Showing posts with label Japan. Show all posts
Showing posts with label Japan. Show all posts

Friday, June 3, 2011

GIANT SQUIDS!!!!

First-ever observations of a live giant squid in the wild.

Kubodera T, Mori K.

The giant squid, Architeuthis, is renowned as the largest invertebrate in the world and has featured as an ominous sea monster in novels and movies. Considerable efforts to view this elusive creature in its deep-sea habitat have been singularly unsuccessful. Our digital camera and depth recorder system recently photographed an Architeuthis attacking bait at 900 m off Ogasawara Islands in the North Pacific. Here, we show the first wild images of a giant squid in its natural environment. Recovery of a severed tentacle confirmed both identification and scale of the squid (greater than 8 m). Architeuthis appears to be a much more active predator than previously suspected, using its elongate feeding tentacles to strike and tangle prey.

Proc Biol Sci. 2005 Dec 22;272(1581):2583-6.

NOTHING IS COOLER THAN THIS!!
 My heart is a big place where I keep feelings for my parents and brothers with the VIP room reserved for my wife. Secretly, I keep a second VIP room that holds my feelings for things like giant squids. Deep down, I know that if I dove into the ocean and swam around, a giant squid would show up and tell me the profound secrets of the deep. I would grab its tentacle and it would take me to a magical world where human fingers are used as currency and the Void calls to us all.
 As you can read from the abstract, the researchers were able to record a giant squid hunting and that is really cool. The particular squid that they observed was about 8 m long! To put that into real numbers, you would need 4.2 John Waynes to get the same length as the giant squid!
 When I think of giant sea creatures, I am reminded of the most devastating creatures ever:
STARRO!!!
 Starro is a gigantic starfish thing that floats in space until it reaches an inhabited planet. When it gets to the planet it releases tons of little Starros that begin feeding on the population to create more gigantic Starros.
Recently, Starro was revealed to be controlled by an alien that had subjugated the Starro queen, but I will not show it because it does not have the visual appeal of a gigantic starfish.

Thursday, March 10, 2011

Review: Transfer of carbohydrate-active enzymes from marine bacteria to Japanese gut microbiota

 When people think about human evolution they usually consider big changes like multiple arms or extra eyes, but the reality is that there are many small changes long before any major change. These small changes occur in our genetic material and can have numerous effects, such as allowing us to process alcohol faster as is the case in alcohol dehydrogenase in peoples of European descent versus peoples of Asian descent. This paper is interesting because evolution is occurring and is opening new food sources to humans, but the thing changing is the genetic material of the microorganisms that live in our gut.
 So, a few words about microorganisms. They are single celled and the term "microorganism" can apply to archaea or bacteria, but for this paper it is bacteria. Humans have 23 chromosomes and two of each of them in each cell except for red blood cells, which don't have any genetic material. The totality of these chromosomes is the human genome. Bacteria only have one chromosome, but some, possibly many, can accept small pieces of DNA from other bacteria. These transferable pieces of DNA are called "plasmids." The transfer of plasmids is responsible for antibiotic resistant strains of Staphylococcus aureus which plague hospitals. This process of transferring plasmids is called "horizontal gene transfer." Many types of bacteria have an outer barrier which is composed of long strings of sugars usually D-galactose or some variation of it. Lastly, bacteria exist everywhere. Every square inch of everything has something growing on it or ready to grow on it should nutrients become available on aforementioned it.
 Now to the paper at hand. The researchers were initially interested in finding enzymes that can breakdown seaweed to its component sugars. By the way, seaweed is a collection of bacteria that grow together and their sugar barriers blend together. The researchers wanted to see what bacteria can eat that sugar barrier and what enzymes are used in that task. To do this they took the sequenced genome of Zobellia galactanivorans and used a computer program to search for genes which code for enzymes most likely to degrade the long sugar chains of seaweed. There search found five genes. Enzymatic analysis showed that only two could degrade seaweed, with Porphyra, commonly known as "nori," being preferentially degraded. These are the first "beta-porphyranases described so far" and represent "a new class of glycoside hydrolases."
 From here, the researchers crystallized those enzymes and identified the features that would allow them to find other enzymes that can degrade nori using the many publicly available sequence databases. During this data mining, they found that all beta-porphyranases were found in marine microorganisms except Bp1689, which is found in the human gut bacterium Bacteroides plebeius.  Curiously, all sequences of B. plebeius are from bacteria collected from Japanese individuals. Genomic sequences of B. plebeius strains collected from western people didn't contain the beta-porphyranase.
 I should give an additional word about microorganisms and their genetic material, they have operons. Operons are genes in very close proximity (<100 basepairs apart) that are part of a metabolic pathway. When studying bacteria, operons are very convenient because they can provide valuable clues about an enzyme's function. The paper, under discussion now, compared the operon of the beta-porphyranase from B. plebeius from Japanese individuals to B. plebeius from western individuals and found many of the former genes to be missing in the latter. Interestingly, the operon from B. plebeius from Japanese individuals is situated between conserved genes coding for "conjugative DNA transfer," suggesting horizontal gene transfer.
 Summing it all up, Z. galactanivorans evolved a beta-porphyranase to degrade nori. Nori is eaten by Japanese people who initially could not digest it. Over the years, the plasmid containing the operon that codes for nori degradation was transferred to B. plebeius in the gut of Japanese people. This allowed Japanese people to eat nori and get some nutritional value out of it. "Tax records from the eighth century list seaweeds as payments to the Japanese government" and since seaweed is not cooked this allows for live bacteria to enter the system.