Cross species transfer of genes has driven evolution

July 9, 2018, University of Adelaide
A graphic representation of the BovB element which shows how it has appeared in species that are wide apart on the evolutionary tree -- for example sea urchins and elephants, cows and snakes. Credit: University of Adelaide

Far from just being the product of our parents, University of Adelaide scientists have shown that widespread transfer of genes between species has radically changed the genomes of today's mammals, and been an important driver of evolution.

In the world's largest study of so-called "jumping genes", the researchers have traced two particular jumping genes across 759 species of plants, animals and fungi. These jumping genes are actually small pieces of DNA that can copy themselves throughout a and are known as transposable elements.

They have found that cross-species transfers, even between plants and animals, have occurred frequently throughout evolution.

Both of the transposable elements they traced—L1 and BovB—entered mammals as foreign DNA. This is the first time anyone has shown that the L1 , important in humans, has jumped between species.

"Jumping genes, properly called retrotransposons, copy and paste themselves around genomes, and in genomes of other species. How they do this is not yet known although insects like ticks or mosquitoes or possibly viruses may be involved—it's still a big puzzle," says project leader Professor David Adelson, Director of the University of Adelaide's Bioinformatics Hub.

"This process is called horizontal , differing from the normal parent-offspring transfer, and it's had an enormous impact on mammalian evolution."

For example, Professor Adelson says, 25% of the genome of cows and sheep is derived from jumping genes.

"Think of a jumping gene as a parasite," says Professor Adelson. "What's in the DNA is not so important—it's the fact that they introduce themselves into other genomes and cause disruption of genes and how they are regulated."

Published today in the journal Genome Biology, in collaboration with the South Australian Museum, the researchers found was much more widespread than had been thought.

"L1 elements were thought to be inherited only from parent to offspring," says lead author Dr. Atma Ivancevic, postdoctoral researcher in the University of Adelaide's Medical School. "Most studies have only looked at a handful of species and found no evidence of transfer. We looked at as many species as we could."

L1 elements in humans have been associated with cancer and neurological disorders. The researchers say that understanding the inheritance of this element is important for understanding the evolution of diseases.

The researchers found L1s are abundant in plants and animals, although only appearing sporadically in fungi. But the most surprising result was the lack of L1s in two key mammal species—the Australian monotremes (platypus and echidna) - showing that the gene entered the mammalian evolutionary pathway after the divergence from monotremes.

"We think the entry of L1s into the mammalian genome was a key driver of the rapid evolution of mammals over the past 100 million years," says Professor Adelson.

The team also looked at the transfer of BovB elements between species. BovB is a much younger jumping gene: it was first discovered in cows, but has since been shown to jump between a bizarre array of animals including reptiles, elephants and marsupials. Earlier research, led by Professor Adelson, found that ticks were the most likely facilitators of cross-species BovB transfer.

The new research extended the analysis to find that BovB has jumped even more widely than previously anticipated. BovB has transferred at least twice between frogs and bats, and new potential vector species include bed bugs, leeches and locusts.

The team believes that studying insect species will help find more evidence of cross-species transfer. They also aim to study other jumping genes and explore the possibility of aquatic vectors, such as sea worms and nematodes.

"Even though our recent work involved the analysis of genomes from over 750 species, we have only begun to scratch the surface of horizontal gene transfer," says Professor Adelson. "There are many more to investigate and other types of jumping ."

Explore further: Road rules for gene transfer are written in DNA

More information: Atma M. Ivancevic et al, Horizontal transfer of BovB and L1 retrotransposons in eukaryotes, Genome Biology (2018). DOI: 10.1186/s13059-018-1456-7

Related Stories

Road rules for gene transfer are written in DNA

June 19, 2018

A new discovery suggests that bacteria's ability to transfer genes, like those associated with antibiotic resistance, are governed by a previously unknown set of rules that are written in the DNA of the recipient.

Rare form of active 'jumping genes' found in mammals

January 3, 2013

Much of the DNA that makes up our genomes can be traced back to strange rogue sequences known as transposable elements, or jumping genes, which are largely idle in mammals. But Johns Hopkins researchers report they have identified ...

Recommended for you

How quinoa plants shed excess salt and thrive in saline soils

September 21, 2018

Barely heard of a couple of years ago, quinoa today is common on European supermarket shelves. The hardy plant thrives even in saline soils. Researchers from the University of Würzburg have now determined how the plant gets ...

Decoding the structure of an RNA-based CRISPR system

September 20, 2018

Over the past several years, CRISPR-Cas9 has moved beyond the lab bench and into the public zeitgeist. This gene-editing tool CRISPR-Cas9 holds promise for correcting defects inside individual cells and potentially healing ...

7 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

betterexists
1 / 5 (4) Jul 09, 2018
If so, Can you put an end to stupid current endeavor wasting precious resources on efforts in Rhinoceros, WHICH IS AN USELESS ANIMAL ? Didn't we already clone Dolly, The Sheep 2 Decades ago and about 50 of the Smallest Dog in the current decade ?
Rather to upgrade our knowledge, why not transfer a mud nest builder bird into a bird that builds only using twigs and vice versa ? Eggs (With Zygotes) of Birds are expelled outside of Mom Bird's Body and hence there will not be any need for cruel & debilitating surgeries. Most Fish also are amenable to such tinkering ! Coming back to the original topic, for sure microbium of the intestines might have played a part.
TheGhostofOtto1923
2 / 5 (4) Jul 09, 2018
Which perhaps lends more credence to this?

"Dr. Eugene McCarthy is a Ph.D. geneticist who has made a career out of studying hybridization in animals. He now curates a biological information website called Macroevolution.net where he has amassed an impressive body of evidence suggesting that human origins can be best explained by hybridization between pigs and chimpanzees. Extraordinary theories require extraordinary evidence and McCarthy does not disappoint."
Ojorf
3 / 5 (6) Jul 09, 2018
why not transfer a mud nest builder bird into a bird that builds only using twigs and vice versa?


But would that make them more useful than a rhino?

Why not rather make an ostrich that can build a house with bricks, won't that solve the housing crisis?
rrwillsj
1 / 5 (1) Jul 11, 2018
Considering the nasty temperament of the ostrich?
Would you really want to give them the capability of flinging bricks at your head?

Just out of idle curiosity and not simply because of my gluttony. Would house-building ostriches be any less delicious than they are now? Would a veldt omelet be any less tasty for being the young of sophonts?

Cause we, as a self-proclaimed civilization, do not seem to have any moral qualms about consuming any primate's younglings.
SURFIN85
not rated yet Jul 16, 2018
Another nail in the coffin of creationism
postfuture
not rated yet Jul 17, 2018
Why not rather make an ostrich that can build a house with bricks, won't that solve the housing crisis?

Or let's solve the energy crisis with genetically engineered monkeys that glow in the dark! And we already started - google 'genetically modified animals that glow ...'.
Cryptodiamond
not rated yet Jul 20, 2018
Cross species gene transfer totally blows Neo-Darwinist, "survival of the fittest", "evolution by mutation" out of the water. Wow.

By the way the above comments dont seem to reference the article

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.