Horizontal Gene Transfer: How parasites control insect host behavior

Published recently in the journal Current Biology, research from a study conducted by the RIKEN Center for Biosystems Dynamic Research has revealed that parasites likely manipulate the behavior of their host organisms using horizontal gene transfer. 

In general, many parasites control their hosts to ensure the survival and reproduction of their species. One example of such a parasitic species is the horsehair worm, born in water but migrating to dry land using aquatic insects. After being eaten by a mantis (terrestrial insect), the worm grows within the host, beginning to manipulate its behavior. Once fully matured, the horsehair worm prompts the insect host to jump into the water and drown to its death, allowing the parasite to complete its life cycle and reproduce. 

Interestingly, previous studies have indicated that the horsehair worm likely manipulates the host’s biological pathways to increase movement towards the light (and approach water) by mimicking molecules found in the hosts’ central nervous system. To better understand how they developed such a mimicry mechanism, researchers analyzed the whole-body gene expression in a Chordodes horsehair worm before, during, and after host manipulation. From this study, researchers found over 3,000 genes that were expressed more during manipulation and 1,500 that were expressed less. In contrast, gene expression in the mantis brain did not change whatsoever, indicating that the parasites were producing proteins that would manipulate the host nervous system. After further analysis, interestingly, it was found that over 1,400 hairworm genes that matched those found in their mantis hosts were absent in species with different hosts. From these findings, researchers concluded that the identified mimicry genes (linked with neuromodulation, light attraction, and circadian rhythms) were likely the results of multiple horizontal gene-transfer events from various mantis species during the evolution of horsehair worm species.

Considering that horizontal gene transfer is far more common in prokaryotes, it was rather interesting to see an application of this phenomenon in eukaryotic species. This was especially the case since it is a primary way through which bacteria evolve antibiotic resistance. In that sense, horsehair worms would likely make ideal model organisms to study the mechanism by which horizontal gene transfer occurs and allows molecular mimicry, advancing current scientific understanding of evolutionary adaptation.

Click here to view the ScienceDaily article release

Click here for more information regarding this research study

The First Direct Observation of 'Natural Transformation''

Many diseases that once killed people can now be treated effectively with antibiotics. However, some bacteria have become resistant to almost all of the easily available antibiotics. A new study published by researchers at Indiana University revealed a previously unknown role a protein plays in bacterial horizontal gene transfer.  A new imaging method invented at Indiana University leads to a discovery on how superbugs acquire antimicrobial resistance. Bacteria use thin hair-like surface appendages called pili for natural transformation. 

IU scientists have made the first direct observation of how horizontal gene transfer that bacteria use to rapidly acquire new traits from its surrounding environment, including antibiotic resistance. It was understood that two motors with two distinct proteins controlled the activity to power pilus. Proteins known as PilB constructed the pili, and PilT, which deconstructed it. They discovered a third motor, PilU, that worked independently and could power the pilus when PilT was inactive. This was an important discovery because the more we understand how bacteria share DNA, the more chances we have at treating antibiotic-resistant bacterial infections. This could help save nearly 1 million people affected by antibiotic-resistant bacteria each year.

References:

Fryling, K. D. (2019, October 21). DNA-reeling bacteria yield new insight on how superbugs acquire drug-resistance. Retrieved October 21, 2019, from https://www.eurekalert.org/pub_releases/2019-10/iu-dby102119.php.

Starr, M. (2018, June 15). For The First Time, Scientists Have Caught Bacteria "Fishing" For DNA From Their Dead Friends. Retrieved October 21, 2019, from https://www.sciencealert.com/cholera-bacteria-using-pili-to-harpoon-dna-horizontal-gene-transfer-antibiotic-resistance.

Parasitic Plants Are Able to Steal Genes From Their Hosts

Researchers at Penn State and Virginia Tech discovered dodder plants steal genetic material from their hosts including over a hundred functional genes. The genes the dodder steal not only contribute to its ability to lock onto the host, but also to its ability to send back genetic weapons.

Dodder plants are leafless, parasitic plants part of the morning glory family. They do not produce energy through photosynthesis, so they live by tapping into the host's nutrients and water supply through their haustoria, a root projection of the parasite. Dodder wrap around their host plants and extend into their vascular tissue. When these parasitic plants extract nutrients, they also grab genetic material which can be incorporated into their genome. The process described is called horizontal gene transfer, but it is usually not seen in plants but is common in bacteria. Researchers described the process as "the most dramatic case known of functional horizontal gene transfer ever found in complex organisms."



To measure if the genetic material is actually being used, researchers used genome-scale datasets since previous studies only investigated single transfer genes. The criteria to determine functionaility were as follows: "The gene had to be full length, they had to contain all the necessary parts of the gene, they had to be transcribed into an RNA sequence that later builds proteins, and they had to be expressed in relevant structures."

They were able to identify 108 genes that the dodder plant stole which happen to contribute to the dodder's haustoria structure, defense, and metabolism. Interestingly, one of the genes stolen were able to produce micro RNAs that could be sent back into the host to silence their defense genes. I believe the discovery by the research team is an amazing find because we usually learn horizontal gene transfer in the perspective of bacteria because of their way to become resistant to antibiotics. The discovery provides a fresh perspective into how parasitic plants become stronger and raises questions on to whether or not other parasites can perform horizontal gene transfer.

Links to Sources:
https://www.sciencedaily.com/releases/2019/07/190722182130.htm
https://www.nature.com/articles/s41477-019-0458-0

A Post-Antimicrobial Era

With the ever-rising misuse of antibiotics, bacterial strains are acquiring antibiotic resistant genes and becoming superbugs.  Horizontal gene transfer allows the resistant alleles to be spread in the bacteria, increasing the spread and emergence of antibiotic resistance.  Some strains of bacteria are actually accumulating resistance to a wide range of antibiotic medications.

Bacteria have short generation times, resulting in the increase of their population sizes.  Humans are promoting antibiotic resistance in multiple ways such as; not finishing their prescriptions, taking other people's prescriptions, and using antibiotics in agricultural settings.  We could be entering a post-antimicrobial era as a result of selection pressures that humans are creating for bacteria.  I think that people need to be educated and reminded that misusing antibiotics will eventually lead to a time when infections will be untreatable.  The only way we can slow down the increase the spread of resistance genes is to reduce the selection pressures that bacteria are being exposed to.

https://www.sciencedaily.com/releases/2016/04/160411124713.htm

http://cid.oxfordjournals.org/content/27/Supplement_1/S12.full.pdf+html

Water Bears' Weird DNA Allows Them To Survive In Space

   Water bears are tiny little micro-animals that are also the only species known to survive in space. Recent studies state that water bears also possess the highest amount of foreign DNA than any other species. About one-sixth of the water bear's genome comes from other animals. This is due to horizontal gene transfer occurring when the water bears are placed under conditions of extreme stress. Researchers believe that under extreme stress, their DNA breaks into small pieces and when the cells rehydrate, they become momentarily permeable which allows other DNA and large molecules to enter. Water bears have the ability to repair their own DNA as well as the ability to patch in foreign DNA while their cell membranes are still "leaky." Like water bears, the human genome also contains foreign though, obviously, not nearly as much.

   This mix of different DNA may be the reason why water bears are able to survive in the extreme conditions that are impossible for other species to survive. The addition of bacterial DNA within the water bear's genome may be the reason why this animal has the ability to survive in space .In 2007, a colony of water bears were shot into space and when they returned, not only were many of them still alive, but some had laid eggs while in space and the offspring were healthily hatched. Water bears can also be placed in a freezer for a year, then taken out and thawed. After 20 minutes, they unfreeze and carry on as nothing happened.
   I have learned briefly about water bears in the past, but this article goes more in depth about the interesting genome of the tiny animals. I did not know that water bears were the only animals able to survive in space and it was also interesting to know of the possible reason why. Further research can lead 

 

That Stinky Cheese is a Result of Evolutionary Overdrive

Did you know that cheese makers use a particular species of mold to come up with the many cheese flavors we eat today? Have you also thought about the genetic histories of mold and how it adapts to life on cheese curds?

Dr. Robert Rodriquez de la Vega and his scientists reported to the journal Current Biology, that cheese makers have thrown their mold into evolutionary drive. Roquefort was one of the first cheeses made in France in a traditional way. The cheese makers used to take loaves of bread and leave in caves. Inside of them Penicillium roquefort would grow on the walls and eventually attack the bread. Then they would take of pieces of the bread and put them on the curds, so the mold would grow on them. In the early 1900s scientists identified what these species were and made it possible for scientists in the laboratories to select certain strains of mold to produce cheese. Could this mean that mold is a genetically modified organism?

Over centuries, mold has picked up large chunks of DNA from other species in order to adapt on cheese curds. Dr. Rodriquez de la Vega and his colleagues were curious about how mold changed once people started using them to make cheese. They were able to see the similarities of these genes, but also noticed chunks of DNA that did not look similar. The genes that looked different were actually genes that were an identical form of distantly relative species. This kind of swapping is called horizontal gene transfer. Horizontal gene transfer is when one organism takes a piece of DNA from another species and creates it own genome. Dr. Rodriquez de la Vega found out that up to 5 percent of the entire genome of each mold was made up of DNA from another species. So this means that new flavors are able to be made, but also gives mold that contaminate cheese a chance to spread and pick up modified genes.

In opinion, I always wanted to know how the different cheese flavors came about. I am only familiar with the common cheeses like cheddar, provolone, american, and pepper jack. I have never seen cheese that was blue, but had an acquired taste like roqueforti. It is interesting how mold can alter genes and change the either the texture of cheese or even its appearance. I also wonder in what ways can cheesemakers protect their cheese from contamination. Can the modified genes be reversed, so the cheese is no longer contaminated?

To read more about the article click here!

I Got It From My Mama - or Maybe a Protist?

In a new study from the University of Cambridge , researchers are finding that not all human genes are ancestrally inherited. While there is no doubt that bacteria partake in horizontal gene transfer, it's been thought that complex animals only receive their genes from their parents. This new study, however, challenges the established idea that there is no horizontal gene transfer in more highly developed animals. In the study, the genomes of four nematode species, twelve fruit fly species, and ten primate species (including humans) were examined and then compared with that of the other species. The researchers then estimated how long ago the similar genes were acquired, and how likely it was that these genes were foreign in origin. Almost 150 human genes were identified as foreign, and thus acquired through horizontal gene transfer, and nearly all of them related to enzymes involved in metabolism. Along with identification, the researches were also able to determine where the genes most likely came from, finding that most of the genes were transferred from bacteria and protists, while some were from viruses and fungi. While some of the other species involved in this study continue to receive genes from outside sources, it's likely that humans and other primates haven't procured genes through horizontal transfer since the common ancestor species  - probably around 5-8 million years ago. The researchers of this study hope that their findings lead to a better understanding of the genomes of complex animals, and hope that bacterial sequences in DNA shouldn't always be written off as bacterial contamination in genomic studies.

Genes Aren't Always From Ancestors

In an article recently published by Science Daily, the concept that certain genes can originate from other sources than ancestors was discussed.  According to researchers, horizontal gene transfer (transfer of genes between organisms in the same environment) does not only apply to simple, single celled organisms.  There is evidence that nematode worms have received genes from plants and some microorganisms and that species of beetles have acquired genes to produce specific enzymes from bacteria.  Finding that horizontal gene transfer can occur in more complex species (compared to bacteria) could explain the origin of certain traits.

Alastair Crisp, the head researcher, found that horizontal gene transfer happens in all levels of animals.  Humans have even experienced horizontal gene transfer.  One of the traits that we acquired from horizontal gene transfer was actually the ABO blood typing.  A significant amount of enzymes used in digestion were also found to originate from horizontal gene transfer.  Crisp confirmed that over one hundred genes can be linked to horizontal gene transfer.  Interestingly, protists, bacteria and viruses were the most common donors in HGT.  Understanding which genes come from HGT will help with the genome project, as it was believed that genes similar to bacteria were from contamination.

Finding out that humans have similar genes to bacteria is really interesting because they're not really as insignificant as we perceived.  If we can receive genes from microorganisms and evolve to be so advanced, why can't other species have genes horizontally transferred to them?  I think that finding out about HGT in complex species gives potential to make stronger species, which is both terrifying and fascinating.  

Secondary Article 

Part Human, Part Plant?

            Although we all present the physical characteristics of humans, a new study has shown that human DNA may be composed of over 145 genes that originated from organisms such as plants and bacteria. Horizontal gene transfer, is a way in which bacteria exchange genetic information with neighboring microorganisms. This is commonly used to allow organisms to acquire resistance. Although this concept is not fairly new, studies reveal that this mechanism may have played a role in human evolution. The article illustrates that while many believe the tree of life is clear and displays the lineages of organisms through generations, it may be much more messy and tangled than we originally believed.

            Biologists from the University of Cambridge sequenced the genomes of 40 different organisms and species, and compared their DNA to that of humans. One hundred and forty five genes are believed to have originated from simpler bacteria's, with seventeen genes that may have been transferred through horizontal gene transfer. The researchers have identified the functions of these genes in our bodies, but they are still investigating the time period in which these genes may have been transferred and the circumstances which may have lead to this.

            This discovery can change everything we believe to know about evolution. The origin of man is often debated in the scientific community, and these studies can provide us with a clue as to where humans have developed from. The article shows that there are many who believe in an alternative explanation for these genes. One possibility suggested by Johnathan Eisen, microbiologist from UC Davis, is that while horizontal gene transfer is a possibility, it is also possible that these genes were passed through by a distant relative that was lost in some generations.

Original Article: http://news.sciencemag.org/biology/2015/03/humans-may-harbor-more-100-genes-other-organisms

Secondary Article: http://amrls.cvm.msu.edu/microbiology/molecular-basis-for-antimicrobial-resistance/acquired-resistance/acquisition-of-antimicrobial-resistance-via-horizontal-gene-transfer

Foreign Genes

Horizontal gene transfer is the movement of genes from one living organism to another. There are three types of horizontal gene transfer (HGT), which are transduction, transformation, and conjugation. Transduction is the transfer of genes via virus, whereas transformation is when an organism picks up the genes floating in its environment. Conjugation involves one organism producing a pilus and injecting the genetic material into another organism. It is believed that HGT plays an important role in the evolution of many single celled organisms and in many simpler animals, such as nematode worms and beetles. However, the notion that HGT takes place in more complex animals, such as humans, has been debated over the years.

Scientists at the University of Cambridge have conducted a study about HGT and have ultimately showed that it occurs in animals more than was previously thought.  It was discovered that HGT has allowed hundreds of active foreign genes to arise in animals and is believed to have contributed to the evolution of a great deal of animals, maybe even all of them. With this new information the scientists have posited that evolution needs to be looked at in a new way.

The study evaluated the genomes of 12 species of the common fruit fly, 4 species of nematode worms, and 10 species of primates, including humans. In order to determine how likely it is that the genes were foreign it was calculated how well the genes matched to similar genes in other species. Making a comparison to other species allowed the researchers to determine how long ago the foreign genes were attained. The analysis of these genomes provided more evidence that the ABO blood group gene and genes related to metabolism enzymes were acquired by vertebrates through HGT. 17 other genes were also confirmed to have been attained through HGT, while 128 genes not previously noted as foreign were detected. The foreign genes discovered were involved in a range of activities from lipid metabolism to immune responses. The researchers also determined that bacteria and protists were the most probable source of the HGT in all species, though HGT from viruses and fungi was also seen. The HGT from fungi may be a reason why other studies have negated the idea of HGT in complex animals as they were only looking for HGT from bacteria.

This study has numerous implications for the future of genome sequencing. When genomes are sequenced bacterial sequences are often removed and are thought of as contamination. Although these bacterial sequences may be due to contamination they may also be part of an organism's genome as a result of HGT. The researchers warn that screening for contamination still needs to be in place, but that this new information about HGT should also be considered.

I think that this is such an interesting concept. When I learned about horizontal gene transfer I had always thought of it occurring between bacteria or some single celled organism. I had no idea that HGT could occur in multicellular organisms and never could have imagined that it could happen in humans. I think that this is positive though as it will contribute to the genetic variation of organisms and ultimately to evolution.  

Link to article: http://www.sciencedaily.com/releases/2015/03/150312123319.htm

Additional link: http://www.sci.sdsu.edu/~smaloy/MicrobialGenetics/topics/genetic-exchange/exchange/exchange.html

  

Horizontal gene transfer in plants

Neochrome is a hybrid of two other plant genes which code for photoreceptor proteins that sense red and blue light. This gene is thought to have been responsible for the evolution of ferns. Most plants sense and grow toward blue light, but under the canopy, there is less blue and more red light. Researchers wanted to know where this gene originated in ferns. They searched through plant genomes and found a similar gene in hornworts.

They came up with 3 hypothesis for the involvement of neochrome in both ferns and hornworts: They could have had a common ancestor, they might have evolved their gene independently, or neochrome could have been moved across species by horizontal gene transfer.  In order to come to a conclusion, teams of scientists looked through land plants and algae and how their light sensitive genes were related. 

Because the ferns and hornworts diverged in evolution 400 million years ago, if neochrome had come from a common ancestor, it would have been passed on to other plants as well, but since no other plants seem to possess this gene that possibility was ruled out. Because neochrome is such an unique gene, it is also extremely unlikely for ferns and hornworts to have evolved the gene independently. Scientists came to the conclusion that the most probable origin of this gene in ferns was through horizontal gene transfer. Scientists are seeing more and more cases of horizontal gene transfer in plants, but they do not know how it is mediated as of yet.

This article was extremely interesting, up until now I only knew of horizontal gene transfer occurring exclusively in bacteria. It only makes me wonder how much we do not know about plants still and how we could use this recent discovery to our advantage.


http://www.sciencedaily.com/releases/2014/04/140414154444.htm    Main article
http://www.decodedscience.com/hornworts-loan-genes-ferns-shady-environments/44670 

DNA predatory device in the cholera bacterium

Scientists have studied more into the mechanism of how the cholera bacterium stabs and kills other bacteria in order to obtain their genetic material and possibly increase its antibacterial resistance in the process.

When this bacterium invades the small intestine it causes cholera, a disease with symptoms of acute watery diarrhea which eventually leads to dehydration.

This bacterium is naturally found in the sea attached to small planktonic crustaceans. It feeds on the chitin of their shells. When chitin is available, the cholera bacterium enters a phase known as “natural competence” in which it attacks surrounding bacteria regardless of species using a small spear like weapon called “type VI secretion system” in order to destroy them and obtain their genetic material afterwards.

Researchers conducted tests using this bacterium. They grew them on chitin surfaces to simulate natural environment. They observed that their “type VI secretion system” is also used in the transfer of genes. They used genetic and bio imaging techniques in order to identify which mechanisms are involved in this type of gene transfer as it happens in real time and observed that a cholera bacterium can obtain at least 40 genes from another bacterium.

This is important research because most bacteria use horizontal gene transfer which leads to an increase in antibacterial resistance and dispersal of virulence factors. If we can better understand the mechanisms that bacteria use in order to obtain genes for antibacterial resistance and virulence factors, we may be able to develop better ways to combat these disease causing bacteria.

http://www.sciencedaily.com/releases/2015/01/150101163629.htm Main article

http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1002778 

Animals Steal Defenses from Bacteria

Research led by Joseph Mougous, University of Washington Department of Microbiology Associate Professor, and colleges has shown that animals can “steal” defense mechanisms from bacteria. Bacteria use deadly toxins that they can inject into rival cells when competing with other bacteria for resources in the environment. 

When going through genome databases, the team saw that toxin genes thought to only be present in bacteria were also present in several animals. Among such animals are several species of ticks and mites. The genes from bacteria had become a permanent part of the genome in certain animals through horizontal gene transfer.

The deer tick in particular is known to transmit Lyme disease, which is caused by a bacterium. The toxin in the ticks’ gut and saliva are used to control bacteria. The researchers observed that when the production of toxin was reduced in the tick, the levels of the Lyme disease bacterium rose. 

The research was published in the journal Nature under the title “Transferred interbacterial antagonism genes augment eukaryotic innateimmune function.”

It is interesting how not only can horizontal gene transfer can be done not only from one bacteria to another, but now it is being seen in bacteria and other organisms. This can become a new way to manipulate the genes in organisms. And considering I live in a wooded area with plenty of ticks, I am looking forward to them understanding more about these toxins and possibly helping stop the spread of Lyme disease.

Link to article: http://www.eurekalert.org/pub_releases/2014-11/uowh-asd112114.php

Horizontal Gene Transfer in Ferns May Have Allowed Them To Elude Extinction

This article discusses a genetic discovery in ferns that may be the reason they still exist. During the age of the dinosaurs, when trees and flowering plants began to evolve, the new plants were flourishing because of their ability to reproduce using micro and mega spores instead of having a true gametophyte generation. Angiosperms were able to reproduce very quickly and in a widespread manner, which can be a death sentence for plants that can't keep up and may become blocked from the sunlight. Scientists at Duke University have discovered a gene that appeared in ancient ferns called neochrome. Neochrome is unique because while most plants sense and move towards blue light, plants with this gene can sense both blue and red light. This was beneficial to the ferns because when trees form a canopy, the light that filters through the leaves to reach the lower plants is mostly red, not blue. This gene allowed the ferns to detect the light they needed to survive and move towards it.

The truly interesting thing about this gene, however, is where it came from. Instead of evolving it on their own, scientists have discovered that the ferns were able to "borrow" the gene from a group of bryophytes called hornworts. Because ferns and hornworts diverged in evolution 400 million years ago, there would be more plants with the neochrome gene if it had been passed on from a common ancestor. As this is not the case, it has been concluded that the gene was given to the ferns through horizontal gene transfer. The idea of horizontal gene transfer in macro organisms is relatively new-it mostly applies to bacteria, and is how many resistances to antibiotics are formed. This particular transfer most likely took place between the hornworts and the gametophyte generation of the ferns-the gametophyte generation is low the the ground, like bryophytes, and doesn't have any sort of protective cuticle on it. The gametophyte is where the sex organs of the fern are housed, so that is where genetic information was most likely exchanged. This discovery is very new, and there is still much research to be done on it. Hopefully there will be more information available in the near future.

Secondary article: http://www.sci.sdsu.edu/~smaloy/MicrobialGenetics/topics/genetic-exchange/exchange/exchange.html

Extremophiles communicate through Horizontal Gene transfer to Survive 

           In one of the most inhabitable places has arisen a very interesting discovery in extremophiles living in an Antarctic’s Deep Lake which seperated from the ocean 3,500 years ago. With this lake being deemed the most unproductive lake in the world because of temperature it makes you wonder how these species live in an environment with such little energy available. The extremophiles found in this lake belong to a group called haloarchaea. Interestingly enough these microbes require high salt concentrations, but even more interesting is the way they respond to their inhospitable environment. The way they respond is through extremely high rates of genetic exchange with other species even species from other genera. The microbes use this as a form of communication through a genetic code. As this code is passed through horizontal gene transfer the organism are able to swiftly implement any changes allowing them to prolong their survival in these harsh conditions. 

              With high rates of gene sharing it was assumed that maybe the species would grow into one homogeneous ecosystem, but instead they have identified four separate genera to have adapted to living in the lake. Although across the groups they genetically have differences but have been sharing a lot of DNA. These separate groups are able to live among each other and not be homogeneous is because each group has developed its own niche and uses different resources from different parts of the lake. It’s been theorized that the high rates of gene swapping might be an adaptation to slow reproductive rates in an effort to maintain genetic diversity between the groups. More research is needed to be done because this is the only hyper saline lake ever been tested under these frigid conditions, but there is a practical reason for studying these microbes. They can be used to aid in cleaning hazardous waste at places in cold climates or be used as temperature sensitive industrial processes.

http://www.sci-news.com/biology/science-microbes-deep-lake-antarctica-01424.html

http://arstechnica.com/science/2013/10/in-antarctic-lake-extreme-conditions-lead-to-extreme-genetics/

Bacteria Can Exchange Genes on a Global Scale

According to a new study, bacteria have the ability to exchange genes with one another on a global level. Bacteria normally transfer genes with each other via horizontal gene transfer, in switch they select for advantageous genes over deleterious ones. However, researchers have recently identified a seemingly global gene network incorporating over 10,000 genes across 2,235 bacterial genomes. What is fascinating about this, is that the vastly different bacteria seem to be exchanging genes without regard to social or geographic borders. The genetic distance these bacterium strains has been compared to the genetic distance between humans and yeast, yet they are evidenced to exhibit identical genes. All these different strains of bacteria seem to be “access the same pool of genetic variants.” This discovery had lead researchers to believe that ecology plays a much larger role in bacterial genetics than lineage or geography.

http://www.popsci.com/science/article/2011-11/bacteria-swap-gene-information-through-global-network (Article Link)

Gonorrhea gets even more personal

Researchers at the Feinburg School of Medicine have discovered a piece of human DNA incorporated in the DNA of the human pathogen Neisseria Gonorrhoeae, the microbe responsible for the sexually transmitted infection known as Gonorrhea. When the DNA of multiple N. Gonorrhoeae was sequenced it was observed that around 11% of them contained a small fragment of human L1 DNA element. Then the researchers sequenced the DNA of very closely related Neisseria species and found no human fragments at all. 
 It is proposed that the fragment of human DNA was incorporated by a horizontal gene transfer. Which up until now were only thought to occur between like types of cells, prokaryotic or eukaryotic. Since N. Gonorrhoeae is known to reside both intracellular and extracellular it is thought by researchers that it would be able to make its way into a position in which a HGE could occur. Also, that since only 11% of the tested population showed the fragment it implies that this transfer event could have happened recently. This observation alone has many implications in evolution as well as disease and immunity research. This could be a possible mechanism in which pathogens are able to build immunities to their hosts.
 I hope these discoveries bring about more research into Horizontal Gene Transfers between bacteria and mammals, not only for the implications into evolutionary mechanisms but also as a tool to better understand the pathogens around us.

Primary Article