sciencenote:

Skin Cells Reveal DNA’s Genetic Mosaic

“We found that humans are made up of a mosaic of cells with different genomes,” said lead author Dr. Flora Vaccarino, the Harris Professor of Child Psychiatry at the Yale Child Study Center. “We saw that 30 percent of skin cells harbor copy number variations (CNV), which are segments of DNA that are deleted or duplicated. Previously it was assumed that these variations only occurred in cases of disease, such as cancer. The mosaic that we’ve seen in the skin could also be found in the blood, in the brain, and in other parts of the human body.”

…

“In the skin, this mosaicism is extensive and at least 30 percent of skin cells harbor different deletion or duplication of DNA, each found in a small percentage of cells,” said Vaccarino. “The observation of somatic mosaicism has far-reaching consequences for genetic analyses, which currently use only blood samples. When we look at the blood DNA, it’s not exactly reflecting the DNA of other tissues such as the brain. There could be mutations that we’re missing.”

“These findings are shaping our future studies, and we’re doing more studies of the developing brains of animals and humans to see if this variation exists there as well,” Vaccarino added.

fuckyeahneuroscience:

Scientists Identify Gene Required for Nerve Regeneration | Sci-News.com

A gene that is associated with regeneration of injured nerve cells has been identified by a team of researchers led by Prof Melissa Rolls of Penn State University.

The team has found that a mutation in a single gene can entirely shut down the process by which axons – the parts of the nerve cell that are responsible for sending signals to other cells – regrow themselves after being cut or damaged.

“We are hopeful that this discovery will open the door to new research related to spinal-cord and other neurological disorders in humans,” said Prof Rolls, who co-authored a paper published online in the journal Cell Reports.

“Axons, which form long bundles extending out from nerve cells, ideally survive throughout an animal’s lifetime. To be able to survive, nerve cells need to be resilient and, in the event of injury or simple wear and tear, some can repair damage by growing new axons,” Prof Rolls explained.

Previous studies suggested that microtubules – the intracellular ‘highways’ along which basic building blocks are transported – might need to be rebuilt as an important step in this type of repair.

“In many ways this idea makes sense: in order to grow a new part of a nerve, raw materials will be needed, and the microtubule highways will need to be organized to take the new materials to the site of growth,” Prof Rolls said.

The team therefore started to investigate the role of microtubule-remodeling proteins in axon regrowth after injury. In particular, they focused on a set of proteins that sever microtubules into small pieces. Out of this set, a protein named spastin emerged as a key player in axon regeneration.

Above: In fruit flies with two normal copies of the spastin gene, a team of scientists led by Prof Melissa Rolls of Penn State University found that severed axons were able to regenerate. However, in fruit flies with two or even only one abnormal spastin gene, the severed axons were not able to regenerate (Melissa Rolls / Penn State University)

Original paper here. 

wespeakfortheearth:

Imperiled Orangutans Need Key Forest Corridor

Sumatran orangutans are in trouble: Only about 6,600 of the animals are left, scattered throughout the northern tip of the Indonesian island where they once flourished.

A new genetic study of the animals has found that deforestation on Sumatra has isolated different groups of the primates, which could lead to inbreeding and further decline. But the research also identified a critical corridor of forested hills that orangutans still travel though, which, if protected, could help the species rebound, according to a release describing the study.

The investigators took DNA from wild orangutan’s hair and fecal samples, as well as blood samples from orangutans from known areas that were kept as pets before being confiscated by authorities.

stressface:

One plant yields 3 clues to biofuel crops

The analysis of gene activity by researchers at Iowa State University and determination of protein structures by scientists at the Salk Institute for Biological Sciences independently identified three related proteins that appear to be involved in fatty-acid metabolism. The researchers used thale cress (Arabidopsis thaliana) as the model plant.

The research groups then joined forces to test this hypothesis, demonstrating a role of these proteins in regulating the amounts and types of fatty acids accumulated in plants.

The researchers also showed that the action of the proteins is very sensitive to temperature and that this feature may play an important role in how plants mitigate temperature stress using fatty acids.

The discovery is published online in the journal Nature.

“This work has major implications for modulating the fatty-acid profiles in plants, which is terribly important, not only to sustainable food production and nutrition but now also to biorenewable chemicals and fuels,” says corresponding author Joseph Noel, a professor and director of the Jack H. Skirball Center for Chemical Biology and Proteomics at the Salk Institute and an investigator with the Howard Hughes Medical Institute.

In this photo: The blue areas in this thale cress plant indicate where the fatty-acid-binding protein one gene is expressed and also correspond to regions where high fatty acids would be synthesized by the plant. (Credit: Eve Syrkin Wurtele and Micheline Ngaki)

Read more here.

Why Some Wild Animals Are Becoming Nicer

Image: ‘The Smiling Macaques’, Tonkean macaques are the least aggressive of all macaque species. They even seem to smile.

Nature is supposed to be red in tooth and claw, and domestication an artificial process for making animals gentle. But it appears that some corners of the animal kingdom are becoming kinder, gentler places. Certain creatures may be domesticating themselves.

This possibility is most apparent in bonobos, a close cousin of chimpanzees. Unlike their violent cousins, bonobos are generally peaceful. And while many animals have evolved to be socially agreeable, bonobos — and possibly other species — seem to be experiencing something more precise and profound: the physical and behavioral changes specifically described in studies of domestication, but as a natural evolutionary process.

“Normally you think of domestication as something that happens at the hands of humans,” said Brian Hare, a Duke University evolutionary anthropologist and co-author of a bonobo research review published Jan. 20 in Animal Behaviour. “The idea that a species domesticated itself is a bit crazy, but there are some species that outcompeted others by becoming nicer.”

scinerds:

To Track Mental Illness, Researchers Are Taking the DNA Of Century-Old Brains In Jars

Zombies aren’t the only ones craving brains, add Scientists to the list..

DNA extracted from canned human brains could help researchers studying mental health disorders, if scientists can figure out how to mine it. Preserved brains taken from autopsied patients — some dating to the 1890s — could serve as a new archive of old data related to mental health.

scinerds:

Babies with Three Parents Possible within Three Years

Researchers have secured £6m in funding to develop the groundbreaking treatment which could prevent genetic conditions affecting the heart, muscle or brain being passed on to children and future generations.

But the method is controversial because it involves transferring the parents’ DNA into a donor egg, meaning the resulting child would inherit a tiny fraction of their genetic coding from a third party.

While regulations currently forbid scientists from implanting such eggs into patients, the Wellcome Trust and Newcastle University has announced a £5.8m package for further lab-based research aimed at assessing the safety of the technique.

Read More

sagrasa:

Psychedelic Bacteria: fluorescent Bacillus subtilis (No photoshop) by Fernan Federici on Flickr.

Pattern formation with fluorescent bacteria (TagBFP, mKate2 and sfGFP).

Genetics & ‘Ganja’: Genome of Marijuana Sequenced and Published

DNA sequencing hit a new high with the release of the Cannabis sativa genome. The raw sequence was posted on Amazon’s EC2 public cloud computing service by a young company called Medicinal Genomics, which aims to explore the genomes of therapeutic plants.

Thus far the company is only posting the raw sequence reads – meaning that the over 131 billion bases of shotgun sequence have not yet undergone the important and arduous process of being assembled into contiguous chunks. For now, the sequence is fragmented into hundreds of thousands of snippets. But Medicinal Genomics founder Kevin McKernan says he estimates the size of the C. sativa genome to be about 400 million bases – roughly three times the genome of that other weed, the model plant Arabidopsis thaliana.

And in case you’re wondering: the DNA was extracted and prepped for sequencing in a laboratory in Amsterdam.

McKernan says he was turned on to the idea of sequencing cannabis by a 2003 publication in Nature Reviews Cancer about the many potential uses – including fighting cancer – of cannabinoids. C. sativa makes about sixty of the compounds. Although THC has gotten the most attention, McKernan hopes his company’s data will help scientists explore a few of the others, and perhaps guide plant breeding programs to generate new Cannabis strains.

Read More via: Nature

scinerds:

Butterflies and Genomes

Each fall, millions of monarch butterflies from across the Eastern United States use a time-compensated sun compass to direct their navigation south, traveling up to 2,000 miles to an overwintering site in a specific grove of fir trees in central Mexico. Scientists have long been fascinated by the biological mechanisms that allow successive generations of these delicate creatures to travel such long distances to a small region roughly 300 square miles in size.

Understanding the relationship between genes, behavior and physiological adaptations in monarchs may also lead to new insights into similar connections in humans. Circadian clocks, for instance, are a crucial component in the complex time-compensated sun compass system governing a monarch’s ability to navigate long distances, and are now understood to play a pivotal role in human biology. Temporal variations in hormone levels, pharmacokinetics and disease processes, such as the increased incidence of heart attacks in the early morning, reveal the prominent influence of the circadian clock on human physiology. Understanding the molecular mechanisms of the circadian clock has already helped reveal how clock gene mutations contribute to disorders of the timing of sleep, and new insights could illuminate how clock gene mutations contribute to diseases such as major depression and seasonal affective disorder.

The First Lady of DNA

The story of Rosalind Franklin never ceases to fascinate, and the publication of her biography as told by Brenda Maddox is indeed pertinent: celebrating 50 years of the most illuminating discovery in life sciences, namely the revelation of the structure of DNA. In the 25th of April 1953 issue of Nature, three consecutive short papers ushered in a new era in biology by unveiling an ingenious model of the DNA structure, together with the X-ray diffraction data crucial for its formulation.

The best known of the three papers is the one by James Watson and Francis Crick, who both then worked at the Cavendish Laboratory of Cambridge University. Watson and Crick proposed that DNA forms a right-handed helix composed of two anti-parallel DNA strands, which are kept together by specific hydrogen bonds between adenines and thymines and between guanines and cytosines. The notion of complementarity was born, and it immediately suggested a conceptually simple mechanism for copying genetic information over generations of cells and organisms.

The other two papers presented X-ray data obtained by two research groups at King’s College, London, one led by Maurice Wilkins and the other by Rosalind Franklin. It was Wilkins who initiated the X-ray diffraction studies of DNA fibres and who obtained the first promising diffractograms suggesting that DNA could be helical.

However, it required the experience and experimental skills of Franklin to obtain high-quality X-ray diffractograms that contained the definitive information that Watson and Crick needed to propose their famous DNA model.

scinerd:

Your Living Conditions as a Child May Be Detectable In Your DNA for Life

Findings published today in the International Journal of Epidemiology suggest that socio-economic status and living standards early in life may actually cause changes to your DNA that you carry with you for life, regardless of how your living conditions change along the way.

Some adult diseases—type 2 diabetes, coronary heart disease, etc.—have been linked to socio-economic disadvantages in early life. But we don’t really know why or how. Researchers in Canada and the UK may have just found the key.

Their sample size is admittedly small, but what they found was significant. In 40 research patients in the UK that are participating in an ongoing study that has documented many aspects of their lives, researchers looked at differences in gene methylation. Methylation is an epigenetic modification to one’s DNA that changes a gene’s activity, generally reducing that activity within the genome.

Various factors can influence methylation, including environmental conditions.