Canine Distemper Virus Mutation Outbreak in Lions and Spotted Hyenas Solved

In 1993 in the Serengeti of Tanzania, there was an epidemic of canine distemper virus in lions and spotted hyenas. Canine distemper virus is a disease in carnivores that is similar to the disease of measles in humans. It attacks the lymph nodes, respiratory, urogenital, gastrointestinal, and nervous systems. Fever, eye discharge, coughing, vomiting and diarrhea are the common symptoms of this disease. A team of international scientists in part with the German Leibniz Institute for Zoo and Wildlife Research discovered why the canine distemper virus outbreak in 1993 was so disastrous for spotted hyenas and lions. This strain of canine distemper virus differentiated from the domestic canine distemper virus due to three rare mutations. Two out of the three rare mutations in the lethal canine distemper virus were found to increase the ability of canine distemper virus in lion and spotted hyena cells. When the canine distemper virus epidemic first occurred in Tanzania, it reduced the lion population by 30% and killed a large amount of spotted hyena pups. After the initial outbreak, the lethal canine distemper virus continued to affect and be fatal toward canines of the Serengeti but did not effect lions and spotted hyenas in later years. This led to a very long debate in scientists about why this canine distemper virus was no longer fatal to lions and spotted hyenas, and why is was so lethal in the original outbreak in 1994. Scientists collected canine distemper virus strains in a range of carnivores since 1993 to 2012 and discovered that in the 1993 strain of canine distemper virus there was a new genetic lineage.

 

This strain of canine distemper virus had a rare mutation in the CDV-H protein and the CDV-V protein. The CDV-H protein plays an important part in facilitating virus entry into host cells and the CDV-V protein enables the virus to manipulate the immune response of the host. This left those infected more vulnerable to the virus and made it more fatal for lions and spotted hyenas. The difference between the strains found in canines of Tanzania and spotted hyenas and lions were that the canine distemper virus also had a rare amino acid sequence in lions and spotted hyenas. This made a clear distinction of the canine distemper virus that was in canines of the Serengeti and the spotted hyenas and lions. The mutation made it easier to infect cat cells rather than dog cells which is why it had a harder effect on lions and spotted hyenas, who are not canid species with dog-type cells. The reason that this strain of canine distemper virus did not continue in lions and spotted hyenas was because it was so deadly that it completely died out. The current canine distemper virus in Tanzania and all over the world is more effective in invading canid or dog cells. 

 

This was the most interesting article I have read since this blog post assignment. I am a veterinary technician and one of the vaccines that veterinarian practices must administer to their dogs is a canine distemper virus vaccine for the canine parvovirus-2/canine adenovirus-2 (CAV-2) strain. This is a required vaccination for dogs in the state of New Jersey, as well as many other states, along with the rabies vaccine. This disease is highly contagious and is air-borne as well. I have seen dogs enter in the hospital with this disease and there is no cure. More times than not, the result is eventually that the owner decides to euthanize their pet because the symptoms can not be alleviated and their pet is in constant pain. Usually anorexia develops in the dog while the virus attacks it's whole system. Although this virus can be controlled with antibiotics and medication, the overall outcome of the situation is unfavorable for any canine that contracts it. Due to the nature of the animal hospital I work at, we see small animals as well. Ferrets are effected by canine distemper virus as well, and the vaccine used in dogs is the same that we use to vaccinate ferrets. It is extremely lethal in ferrets and most owners, although not required by the state, get this vaccination for their pet. Canine distemper virus effects more animals than it's name suggest and this article is further proof of it's presence in wild animals as opposed to domesticated dogs. I was surprised that this strain effected non-canid species despite knowing it effected an array of other carnivores, I was always told cats were the exception to the rule. With more genetic information being available and biotechnology continuing to make great strides, one can hope that eventually canine distemper virus will have a cure.

Sources:

Burgess, Mark, and Carla Almaraz. "Canine Distemper in Ferrets." Canine Distemper. MiamiFerret.Org Ferret Health Care, 2013. Web. 08 Dec. 2016. <http://miamiferret.org/distemper.htm>. 

Creevy, Kate E. "Overview of Canine Distemper." Canine Distemper. The Mereck Veterinary Manual, June 2013. Web. 08 Dec. 2016. <http://www.merckvetmanual.com/mvm/generalized_conditions/canine_distemper/overview_of_canine_distemper.html>. 

Forschungsverbund Berlin E.V. "Rare Combination of Genetic Changes Increases the Virulence of Canine Distemper Virus." Science News: Genetic News. ScienceDaily, 8 Dec. 2016. Web. 08 Dec. 2016. <https://www.sciencedaily.com/releases/2016/12/161208085841.htm>. 

Roelke-Parker ME, Munson L, Packer C, and Et Al. "A Canine Distemper Virus Epidemic in Serengeti Lions (Panthera Leo)." PubMed: US National Library of Medicine. Nature., 1 Feb. 1996. Web. 08 Dec. 2016. <https://www.ncbi.nlm.nih.gov/pubmed/8559247>. 

Shapiro, Leo. "Canidae: Overview." Encyclopedia of Life. Biodiversity Heritage Library, 2016. Web. 08 Dec. 2016. <http://eol.org/pages/7676/overview>.

Mutant Two-Headed Sharks Are Becoming A More Frequent Occurrence

Two-headed sharks are real and they are being found more frequently worldwide. This mutation appears to be a lethal gene for the two-headed sharks since the reported two-headed sharks were found dead as pups or still in their birthing sac. There have been reports internationally about the findings of two-headed shark embryo being found from Mexico to the Indian Ocean. The majority of the two-headed shark fetuses are a member of the species; the blue shark. In the wild, there is more likely a chance of a mutation to occur in blue sharks' genetics due to the large number of offspring they are able to produce. However, scientists are starting to see this same mutation in laboratory captivity of sharks where there was no exposure to infections, chemicals, or radiation. The main reason for this mutation of two-headed sharks appears to point at a genetic disorder. Other theories for the malformations include environmental factors such as dwindling down gene pool due to overfishing and water pollution. There are some that consider this to be a viral infection or a metabolic disorder. Conservationists are seeming to take this as evidence of overfishing most of all to blame. Overfishing causes fish to inbreed and their genetic diversity to shrink. This causes mutations to happen. This is a difficult topic to research because although there are more sightings of two-headed shark embryos, it is still a random and rare process to find them. 

Genetic mutations are becoming more and more of a frequent news story for animals. I think, and have been reading many articles to support my thought process, that most genetic mutations in animals in the wild come from environmental factors. The way we treat this world it is surprising that more animals aren't horribly mutated. In marine animals, this is an especially prevalent issue. There are over two million tons of sewage, industrial and agricultural waste polluting our water by discarding every single day. When the water is full of carcinogens and chemicals the natural cycle will respond with more genetic deformities in animals. Realizing that overfishing minimizes the gene pool and causes for more inbreeding and thus mutations makes you realize that overfishing hurts not only the fish we are killing but the ones we leave in the water as well. If a two-headed shark mutates to be able to live past sexual maturity and fall into it's place in the food chain, the waters will have a much scarier version of Jaws than anyone ever wanted to see. I believe funding for conservation efforts will minimize genetic deformities because it will provide a larger gene drift.  I believe that there will be more horror stories about mutations in animals as the future comes, with it hitting marine animals even worse. This is especially true if shale energy and the fracking industry continue to pollute our waters.

Sources:

ABC News. "Is Overfishing Changing the Gene Pool?" ABC Biotechnology News. ABC News Network, 19 Jan. 2006. Web. 22 Nov. 2016. <http://abcnews.go.com/Technology/story?id=1514544>. 

FAO. "Prionace Glauca (Linnaeus, 1758)." Species Fact Sheet. FAO Fisheries & Aquaculture, 2016. Web. 22 Nov. 2016. <http://www.fao.org/fishery/species/2018/en>. 

Learn, Joshua Rapp. "Two-Headed Sharks Keep Popping Up-No One Knows Why." National Geographic Weird & Wild News. National Geographic Society, 2 Nov. 2016. Web. 22 Nov. 2016. <http://news.nationalgeographic.com/2016/11/sharks-two-headed-oceans-mutations/>. 

Public Engagement Team from Wellcome Genome Campus. "What Is a Genetic Disorder?" Targeting Disease Facts. Wellcome Genome Campus, 13 Nov. 2014. Web. 22 Nov. 2016. <http://www.yourgenome.org/facts/what-is-a-genetic-disorder>. 

Ross, Nancy. "Global Water Pollution." World Water Quality Facts and Statistics. Pacific Institute, 2010. Web. 22 Nov. 2016. <http://pacinst.org/app/uploads/2013/02/water_quality_facts_and_stats3.pdf>.

Terminating Aedes Aegypti

Zika virus has been the latest news people have been talking about due to the danger it opposes to humans. There are many ways Zika can be fought with but will the regulatory agencies allows for these methods to go through is the real question. In the past, the devastating situation of screwworms flies was fought and eradicated by genetically modifying them. Dr. H. J. Muller, a geneticist specializing in Drosophila (fruit flies), and Dr. Edward Knipling noted X-ray can change the biochemistry of fruit flies. When fruit flies are exposed to radiation on a greater scale they become sterile even though they can still mate but not reproduce. Releasing these sterile insects to mate with the screwworm flies should alter the screwworm biologically and this should eradicate the species, in which this experiment was successful.

Zika Virus, along with dengue chikungunya and yellow fever outbreaks of the past, are all spread from the same mosquito: Aedes Aegypti.This experiment is going to be called Oxitec which refers to mosquitoes embedded with a lethal gene to prevent offspring’s development. Only the male pupae will be released and hope to exterminate the species.

Although it is understandable of the long process these experiments have to go through, I believe this is necessary to maintain genetic modifying things. This is a well-constructed experiment. For those of us who are not extremely familiar with the realm of genetics, genetic modifying and inducing lethal genes may be a difficult concept to grasp and even harsh. There may be questions: such as what if those lethal genes affect us in some way? This is the reason why we need regulatory agencies to look over things researchers may not have thought of. I absolutely believe in going through these systems is a good way to keep a balance of genetic modification.