Toggling CRISPR Activity with a Chemical Switch

Researchers design a Cas9 enzyme that cuts DNA only in the presence of particular drug.

 

There are various ways to turn CRISPR/Cas9’s gene-editing activity on and off in cells, such as exposing tailor-made Cas9 enzymes to a particular type of light or to specific drugs. Each technique developed so far has drawbacks—either being complicated or irreversible. So researchers took inspiration from the Cre-recombinase-based method to control gene expression and built a “user-friendly” protocol for reversibly activating and inactivating CRISPR.

 

Read at TheScientist

Hematopoietic Stem and Progenitor Cell Gene Therapy

The recent regulatory approval of the first hematopoietic stem and progenitor cell gene therapy (HSPC-GT) signals the start of a new era for gene therapy and highlights the potential contribution by high-throughput cell culture technologies in propelling HSPC-GT from curing rare diseases to curing more common diseases.

Hematopoietic stem cells (HSCs) are the “fountain” for all blood cells that circulate in our bodies throughout life. Arguably, no other cell type has more profound and far-reaching influence on our well-being than HSCs. They reside in our bone marrow and continuously produce a variety of cells with vital tasks, for example, oxygenation via red blood cells, termination of bleeding via platelets, and immunity via leukocytes, which also provide immune defense to the central nervous system.

There is, however, a flipside to the pre-eminence of HSCs. When faulty HSCs emerge, devastating outcomes can ensue, such as autoimmune diseases like multiple sclerosis and blood cancers like leukemia. Thankfully, a solution to these life-threatening indications is well at hand because HSCs can be removed and replaced with healthy HSCs using HSC transplantation (HSCT)—a highly effective procedure pioneered by Nobelist E. Donnall Thomas over five decades ago.

 

Read at GEN

Genetic Studies’ Lack of Diversity May Lead to Misdiagnoses, Researchers Say

Harvard team concludes black patients’ gene mutations were misclassified as a higher heart-condition risk

Doctors increasingly rely on genetic testing to help diagnose a patient’s illness or risk of getting a disease. Now a new study warns of the potential for the technology to lead to misdiagnosis.

The study looked at gene mutations previously linked to the genetic heart condition called hypertrophic cardiomyopathy and found that some patients may be at risk of being falsely diagnosed with the disease because some of the mutations are no longer considered a cause for concern.

 

Read at WSJ

DNA revelations from Ötzi the Iceman’s leather and furs

5,300-year-old mummy found in the Italian Alps wore clothes made from many different animals.

or the past two decades, scientists have analyzed every minute detail of Ötzi, a 5,300-year-old natural mummy found in the ice of the Italian Ötztal Alps. But one remaining mystery was the provenance of his clothing, made from leather and fur. Now, thanks to refined techniques in DNA sequencing, a team of scientists has identified how the clothing was made—and discovered something surprising about Ötzi’s domestic habits.

Ötzi lived during the Copper Age, when humans had been domesticating animals for a few thousand years, and our cutting-edge technologies included stone tools and fired pottery. From previous studies, we know that Ötzi was likely murdered by an arrow and a blow to the head. We also know he suffered from arthritis, and he ate a meal of deer and berries before he died.

The team’s new findings, published in Nature Scientific Reports, are as much a demonstration of DNA sequencing wizardry as they are about ancient fashion. It’s incredibly difficult to get genetic material out of tanned hides, because they’ve generally been scraped, heated, and exposed to fatty acids. Plus, the hides and furs themselves had disintegrated. But the researchers used several methods for extracting DNA from the hides that made up Ötzi’s shoelace, hat, loincloth, coats, leggings, and quiver. First they compared the strands of DNA they did find with other mapped genomes to identify species. Then the researchers targeted very small, specific regions in the DNA for reconstruction to learn more about the animals’ relationships with today’s domestic breeds.

 

Read at ArsTechnica

Large DNA study using 23andMe data finds 15 sites linked to depression

Scientists announced on Monday that they had pinpointed 15 locations in our DNA that are associated with depression, one of the most common mental health conditions and one that is estimated to cost the world billions in health-care costs and lost productivity.

Although gene association studies — which link DNA inherited from our parents to particular diseases, conditions or even habits such as vegetarianism — are published practically every week, this is a particularly important one. It’s the first large study on major depressive disorder in people of European descent, and it shows that the genes that may be involved in the condition correspond to those involved in the development of neurons in the brain. There is also overlap between the genetic regions implicated in depression and those that have been linked to other psychiatric disorders such as schizophrenia. This finding supports another key study published in April that focused on genetic factors related to well-being and depression, which found that the genetic variants for those genes had some “moderate” overlap with those with schizophrenia and bipolar disorder. This may suggest that scientists study these genes and traits jointly in future work.

The new study, published in Nature Genetics, involved an analysis of genetic variations of 75,607 people of European ancestry who self-reported having depression and 231,747 healthy controls.

 

Read at Washington Post

Do Amish hold clue to preventing asthma in children?

The Amish community in the US has long been famous for shunning modern technology and preserving traditional ways of life, using horses for farming and for transport.

Now it appears that their closer contact with animals could have an unexpected benefit – preventing asthma in children.

A new study from the US compared the Amish with a similar community, the Hutterites, who use more modern farming methods.

Both groups have similar genetic ancestry and follow similar diets, but researchers found that childhood asthma rates differed strongly.

About 5% of Amish schoolchildren tested in the study had asthma compared with 21.3% of the Hutterite children.

The study in the New England Journal of Medicine suggested that children’s immune systems in the Amish community were being bolstered by house dust that contained more microbes from farm animals.

 

Read at BBC News

NIH panel to review proposal for first in human test of CRISPR

  • A federal advisory panel  will review a proposal for the first in human test of CRISPR/cas9 gene-editing technology, according to the National Institutes of Health (NIH).
  • Researchers at the University of Pennsylvania plan to edit two genes in T-cells using CRISPR in a study aimed at targeting myeloma, melanoma, and sarcoma tumor cells, reports MIT Technology Review.
  • The study proposal will be reviewed by the Recombinant DNA Advisory committee (RAC) at its meeting to be held on June 21 and 22.

Read at BioPharma Dive

Panel Endorses ‘Gene Drive’ Technology That Can Alter Entire Species

A revolutionary technology known as “gene drive,” which for the first time gives humans the power to alter or perhaps eliminate entire populations of organisms in the wild, has stirred both excitement and fear since scientists proposed a means to construct it two years ago.

Scientists dream of deploying gene drive, for example, to wipe out malaria-carrying mosquitoes that cause the deaths of 300,000 African children each year, or invasive rodents that damage island ecosystems. But some experts have warned that the technique could lead to unforeseen harm to the environment. Some scientists have called on the federal government to regulate it, and some environmental watchdogs have called for a moratorium.

On Wednesday, the National Academies of Sciences, Engineering and Medicine, the premier advisory group for the federal government on scientific matters, endorsed continued research on the technology, concluding after nearly a yearlong study that while it poses risks, its possible benefits make it crucial to pursue. The group also set out a path to conducting what it called “carefully controlled field trials,” despite what some scientists say is the substantial risk of inadvertent release into the environment.

Read at New York Times

Breast cancer: Scientists hail ‘milestone’ genetic find

Scientists say they now have a near-perfect picture of the genetic events that cause breast cancer.

The study, published in Nature, has been described as a “milestone” moment that could help unlock new ways of treating and preventing the disease.

The largest study of its kind unpicked practically all the errors that cause healthy breast tissue to go rogue.

Cancer Research UK said the findings were an important stepping-stone to new drugs for treating cancer.

To understand the causes of the disease, scientists have to understand what goes wrong in our DNA that makes healthy tissue turn cancerous.

The international team looked at all 3 billion letters of people’s genetic code – their entire blueprint of life – in 560 breast cancers.

They uncovered 93 sets of instructions, or genes, that if mutated, can cause tumours. Some have been discovered before, but scientists expect this to be the definitive list, barring a few rare mutations.

 

Read at BBC