'Zombie Genes' Spur Some Brain Cells to Grow Even After Death

 

This newfound awareness of the activity of "zombie genes" has the potential to cause an affect on research  regarding diseases that affect the brain. For this study, researchers used fresh brain tissue taken from surgery. With this they found that some cells continued gene expression even after death. Dr. Jeffrey Loeb says, "Most studies assume that everything in the brain stops when the heart stops beating, but this is not so. Loeb and his team observed that these patterns of gene expression in that of fresh brain tissue did not match the published findings in tissue that was analyzed after death. 

I found this article to be very fascinating, because like Dr. Jeffrey Loeb said, I too believed that everything in the brain stopped when the heart stopped beating, however that was clearly proven incorrect. With further research on this topic, who knows what medical advances can comes from the continued activity of the brain after death.

Scientists Have Created Four New Letters of Artificial DNA

In an article written by Roni Dengler, “Scientists Have Created Four New Letters of Artificial DNA”,  he discusses the creation of four new letters of artificial DNA. These new letters were constructed by Steven Benner and his team. It is monumental to think that DNA holds the building blocks for life, and this alphabet is now doubled. Benner was able to accomplish the feat by using basic chemistry. It was simply a matter of making sure they were the right shape, substance, and able to make the necessary connections regular base pairs can. 

I found this article particularly interesting based on a discussion I had last year in Cells and Molecules. Our professor mentioned how it was not a matter of memorizing the base pairs, but more so understanding how they work. He said it did not have to be A, T, C, G, but it just had to be able to perform the chemistry with other pairs. This is the entire explanation to how uracil takes the place of thymine in RNA. 

Figure 1: Above conveys how base pairing is just the use of chemistry through hydrogen bonding. As long as the chemistry can happen, the base pair letter does not matter. 

Going back to the recent discovery, the new DNA already meets four out of the five requirements for life. Unfortunately, it needs to be able to be self sustaining to meet the fifth. However, there seems to be progress with the base pairs outside of the test tube already. 

A newer article, “Scientists Created Bacteria With a Synthetic Genome. Is This Artificial Life?”, by Carl Zimmer says scientists have created life from scratch. Using synthetic DNA, they have been successful in making a colony of E. Coli. We are actually able to use the DNA that we make. The article goes on to discuss the implications of such a discovery. Now, the world of science could potentially be able to create as Carl Zimmer writes, “living factories”. These could make important molecules or even medicine. 

Overall, it is quite miraculous that scientists were able to construct versions of the very things that construct ourselves. The article ends on the point that with this new discovery, we might have further insight into life outside of our planet. If it was possible to create a different genetic code, there could very well be life out there without the alphabet of A, T, C, and G. 

http://blogs.discovermagazine.com/d-brief/2019/02/21/scientists-doubled-the-genetic-alphabet/

https://www.nytimes.com/2019/05/15/science/synthetic-genome-bacteria.html

https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Map%3A_Organic_Chemistry_(McMurry)/Chapter_28%3A_Biomolecules_-_Nucleic_Acids/28.02_Base_Pairing_in_DNA%3A_The_Watson-Crick_Model

No Matter The Size Life Exists

After continuous study of the genes necessary for life, the first artificial organism with the smallest genome has been created. Mycoplasma mycoides JCVI-syn3.0, carries a total of 473 genes including 149 genes of unknown function. The creation of this organism involved constant back and forth trials to determine the genes that were needed to sustain life and allowed for reproduction. There was only one particular organism with a low genome such as the JCVI-syn3.0, and it was fully sequenced in 1995 by the same group of researchers and contains a total of 525 genes. The differences between 473 genes and 525 genes are size and reproduction rate. The size and growth rate for JCVI-syn3.0 makes it more practical for lab work and manipulation. This discovery makes way for study in areas of science related to cell customization for effective drug development and alternatives for fossil fuels.  In combination with CRISPR gene editing, biologists and scientists are changing the future of biology.

Article

Mycoplasm Mycoides Before the Creation

The Origin of Life on Earth

Based on many years of data and observations, scientists approximate the Earth to be around 4.5 billion years old. The earliest evidence of life that has been found exists in Greenland, and consists of fossilized remains of cyanobacteria, otherwise known as stromatolites. These fossils date back to 3.7 billion years ago, and even still, scientists believe that life may have gone back even further, due to rocks in Australia that contain high levels of carbon--an element that is majorly involved in most biological processes. This evidence raises the question of how life actually formed all those years back, and many different scientists propose different theories. Some of these include life coming from outer space, finding its way to Earth by means of an asteroid or comet. Others believe that there are several origins of life, and that life formed on Earth through a series of chemical reactions. These reactions are hypothesized to have led to the creation of self-sufficient systems that formed organisms. Whether one theory is correct or not, scientists still do not know for sure. However, by looking at the existing evidence, such as the cyanobacteria that is still around today, and by examining RNA and DNA qualities, they have a better idea of what very well might have been.

Scientists have widely accepted the idea that the primary molecule for life was RNA, a molecule made up of nucleotides that aids in protein synthesis and works as an on/off switch for many genes. However, upon the emergence of DNA, RNA was replaced due to the more stable and better performing nature of DNA. Since DNA is the basis of all life in organisms today, we can study it and gain multitudes of knowledge from studying its structure and functions. Perhaps we will never know the exact origins of life on Earth, but by continuing research on these molecules that we know have been around since the start, there is a much better chance at getting there. I think that the fact that we do not know the exact origin of life on Earth is very interesting because there are so many different explanations that can account for it. However, the fact that we know that RNA was the primary molecule is a step in the right direction because we have a lot of knowledge about it, and continue to study it nowadays. Perhaps one day we will make a discovery that answers how exactly life began on Earth, but until then we can only wonder.


Link: http://www.livescience.com/1804-greatest-mysteries-life-arise-earth.html

On the Origin of Life: Studying how the First Biomolecule Self-Replicated

Researchers propose that RNA is the "mother" molecule that led to the formation of life.  In order to reproduce; plants, animals and other organisms need to make copies of their DNA and pass it on to the next generation.  This is possible with the aid of enzymes and through Watson-Crick Base Pairing (genetic material is made up of nucleotide bases which match to one another in a specific order).  Scientists hypothesize that before life began, there had to be one molecule that was able to replicate without any help.  They suspect that this molecule is RNA due to its ability to specific base-pairing like DNA, and catalyzing reactions like an enzyme.  Jack Szostak and colleagues used X-ray crystallography to monitor how free nucleotides interacted with a short piece of RNA.  They did this to investigate how RNA matches up with free base pairs.  The RNA formed the expected Watson-Crick pairs as well as other different match ups that may have stopped replication.  This information led scientists to believe that steps toward life may have taken much longer than expected.

https://www.sciencedaily.com/releases/2016/11/161102085329.htm
https://www.acs.org/content/acs/en.html

Asians and Europeans; Lactose-Intolerant 5,000 Years Ago

     Studying ancient DNA has always been a big part of genetics as it gives insight into the past history of humans. What was generally already found is that around 5,000 years ago, Europeans and Asians are generally light-skinned and - surprisingly - lactose intolerant. During the Bronze Age, which ranged from the years of 3,000 - 5,000 years ago, was a time of mass human migrations throughout the region of Europe and Asia. Because of these large migrations, the present-day demographic structure has been developed. 

     Researchers have sequenced genomes from 101 unearthed ancient humans from Europe and Asia. Although DNA sequences have previously been studied using ancient DNA, the new technology that is available makes for clearer data. It has recently been discovered by Morten Allentoft of the University of Copenhagen’s Natural History Museum and his colleagues that light-skinned Europeans were present at a high frequency already in the Bronze Age, thus implying that light-skinnedness was first developed previous to 5,000 years ago. Another conclusion from their data tells that during the Mesolithic hunter-gatherer age, the presence of blue eyes was already established. 

     These data are set to answer the question, could there be a greater distribution of Neanderthal DNA in the genomes of Europeans and Asians? This is still unclear, however the findings suggests that these humans were settled into Europe and Asia before the Bronze Age.

     Something also interesting about the data is that 5,000 years ago, humans had not evolved the enzyme to break down lactose - the sugar found in milk. In an evolutionary perspective, this makes sense because ancient humans and - in fact, mammals in general - do not need to drink milk to survive after infancy, thus the lactose intolerance. When humans began to produce the enzyme to break down that indicated the start of domestication of animals which did not occur much before 5,000 years ago thanks to the data. 

     I personally think that this article is interesting because there are people who today are still lactose intolerant. The article tries to explain this as their ancestors did not drink much milk, thus never needing the enzyme to break down lactose. It is amazing how using the preserved DNA from bones that have been under the earth for so long can lead to vast discoveries like this. This discovery tells a lot about the time line of when humans became what we are today.

Original Article

More about the Bronze Age

A New Tree

 

 

Professor Simon Turner from the Faculty of Life Sciences led the research: "The rate at which trees grow is determined by the rate of cell division in the stem. We have identified two genes that are able to drive cell division in the stem and so override the normal growth pattern." The two genes they found were PXY and CLE. They control the growth of the tree trunk, when overexpressed the trees grew faster, wider, taller and produced more leaves.

 

I think this is great research being done and can lead to a better future. It could help with global warming. It would lead to more oxygen being released into the air than CO2. Because at the rate we at we will be walking around with oxygen tanks on our backs.

 

Source:

http://www.sciencedaily.com/releases/2015/04/150416083355.htm

Hope to Live to 100? Check Your Genes

          Healthy eating and exercise might help most people live to a respectable old age, but making it to 95 or 100 might require help from your DNA. A Study led by the professor of biostatistics, found that people who lived to age 90, the chances that their siblings also reached 90 was only about 70 percent higher than for the average person born around the same time. When studied further, it was statistically shown that siblings of people who lived to age 95,  had a 3.5 times higher than the normal chance of also reaching the age of 95. For people who lived to 100, the chances of their siblings also reaching 100 was 9 times higher than normal. And for the few who lived to 105, the chances of their siblings also reaching 105 was 35 times higher than normal.  Researchers say that genes play a strong role in living to extreme ages. Also, that the combinations of longevity-linked genes that help people live to 95, may be different than the ones who help people live to 105.

I find it interesting that genes play a role in age, especially because it is thought that all you need to live a long life is to be healthy. It would be cool to see if future geneticists could somehow alter genes to lengthen peoples lives. 

original Article 

Physical Activity is Beneficial for Late-life Cognition

In a study conducted at the University of Eastern Finland, it was found that those individuals who engage themselves in any form of physical activity at least twice a week had a lower risk of dementia than individuals who were less active. Individuals continuing physical activity after midlife were also found to lower their risk of dementia as well. Leisure-time physical activity (LTPA) has always been important to one's ones in general, especially, their cardiovascular health. The correlation between LTPA and lowering the risk of dementia was seen to be particularly strong among overweight and obese individuals.

Since the sample size was relatively small, I would like to definitely see some more studies conducted to confirm this correlation being made. More information about dementia can be read from WebMD.