Showing posts with label DNA. Show all posts
Showing posts with label DNA. Show all posts

Tuesday, 3 December 2024

The African Roots of Humanity: A Journey Through Time and Space

https://drive.google.com/uc?export=view&id=1LXL1qk5zeM_AP8M57tvs4VbJPLZJW1JQ


It is an undeniable truth: every human being on this planet shares a common origin, and that origin is Africa. From the bustling cities of New York to the serene landscapes of rural Asia, the genetic and anthropological evidence leads us back to one place—Africa, the cradle of humanity.


Around 60,000 years ago, our ancient ancestors began their great migration out of Africa, spreading across the continents and populating the world as we know it. This migration was not a single journey but a complex web of movements over tens of thousands of years, influenced by changing climates, evolving ecosystems, and the innate human drive to explore.


The Evidence: DNA and Fossils Speak


Scientific advancements have allowed us to trace this epic journey with remarkable clarity. The analysis of mitochondrial DNA (passed down from mothers to their children) reveals that all non-African populations can trace their ancestry to a single group that left Africa approximately 60,000 years ago. Fossil evidence supports this timeline, with early human remains discovered in the Levant and beyond, showing a clear pattern of migration.


Dr. Spencer Wells, a geneticist and National Geographic Explorer-in-Residence, explains, “The human journey represents a genetic thread that connects all of us in a single global family tree.”


Africa: The Birthplace of Innovation


Africa was not merely the starting point of this journey but also the birthplace of human ingenuity. Early humans in Africa developed tools, mastered fire, and began forming complex social groups. These innovations were critical for survival and laid the foundation for modern civilisation.


Paleoanthropologist Dr. Richard Leakey once remarked, “The extraordinary thing about human beings is their adaptability. That is what allowed our ancestors to leave Africa and ultimately populate the entire world.”


Breaking Down the Myths of Division


Understanding our shared African heritage is a powerful antidote to the myths of division that have plagued humanity. Despite cultural, linguistic, and physical differences, the genetic variations between humans are minuscule. As the geneticist Dr. Craig Venter famously noted, “There is only one race—the human race.”


Recognising our shared origins fosters a sense of unity and reminds us of the interconnectedness of all people. It is a reminder that the story of migration, survival, and innovation is not just the story of some of us—it is the story of all of us.


A Call to Celebrate Unity


Today, as humanity faces global challenges like climate change, pandemics, and social inequalities, acknowledging our shared ancestry is more important than ever. We are all descendants of a group of pioneering Africans who dared to explore beyond their known world, carrying the seeds of what would become a global civilisation.


Let us celebrate the fact that, whether we identify as European, Asian, Australian, or any other identity, we are all Africans under the skin. In the words of Nelson Mandela, “We must use time creatively and forever realise that the time is always ripe to do right.” It is time to embrace our shared heritage and work together for a brighter, united future.


The story of humanity is a story of resilience, migration, and innovation, rooted deeply in the African soil. And that, whether we like it or not, is a truth worth celebrating.

Tuesday, 21 March 2023

Intermittent fasting may change how your DNA is expressed

A new study found that a time-restricted diet reshaped nearly 80 per cent of all gene expression in mice — leading to reductions in obesity, health improvements and more.
A new study found that a time-restricted diet reshaped nearly 80 per cent of all gene expression in mice — leading to reductions in obesity, health improvements and more.

Mice who only ate at specific times of the day experienced “profound” changes in genetic expression, leading to health benefits like reduced risk of obesity and inflammation, new research found.

To an extent, it’s not about  what you eat as much as when you eat it — so says recent research that sheds new light on the benefits of intermittent fasting. 

The study, published Tuesday in journal Cell Metabolism, found that mice fed only during certain blocks of time experienced “profound” changes in gene expression. Nearly 80 per cent of all genes were impacted in some way, the paper reads.

The changes resulted in a plethora of health benefits, the authors wrote, including: improved blood sugar regulation, decreased risk of obesity and even a reversal of certain hallmarks of ageing.
You can think of a gene as the blueprint for a specific protein, written in DNA. When a gene is expressed, the blueprint is converted into its protein product by cellular machinery. Because proteins are responsible for most cellular functions from fat metabolism to immune response, even slight changes in gene expression could leave a massive impact.

According to the research, restricting when mice could eat reshaped when and to what extent certain genes were expressed — for example, some organs learned to switch on the genes for regulating blood sugar when it came feeding time, and to repress them when it was time to fast.

The researchers say their findings opened the door for further research into how dietary interventions might impact our genes and what this means for those suffering from issues like diabetes, heart disease and cancer.

What is time-restricted eating?

Shaunak Deota, first author of the study and a post-doctoral fellow at the Salk Institute for Biological Studies in San Diego, explained time-restricted eating as “eating consistently in a narrow window of 8 to 10 hours” when one is most active and fasting the remainder of the day. Intermittent fasting is a form of this practice, he said.

By feeding and fasting at the same time every day, we are reinforcing a biological rhythm in our bodies, Deota said: “Our body is getting the food at the same time every day, so all our organ systems know when the food is going to come and they’re prepared for it.”

Previous studies have shown that time-restricted eating may reduce the risk of obesity and diabetes, help to improve cardiovascular health, provide benefits for gut function and cardiovascular health and more.

Deota’s research now contributes, to his knowledge, the first “holistic” look at how time-restricted eating impacts the body as a system.

To achieve their results, the researchers put two groups of mice on the same high-calorie diet. One group was only allowed to eat during a nine-hour window when they were most active. The other could feed whenever they wanted.

After seven weeks, the mice on a time-restricted diet gained less weight than their counterparts, despite eating the same amount of food. 

The researchers then killed 48 of the mice — 24 from each group — to investigate the diet’s impact on the body. They sacrificed two mice from each group every two hours over a 24-hour period, noting how their organ systems changed over time.

How time-restricted eating changes the body

After studying the mouse organs, Deota and his team made a “pretty surprising” discovery; mice on the time-restricted diet had synchronized their gene expression with their feeding schedules.

“That is important because these genes will get translated into proteins,” Deota said. “Those proteins are helping our body to anticipate that there is food coming.”

According to their paper, roughly 70 per cent of all mouse genes fell into rhythm with the feeding schedule. Come mealtime, individual organs could promote genes in charge of nutrient metabolism while suppressing those responsible for inflammatory signalling and immune activation.

Moreover, the scientists found the diet reversed several hallmarks of aging, leading to reduced inflammation, increased cellular housekeeping, improved RNA and protein balance and more.

“Molecularly speaking, we saw a lot of pathways which are activated by (the time-restricted diet) in multiple organ systems. And a lot of these pathways actually have been implicated in improving health and leading to a longer, healthy life,” Deota said.

The limitations

All that being said, we need to remember these results were seen in mice, not humans — we’re still a long way off from demonstrating the same phenomenon happens in people, said Dani Renouf, a registered dietitian at St. Paul’s Hospital in Vancouver. For now, these results represent a “wonderful start to a conversation.”

“We’re just prototyping at this point because we’re using animal models and looking at things on a cellular level,” she said. “In order to now make conclusions in human beings, we need to take several steps before we can definitively do that with time restricted-eating.”

Renouf also noted the experiments took place in a tightly controlled environment. Real life is messy and chaotic, she said, and will likely influence results.

On the flip side, Deota believes “most of these benefits can be translated to humans” because his lab’s findings line up with what clinical studies into time-restricted eating have discovered.

Wednesday, 19 February 2020

SCIENTISTS CREATE ARTIFICIAL GENOME THAT CAN REPRODUCE

https://drive.google.com/uc?export=view&id=16gNbc-4CIpGroJsCrn4kWkOV91zIOQJz
German scientists say that for the first time ever, they’ve created a lab-grown artificial genome that can reproduce itself like a natural one.

It’s not quite one of those replicants from “Blade Runner,” but it’s a step toward the holy grail of synthetic biology: fully artificial organisms that can survive and reproduce like the real thing.
In a paper published in the journal Nature Communications this week, researchers from the Max Planck Institute of Biochemistry describe how they assembled genomes made up of blueprints for proteins — and demonstrated that it was capable of replicating 116 kilobytes worth of its own RNA and DNA.

Next up, according to a press release, the team plans to build an “enveloped system” that can reproduce like this last one — but also consume nutrition and dispose of waste, like a living cell.

READ MORE: Reproductive genome from the laboratory [Max Planck Society]


Monday, 5 June 2017

A World First CRISPR Trial Will Edit Genes Inside the Human Body

A new CRISPR trial, which hopes to eliminate the human papillomavirus (HPV), is set to be the first to attempt to use the technique inside the human body. In the non-invasive treatment, scientists will apply a gel that carries the necessary DNA coding for the CRISPR machinery to the cervixes of 60 women between the ages of 18 and 50. The team aims to disable the tumor growth mechanism in HPV cells.
The trial stands in contradistinction to the usual CRISPR method of extracting cells and re-injecting them into the affected area; although it will still use the Cas9 enzyme (which acts as a pair of ‘molecular scissors’) and guiding RNA that is typical of the process.
20 trials are set to begin in the rest of 2017 and early 2018. Most of the research will occur in China, and will focus on disabling cancer’s PD-1 gene that fools the human immune system into not attacking the cells. Different trials are focusing on different types of cancer including breast, bladder, esophageal, kidney, and prostate cancers.

MODIFYING OUR WORLD

The study, if it succeeds, will be promising for sufferers of HPV and act as a milestone in the CRISPR process. Although HPV is not necessarily cancerous, it can cause cervical cancer. In the U.S. alone, there are more than 3 million new infections every year. Although there is a vaccine for the virus, currently, once you have it you can never get rid of it.
More generally, the CRISPR process could be nothing short of a miracle: if it passes all medical tests it wouldn’t just make medicine a whole new kettle of fish, it would reinvent the kettle…and the fish, for almost any field. It is cheaper than other gene editing therapies, and could potentially save millions of lives by curing diseases we can only deal with therapeutically like cancer, diabetes and cystic-fibrosis. Crops could be altered more effectively using the process. Drugs and materials that were never possible before could be pioneered.
However, it is still extremely nascent technology, and many fear that there could also be a host of unexpected consequences. Recently, it has been found that it causes hundreds of unexpected mutations in DNA. While these concerns are valid, more research is necessary. Which is why the upcoming studies over the next few years are so vital to the future of our health.
References: New Scientist, Newsline, Clinicaltrials.gov

Sunday, 26 March 2017

Secret of Our Life

The true secret to life does not lie within your DNA, but rather within the mechanisms of your cell membrane.
Each cell membrane has receptors that pick up various environmental signals, and this mechanism controls the "reading" of the genes inside your cells. Your cells can choose to read or not read the genetic blueprint depending on the signals being received from the environment. So having a "cancer program" in your DNA does not automatically mean you're destined to get cancer. Far from it. This genetic information does not ever have to be expressed...
What this all means is that you are not controlled by your genetic makeup. Instead, your genetic readout (which genes are turned "on" and which are turned "off") is primarily determined by your thoughts, attitudes, and perceptions!
The major problem with believing the myth that your genes control your life is that you become a victim of your heredity. Since you can't change your genes, it essentially means that your life is predetermined, and therefore you have very little control over your health. With any luck, modern medicine will find the gene responsible and be able to alter it, or devise some other form of drug to modify your body's chemistry, but aside from that, you're out of luck… The new science, however, reveals that your perceptions control your biology, and this places you in the driver's seat, because if you can change your perceptions, you can shape and direct your own genetic readout.