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A new species of turtle in Texas that lived almost 100 million years ago has been classified

Analyzing the remains found at the Arlington Archosaur Site, a site with various fossil remains from the late Cretaceous period in Texas, a team of researchers described four species of extinct turtles, one of which is named after paleontologist Derek Main.

This site was discovered in 2003 and proved to be a prolific location for late Cretaceous remains, remnants of life forms that lived more than 90 million years ago. It is a wetland located near the shore of a peninsula and already in the past has provided several fossils of ancient crocodiles, dinosaurs, mammals, amphibians, fish, invertebrates and even plants.

However, the turtle fossils discovered at this site had proved quite rare, at least until this study that was published in Palaeontology Electronica. The new species was named Trinitichelys maini. It is a Baenidae turtle, an extinct group of North American aquatic turtles that lived from the Cretaceous to the Eocene era.

Of medium size, these turtles showed strongly fused bones and upper shell and lived near rivers. The Trinitichelys maini is the oldest turtle of this group found in the North American subcontinent of Appalachia, a region that during the Cretaceous period was separated from Laramidia, the western subcontinent of North America.

In addition to the new classification, researchers described three other turtles, one of which is the oldest side-necked turtle (Pleurodira order) ever found in North America. These turtles are characterized by the particular way they withdraw their heads inside their shells: they do so by bending their necks on the horizontal plane.

The other two turtles described are one belonging to the group of trionichids (Trionychidae), or soft-shelled turtles, and another belonging to the genus Naomichelys (family Helochelydridae ).

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Psilocybin produced by Escherichia coli modified with magic mushroom genes

A team of researchers at Miami University in Ohio has managed to engineer Escherichia coli bacteria to produce psilocybin, a psychedelic substance usually produced by so-called “magic mushrooms” and which in recent years is proving increasingly interesting in the treatment of people suffering from depression or other mental illnesses such as addiction.

Since mushroom cultivation can be quite difficult and can take months, it has never proved to be very practical for the production of drugs. On the other hand, the synthetic production of psilocybin itself is equally difficult and the process is very expensive. The researchers have therefore thought of modifying these microbes so that they can generate up to 1.16 grams of psilocybin per litre of culture medium. This is the highest yield to date for engineered microorganisms producing this substance and opens the door to more widespread therapeutic use.

They have in particular ensured that the Escherichia coli bacteria incorporated three genes of the fungus Psilocybe cubensis. In this way the bacteria began to synthesize psilocybin from the 4-hydroxyindol molecule.

As Alexandra Adams, a chemical engineering student at the above mentioned university and one of the authors of the study published in Scientific American, explains, the main advantage of this procedure is that it is much cheaper than all the other methods.

Currently the only limit is represented by the danger that these bacteria could also generate toxic or allergenic microbial material and the latter must be absolutely removed before any possible use of the resulting psilocybin but in any case the results seem impressive.

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Scientists discover how sharks shine green to get noticed by their mates

There are some species of sharks that in the depths of the sea seem to emit a bright green light. This is a biofluorescence phenomenon that only other sharks of their species can see.

The phenomenon of biofluorescence in certain species of sharks has never been fully studied, at least until today: David Gruber, a professor at the City University of New York, has published with his colleagues a new study on iScience to clarify this mechanism and is quite different from those who use other sea creatures to “shine”.

Gruber, along with his colleague Jason Crawford, a professor at Yale University, analyzed in particular this characteristic in two species of sharks, Cephaloscyllium ventriosum, endemic to the eastern Pacific, and Scyliorhinus retifer, endemic to the western Atlantic.

They first understood that the skin of these two sharks could present two shades, one lighter and one darker, through the extraction of particular chemical substances. They finally discovered that it was a particular fluorescent molecule responsible for the effect, a molecule that was present only in fair skin.

As Gruber himself explains, “the exciting part of this study is the description of a completely new form of marine biofluorescence from sharks – one based on brominated metabolites of small molecules of tryptophan-quinurenine.”

Thanks to this system, they can see each other better without the other animals being able to see the difference in color and in the fluorescence of the skin: “Imagine if you were bright green, but only you could see me bright green and the others could not,” reports Crawford hinting how this feature can be beneficial in many situations. In addition, scientists have discovered that these molecules that carry out biofluorescence also show antimicrobial properties.

Ore ii two scientists intend to exploit this knowledge to see if they can be useful to generate “molecular systems for imaging in the laboratory or in medicine,” according to Crawford, according to which “imaging is an incredibly important biomedical target that these types of systems could help progress in the future.”

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Mitochondria in live cells observed with unprecedented details

Currently, to look inside a living cell, optical microscopy is used because the electron microscopes are characterized by a strong heat relative to the beam of electrons they emit heat that can literally burn the object of the analysis. Furthermore, the electron microscope is characterized by a mostly two-dimensional vision.

A typology of microscopy that is advancing so much in the last few years is the fluorescence one: a molecule specially designed to be fluorescent can mark the biomolecules of the structure to be analyzed so that it can be distinguished from the surrounding environment.

The same fluorescence microscopy has undergone considerable technical progress year after year, the most important of which was that developed by Stefan Hell in the second half of the 90s when he discovered the STED microscope (Stimulated Emission Depletion), a discovery for which he then received the Nobel Prize for Chemistry in 2014.

STED microscopy uses two lasers that illuminate the same point, a complicated technology on the basis of which it has been possible to make a huge leap forward in particular in life sciences and biology in general.

A further step forward has now been made by Shigehiro Yamaguchi and Masayasu Taki, two researchers from the Institute for Transformative Bio-Molecules (ITbM) of the University of Nagoya. The two have developed a particular marker molecule, called “MitoPB Yellow”, which can be absorbed by the inner membrane of the mitochondria and which has a long life under a STED radius.

Through this new molecule, researchers were able to observe the survival and death processes of mitochondria live at unprecedented resolution, after having treated them with a particular reagent that suppresses DNA replication.

They were able to create still images with a resolution of 60 nanometers (roughly one-thousandth in the width of a human hair) and various time-lapse sequences that show how mitochondria react, within a few minutes, to a nutrient deprivation changing shape to survive.

Needless to say, being able to see how processes inside mitochondria occur in living cells could be crucial to diagnosing or even treating different mitochondrial diseases.