Genomic Effects of Inbreeding on Scandinavian Wolves

 

Researchers at Uppsala University studied the genetic origins of the Scandinavian grey wolf population, which began with only three wolves from Finland in the 1980s. After five generations of inbreeding, between 10 and 25% of the original genetic variation was lost, amounting to 160,000 genetic variants. The founding wolves weren't entirely unrelated, contributing to a reduction in initial genetic diversity. Professor Hans Ellegren highlighted the need for inbred populations to receive new genetic material from diverse sources. Despite recent genetic contributions from immigrating wolves, the high level of inbreeding threatens the retention of these new variants.

The Uppsala University study on Scandinavian grey wolves vividly highlights the perils of inbreeding. With just five generations resulting in a loss of up to 25% of original genetic variation, the fragility of such limited gene pools becomes starkly evident. This research is a potent reminder of the need for diversity to ensure the long-term health and survival of species. The second article, which is focused on human inbreeding shows that inbreeding between closely related individuals can result in significant health risks for offspring, including the increased likelihood of inheriting rare genetic diseases. Research shows that inbred children exhibited decreased cognitive abilities, reduced height, and lung function, and were more susceptible to diseases in general. 

Links: 

https://www.sciencedaily.com/releases/2022/02/220208143310.htm

https://www.discovermagazine.com/health/what-scientists-found-after-analyzing-cases-of-inbreeding-in-the-uk

Most Dog Breeds Are Highly Inbred -- and Unhealthy

 

Within this article traits that are specific to certain dog breeds have been found to be most commonly achieved through inbreeding which significantly increases the amount of health risks for these dogs. An average rate of inbreeding was found to be 25% which is about as equal to how much DNA siblings share, this a a very concerning level to share for any animal or even human in general. In any species strong breed predispositions to health effects such as autoimmune diseases highlight how important it is that inbreeding dogs puts the dogs health at huge risks. Since there is so much inbreeding in the dog world there is a lack of genetic diversity within dogs and there should be more of a focus to preserving the genetic diversity among dogs. There should be a focus and careful management  to not lose the already existing genetic diversity through things such as breeding education and having inbreeding levels monitored.  

Genetic Risks of Inbreeding

    In our society today the term "inbreeding" is typically only used when it pertains to animals. For example, a dog having blue eyes is a recessive trait to the dominant brown eyes. The most efficient way to reproduce a generation of dog offspring with blue eyes is breed a male and female dog that carry the blue eyed phenotype, meaning they are homozygous recessive for it. As illustrated in the flow chart, it is possible for an offspring to inherit the homozygous recessive trait from parents who do not physically show it. These are the risks that are posed when inbreeding occurs amongst humans. Hypothetically, imagine the recessive trait in this instance was a chronic auto-immune disease, skeletal abnormality, or chronic genetic disorder. According to a study done in 2011, inbreeding practically doubles a person's susceptibility to inheriting a genetic disorder. If a person were to mate with someone outside of their family gene pool, if they do not carry the recessive trait for the unfavorable disease the offspring can resist being born with that phenotype. 

    There are many undesirable traits that put an offspring at risk when inbreeding. The offspring is susceptible to reduced fertility, birth rate, and immune function. They also have increased risk of cardiovascular disease, facial asymmetry, and risk of genetic disorders. The rates of child mortality is higher, and the growth of the human body as an adult is smaller. The most common genetic disorders that inbreed offspring face are schizophrenia, limb malformation, blindness, congenital heart disease, and neonatal diabetes. 

Link: https://www.thoughtco.com/inbreeding-definition-effects-4171861

Link: https://www.bbcearth.com/news/what-are-the-effects-of-inbreeding

Scientists Look at How Some Yellowstone Wolves Avoid Mange

Wolves that inhabit Yellowstone National Park have been inbreeding for 25 years, the result of this has caused these wolves to be genetically similar. The benefit to this is that it can help wolves fight off mange which is a skin disease caused by parasitic mites. Dan Stahler, a wildlife biologist collaborated on this research which includes 25 years of wolf pedigrees, these pedigrees were used to look at links between genetic information and disease dynamics. In the article it states, that wolves with severe mange tend to have less genetic variation than wolves with mild symptoms. Symptoms from mange from severe to less severe can depend on the wolves "tools" to fight the infection given from genetic variety. 

Some reactions the scientist saw were one wolf had over 50 percent hair loss and others had cleared the infection in no time. The wolves who had the most serve symptoms would either die off or not mate at all so they are taken out of the gene pool. The allows that wolves with the best genes to fight off mange to continue to breed together giving their offspring a better chance of fighting off mange. I think this important because maybe more research can be done based off this to see why one wolf gets worse symptoms then other wolf. 

Picture is from article and research article is another good source to find out more. 

think before you drink...milk

Penn State researchers traced more than 99% of these dairy cows back to one bull, born in the 1960s.  This genetic homogeneity increases the risk of inherited disorders.  Researchers bred a small batch of new cows using the preserved semen of deceased bulls and compared them to modern-bred dairy cows with the hopes to address any traits that have been lost due to prolonged inbreeding.

article: https://www.scientificamerican.com/article/from-two-bulls-nine-million-dairy-cows/

related article: https://www.sciencedirect.com/science/article/pii/S0022030215000727

Genetic Diversity in Dogs to Save a Breed

Eleanor Cummins in To Save a Dog Breed, Change It has found that a rare breed out of Norway called Norwegian Lundehund which was used for hunting puffins, had six toes to be able to grasp rocks and mountains but was also able to bend its neck backwards to fit into small caves. In the 1960s there were only five dogs left due to them catching canine distemper, which is fatal.Since so many Norwegians thought of the dog as a national symbol they built the population to a few hundred but it was done by inbreeding. 87% of the genes of the dogs came from the same genetic pool, so many of these dogs had health issues such as stomach cancer and skin conditions. To increase their genetic diversity, breeders had begun breeding with similar dogs that produce ones that look like the Lundehunds. Cummins has a one year old mix of a Lundehund and a Norwegian buhund, but the puppy is still too young to see if he will have the issues like a Lundehund. Many purebred enthusiasts do not agree with intermixing the breeds, but the distinct traits of the Lundehund are still produced.

Inbreeding causes so many issues for dogs and it is usually due to humans getting involved to keep the breed around. I agree that intermixing was the correct thing to do, even though it is no longer a purebred, the dogs have similar qualities and will live a healthier and happier life.  The intermixing will keep the people who want Lundehunds happy but also produce healthier dogs.

Genome Sequencing of Scandinavian Wolves shows Extensive Inbreeding

A study published in Science Daily describes the full genetic effects of intense inbreeding within a threatened species. The Scandinavian Wolf population was originally started in the 1980's with only two animals. The species grew, but it still incredibly threatened and populations are still low. Due to this low population, inbreeding is incredibly common. The research, which was conducted by Uppsala University, sequenced the entire genome of 100 wolves, and showed how incredibly inbred the species is.

Inbreeding, as we know, lowers the overall genetic diversity within a species. Genetic diversity is key in survival of a species, especially those with low populations and species that are endangered. Efforts have been put forth towards diversifying and protecting these wolf populations, however biology is working against the scientists. Disease or some other mutation could easily run through the small population and destroy it very quickly, where otherwise it could not. I think this study is great in showing us the problems with these wolves, however unfortunately there is no simple solution towards fixing the problem and regrowing the population. This gives great insight into the problem, but no solutions.

Reestablishing Genetic Diversity in California Condors

California Condors have experienced a huge lack of genetic diversity in the last century due to a genetic bottle-necking event that occurred in the 1900's, causing the population to diminish rapidly. A recent study carried out for The Condor: Ornithological Applications has examined 93 Condor specimens from various museums on the west coast that dated between 1825 and 1984, and aimed to analyze how much genetic variation was present before the rapid decline of the Condor population. The DNA that was collected for the study was Mitochondrial DNA. By comparing the diversity that exists today with that of the specimens, researchers determined that approximately 80% of Condor genetic diversity has been lost due to this bottle-necking event.

An unavoidable result that comes out of the population being diminished is that due to low numbers, Condors are forced to breed with an available Condor if they wish to reproduce. The lack of choices results in inbreeding, and inbreeding can create many problems in itself. Most importantly, for the purpose of this study, it prevents the Condors from being able to create a lot of genetic diversity since they are basically passing down the same traits from one generation to the next. Genetic diversity is hugely important because it is what helps these creatures to adapt and sustain life in different environments, thereby creating a larger population. With the help of professionals and by using the capture and release method, it is possible to prevent inbreeding and to work on repopulating this species. Further research and active participation can bring the California Condor back before it is too late, but action needs to be taken.

I believe that it is a very important goal to increase the number of California Condors and to aid them in increasing their genetic diversity. Variation in a population is extremely necessary for the species survival and inbreeding is severely inhibiting this effort. By spreading awareness and working actively with this species, they can definitely improve over time, but actions need to be taken before it is too late. The California Condor is a beautiful creature and it would be a shame to see them wiped off the planet.

Link: https://www.sciencedaily.com/releases/2016/10/161016141132.htm

Extreme inbreeding likely spells doom for Isle Royale wolves

Extreme inbreeding likely spells doom for Isle Royale wolves

  The last know two members of a wolf family identified as a male and female of a 

Isle Royal, Michigan were examined and tracked by  The National Park Service. Christine Mlot quoted a document reporting that the two wolves are in fact "They are father and daughter as well as half siblings, born 2 years apart to the same mother" (Mlot 2016)

   The wolves are so deeply inbred that researchers do not believe that population can thrive from the two wolves. researchers said that wolves in general try to avoid inbreeding. However with such a small population in a remote location, its as though other options were thrown out the window.  

  solutions for this problem were being thrown around for example bringing in new wolves into the gene pool however that was shortly overturned. now solutions are still in process but nothing is set.

opinion.: its a shame how a family of wolves can be erased this easy. i do agree with the solution to bring in new wolves to expand the gene pool, but also taking eggs from the femal and sperm from the male, then mutating the genes and implanting it back into the female hoping for new progeny. 

Inbreeding and Artificial Selection of Dogs May Have Harmed Them

Dog domestication may have inadvertently lead to harmful genetic changes. Domesticating the dogs from gray wolves involved artificial selection and inbreeding. Artificial selection is the selection of a specific trait, such as smaller body size or smaller head size. These have caused many complications for the dogs. It has also caused a temporary reduction of population size known as bottlenecks. 

"Population bottlenecks tied to domestication, rather than recent inbreeding, likely led to an increased frequency of deleterious genetic variations in dogs," said Kirk Lohmueller, senior author of the research and assistant professor of ecology and evolutionary biolgy in the UCLA College. 

 They have discovered that the use of small populations artificially bred for desired traits may have lead to multiple harmful genetic variation in dogs.

This article was not too informative on how it would harm the dogs, but they have only researched this so much. They cannot give a definitive answer right away. I thought this was rather informative either way, because not a lot of people realize that their dog can be at a much higher risk if it is not bred correctly. I have seen pitbull and chihuahua mixes before. That cannot be a healthy dog.

Plants Rejecting Their Own Pollen

A study done by scientists at the University of Birmingham found that it is possible to genetically modify a plant in order to prevent self-pollination. By preventing self-pollination, the new plants will become more stronger and resilient, provide better yields for plant breeders at a lower cost, and have healthier offspring, since self-pollination causes inbreeding and offspring of which are weaker since the gene pool will shrink.

Two genes were transferred from a poppy plant to thale cress, a self-fertile plant, which resulted in the thale cress rejecting its own pollen but also allowing for cross-pollination. Not only does it reject its own pollen, but pollen of close relatives as well.

The research team had done many studies previously before this one, where one included them demonstrating that the thale cress plants which co-expressed for both the pollen and stigma SI genes resulted in them completely rejecting self-pollination.The lead author of the study, Professor Noni-Franklin-Tong from the University's School of Biosciences, said that by putting these two genes together, another signaling pathway and outcomes can be found. More information regarding this study can be found here

This study will help plant breeders with their crops in the future in order for them to breed better and more effective plants at a lower cost. Although this study does not have a huge impact on us humans on a day to day basis, for plant breeders this is a huge step in the right direction. It is interesting to me what plants are capable of doing and what we can change about them to have them do something else.

Original Journal Article

Seal Placentas Aid in Conservation Efforts

A recent article in Scientific American discusses the new importance found in seal placentas. Recent research has displayed that seal placentas are very effective in genetic research, showing the amount of inbreeding and even the gender of the offspring. This method of collection allows conservationists to collect DNA samples easier, with no risk to themselves or the seals being studied.

Seals are being monitored for inbreeding due to the occurrence of a small gene pool. When an animal becomes endangered, a limited amount of breeding choices result in a much greater risk of inbreeding within the population. Scientists wish to observe inbreeding to gain a better understanding of the risks involved with extremely endangered species.


A group of Finnish researchers collected several placentas from the extremely rare Saimaa ringed seals. Material extracted from the side of the placenta attached to the uterine lining contained DNA from the mother, while the side connected to the fetus gave DNA from the offspring. The sample of collected placentas exhibited the expected low amount of genetic diversity.With only an estimated number of three hundred seals remaining in the wild, inbreeding becomes a very critical issue. Unfortunately, this collection technique can not be applied to most mammals because the vast majority exhibit placentophagia, or eating the placenta after the birthing process.

A New Tool for Conservation Genetics: Seal Placentas

Not only are seal populations on the decline due to loss of habitat, competition for resources, and hunting, but now a lack of genetic diversity is also causing problems with the Pinnipeds. The issue is inbreeding, which can lead to birth defects and other problems that threaten the lives of these animals.

Conservation biologists test the DNA of endangered species when they are able to obtain a sample. However, it is often difficult to get a sample from a wild animal because they either cannot be found in their natural habitat, there is too little DNA in hair or feces that are found, or it is hazardous to the researcher or the animal to get close to each other. The new way of genetic testing is performed by obtaining the placentas of newborn seals. By using the placenta scientists can learn additional information as well, such as the gender of the pup or if inbreeding occurred.  

This study was performed in Finland on Saimaa ringed seals, one of the most rare species of seal on earth. From 2009-2011, scientists collected 59 placentas from these seals. Even though they were not completely fresh and new, the placentas still contained a vast amount of testable DNA. Unfortunately, what the researchers discovered was that many of the pups born were stillborn. The genetics of the pups revealed there was not much diversity in the genes and led to fatal birth defects.

This is only the beginning of this new method of genetic testing. The information placentas can give about a newborn seal (or any animal) could be extremely beneficial to conservation efforts. The reason this study works well with seals is because the mothers do not eat the placentas after giving birth, as many species of animals do. 

I was very happy to see this article and read about the ways we are using genetics to help with conservation efforts. As someone interested in working in wildlife conservation, it gives hope to the future of these animals. It seems as though the key to solving many of the problems occurring in animals, including humans, lies within the field of genetics. 

Original Article

Related

Inbreeding from pedigree analyisis

The domesticated dog has recently become a very important resource as model species for human disease. Purebred dogs have been used in studies as models for  Mendelian disorders such as narcolepsy and hereditary kidney cancer. Dogs match humans with their larger generation time and they are often exposed to similar environments as their human owners. Dogs can also be studied using controls and population case studies so that the raising of animals in laboratories is not an issue. Certain pure bred dog breeds are linked with diseases common to their specific breed which makes them easier to map within specific breeds than in humans. Dogs have been used in studies for diseases in humans like cancer, autoinflammatory diseases, retinitis pigmentosa. They can use a database to study about ten different dog breeds and also track inbreeding. Researchers compare coefficient f and kinship coefficient and average them down to two generations in that breed. In random mating both coefficients are similar, so any discrepancy between the two can help measure the tendency of consanguineous matings within a breed.  Many dogs are found to be extremely inbred, such as golden retrievers and Labrador retrievers. Greyhounds seem to be one of the only ten breeds with almost no signs of being inbred. The use of highly inbred dogs in disease studies should be avoided because of disease concentration in each specific breed.
Link
Link 2
Using dogs in case studies to track and better understand diseases and cancers is a great way to get more information. These animals can be very helpful in the development of further medical advancements.

Mountain Gorillas may be Successful at Inbreeding

Mountain Gorilla

The mountain gorilla is a highly endangered primate species of only 500-700 members, mostly located in the Virunga mountain range of Africa. Although the species is studied in great detail, this has been the first in-depth analysis of the mountain gorilla on a genomic level.

Three years after the sequencing of the reference gorilla genome, scientists are now able to compare specific gorilla species genomes to one another. It was found to much surprise that many deleterious genes were were eliminated through the inbreeding of mountain gorillas. Normally inbreeding results in the expression of more deleterious alleles, not less. The study not only shows how gorillas may be adapting to living in small populations, but also provides insight into how populations in general may adapt to limited population sizes.

King Tut and His Inbreeding Issues

     Researchers from the Institute for Mummies and Icemen in Italy have confirmed that King Tut's parents were brother and sister. As we have just learned, matings between full siblings result in a child with 25% of its genes being homozygous. The researchers of this study have concluded that this increase in homozygosity led King Tut to have the alleles for many genetic disorders. The study reports that King Tut had a club foot, which prevented him from walking. Evidence of his burial shows that there were also 130 canes buried along with him, further suggesting that he had this genetic disorder. Because of these conclusions from these Italian researchers, King Tut's death is being questioned. It was originally stated that he died from a chariot crash. However, the researchers are stating that he could not have been riding in a chariot with a club foot; therefore, there is no way he died from this kind of accident. Instead, the researchers are insisting that his increased levels of homozygosity (due to his parents inbreeding) led him to have a lowered immune system. Thus, he could have died from debilitating diseases, such as malaria (it was suggested he suffered frequently from this disease). The researchers are planning on furthering researching these issues and exploring possible reasons for his death.
     I think it's really cool how this idea of inbreeding has led to a pharaoh's death being completely discredited. If this theory about King Tut's parent being sibling wasn't established, then everyone would still think he died of a chariot crash. Furthermore, it makes me question why he was originally thought to die from a chariot crash, even with a club foot? Was there something that was covered up? Or was it a mere lack of knowledge that led former researchers to believe this conclusion? Also, I just think this article is a cool way to further show how inbreeding affects offspring of human beings.






Original Article
Learn More About King Tut

Genetics Could Be Causing Intellectual Disabilities

In recent studies, Dr. John Vincent has been researching the genetic causes behind intellectual disabilities.  According to this article although there may be other causes behind intellectual disabilities in children such as trauma in the womb, but genes are one of the main sources. Dr. Vincent performed these studies on families where the popular culture includes intermarriage between first cousins.  Such inbreeding could produce a larger likely hood that the children of these couples will receive defective recessive genes.  Although this decreased cognitive development is extremely common within inbreeding families, it is also found in non inbreeding situations.  This and other research has shed light on just how many genes can and do affect the inheritance of intellectual disabilities.  This supporting article discusses a study that researches the affects METTL23 gene has on cognitive development.

I think that this research will be very beneficial for scientists in the field of cognitive studies.  Research has been done to prove just how much traumatic injuries can affect brain development and functioning but more research needs to be performed to see just how genes affect the brain.  The research could open many more doors for scientists to genetically test parents prior to having children.  Since the brain development is such a vital part of growing up it is important to be aware of possible troubles. Genetic testing can help parents know the risk of their child inheriting such detrimental genes.  I am in full support of parents being pre-tested before having children in order to understand the risk of having a child.  

Marius the Giraffe: The Debate Between Geneticists and Animal Rights Activists

   This is Marius. He lived in a zoo in Copenhagen, Denmark. He spent most of his days walking around his enclosure, grazing on acacia leaves and interacting with his fellow giraffes. This past Sunday, Marius was lured out of his enclosure with a piece of bread and shot in the head with a bolt gun. The zoo's reasoning of why they did this and then dissected his body in front of visitors and fed him to the lions? His genetics. Apparently, the genes that Marius had were over-represented among giraffes in captivity, and therefore, he needed to be put down. Needless to say, this has outraged much of the public and animal rights activists, but many geneticists are supporting this decision. Their argument is that when animals in captivity are not properly monitored, inbreeding occurs, and can hurt conservation efforts. 

   While I agree that conservation is very important when it comes to threatened and endangered species, I simply cannot agree with euthanasia when it comes to a healthy animal. Do I believe that he should have become a sire to all of the other female giraffes? Well no, of course not. But there were other options that the zoo had that did not involve a bolt gun. Marius could have been relocated to somewhere else that would take care of him, or he simply could have been sterilized so that he was unable to reproduce. The Copenhagen Zoo did not even stop to think and consider either of those options, even after mass petitioning from the public and an offer from Yorkshire Wildlife Park to take him. That is the part that I believe is completely wrong and inhumane. Marius was only 18 months old, still just a baby in giraffe terms, since males are not sexually mature until 4 or 5 years old. There is not even a remotely acceptable reason as to why he needed to be killed. Hopefully this unfortunate event can act as an impetus to stop zoos from killing animals unnecessarily in the future.       

Article Link: http://www.independent.co.uk/news/world/europe/the-killing-of-marius-the-giraffe-opens-an-important-debate-about-genetics-animal-rights-and-zoo-inbreeding-9120219.html

Related Link: http://www.giraffeconservation.org/

Descendants of the Blue Skinned Fugates

Recently, it was found in medical records that a patient was born in Kentucky in 1975 with a condition called Methimoglobinemia. This blood disease was popularized by the account, "The Blue People of Troublesome Creek".  The work outlined the Blue Fugates, the descendants of a French immigrant that settled in Kentucky in the early 1800s. Many members of the family line had this condition, and were noticeably blue. The condition causes the skin to turn blue, and is extremely rare. Over the past century, it has rarely been seen anywhere but Kentucky, in a small geographical region. It has nothing to do with the environment there, but with genetics.

[caption id="" align="alignnone" width="446" caption="The Fugate Family"][/caption]

Methimoglobinemia is a recessive condition that is mostly perpetuated by inbreeding, which is exactly what was going on in the Fugate family line. The information found in medical records from 1975 was that of Benjamin Stacy, who has been proven to be a direct bloodline to the infamous 19th century family.