When Being Small is Better

Salmon genetics have been changing over time according to Finland scientists from the University of Helsinki. By extracting DNA from salmon scale samples for over 40 years, scientists have found that male salmon have been maturing at earlier ages. Thus these salmon are significantly smaller in size compared to older aged salmon reaching sexual maturity. After a 144 genome-wide assessment of single nucleotide polymorphisms (SNPs), a single gene called the VgII3 gene was demonstrated to have reduced in allele frequency. VgII3 is the gene that controls the age of late maturing. This alteration of genotypic frequency may be an evolutionary advantage for smaller salmon compared to larger sized ones. Lead scientist, Czorlich, hypothesizes that larger salmon are more likely to be caught by anglers and less likely to reach their natal streams to mate and produce fecundity. In contrary, smaller salmon are able to escape human predation, spawn, and pass on their genes to the next generation.

As salmon fishing, commercial, and recreational continues to be a major source of profit for some areas, studying salmon populations becomes increasingly important. I think more investigation should be focused on whether or not other factors influence this gene change. Habitat destruction or the effect of climate change could be possible explanations. Identifying these factors and also the extent of change each has on salmon populations need to be thoroughly studied.

Links:
https://www.sciencedaily.com/releases/2018/11/181114104356.htm
https://ghr.nlm.nih.gov/primer/genomicresearch/snp
https://www.biorxiv.org/content/biorxiv/early/2018/05/10/317255.full.pdf

Bear Saliva Found in Salmon Carcasses Turn Out to be a Goldmine of Information

Thousands of salmon carcasses can be found by streams and rivers all over Alaska during spring and summer. This is because salmon act as a very important food source for brown bears living in the area, and if the salmon are in great abundance the bears tend to only eat specific parts of the fish, such as the brain, leaving the rest behind. This is fortunate to wildlife and population biologists, as it has been recently discovered that the leftover drool found on these carcasses are a great source of genetic material. This data gathered from the drool provides an excellent source of DNA from the bears which in turn contains a great amount of information allowing biologists to identify individual bears living in the area based solely on their saliva. This is very promising as it could greatly benefit the research conducted on bear population and health.

 Before drool was discovered as a means to gather genetic material from bears, the data was originally gathered based on visual observations and analysis of fecal samples. It has also been proven that not only is this new method more efficient, it costs less too. This was tested by comparing the new method to to the old one by examining 156 salmon carcasses and comparing the data from that to the data collected from 272 fecal samples. Results showed that they were able to get genotypes for 55% of the salmon carcasses compared to only the 34% gathered from fecal samples. The saliva method also cost around $200 less per bear than fecal samples  did..

This new method seems like a great advancement that will allow for more detailed research to be conducted on brown bears. I would like to see if it is possible to modify this technique to better study other organisms as well, and if so what kind of effect this will have on the field as a whole.

https://www.sciencedaily.com/releases/2016/11/161109182848.htm

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0165259

Genetically Modified Salmon

On November 19^th, 2015 the Food and Drug Administration (FDA) approved the first genetically modified (gmo) animal cleared for human consumption.  AquaBounty initially approached the FDA in the 1900s with no luck. Once approved AquaBounty stated that the fish were safe and ready to eat more than five years ago. Immediately after approval some consumers and environmental groups fiercely opposed to the gmo salmon. Fearing the safety of other species if the engineered fish were to escape into the ocean and rivers. The salmon is expected to grow full size in half the time of a wild salmon. Although it grows very fast it would take approximately two years before it can reach the local supermarkets.

I completely disagree with the approval of gmo salmon. It’s devastating to the population of wild salmon if an engineered salmon were to escape. It will out compete the wild salmon thus eliminating their existence. So what would happen to the people that want to eat wild salmon? There is no way of ever retrieving a species once its outcompeted and extinct. Its also devastating how slowly we’re killing our environment just for the profit. So at the end what is there left if we have destroyed our earth and its species? 

Salmon is the first Genetically Engineered Animal to win US Approval for Food

     

          The first genetically modified animal approved by the FDA for consumption is the Atlantic Salmon.  A company named AquaBounty Technologies have been breeding the genetically enhanced fish in closed off farms.  The main improvement to this AquaAdvantage salmon is that it takes much shorter for them to grow to full length. They are able to grow year round rather than just in the Spring and the Summer.  This allows the fish to grow to full size in 18 months rather than how long it usually takes which is 3 years.
      Transgenic organisms are animals or plants that have a foreign gene from a different species that was deliberately inserted into its genome.  The foreign gene is formed using Recombinant DNA technology. This is done in order to improve a specific aspect of the host animal.  For the atlantic salmon it was to enhanced its growth rate.  One of the foreign genes added to the salmon's genome of 40,000 genes was a growth hormone regulating gene from a Chinook Salmon.  The other foreign gene was a DNA promoter from an ocean pout.
        Of course with all genetic modified organisms there is always controversy.  This case is no different.  The opponents of the AquaAdvantage salmon are concerned that if the salmon are able to escape their farm that they will alter the ecosystems of surrounding fish.  Also the opponents believe that the salmon that is genetically modified should at least be labeled, however at the moment the FDA says they do not need to be labeled.
        In my opinion I feel like this is an enormous step for the science community.  Hopefully this will lead to more approvals from the FDA of genetically improved food.  I feel that with the technology that we have we can do so much to make the starvation problem around the world diminish.

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Genetically Engineered Salmon Now Safe for Consumption

Well known to today's media are the familiar phrases genetic engineering and GMO's. All the attention of the media lately has been turned on genetically modified corn and genetically modified chickens. However, there is a new organism in the spotlight-salmon. A committee that was put together in order to advise the FDA on whether or not genetically modified salmon is safe for consumption and for the environment has deemed it safe for the population and mother nature. The super-salmon was studied very closely by this committee, because this is the first genetically engineered organism to enter the American food market. Of course, organisms before salmon were genetically modified and manipulated, but never totally engineered. The difference between the salmon and other organisms is that this salmon contains a hormone that causes it to grow to a marketable size twice as fast as a wild salmon would.

These fish would be grown in farms and have a very low chance of escaping into the wild where they could reproduce. A few committee members insinuated that there might be a slight chance of an increase of risk of allergic reaction to the modified fish, but that was never confirmed through studies. The FDA did not see any "glaring holes" in the committees presentation, and approved of the genetically engineered salmon hitting the food market. Of course there is going to be surveillance of the fish after it goes on the market just to ensure that the safety evaluation is correct in assuming that it is safe for consumption.

The approval of this salmon could pave the way for new technology to be used on animals when genetically engineering them. For example, a pig was genetically engineered in Canada to be more environmentally friendly. This could increase food source as well as minimize the amount of space that is taken up in order to farm animals. The influence could be beneficial for the environment.

While the genetic engineering of a commonly consumed food item might be intimidating to hear, the rearrangement of a simple pattern of genes has not completely changed the food product all together. While it may be different than traditional farm grown salmon, the FDA's approval should put the public's mind at ease, because they would not allow unsafe food to enter the market. I personally think this is a great advancement in technology and could allow smaller farms with the same output of salmon and could help with lowering food company's carbon footprint. Hopefully this technology will be applicable in the near future to a variety of foods.

The original article can be found here.
Frequently asked Q&A on genetically modified food can be found here.

Transgenic Salmon and the use of genes from the Zebrafish to better protect these cultured fish from diseases and pathogens.

The article, "Isolation of the Atlantic salmon β-actin promoter and its use to drive expression in salmon cells in culture and in transgenic zebrafish," portrays how genetic roles with salmon aquaculture are continuously growing. Researchers are working towards successful genetic improvement of the fish. Many scientists study which genes are in control of disease protection or which genes can be enhanced to enlarge the size of the fish. Transgenic salmon have recently been introduced to the world of aquaculture. Those genes that control the growth hormones in the salmon are altered to be more receptive and therefore pump more of this hormone into the fish. This will increase the size, as stated before, and furthermore increase the production of the salmon crop. To salmon famers this sounds like a dream come true. However, the general consensus of the human population is not as confident with consuming transgenic salmon. This feeling of doubt is not uncommon since there is still minimal evidence of the effects, if any, on human life after they eat these salmon.

I personally feel that introducing genes from another organism into the salmon populations, controlled in cultures, is a smart idea, but with multiple outcomes. I agree with the general consensus of the public,  and demand more answers before this becomes an everyday occurrence in salmon aquaculture. There are so many "what if" questions that come from mixing genetics of different species. Therefore research must be conducted to test not only how the new genes will effect the fish, but also how ingesting the fish will affect the humans who eat them. 



Source: http://fx5ly8ju5l.search.serialssolutions.com

Below is a link to another article which provides more information about the Zebrafish:
http://www.academia.edu/528432/Zebrafish_as_a_model_organism_for_nutrition_and_growth_towards_comparative_studies_of_nutritional_genomics_applied_to_aquacultured_fishes

Genetic consequences of interbreeding between wild and cultured Atlantic Salmon 

             A worldwide issue, that has increased from the use of farm grown salmon, is the mixture of wild and cultured salmon genes. The two separate fish have the chance to interact when the farmed salmon escape from their pens and make their way to the native salmon’s habitats. Once they reach each other, the option to reproduce is available, but would then result in a variety of genetic combinations. The mixture between the two types of salmon is considered a “hybridization.” Typically genetic diversity can be beneficial to the organisms, but not always. In this case, when the wild salmon and the farmed salmon mix the results have shown unexpected patterns within the inheritance of the genes from the parent fish. This creates field of unknown for researches. In addition to unpredicted circumstances, researchers have found that the presence of the farmed salmon in the native territories can greatly increase the chances of the wild salmon’s extinction. 
            The farmed salmon have this negative effect on the wild populations because of a few distinct reasons. First, the cultured salmon could potentially carry diseases over to the wild populations. Second, the basic addition of more than the normal environmentally supported population of salmon can decrease resources for the native fish. And lastly, when the two interbreed, the process alters the regulation of the transcription of the salmon’s genes. 
          Gene transcription is incredibly important to the survival of the salmon, both wild and farmed. Wild salmon have their own set of genes that have been through the necessary adaptations needed to survive in their natural habitats. These genetic components allow the fish to live, to protect itself from the components of the water they live in, and to internally regulate their bodies to be able to live successfully, etc. Their gene transcriptions are their directions to life, and when they are tampered with by an outsider’s genetic instructions, important information can be lost. In the end, the main goal is to do what ever is possible to contain the farmed salmon and prevent the combination of the two fish.

Source: http://fx5ly8ju5l.search.serialssolutions.com

Another source that has further information on the topic: http://www.nature.com/news/transgenic-salmon-nears-approval-1.12903

Genetically Altered Salmon Get Closer to the Table

[caption id="attachment_7309" align="alignleft" width="273" caption="Genetically altered fish and normal fish at same age"][/caption]

The New York Times published an article called "Genetically Altered Slamon Get Closer to the Table" written by Andrew Pollack.  The article is about a company called AquaBounty Technologies who is trying to get their creation of genetically altered salmon approved by the FDA. These salmon are altered in order to grow faster.  By combining hormones from Chinook salmon and gene switches from pout, the salmon are able to reach full adulthood by 1.5 years instead of 3.  AquaBounty has been trying to get this passed for over a decade, but many arguments as to why it should not be still remain.  If it does get passed by the FDA, questions of how it should be labeled for consumers is also an issue.  Genetically altered crops are not labeled,

but should the salmon be?  Getting the salmon approved would be a major advancement in genetics and food production and it could open the door to more genetic alterations.

The Positive Side of Salmon Spawning

There is new research being done that suggests that more salmon escaping from fishing nets to reproduce in streams can improve the natural environment and be beneficial to both the ecosystems and humans.   Salmon are a unique source of food in that they not only help the marine food webs but also terrestrial.  Studies were done that showed with more salmon available in streams, bears would be less likely to eat the entire fish and would instead eat only the parts with the most nutrients (mostly the brain and the eggs).  When this happens, the bear will toss the rest of the fish aside which allows other scavenger animals to benefit and also allows the land to benefit from this salmon fertilizer.

Bears eat salmon at a very high rate, so the more salmon available in their environment is an obvious positive for the bears.  When there are less salmon available for the bears, they still need to eat around the same amount, so there is less salmon available for other animals downstream.  Studies showed that more salmon in the streams would have a direct impact on the growth of salmon in the ocean as well, which leads to larger harvests for the fishermen.

[caption id="" align="alignnone" width="468" caption="More of this"][/caption]

While I agree that it makes sense that more salmon escaping from fishing nets would help the ecosystems around streams, I am a little doubtful about the increase in harvest for the fishermen.  If the only way to increase their harvest in the end is to allow more salmon to escape their nets and decrease their initial harvest, it just seems as if the final result would be about the same.

 

The Fish Flu

Recent research at the National Institute of Standards and Technology has determined the genetic structure of the reproductive genes of a particularly deadly strain of infectious salmon anemia virus. This virus has an extremely high mortality rate over 90% in Pacific Salmon. This virus is commonly known as the fish flu, and has been plaguing fish farms in the Pacific. In recent times the virus has branched out into the wild population of the species. Given the mortality rate of this virus it is imperative that measures be taken to prevent the complete collapse of the population.

The problem with containing the virus is that it would require much more effort to properly inject the vaccine the fish  then reasonably possible. The researchers suggested that a more feasible way to vaccinate the fish. By creating a vaccine that interferes with the genetic coding for the replication of the virus which would eventually kill the virus. This method would not require the injection of each and every fish; making it much more practical for fish farmers and conservationists alike. I found this research to be particularly interesting because I had never considered how difficult it would be to deliver a vaccine to a population of fish.

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