DNA Methylation Provides Accurate Genetic Clock To Measure Biological Age of Tissues and Organs

A scientist at the University of California- Los Angeles, has discovered a genetic biological clock that accurately measures the biological age of tissues and organs in the body. Using a ntural process called DNA methylation and monitoring 353 biological markers, the clock can measure how each part of the body and its age is comparable to others. The scientist, UCLA geneticist and biostatistician Steven Horvath, Ph.D., noted for example that a woman's breast tissue, age faster than the rest of the body.

DNA methylation is a genetic process that alters the expression of genes in cells as cells divide and differentiate from embryonic stem cells into specific tissues. As mentioned in the embedded video, DNA methylation is similar to a light dimmer switch where it can suppress a specific type of gene from expressing itself.

Using 8,000 samples of 51 types of tissue, Dr. Horvath narrowed focused on 353 biomarkers that change with age and are present throughout the body. These markers measure the biological age of the target tissue rather than its chronological age.

The next step in the research would be to find out if stopping or halting this clock can also stop aging.

Mysterious Ancient Human - Denisova Hominins Travelled From Northern Asia to Australia

Neanderthals and Denisovans were closely related. DNA comparisons suggest that our ancestors diverged from theirs some 500,000 years ago.
Credit: NGC, CHIP CLARK, SMITHSONIAN INSTITUTION

Scientists from the University of Adelaide in Australia and Pthe Natural History Museum in the UK have proposed that human ancestor, Denisova hominins, managed to travel from Indonesia on the way to Australia and New Guinea and interbred with modern humans on the way. DNA studies show that Denovan DNA is not present in indegnenous humans at the northern asian region where the first of the species have been discovered but were prevalent in Australia, New Guinea and surrounding areas.

This observation means that Denisovans have managed to cross the Wallace line, one of the world's biggest biogeographic barriers which is formed by a powerful marine current along the east coast of Borneo.

The Denisovan species were discovered from a 41,000 year old finger bone fragment of a juvenile female found in the Denisova Cave in the Altai Mountains in Siberia, a cave which has also been inhabited by Neanderthals and modern humans. It is believed that Denisovans have coexisted in Asia with Neanderthals and early modern humans.

Denisovans are defined so far only by the DNA from one bone chip and two teeth and is generally referred to as the "Third Human".

Genetic Discovery Hints at Hereditary Risk of Esophageal Cancer and Barrett's Esophagus

Researchers at the Fred Hutchinson Cancer Research Center and the QIMR Berghofer Medical Research Institute in Australia studied the DNA samples and medical data of more than 8,000 patients and have found four genetic variants in DNA that is associated with increased risk of esophageal cancer and Barrett's esophagus.

Barrett's esophagus is a disorder in which the lining of the esophagus (the tube that carries food from the throat to the stomach) is damaged by stomach acid and changed to a lining similar to that of the stomach. There is a small chance that people afflicted with Barrett's esophagus develop esophageal cancer.

Previously, esophageal cancer and its precursor, Barrett's esophagus are blamed on factors such as obesity, gastroesophageal reflux , smoking and an unhealthy diet. This latest discovery hints that the disease can also be hereditary.

Developing More Efficient Hearing Aids Through OCH Transduction

Researchers are studying how the cochlea, located in the ear, processes and amplifies sound. This research could lead to better hearing aids.

Scientists have discovered that hearing relies on a mechanical traveling wave that is actively boosted by electromechanical forces in sensory outer hair cells (OHCs). By studying the process of OHC transduction, better devices that can send more accurate sound signals to brain can be developed.

Transduction is the conversion of a sensory stimulus (hearing, sight, taste, etc) to a sensory signal that the brain can process.

Just recently, scientists have also discovered a protein called TMHS that may be a critical component in converting soundwaves to electrical signals that the brain can process.

SIGIRR Protein Found To Protect Gut Flora From Toxins

Credit: Barcroft/Fame Pictures/NPR

Scientists have discovered that the SIGIRR protein protects the beneficial bacteria in the gut (known as Gut Flora) from toxins and substances that can cause food poisoning and bowel inflammation. The Single Ig IL-1-Related Receptor (SIGIRR) is a protein encoded by the SIGIRR gene in humans.

The human body carries over a thousand species of bacteria. Most of these can be found in the human intestinal tract or the gut. These bacteria, collectively called Human Gut Flora comprises about 500 species and is beneficial to the body.

Gut flora performs important functions such as fermenting unused energy substrates, training the immune system, preventing growth of harmful, pathogenic bacteria, regulating the development of the gut, producing vitamins (such as biotin and vitamin K) for the host, and producing hormones to direct the host to store fats.

Although the positive relationship between gut flora and the human body, there are certain situations and conditions that bacteria can cause infections, disease, and even cancer.

Mapping and DNA Sequencing the Genomes of Uncharted Microbial Organisms - Microbial Dark Matter

Great Boiling Spring in Nevada
Credit: Brian Hedlund, University of Nevada, Las Vegas

Scientists led by the U.S. Department of Energy Joint Genome Institute (DOE JGI) are mapping the genetic make up of previously uncharted branches in the bacterial and archaeal cells and organisms. These cells, referred to as "microbial dark matter" cannot be cultured in a laboratory and because they live in specific conditions and environments, are hard to reproduce.

Living organisms are divided into three kingdoms or domains, Eukaryota, Bacteria, and Archaea. They are classified based on their cellular organization, biochemistry, and molecular biology which each share on a fundamental basis with others in the domain regardless of the diversity.

Microbes are important to life. Bacteria, for example, comprises about 10% of a human body's weight and can be found in all organs and tissues. These organisms have great influence on a body's biological and even behavioral processes. The influence of microbial life is not restricted to the human body, it can also have influence over other areas such as the environment, global cycles, and also climate processes. A recent study points to microbes as the cause for rising methane levels in the ocean.

With this undertaking, scientists visited nine habitats around the world to collected uncultivated microbial cells from which they were able to reassemble and identify 201 distinct genomes. The data can be used to align with 28 major previously uncharted branches of the tree of life.

The nine habitats visited were Sakinaw Lake in British Columbia; the Etoliko Lagoon of western Greece; a sludge reactor in Mexico; the Gulf of Maine; off the north coast of Oahu, Hawaii, the Tropical Gyre in the south Atlantic; the East Pacific Rise; the Homestake Mine in South Dakota; and the Great Boiling Spring in Nevada.

Synthetic Biology: New Approach To Activating Genes

A new breakthrough in synthetic biology involves building a synthetic protein known as a transcription activator-like effectors or TALE (see image). TALEs are artificial enzymes that can be engineered to attach or bind to almost any gene sequences. This allows biologists and genetic engineers to turn on genes inside cells to levels that were not previously possible.

Synthetic biology is an emerging field of science (biology) where biological parts, devices and systems are designed and constructed for a specific purpose using cells and molecules. It also covers redesigning existing systems to address a specific situation. Synthetic biology covers technologies such as DNA nanotechnology and bionanodevices.

Synthetic biology involves creating cells that copy or mimic natural molecules or using natural cells and molecules and place them within a redesigned system. The purpose for synthetic biology is to understand the factors involved in a problem wherein observation and analysis are not enough. Construction of new models and redesigning biological systems are needed to further comprehend it. Being able to design and build a system further enhances the measure of understanding of the factors involved.

Currently, synthetic biology have developed devices that can diagnose diseases, monitor and identify cancer cells in the blood stream, and even be used to treat common diseases such as acne (See Related Links below).

This is done by creating cells through genetic manipulation. DNA manipulation is similar to coding a computer. The Human Genome Project successfully mapped and sequenced the human gene from both the physical and functional standpoints. By combining certain gene sequences that activate a process, a synthetic biologist can construct a biological system or device. This can be compared to using Lego building blocks to create a structure.

A common application for synthetic biology is creating artificial molecules that mimic natural molecules such as enzymes. Enzymes are large biological molecules responsible for chemical reactions within the body to keep it going.

XPD Protein Discovered To Scan For Damaged DNA

The XPD scanner (green)is in close contact with a damaged point (red) on the DNA double helix. The damaged DNA strand lies in a deep pocket of the protein to enable a ferrous sensor (Fe) to come into contact with the damaged point, thereby halting the protein as it moves along the DNA.
Image: UZH

Xeroderma pigmentosum group D (XPD) protein, a protein associated with repairing DNA has been discovered to also scan for damaged DNA.

Deoxyribonucleic acid (DNA) is a molecule that contains genetic code or instructions used for the development and function of living organisms. DNA encodes its genetic information through the sequence of four nucleotides (guanine(G), adenine(A), thymine(T), and cytosine(C)).

Whenever DNA is damaged through ultra-violet light, cigarette smoke, toxic fumes, toxins, X-rays and radiation, and metabolic processes, it is repaired by proteins and enzymes such as Superoxide dismutases and methyl guanine methyl transferase (MGMT). Roles of these proteins and enzymes vary from recognizing damage, to correcting the damaged portions or remove them.

Unrecognized damage which does not get repaired, accelerates aging and causes cancer and genetic disorders. There are DNA disorders that involve the body having difficulty repairing DNA. Xeroderma pigmentosum (XP) and Trichothiodystrophy (TTD) are two of these disorders.

A team headed by veterinary pharmacologist and toxicologist Hanspeter Nägeli has now discovered that the protein XPD plays a key role in locating damaged DNA.

Scientists Discover Molecule Responsible For Converting Soundwaves To Brain Signals For Hearing

Scientists have identified a critical component responsible for converting soundwaves into electrical signals that the brain can process into sound. The discovery of this protein called TMHS may lead to a better understanding of the hearing process and lead to novel treatments for deafness.

The ear converts soundwaves into neurological impulses that the brain can process into the sounds that we hear.

When soundwaves enter the ear, the eardrum starts vibrating and passes these vibration into the middle ear and is amplified as it goes to the inner ear. These vibrations are then translated into electrical signals that brain synapses can pass on to the brain.

There is a distinct shift from a mechanical process from the vibration of the eardrum to an electrical process where the brain synapses transmit these vibrations as electrical impulses.

Although the process of hearing is basically understood, the way the ear converts the vibrations caused by the sound waves into electrical impulses is not. By identifying the specific chemical or protein that is responsible for this conversion process, it can open up medical possibilities in improving conditions and therapy for the deaf and hearing impaired.

Fat Accumulation Can Be Blocked By Activating Androgen Receptors In The Body

New research show that the relationship between androgen receptors and glucocorticoids have an active role in the accumulation of fat which may result in obesity.

Nuclear receptors are proteins found inside cells that sense steroid and thyroid hormones and certain other molecules. Androgen receptors (AR) are nuclear receptors that sense and act on androgen, a hormone vital to male sexual development such as puberty. Androgen receptors respond to androgen hormones by binding to them which in turn attaches to the person's DNA.

Its role is to regulate the activity of androgen-responsive genes by activating or deactivating them. This helps the AR to regulate and direct the development of male sexual characteristics as well as functions in both males and females such as hair growth and sex drive.

Glucocorticoids

Glucocorticoids (GC) are natural occurring steroids that regulate the metabolism of glucose and its synthesis in the adrenal cortex.

GCs are used by the immune system to slow down or turn down immune system activity such as inflammation. These steroids also have the ability to control, regulate, and sometimes interfere with the internal mechanisms of cancer cells.

Because of these properties, glucocorticoids are used heavily in medical treatments that range from cancer therapy to autoimmune diseases. Despite the positive benefits GC properties have, it also has many other effects that may prove harmful when used without proper medical supervision.

A side effect on the use of glucocorticoids is that it can increase weight gain by encouraging fat buildup and appetite stimulation.

Manipulating hormone receptors may help in the fight against obesity

In the body's ongoing effort to maintain a healthy weight, an arsenal of cellular proteins called androgen receptors is critical for blocking fat accumulation. Now researchers reporting in the September issue of the Cell Press Journal Chemistry & Biology have discovered that naturally occurring steroids called glucocorticoids can thwart the receptors' activity, ultimately encouraging fat buildup.

"This has implications in this era of an obesity epidemic," says senior author Dr. Michael Mancini, from Baylor College of Medicine. "If you can reduce glucocorticoids, you might be able to upregulate, or increase, androgen receptor activity and regulate fat storage."

$500,000 Gruber Foundation Genetics Prize for 2012 Goes To Douglas C. Wallace

The Genetics Prize of the Gruber Foundation is presented to leading scientists in recognition of groundbreaking contributions in genetics research. It can be awarded from one to up to three scientists.

The Genetics Prize was established in 2001. It was awarded to Rudolf Jaenisch. His work has produced important advances in understanding cancer, neurological disorders, connective tissue diseases, and developmental abnormalities in bone and muscle.

Since 2001, the Prize, comprising of a gold medal and an unrestricted $500,000 cash award, has been awarded for fundamental insights in the field of genetics. These may include original discoveries in genetic function, regulation, transmission, and variation, as well as in genomic organization.

The Gruber Foundation is now established at Yale University.

$500,000 Gruber Foundation Genetics Prize goes to Philadelphia scientist

Douglas C. Wallace, PhD

Douglas C. Wallace, PhD, a pioneering genetics researcher who founded the field of mitochondrial genetics in humans, will receive the 2012 Genetics Prize of The Gruber Foundation. Wallace is being honored with this prestigious international award for his groundbreaking achievements in helping science understand the role of mitochondria—the "power plants" of cells—in the development of disease and as markers for human evolution.

He will receive the award November 9 in San Francisco at the Annual Meeting of the American Society of Human Genetics, where he will also deliver a lecture titled "A Bioenergetic Perspective on Origins, Health, and Disease".

"Douglas Wallace's contributions to our understanding of mitochondrial genetics have changed the way human and medical geneticists think about the role of mitochondria in human health and disease," said Elizabeth Blackburn, chair of the Selection Advisory Board to the Prize. Blackburn is the 2006 Gruber Genetics Prize laureate and shared the 2009 Nobel Prize in Physiology and Medicine.

DNA Nanotechnology To Create Programmable Nanodevices For Drug Delivery Created

Three different types of DNA single strands stepwise assemble into symmetric three-point-star motifs (tiles) and then into polyhedra in a one-pot process. There are three single-stranded loops (coloured red) in the centre of the complex. The final structures (polyhedra) are determined by the loop length (3 or 5 bases long) and the DNA concentration. Credit: Nature

James Watson and Francis Crick announced in 1953 that they had just discovered the secret of life. Their discovery, which they first announced in a Cambridge pub, is now accepted as the first correct double-helix model of DNA structure. It explained how cells divide and develop.

DNA contains information that cells use to create and maintain cells and organisms. The DNA segments carrying this genetic information are called genes. Nearly every cell in a person’s body has the same DNA.

The information are stored in four chemical bases: Adenine (A), Cytosine (C), Guanine (G) and Thymine (T). Depending how these bases are arranged, it dictates how the protein is constructed. The human DNA contains around three billion base pairs.

Harvard's Wyss Institute develops nanodevice manufacturing strategy using DNA 'building blocks'

Researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University have developed a method for building complex nanostructures out of short synthetic strands of DNA. Called single-stranded tiles (SSTs), these interlocking DNA "building blocks," akin to Legos®, can be programmed to assemble themselves into precisely designed shapes, such as letters and emoticons. Further development of the technology could enable the creation of new nanoscale devices, such as those that deliver drugs directly to disease sites.

The technology, which is described in today's online issue of Nature, was developed by a research team led by Wyss core faculty member Peng Yin, Ph.D., who is also an Assistant Professor of Systems Biology at Harvard Medical School. Other team members included Wyss Postdoctoral Fellow Bryan Wei, Ph.D., and graduate student Mingjie Dai.

Heliconius Butterflies Survive By Acquiring and Sharing Genetic Data From Other Species

Common Postman (Heliconius melpomene)

A species is a group of organisms that can interbreed in nature to produce a fertile offspring. It is a unit of biodiversity or the degree of variation of organic life forms within a given species, ecosystem, biome, or an entire planet.

Within a group of species, new biological species may arise. This is called speciation. It is the splitting from a main branch of species to form an altogether new line.

One such such species being studied and used as models for speciation are the Heliconius butterflies. Hybrid speciation has been hypothesized to occur in this genus and may contribute to the diverse mimicry found in Heliconius butterflies. The species Heliconius Heurippa is said to be a hybridized version of two Heliconius species; Heliconius Cydno and Heliconius Melpomene. Hybrid speciation is a form of speciation wherein hybridization between two different closely related species such as the two heliconius butterfiles leads to a novel species; the heliconius heurippa.

This form of speciation is popular among plants but is considered extremely rare outside of the plant world.

Colorful butterflies increase their odds of survival by sharing traits

Bright black-and-red butterflies that flit across the sunlit edges of Amazonian rain forests are natural hedonists, and it does them good, according to genetic data published today in the journal Nature.

An international consortium of researchers at UC Irvine and elsewhere discovered that different species of the Heliconius butterfly are crossbreeding to more quickly acquire superior wing colors. They also have a surprisingly large number of genes devoted to smell and taste.

The use of color to attract mates and fend off predators is widespread in daytime-loving butterflies, while night-flying moths are famous for having large antennae to sniff out potential mates' pheromones. Thus, researchers predicted that because they're such visual creatures, the butterflies would not be able to smell or taste very well.

Older Than Estimated - Genome Show Polar Bear Existed 600,000 Years Ago.

The polar bear is the world's largest land carnivore. It is also the largest bear. An adult male weighs around 350–680 kiloggrams (770–1,500 lb),while an adult female is about half that size.

The polar bear is native to the Arctic Circle.

Compared to its close cousin, the brown bear, the polar bear has many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet.

Polar bears are born on land but spend most of their time in the waters hunting seal. Their scientific name (Ursus maritimus) means "maritime bear", and derives from this fact. Polar bears can hunt their preferred food of seals from the edge of sea ice, often living off fat reserves when no sea ice is present.

Polar bears older than previously thought

Polar bears diverged from their closest relatives about 600,000 years ago, according to a new genetic study published in the April 20 issue of the journal Science.

The findings suggest the cold adapted species is about five times older than previously thought, and may have had more time to adapt to arctic conditions than recently assumed. Previous studies of polar bears focused mainly on mitochondrial or mtDNA, which is passed on from mother to offspring and only comprises a very small portion of the entire genome.