The Blog of Bioscience!

but not this Calostoma cinnabarinum?

It’s hard to pick just one as there’s so many, and it depends on what you define as “strange looking” but the first one that comes to mind that I’m always blown away by are Brazilian Treehoppers (Membracidae)

About 15 years ago, UNC Lineberger’s Dale Ramsden, Ph.D., was looking through a textbook with one of his students when they stumbled upon a scientific mystery.

A small line in the book indicated that a protein that helps repair major breaks in our genetic code did so by adding DNA, or deoxyribonucleic acid, as expected. However, there were hints that it could also add RNA, or ribonucleic acid, at least in a test tube. It seemed unlikely that this would occur during repair of DNA in living cells, since RNA is normally used only as a messenger to carry information from the genetic code to make proteins.

“You would think they must only add DNA during repair of our genetic code, because that’s the core of the central dogma of life; genetic information has to be DNA all the time,” said Ramsden, who is a professor in the UNC School of Medicine Department of Biochemistry and Biophysics. “That’s the way it’s supposed to be. That’s what we’re taught in school.”

Fast forward to today, as the Ramsden lab publishes a major study in the journal Science showing that in living cells, this protein, which is a type of genetic repair and replication tool called a polymerase, most often adds RNA when fixing major breaks in our DNA genetic code. Their research also revealed surprising insights into why RNA is used.

Bug of the Day

Herbarium of France; (Fungi of France)

Sporozoites of the parasite Cryptosporidium parvum emerging from their oocyst to infect gastrointestinal epithelial cells.

Cryptosporidium, commonly known by the comic book supervillian name “Crypto,” is transmitted by ingesting water or food contaminated with Crypto oocysts. Once ingested, the oocyte ruptures, and the sporozoites contained within infect the gut of their new host, causing watery diarrhea. 

Though outbreaks occasionally occur in the developed world, few infected in those outbreaks die from Crypto. However, in the developing world, some of those infected with Crypto develop chronic disease and die, particularly small, malnourished children.

For more on Crypto and how scientists are tackling this tricky parasite, check out this article on NPR’s All Things Considered about the work being done by the Striepen lab at the University of Georgia Center for Tropical and Emerging Global Diseases.

Dinoflagellates! These bizarre microorganisms are found all over the ocean, and occasionally freshwater lakes and ponds. Some are photosynthetic, some are predators, some are both! They are also the plankton responsible for toxic red tides. 

The first two pictures show Pyrocystis dinoflagellates.  These are closely related to the dinoflagellates that bioluminesce a bright blue along coastal waters. In the top picture, you can see a cell dividing its nucleus into two, as well as some sort of protective cyst in the lower right corner.

The 3rd picture is a bloom of Gymnodinium dinoflagellates, and the last picture is a close-up. See the nucleus?