Category: DNA

The New Scientist

By McMaster University

When the Human Genome Project reached its ambitious goal of mapping the entire human genome, it seemed the world was entering an era of personalized medicine, where evidence from our own specific genetic material would guide our care.

That was 2003, and nearly a generation after that spectacular collaborative achievement, we are still waiting for that promise to materialize. We may know that a person carries a gene associated with breast cancer, for example, but not whether that person will go on to develop the disease.

New research by McMaster University evolutionary biologist Rama Singh suggests the reason is that there is another, hidden layer that controls how genes interact, and how the many billions of possible combinations produce certain results. That layer is composed of largely uncharted biochemical pathways that control gene expression in cells through chemical reactions.

Scientists mailed freeze-dried mouse sperm on a postcard and birthed pups on the other side, a major advance for affordable long-distance sperm transfer.

By Becky Ferreira

It’s always a delight to receive a thoughtful letter in the mail, but scientists in Japan have added a whole new layer to the experience by sending each other postcards containing freeze-dried mouse sperm. What’s more, the researchers were able to produce viable mouse offspring with the sperm that landed in their mailboxes after days in the post.

The unprecedented experiment could transform the way that sperm from many different species is transported, pioneering applications for “infertility treatments, livestock production, maintenance of strains of genetically modified individuals, and conservation of genetic resources, including those of endangered species,” according to a study published on iScience on Thursday.

“This is the first report in the world [to show] that freeze-dried mouse sperm can be preserved in a thin plastic sheet (0.2 millimeters) instead of conventional glass ampoules,” said Daiyu Ito, a PhD student at the University of Yamanashi who led the new study, in an email. 

“We went through various trials and errors and finally succeeded,” he continued. “When we were able to develop a method of preservation of mouse sperm freeze-drying on a sheet, we thought that mouse sperm should be able to be mailed on a postcard by this method” which is the “absolute cheapest” technique ever developed to transport sperm.

By RIKEN

Genome editing targeting a gene responsible for making body pigments resulted in albino offspring, suggesting that the genetic engineering was successful in marsupials. Credit: RIKEN

Researchers at the RIKEN Center for Biosystems Dynamics Research (BDR) have succeeded in creating the first genetically engineered marsupial. This study, published in the scientific journal Current Biology, will contribute to deciphering the genetic background of unique characteristics observed only in marsupials.

Genetically modified animals, particularly mice and rats, are extremely important tools for researching biological processes. For example, researchers often silence genes to find out what their normal functions are. Since marsupials have unique characteristics, studying them requires developing a representative animal model. To date, the best option is the opossum, which is thought to be the ancestor of all marsupials. The first marsupial to have its entire genome sequenced, the opossum makes a good model animal because its size and breeding characteristics are similar to those of mice and rats.

Normal and sickle-shaped red blood cells.

• By Carolyn Barber 

A genomic revolution is poised to cure sickle cell and other genetic diseases

For as long as he could remember, Razel Colón had known pain. It ripped down his neck and back, shot through his legs and traveled on to his feet, often leaving him writhing and incapacitated. He suffered occasional attacks of “acute chest,” in which breathing suddenly becomes difficult. “It felt like an elephant was sitting on my chest, with tight, tight pain,” Colón tells me. Trips to the emergency department and the hospital were commonplace. “If I was lucky,” he says, “I could stay away for a month.”

Colón, from Hoboken, N.J., is just 19, but the sickle cell disease that produced these effects had been a constant, if unwelcome, companion. But he tells his story now from the perspective of one who has gone a year and a half without that pain. He can do things that previously were out of the question: play basketball, lift weights, swim in cold water. His treatment, says his long-time physician Stacey Rifkin-Zenenberg, a pediatric hematologist-oncologist at Hackensack University Medical Center, “changed him from having the disease to being a carrier.”

Colón’s case represents a point on the curve of an emerging technology that may forever alter our approach to treating diseases like sickle cell. That world, the cutting-edge world of innovative genomic therapies, is once again in the midst of explosive change—and designer DNA lies at the heart of the conversation.

Lined on the inside with virus-binding molecules, nano-shells made of DNA material bind viruses tightly and thus render them harmless.

by Technical University Munich

To date, there are no effective antidotes against most viral infections. An interdisciplinary research team at the Technical University of Munich (TUM) has now developed a new approach: they engulf and neutralize viruses with nano-capsules tailored from genetic material using the DNA origami method. The strategy has already been tested against hepatitis and adeno-associated viruses in cell cultures. It may also prove successful against corona viruses.

There are antibiotics against dangerous bacteria, but few antidotes to treat acute viral infections. Some infections can be prevented by vaccination, but developing new vaccines is a long and laborious process.

Now an interdisciplinary research team from the Technical University of Munich, the Helmholtz Zentrum München and the Brandeis University (USA) is proposing a novel strategy for the treatment of acute viral infections: The team has developed nanostructures made of DNA, the substance that makes up our genetic material, that can trap viruses and render them harmless.

Researchers in Australia said the tool was effective against viral transmissions in lab tests, adding that they hope soon to begin animal trials on the method

Scientists have used CRISPR gene-editing technology to successfully block the transmission of the SARS-CoV-2 virus in infected human cells, according to research released Tuesday that could pave the way for Covid-19 treatments.

Writing in the journal Nature Communications, researchers in Australia said the tool was effective against viral transmissions in lab tests, adding that they hoped to begin animal trials soon.

CRISPR, which allows scientists to alter DNA sequences and modify gene function, has already shown promise in eliminating the genetic coding that drives the development of children’s cancer.

The team in Tuesday’s study used an enzyme, CRISPR-Cas13b, that binds to relevant RNA sequences on the novel coronavirus and degrades the genome it needs to replicate inside human cells.

Chemistry professor Yi Lu led a team that developed a technique that allows DNAzymes to cut double-stranded DNA, enabling a wide range of genetic engineering applications.

by Liz Ahlberg Touchstone , University of Illinois at Urbana-Champaign

Move over, gene-editing proteins—there’s a smaller, cheaper, more specific genetic engineering tool on the block: DNAzymes—small DNA molecules that can function like protein enzymes.

Researchers at the University of Illinois Urbana-Champaign have developed a technique that, for the first time, allows DNAzymes to target and cut double-stranded DNA, overcoming a significant limitation of the technology. DNAzymes have been used in biosensing, DNA computing and many other applications. However, when it comes to genetic engineering applications such as gene editing or gene therapy, they have faced a challenge: DNAzymes have only been able to target sites on single-stranded DNA, while the DNA coding for genes in cells is double-stranded. The researchers published their new technique in the Journal of the American Chemical Society.

by Thomas Jefferson University

Cells contain machinery that duplicates DNA into a new set that goes into a newly formed cell. That same class of machines, called polymerases, also build RNA messages, which are like notes copied from the central DNA repository of recipes, so they can be read more efficiently into proteins. But polymerases were thought to only work in one direction DNA into DNA or RNA. This prevents RNA messages from being rewritten back into the master recipe book of genomic DNA. Now, Thomas Jefferson University researchers provide the first evidence that RNA segments can be written back into DNA, which potentially challenges the central dogma in biology and could have wide implications affecting many fields of biology.

“This work opens the door to many other studies that will help us understand the significance of having a mechanism for converting RNA messages into DNA in our own cells,” says Richard Pomerantz, Ph.D., associate professor of biochemistry and molecular biology at Thomas Jefferson University. “The reality that a human polymerase can do this with high efficiency, raises many questions.” For example, this finding suggests that RNA messages can be used as templates for repairing or re-writing genomic DNA.

Written by Meagan Drillinger 

• For the first time, scientists are altering DNA in a living human.
• With more research this study could help lead to the development of procedures that can help to correct other genetic disorders.
• The study uses CRISPR technology, which can alter DNA. 

Researchers from the OHSU Casey Eye Institute in Portland, Oregon, have broken new ground in science, medicine, and surgery — the first gene editing procedure in a living person.

For the first time, scientists are altering DNA in a living human. With more research the study could lead to the development of procedures that can help to correct other genetic disorders.

Known as the BRILLIANCE clinical trial, the procedure is designed to repair mutations in a particular gene that causes Leber congenital amaurosis type 10, also known as retinal dystrophy. It is a genetic condition that results in vision deterioration and has previously been untreatable.

“The Casey Eye Institute performed the first gene editing surgical procedure in a human being in an attempt to prevent blindness from a known genetic mutation,” said Dr. Mark Fromer, ophthalmologist at Lenox Hill Hospital in New York. “The abnormal DNA is removed from a cell with the generating mutation. This will potentially offer sight to people with a form of previously untreatable blindness.”