How to get DNA out of decades-old, pickled snakes
There are countless jars containing biological specimens floating in liquid in museums around the world.
Near perfectly preserved in a mixture of formalin – a solution of formaldehyde gas and water – and alcohol, the animals’ tissues become rubbery and rigid. But, unfortunately for geneticists, this process alters the DNA inside the cells.
“It does something called crosslinking, which binds up the DNA,” says Dr Sara Ruane, assistant curator of herpetology at the Field Museum in the US, and senior author of a study using new approaches to maximise the DNA extracted from such specimens. “If you want to study its DNA, you need to undo or try to force the DNA out from those crosslinks.”
The study focused on a rare, greenish-brown snake called the olive small-eyed snake (Hydrablabes periops). The snake is endemic to Borneo but is poorly known and there are no fresh tissue samples available, so chemically treated museum specimens are the only opportunity to determine its taxonomy.
Researchers took small samples of liver tissues from two snake specimens from 1993 and 1964, and modified DNA extraction techniques (making it hotter for longer and using more digestive enzymes) to analyse their genetics.
“The chemicals used to preserve the snakes sheared their DNA into shorter pieces of code, which made them hard to compare with longer, more complete genes from other specimens,” says first author Dr Justin Bernstein, a researcher in the Department of Biological Sciences at Rutgers University, US.
By using software to visualise the gaps in the snake’s genome and adding the data to larger, published genetic datasets, the team were able to determine that H. periops is a member of the family Natricidae.
The research has been published in Frontiers in Ecology and Evolution.
Demand for abortion medications following leaked US Supreme Court draft ruling
On 24 June 2022, the Supreme Court of the United States’ (SCOTUS) ruling in the case known as Dobbs v. Jackson Women’s Health Organization overturned Roe v. Wade – the 1973 ruling that had established a constitutional right to abortion.
This week, new research about the effects of the initial leaked Dobbs draft ruling – made public in early May – has found that internet searches for abortion medications reached record national highs, and searches were more common in US states with more restrictive reproductive rights, following the leak.
Researchers analysed Google search queries from the US that mentioned “abortion pill” or specific medication names, from 1 January 2004 through 8 May 2022.
Searches for abortion medications spiked the hour the draft was leaked online and were 162% higher during the 72-hour period following the leak compared to before. There were about 350,000 internet searches in the week of the leak (May 1–8).
“Accessible information about abortion medications should be prioritised online; including encouraging evidence-based telehealth for those seeking abortion medications,” says co-author Nora Satybaldiyeva, a doctoral student at the University of California San Diego.
Understanding how hawks land could help robotics systems
While aircraft can use runways to brake and reduce their speed after landing, birds aren’t as lucky. Instead, they have to brake before they arrive at a perch.
But slowing down to a safe speed while still in flight risks stalling and a sudden loss of control.
In a new study published in Nature, researchers have found how hawks control their flight to ensure the safest landing conditions when perching.
Four Harris’s hawks (Parabuteo unicinctus), wearing tiny retroreflective markers, were tracked flying back and forth between two perches. Their movements were recoded by 20 motion capture cameras, which allowed the researchers to reconstruct their flight paths and then use computer simulations to understand why the birds chose their particular path to the perch.
They found that to minimise stall, the hawks dived downwards while flapping before spreading their wings into a gliding posture as they swooped up to the perch. By using the right speed, and position from which to swoop up from, the birds were always safely within grabbing distance of the perch when they inevitably stalled.
“Motion capture technology has allowed us to analyse thousands of flights at a time, tackling questions that we never could have done before,” says senior author Graham Taylor, a professor in the Department of Zoology at the University of Oxford, UK.
“Looking forward this opens the tantalising possibility of understanding how animals learn complex motor tasks, like learning to fly, and of revolutionising how robotic systems can do the same.”
Health-conscious youths pay premium prices for “healthy” drinks
A study of more than 1,000 hospitality consumers from Australia and New Zealand has found that younger consumers (aged 18–24 years) are more likely than older customers to be interested in “healthy” drinks.
More than a quarter – 27% – of consumers would pay nearly double the price for drinks that contain low or no sugar, natural or no additives, or vitamins and minerals. Those who ate out at least once per week were inclined to pay more for healthy drinks, and those who ate out more often were willing to pay a larger premium.
These findings have implications for the restaurant sector as it shifts back into gear after being hit hard by the pandemic.
The research has been published in PLOS One.
The most distant galaxy rotation ever observed
The most distant galaxies telescopes can detect are some of the earliest to have formed in our universe. They recede away from us as the universe expands, and the further away a galaxy is, the faster it appears to move away from us.
Now, according to a new study published in the Astrophysical Journal Letters, astrophysicists have detected the most distant rotating galaxy ever observed (MACS1149-JD1).
Scientists can estimate how fast a galaxy is moving, and when it was formed, based on how “redshifted” its emissions appear. By measuring small differences in the redshift from position to position inside the galaxy, they were able to determine that JD1 is rotating at about 50 kilometres per second (the Milky Way rotates at 220 km/s).
“The rotation speed of JD1 is much slower than those found in galaxies in later epochs and our Galaxy, and it is likely that JD1 is at an initial stage of developing a rotational motion,” says co-author Akio Inoue, a professor in the School of Advanced Science and Engineering at Waseda University, Japan.
These findings provide further insight into understanding the process of galaxy formation in the early universe.
Imma Perfetto is a science journalist at Cosmos. She has a Bachelor of Science with Honours in Science Communication from the University of Adelaide.
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