Ant Royalty: How Juvenile Hormone Determines Ants Social Hierarchy

Scientists at the University of Copenhagen have been researching the system ants use to determine the types between them in the colony; an example of this could be a worker compared to the queen. The researchers focused on a hormone named juvenile hormone (JH) and its role in developing ants into different types, such as workers or queens. The specimen used for the experiment was pharaoh ants, as in the species, an ant's role in the colony is decided upon birth. The researchers fed 237 baby worker pharaoh ants during the last stage of their development to see whether the juvenile hormone would affect the ants, changing their type from worker ant to queen ant, determining how the juvenile hormone affects the physical features of different ant types.

The study produced intriguing results. When born, worker ants fed the juvenile hormone during the final stages of development started to look similar to young queen ants. These modified workers showed phenotypes of longer bodies, extra eyes on the forehead, and the development of wings with the muscles required for flight. The modified workers also showed the development of a unique organ inside queen ants that stores sperm. However, one significant difference between a natural-born queen and the modified worker ants was that the treated workers did not grow ovaries, which is crucial in making eggs. This data shows that the primary time where the juvenile hormone affects the ant's development does not happen in the egg, as while some changes were observed among the modified workers, the crucial component of ovaries for reproduction was missing. The research also helps explain how new types of ants, like soldiers, might have evolved in other ant species, as natural selection may have favored certain ants with higher levels of juvenile hormones. This hybrid ant between workers and queens may be more favorable for survival in natural selection leading to a new type of ant within the colony.

This study shows that ant colonies act a little like cells work in an animal's body, suggesting that how ants are developed in the colony is more flexible than first believed. The juvenile hormone controls the development of the ant, predetermining the job an ant will have within the colony. This research also allows us to see how much hormones affect a species when being developed as a kid and how it may affect the development.


Article: https://www.sciencedaily.com/releases/2024/11/241122130358.htm

Original Paper: https://journals.biologists.com/jeb/article/220/1/53/33443/Caste-development-and-evolution-in-ants-it-s-all

Common Gene Mutation linked to Longer Life in Males

An article in the New York Times discusses a gene described in the journal, Science Advances.  This gene has been found to increase the lifespan of males by ten years; the gene was found to have no effect on women.  Heredity is not the only factor that determines how long a person lives; in Germany the life expectancy in 1875 was 39 years, today the life expectancy is around 80 years.  The almost 50 year difference is a result of access to clean water, modern medicine, and other measures rather than evolution.  Although there are many outside factors, research has shown heredity definitely plays a large role in lifespan determination.  Many studies have shown identical twins have a much closer lifespan than fraternal twins due to the fact that they share the same genes.  Research on this topic has been rather disappointing to scientists; however, they did find a connection between the size of an animal and their lifespan.  Research has shown that smaller animals typically live longer than large animals.  These developments have lead researchers to look more closely at the molecules that causes our bodies to grow; specifically our growth hormones.  Researchers have found that about 1/4 of people have a mutation in the gene for growth hormone receptors which causes them to have a missing chunk of DNA.  Dr. Barzilai conducted a study using 567 Ashkenazi Jews and their children.  Dr. Barzilai found that 12% of men over the age of 100 possessed the growth hormone mutation which is about three times higher than the percentage of males over the age of 70.  For women in the study the gene was equally present in both age groups.  Researchers believe they have been able to establish a connection between longer-life and the growth hormones but need more research and a larger group to make a real connection.  A 2008 study showed a mutation in a different growth gene which only effected women; this shows that men and woman take a different genetic path toward longer lifespans.  Dr. Barzilai and many other scientists are still researching these genetic mutations and believe an answer is not far away.

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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Alzheimer's May Have Been Transmitted via Human Growth Hormone

Alzheimer's is a form of dementia that affects memory, thinking, and behavior. The human brain is composed of neurons, nerves, and many connection networks. Together, all of these parts of the brain work together like a factory. Alzheimer's prohibits the brain from acting and performing in this systematic and connected way.  Symptoms of this disease start with memory loss and confusion, and later lead to disorientation, changes in mood and behavior, unfounded suspiscions about family and friends, difficulty speaking, swallowing, and walking.

There is question as to whether there is a connection between human growth hormone and Alzheimer's transmission between humans.  Professor John Collinge noticed the relative connection as he extracted growth hormone from the pituitary gland of eight deceased patients; all of which had injected growth hormone as a child. It was found that all eight patients had contracted Creutzfeldt-Jakob Disease (CJD) via the hormone and died.  It was confirmed that none of the patients were carriers of known genes for Alzheimer's.  However, autopsies revealed that six of the eight patients had amyloid plaques, which are seen in patients with Alzheimer's.  To rule out the idea that CJD had a connection to amyloid proteins, a study was done on 116 deceased patients that died of CJD, but did not receive growth hormone. None of the deceased patients with CJD had any signs of the amyloid protein.  This meant that there was no connection between having CJD and amyloid proteins.  There was also no presence of tau tangles (proteins that are indicators of Alzheimer's).  However, researchers found that in people who died of Alzheimer's, there was presence of amyloid proteins. 

In my opinion, I believe there is an underlying connection between Alzheimer's and the human growth hormone.  In the article, it spoke of a study recently conducted that injected human amyloid brain material into the brains of mice.  This material remained dormant in the mouse's brain, but later on regained the ability to cause disease.  This shows that even though the amyloid protein remains inactive and basically "hides", it is still there and can cause disease later on in the organism's life.  I feel that this may be the case for humans.  For example in the case of the eight donors that had growth hormone extracted from their brains, they died of CJD which made it impossible to see if they contracted Alzheimer's later on in their lifetime.  Professor John Collinge definitely sparked a fire for Alzheimer's research to progress.

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

Longevity in Brandt's Bat

The Brandt's bat is a species of bats that only weighs four to 8 grams as an adult. However, it can live to more than 40 years. Usually, small animals live short lives, however, this species says otherwise. This species of bat has the greatest disparity between its weight and longevity. Researchers became interested in this species and published an article revealing insights on the longevity of the bat. Through gene sequencing and genome comparison, specific sequence changes in the growth hormone (GH) and insulin-like growth factor 1 (IGF1) receptors along with their adaptations like hibernation and low reproductive rate are seen to contribute to the bat's longevity. On a molecular level, the altered sequences in the GH and IGF1 are only sequences seen (as of right now) to have the strongest relationship to longevity.

Brandt's Bat

The fountain of youth, immortality, and extending life had always been a fascinating when I was growing up. Sure, immortality is still out of the question, but gene sequencing has brought aging under a whole new light. With genetics, the potential for slowing aging and extending life are now plausible. This research could lead to many revolutionary changes while also spring forth a whole variety of ethical concerns. Many issues that could be brought up may regard sustainability, the economy, and the future of aging. For future possible studies, a plan should be devised to use techniques based on gene regulation in order to extending life in other species of bat, or even other mammals.