DNA •

Human DNA Is Not That Human

March 23, 2016 By James Faulkner Leave a Comment

Our DNA might contain ancient virus DNA

STATES CHRONICLE – We know that DNA is what makes us who we are: humans, our parent’s children, our siblings’ sibling, our children’s parents and so on. But according to a new study, what we previously thought that makes us human might actually be less human. More precisely, researchers have managed to find 19 new pieces of non-human DNA.

The study was conducted by a team of scientists at the University of Michigan on 2,500 subjects. Their findings suggest that the non-human DNA pieces are remains of viruses which have infected our human ancestors probably some hundreds of thousands of years ago.

The fragments of non-human DNA were compared to a “reference” human genome and this is how scientists figured out where the viral pieces have come from. What is not yet known is whether this strand of virus DNA can replicate or reproduce. However, other studies have showed that this ancient virus DNA could affect people who carry it.

Other studies have tried linking these viruses to cancer and other disease but without success as researchers haven’t been able to find all of the ancient pieces of DNA yet. However, the new discovery gives more insight on human evolution and shows us that we might not be as human as previously thought.

The researchers have been looking at genomes of people from all over the world, including Africa, where our first ancestors lived before relocating to other parts of the world. But the virus DNA was only found in 50 of 2,500 people, which means that although the finding proves our DNA is not only human, more studies must be conducted on a wider subject range, in order to get more conclusive results.

To give you a better idea of how we are not that human, you should know that according to estimates, about 8 percent of our DNA comes from viruses. The study provides information on how human DNA evolved along with virus DNA. This has certainly raised curiosity among scientists and will lead to further research which should eventually show exactly what our DNA is made of and whether it contains DNA not only of viruses but other organisms as well.

Image source: www.bing.com

World’s Longest-Distance Flyer is a Dragonfly

March 3, 2016 By Janet Vasquez Leave a Comment

The Pantala Dragonfly can fly over 4,400 miles

STATES CHRONICLE – Most flying insects usually stay around their home, without flying too far, except if they are migrating. And even if they do fly farther, they need to rest from once in a while. After all, they are very tiny and have small, fragile wings which cannot get them too far.

There is, however, an insect that can fly far although it is only an inch and a half long, the dragonfly Pantala flavescens. According to the latest research, the dragonfly broke the world record for the longest insect flight, more than 4,400 miles which is almost twice as long as the prior record set by the monarch butterfly, which flies about 2,500 miles, when it migrates across North America.

Not only is the dragonfly impressive, but the study is also impressive as it is the first in which researchers used DNA to find how far a dragonfly can travel. How exactly they used DNA to measure that? Well, they didn’t measure the distance per say, but rather saw that the genes of the dragonflies were not pure American Pantala or pure Japanese Pantala, but they were mixed up.

Having mixed DNA meant that the insects travel around the world, and breed with dragonflies from different areas, creating thus a common gene pool worldwide. What makes the long travel of the dragonfly so incredible is that the tiny insect cannot carry much “fuel” to power its trip.

Birds are usually the ones that carry fat so they can power up for the trip. When it comes to the dragonfly, its amazing flight abilities reside more on their body’s design and their technique. They use the wind to carry them, gliding for long periods, so they don’t constantly flap their wings.

The reason they fly for such long distances is that they follow the weather, going from regions with a dry season to regions with a moist season, every year. They also need to be near a freshwater source as they need it for reproduction, laying their eggs in freshwater pools.

Once the eggs hatch and the babies are mature enough to fly, which happened in only a few weeks, they join the swarm and fly away.

All in all, the flight of the dragonfly is pretty impressive for such a small insect, but they do have a certain technique which helps them go on for a long time, without the need to rest.

Image source: www.bing.com

Scientists say real shape of chromosomes is not X

September 28, 2013 By Janet Vasquez Leave a Comment

Now it’s time to revise the high school biology textbooks as a new study says the shape of X-chromosomes is not X, as it is believed, but somewhat like ‘O’.

The new finding says X-shaped chromosomes are in fact much more complex and look much messier. That’s the finding of a new project that relied on DNA sequencing to produce accurate 3D images of chromosomes.

Scientists say, the first 3D models of chromosome structure have overturned a long-held belief about their shape – the X chromosome looks nothing like an X!

Scientists at the Babraham Institute in UK, working with the University of Cambridge and the Weizmann Institute, have produced beautiful 3D models that more accurately show their complex shape and the way DNA within them folds up.

According to the researchers, the X-shape, often used to describe chromosomes, is only a snapshot of their complexity and not its real shape.

“The image of a chromosome, an X-shaped blob of DNA, is familiar to many but this microscopic portrait of a chromosome actually shows a structure that occurs only transiently in cells – at a point when they are just about to divide,” Dr Peter Fraser of the Babraham Institute, said.

“The vast majority of cells in an organism have finished dividing and their chromosomes don’t look anything like the X-shape. Chromosomes in these cells exist in a very different form and so far it has been impossible to create accurate pictures of their structure,” said Fraser.

This latest research, published in journal Nature, puts DNA into its proper context in a cell, conveying the beauty and complexity of the mammalian genome in a far more effective way than volumes of text previously have.

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