A new technique to light up nerve cells in living tissue – including the dense tangle of nerve endings just beneath skin’s surface – is giving an unprecedented view of the way our sense of touch works. The technique involves genetically engineering lab mice so that their nerve cells produce a protein called SNAP, then injecting a fluorescent dye that selectively sticks to SNAP. “This is my favourite image – we’d never seen anything like this until we used this technique,” says Paul Heppenstall from the European Molecular Biology Laboratory in Monterotondo, Italy, who developed the technique. “It shows that free nerve endings [red] in the skin split into an incredible number of branches.” Labelled in blue are the nuclei of the skin’s cells.
Frozen in place
This frozen baby woolly rhinoceros looks like it died yesterday, but it’s 10,000 years old! It’s the best specimen ever found. Sasha’s remains were so well preserved in Siberia’s permafrost that an ear, an eye, a skull, a set of small horns and most of its fur are intact. If its DNA is intact too, scientists will be able to learn more of this animal’s secrets.
Scientists have discovered a tiny frog – only 23 millimetres at best – in the Andes in Ecuador that changes its skin texture from spiny to smooth in minutes. The “mutable rain frog” (Pristimantis mutabilis) is the first shape-shifting amphibian ever found. The discovery was reported in the Zoological Journal of the Linnean Society.
It was first seen by Katherine Krynak, a biologist, and Tim Krynak, a naturalist, in 2006 on a routine survey of a protected area, Reserva Las Gralarias. At first they didn’t recognise it as a new species. Then in 2009, the Krynaks finally found another specimen and put it in a small plastic cup overnight. But when Katherine Krynak opened the cup the next morning, the frog’s spines were gone. Thinking she had nabbed the wrong frog, she added moss to the cup to make it more comfortable until they could return it to the forest that night. When they next checked, the Krynaks were astonished to see the frog’s spiny skin texture had returned.
The surface of our skin is a chemical wonderland. That’s what Pieter Dorrestein at the University of California, San Diego and colleagues found when they took multiple skin swabs from two volunteers to chart their chemical and microbial diversity. The chemical diversity of their skin is represented here on these colourful dot maps – ranging from low (blue) to high (red).
So where do all these chemicals come from? Skin cells and microbes make them and many come from the products we smear on ourselves. But chemical reactions that take place on the skin also create new compounds. More than 80% of the molecules on the volunteers’ skin did not match known compounds, the research showed. Of those molecules that could be identified, ingredients from the volunteers’ hygiene and cosmetic products dominated many areas – even though the volunteers had not applied these products, or even showered, for three days before the study. The researchers will use these maps to see how chemicals affect the make-up of microbes on the skin. The study was published in the Proceedings of the National Academy of Sciences.
See the full gallery here: Charting the molecular diversity on human skin
The ocean’s secrets
Australian scientists have created the first digital map of the ocean floor’s composition. The last hand-drawn map of this type was made in the 1970s.
“In order to understand environmental change in the oceans we need to better understand what is preserved in the geological record in the sea bed,” says lead researcher Adrianna Dutkiewicz from the University of Sydney. Published in the August edition of Geology, the map reveals the deep ocean basins are more complex than previously believed. “The deep ocean floor is a graveyard with much of it made up of the remains of microscopic sea creatures called phytoplankton which thrive in sunlit surface waters,” says Dutkiewicz. “The composition of these remains can help decipher how oceans have responded in the past to climate change.”
For instance a special group of phytoplankton called diatoms produce about a quarter of the oxygen we breathe. The new map show diatom accumulations on the sea floor are nearly entirely independent of diatom blooms in the Southern Ocean. More research is needed to better understand the relationship (see here: Lab talk: another reason to save the whale).
Why do these corals glow?
When biological oceanographer Jörg Wiedenmann from the University of Southampton shone a torch light on corals living 50 metres under the Red Sea he was amazed to see them glow intensely in a range of colours. Given the light barely reaches these corals why do they respond to it? The question has researchers scratching their heads. Wiedemann published his deep-sea discovery in the journal PLOS ONE in June.
Learn more about them here: Glowing corals discovered deep in the sea