfish releases stored calcium ions, these ions bind to the aequorin protein which then causes it to produce a blue light.  The blue light produced by the aequorin protein then activates the green fluorescent protein, which then produces a bright green light.  Crudely, you can think of it along the lines of a glow-in-the-dark ball.  In order to get the ball to glow green, you first need to shine a light on it, much like how the green light isn’t produced in the jellyfish until a blue light hits the protein.

In the short video below, you can see both the blue and the green light produced by the jellyfish.  The blue light is emitted from the majority of the jellyfish’s body while the green light only appears around the rim.

The bioluminescence is activated when the jellyfish are in stressful situations, serving as an anti-predator defense.  Perhaps the bright colors scare away most predators or at the very least confuse them long enough for the jellyfish to disappear into the ocean depths.  It is this green fluorescent protein- GFP for short- that scientists have adapted for use in biochemical, cellular and genetics research.

GFP and its Applications

GFP highlighting the cell membrane of a zebra fish embryo.  Image from Wellcome images (flickr.com)

GFP highlighting the cell membrane of zebrafish yolk cells. Image from Wellcome images (flickr.com)

GFP is used as a biological tracker or highlighter in a cell.  Essentially, scientists attach the gene for GFP to the end of a gene in a cell that codes for a protein they are interested in.  The GFP will follow the protein of interest through the cell or organism and by fluorescing the GFP, scientists can identify where the protein travels.

For example, let’s say that a scientist attaches the GFP gene to the end of a gene that makes a protein which is a part of the cellular membrane.  When the gene creates the cellular membrane protein, the GFP will also be made and will be attached to the membrane protein.  Therefore, scientists can then shine a blue light on the cell which causes the GFP to fluoresce, thus revealing the outline and location of the cell membrane.

GFP derivatives.  Image taken from ZEISS Microscopy (flickr.com)

GFP derivatives. Image taken from ZEISS Microscopy (flickr.com)

While this may seem like a very abstract discovery, the implementation of GFP and now it’s many variously colored derivatives has led to an indescribable expansion of the limits of the scientific research.  One study states that “the green fluorescent protein (GFP) from the jellyfish Aequorea victoria has vaulted from obscurity to become one of the most widely studied and exploited proteins in biochemistry and cell biology.”  That study was from 1998, only 3 years after its first use in a scientific experiment.  Since then GFP has been used for such things as:

  • Tracking protein movements within cells
  • Creating fluorescent plants and research animals
  • Understanding the differences between cancer cells and normal cells
  • Creating images of cellular and tissue structures

The GFP has been so vital to modern biochemical research that in 2008, the Nobel Prize for Chemistry was awarded to Dr. Osamu Shimomura, Dr. Martin Chalfie and Dr. Robert Tsien, the three scientists who first discovered and isolated the protein from the Crystal Jellyfish.

Final Remarks

So, jellyfish are much more than lean, mean stinging machines.  They have provided us with one of the most important biological compounds to research in recent years and opened new avenues for scientific exploration.

Until later,

MGB

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The Lucky Horseshoe(crab)

A Crab it is not

While it has the name crab, a horseshoe crab is not in fact a crustacean.   In reality, horseshoe crabs are closely related to spiders and scorpions, despite a few extra legs.  As you can see in the picture below, horseshoe crabs have a tough exoskeleton that protects their underbelly which houses their legs, mouth, and gills.  The eyes, which are only adept as sensing light, are actually located on top of the shell.

Images taken from http://tinyurl.com/mvfpkjx and http://tinyurl.com/lj4xeph

Dorsal and ventral halves of a horseshoe crab.  Images taken from http://tinyurl.com/mvfpkjx and http://tinyurl.com/lj4xeph

Horseshoe crabs are often called a “living fossil” because they originated from a very ancient lineage of organisms.  Fossils of ancient horseshoe crabs, which are shockingly similar in appearance to the modern day species, have been found dating back over 250 million years ago and some even longer; that’s long before the time of the dinosaurs!

Image taken from http://tinyurl.com/mx2z5mv

Fossil of an ancient horseshoe crab. Image taken from http://tinyurl.com/mx2z5mv

The horseshoe crabs of today can live for about 17 years, able to reproduce around year 9 or 10.  They spend most of their life crawling along the ocean floor, eating mollusks, worms and sometimes small fish.

So now you’re probably thinking, “Ok, horseshoe crabs have been around for millions of year, how could they possibly be helpful to humans?”  Well, they are helpful to people because of their blood!

The Blue Blooded Hero

Horseshoe crab blood is fairly different than human blood.  While ours is iron-based and consequently red, horseshoe crab blood is blue because it is copper based, which is considered to be a more primitive blood system.  However, the fact that their blood is blue is not important, rather, it’s what is in the blood that matters most!

The blue blood of the horseshoe crab.  Image taken from http://tinyurl.com/pl92fry

The blue blood of the horseshoe crab which contains LAL.  Image taken from http://tinyurl.com/pl92fry

Because horseshoe crabs are an ancient species, they lack a fully developed immune system like that of humans and other mammals.  Therefore, horseshoe crabs rely on chemicals released by amoebocytes (their version of blood cells) to fight off the many bacteria and viruses that they are exposed to in the ocean, because if you did not already know, ocean water is filthy.

 

The main chemical defense in a horseshoe crab’s immunological arsenal is called Limulus Amebocyte Lysate(LAL), a compound that binds to and forms clots around bacteria, viruses, fungi and bacterial endotoxins that infect the horseshoe crab.  Humans have been able to put this protein to good use.

How a Horseshoe Crab has saved your Life

Humans have taken LAL from horseshoe crabs and found ways to utilize it in the pharmaceutical industry.  Specifically, this helpful compound is now used to detect bacterial contamination in many pharmaceutical products ranging from drugs and vaccines to medical devices such as needles.  In addition to ensuring that these products are sterile, LAL can be used to verify that the products are non-toxic because of its ability to bind to endotoxins.

Electron microscope image of E. coli bacteria.  Image taken from http://tinyurl.com/mnpej6n

Electron microscope image of E. coli bacteria. Image taken from http://tinyurl.com/mnpej6n

Endotoxins are fever inducing toxic compounds produced by gram-negative bacteria, such as E. coli, that can be extremely harmful to humans.  Generally, bacteria coexist peacefully with humans and we never have to worry about getting sick from them.  However, occasionally an environmental change or an introduction to the human blood stream can turn a typically harmless bacterium into a pathogen that can cause disease, such as meningitis.

Therefore, the importance of LAL in producing safe pharmaceutical products cannot be undervalued.  Think of all of the drugs you have taken or all of the shots you have received in your lifetime.  I bet you can’t even count them all and so, if you think about it, you really owe the horseshoe crab a lot, and maybe even your life.

Final Remarks

Kabuto, a Pokémon based off of the horseshoe crab.  Image taken from http://tinyurl.com/qhmpjnx

Kabuto, a Pokémon based off of the horseshoe crab. Image taken from http://tinyurl.com/qhmpjnx

Horseshoe crabs are considered living fossils, having been around for millions of years, and I find it truly amazing that humans have been able to develop such an important medical test from a protein found in their blood.  However, it is unfortunate that in recent years the horseshoe crab numbers have begun to dwindle due to various factors ranging from over-harvesting to the increase in shorebird populations.

Still it seems likely that an increase in awareness of their ecological importance and also utility to humans will help to fuel conservation efforts.  Perhaps even the fact that a Pokémon was based off of the horseshoe crab, albeit one of the original 150, will help people to care about this incredible and valuable organism.

Until later,

MGB

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Regeneration is the name of the game for the Axolotl

What is the world is an Axolotl?

Next up on our exploration of animal adaptations and human applications, we have the axolotl.  What is an axolotl you may ask?  Well although it might look like an alien (E.T. anyone?), it is actually an amphibian, specifically a salamander.

They look fairly similar, don't they?  http://tinyurl.com/pxcuszj  http://tinyurl.com/p95xpzz

They look fairly similar, don’t they? (http://tinyurl.com/pxcuszj ; http://tinyurl.com/p95xpzz)

Now, for those of you that are familiar with salamanders, you may think that the axolotl looks a little atypical.  Well you are right, because the axolotl is special in that it retains larval characteristics (gills, fully aquatic lifestyle) into adulthood unlike most other salamander species.  These aquatic salamanders are native to Mexico, and unfortunately due to immense pollution, are nearly extinct in the wild.  However, there are many axolotls thriving in captivity and so this species is not going anywhere anytime soon.

Regeneration?

Regeneration as per Iron Man III (http://tinyurl.com/q732szg)

Regeneration as per Iron Man III (http://tinyurl.com/q732szg)

As you can see from the picture, the axolotl is a happy little fellow.  Behind that innocent, smiley little face hides an incredible power, the power of regeneration.  Now, the regeneration I’m talking about isn’t as dynamic as that from Iron Man III or even the new Wolverine movie, but it is still rather incredible!

Axolotls can re-grow most parts of their bodies, ranging from limbs to even parts of their brains and CNS.  The process takes some time, but it is very powerful, restoring the missing body parts and leaving minimal to no scar tissue behind.  One caveat, at least with the regenerated limbs, is that they are not as strong as the original.

How does regeneration work?

While we know that axolotls are really good at regeneration, we still don’t know exactly how this process works.  We do know some things, however.  For example, when a limb is cut off, scientists are aware that a mass of stem cells called a blastema forms at the site of the injury.  These stem cells are rather interesting because they retain a “memory” of the tissue from which they came.  This means that when something like an arm gets bit off, these cells “know” how to divide to reform the missing parts of the limb, including all of the digits of the foot.

Scientists have even shown that if you remove the blastema and place it elsewhere on the axolotl, you can grow limbs in strange places.  This process is slow, often taking about a month, but is fairly accurate.  Interestingly, humans have some degree of regenerative ability too, but it tends to wane with age, unlike the axolotl which maintains its impressive regenerative abilities throughout its lifetime.

Graph showing that axolotls retain their regenerative properties throughout their lives while those of frogs and humans taper off after reaching a certain point.  Graph taken from http://www.sciencedirect.com.ezaccess.libraries.psu.edu/science/article/pii/S0531556508002933#)

Axolotls retain their regenerative properties throughout their lives while those of frogs and humans taper off after reaching a certain point. Graph taken from http://tinyurl.com/nxtm5h4

While scientists know that this blastema forms, there is still a lot more to learn about the process.  Very recently, scientists learned that macrophages (a component of the immune system) are essential to the regeneration process.  If all of an axolotl’s macrophages are experimentally removed, the regenerative process is halted.

Human Applications

Obviously we still have a lot to learn about the ins-and-outs of the regenerative process of the axolotl, but in the meantime we can still postulate the applications.  This review of recent axolotl research gives a nice overview of many of the recent findings and potential applications of mastering regenerative abilities.

A U.S. soldier with a prosthetic leg sits upon a stage.  http://images.politico.com/global/2012/04/120404_amputee_soldier_reuters.jpg

A U.S. soldier with a prosthetic leg sits upon a stage. http://images.politico.com/global/2012/04/120404_amputee_soldier_reuters.jpg

The first obvious application is to amputees.  If the secrets of regeneration can be unlocked, then amputees would be able to regrow their limbs, eliminating the need for prosthetics.  Think of all of the soldiers that could benefit from re-growing an arm or a leg.

Furthermore, since axolotls show some ability to regenerate brain and nerve tissue, we may one day use regeneration to cure neurodegenerative disorders.  Perhaps the cure to Alzheimer’s or Parkinson’s disease lies in the regenerative properties of the axolotl?  Maybe unlocking the secrets could help paraplegics and quadriplegics to walk again?  Even beyond neurodegenerative disorders, regeneration could assist with organ failure or diseases such as osteoporosis.

What it will look like

Scientists envision some sort of solution which can be applied to amputated body parts or injected into the brain or damaged nerves or organs that could stimulate regeneration, thus restoring functionality.  How strange to think that someday you might be able to just rub a paste onto your amputated limb and in a few months time, you have an arm or a leg back.  Obviously we are still a far ways off from being able to re-grow human limbs, but each day we get closer to this inevitable future.

Oh and one last thing.  In addition to being able to regenerate limbs, the axolotl also doesn’t get cancer.  So just in case it wasn’t awesome enough for you already, there’s that.

Until later,

MGB

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Slime Time Live with the Hagfish

The aptly named hagfish is the next organism to be examined in my search for animal adaptations with human applications.

Why the Hagfish?

Hagfish

A hagfish twisted up into a knot. Image borrowed from http://tinyurl.com/3zzamc6

Now what might this terror of the depths, which looks more like a worm than a fish, have to offer humans?  Could it taste incredible with a side of chips?  Perhaps it produces a chemical that cures athlete’s foot?  Maybe its skin can be used to create moisturizers.  Well, none of these guesses are correct.

Hagfish are useful to people because of their slime!

You might be thinking, slime that sounds gross, why should I possibly care about slime? Much like the spider silk I talked about in my first blog post, the slime of the hagfish is protein-based, eco-friendly, and could have various applications in the medical field or textile industry.  However, this glorious slime doesn’t come without its drawbacks.

The slime is produced upon a reaction with water.  Image borrowed from http://caitbiology.wikispaces.com/Hernandez-+hagfish%28Myxinidae%29

The slime is produced upon a reaction with water. Image borrowed from http://tinyurl.com/o2uvyln

The Problems of Hagfish Slime

One of the problems of working with hagfish slime is converting the slime into a useable form.  Apparently, it’s challenging to make clothes from the giant gooey blob that forms when hagfish slime comes into contact with water (see image to the left).  However, some scientists have begun to experiment with converting this goo into a more usable form.

A group of researchers from McMaster University, Dalhousie University and the University of Guelph in Canada performed a study in which they tested various methods of converting this hagfish slime into threads and fibers that could be more easily manipulated.  They tested the tensile abilities and flexibility of their creations with hopes of eventually finding a cheap and effective method of producing hagfish slime threads.   Science Daily published a nice article summarizing the major points of research paper.

I’ve talked about the human application of slime, but I guess I haven’t really mentioned the animal adaptation aspect yet.

Hagfish are friends, not food.

So why does the hag fish have the slime in the first place?  Let’s think: the hagfish is small, has poor eyesight and doesn’t appear to be very fast.  If a predator comes along and tries to eat it, what does it do?  Well, it slimes its predators in the mouth.

Take a look at the below video of a hagfish fending off a few different predators including a shark!

http://www.youtube.com/watch?v=4ZsZweUjfjo

Look at the shark’s mouth 6 seconds into the video to see the slime in action!

When attacked, the hagfish produces a mouthful of slime that gums up the mouth and gills of any potential predators, effectively forcing them away and allowing the hagfish to go on with its business.  The hagfish only needs to produce a small amount of slime to create a giant gooey mass in the water, as the video below clearly shows:

Just imagine how you would react if the next time you went to bite down on a pretzel, your whole mouth filled up with sticky caramel or bubble gum.  You might want to stop eating pretzels for a while, that is, if you even survive.

Final remarks

Hagfish slime may become the fabric of the future.  Who knows, perhaps one day the entire world may wear clothes made of hagfish slime and spider silk.  Think about it.

Until Later,

MGB

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The Spider’s Secret

What is the Spider’s secret and what does it have to do with humans?  You’ll just have to keep reading to find out!

Spiders are more than just 8-legged Monsters

Courtesy of http://www.cracked.com/funny-1934-spiders/

Courtesy of http://www.cracked.com/funny-1934-spiders/

So I know that most people have an inherent aversion to these creepy-crawlies and think of them just like the image from cracked.com.

However, spiders have a lot to offer.  Typically a source of fear, spiders perform many useful functions such as eating other insects, specifically of those pesky house flies and mosquitoes.

Recently however, scientists have recognized the importance of another spider ability; silk production.  Spider silk is an incredible bio-material, it’s made of proteins, and is far more complex than you may imagine.

The Spider’s Sexy Silk

How many of you knew that each species of spider can make seven different kinds of silk?  I was unaware until I watched an intriguing TED Talk about the complexities and beauty of spider silk.

The silk’s most appealing properties are its immense flexibility coupled with its great strength; spider silk is about five times as strong as piano wire when taking into account weight.  If you are sitting there thinking, “Huh, that doesn’t sound very strong”, then watch the below video of a spider ensnaring a bat in its gossamer web, perfectly demonstrating these two properties.  And yes, I did say a bat.

Why should I Care?

So you are probably thinking by now, “Well why should I care about spider silk?  It’s cool and all, and this guy has been talking about it for a while, but what can it do for me?”   Well as it turns out, many scientists study spider silk to find ways of utilizing its unique properties to benefit humans.

Recently, a group of scientists from Florida State University published a research paper which explores how spider silk could be the next big thing in electronics.  For those of you, myself included, who don’t really enjoy scientific papers, you can read a lovely summary of the research paper from Science Daily.

For now, you should know that when spider silk and carbon nanotubes combine, you get a stellar material that can perform a variety of functions ranging from a humidity sensor to an electrical wire.  Best of all, compared to current materials, spider silk is extremely eco-friendly meaning that once spider silk can be mass-produced, electronics will likely be much cheaper AND greener, both saving you money and saving the environment!

Outside of the realm of electronic devices, spider silk has found many other uses including the creation of bullet proof material, ropes, nets and even bandages.  So, what spiders use to catch prey can be adapted by humans to make our lives easier!

So what is the Secret of the Spider?  If you didn’t figure it out by now, it’s their silk!  So I hope the next time you walk into a cobweb or go to clear one out of the corner of your room, you hesitate for a moment and appreciate its complexity and value before tearing it down, if you even choose to at all.

Until later,

MGB

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