As A Chemist, This Entire Conversation Is Triggering My Lab Safety Nerves. Have You Geologists Heard

We were just discussing in class today in the context of ubiquinated H2B. Neat!

Ubiquitin is a regulatory protein found in most tissues of many walled-celled organisms.  Originally known as  ubiquitous immunopoietic polypeptide, ubiquitin was discovered in 1975 and its mechanism identified by a team including  Aaron Ciechanover, Avram Hershko, and Irwin Rose of the Fox Chase Cancer Center, for which they were awarded the Nobel Prize in Medicine in 2004.  Ubiquitins act as traffic control agents within the cell, directing other proteins to various compartments within the cell including tagging proteins for destruction.  

The word ubiquitin was formed in 1975 from the English adjective ubiquitous which dates only from 1837.  Ubiquitous derives from the noun ubiquitary which dates from 1580s from the Latin preposition ubi meaning where and que meaning any, also, ever.  Ubiquitary (meaning everywhere) originally referred to the Luthern doctrine that Christ is omnipresent.  

Representation of ubiquitin protein, highlighting the secondary structure. α-helices are coloured in blue and β-strands in green. The sidechains of the 7 lysine residues are indicated by orange sticks. The two best-characterised attachment points for further ubiquitin molecules in polyubiquitin chain formation (lysines 48 & 63) are labelled.

Image of ubiquitin protein courtesy rogerdodd under a Creative Commons 3.0 license, used with permission.

Geminids of the South : Earth’s annual Geminid meteor shower did not disappoint, peaking before dawn on December 14 as our fair planet plowed through dust from active asteroid 3200 Phaethon. Captured in this southern hemisphere nightscape the meteors stream away from the shower’s radiant in Gemini. To create the image, many individual frames recording meteor streaks were taken over period of 5 hours. In the final composite they were selected and registered against the starry sky above the twin 6.5 meter Magellan telescopes of Carnegie Las Campanas Observatory in Chile. Rigel in Orion, and Sirius shine brightly as the Milky Way stretches toward the zenith. Near Castor and Pollux the twin stars of Gemini, the meteor shower’s radiant is low, close to the horizon. The radiant effect is due to perspective as the parallel meteor tracks appear to converge in the distance. Gemini’s meteors enter Earth’s atmosphere traveling at about 22 kilometers per second. via NASA

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Two jets colliding can form a chain-like fluid structure. With increasing flow rate, the rim of the chains becomes wavy and unstable, forming a fishbone structure where droplets extend outward from the fluid sheet via tiny ligaments. Eventually, the droplets break off in a pattern as beautiful as it is consistent. (Photo credits: A. Hasha and J. Bush)

@sheck on Instagram. 💫🌱

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Tetrodotoxin

Tetrodotoxin, frequently abbreviated as TTX, is a potent neurotoxin. Its name derives from Tetraodontiformes, an order that includes pufferfish, porcupinefish, ocean sunfish, and triggerfish; several species that carry the toxin. Although tetrodotoxin was discovered in these fish and found in several other animals (e.g., blue-ringed octopus, rough-skinned newt, and Naticidae) it is actually produced by certain symbiotic bacteria, such as Pseudoalteromonas tetraodonis, certain species of Pseudomonas and Vibrio, as well as some others that reside within these animals.

Tetrodotoxin inhibits the firing of action potentials in nerves by binding to the voltage-gated sodium channels in nerve cell membranes and blocking the passage of sodium ions (responsible for the rising phase of an action potential) into the nerve cell.

TTX is extremely toxic. The Material Safety Data Sheet for TTX lists the oral median lethal dose (LD50) for mice as 334 μg per kg. For comparison, the oral LD50 of potassium cyanide for mice is 8.5 mg per kg, demonstrating that even orally, TTX is more poisonous than cyanide. TTX is even more dangerous if injected; the amount needed to reach a lethal dose by injection only 8 μg per kg in mice.

Check out the colors on this one!

Reverse psychology that's not in psychology. Reverse biology...?

How did you decide to do a project with RNA?

I was having a conversation with someone in our department about how useful and cheap next-gen sequencing is, and how I was considering spending out my grant on a project looking at immune gene expression in spiders. He told me flat out that I wasn’t capable of doing it, because I wouldn’t understand it enough to ever publish. So I used a kit to extract RNA, sent off the samples, read a few books in the meantime, learned to code, wrote the scripts for R and the supercomputer, then did it. I’m writing it up now, and have found some pretty cool stuff! I’m glad I learned it too, since it’s a good skill to have.

TL;DR: some asshole told me I couldn’t do it, so I decided to do it.