New DNA modification ‘signature’ discovered in zebrafish — ScienceDaily

Researchers at the Garvan Institute of Medical Research have uncovered a new form of DNA modification in the genome of zebrafish, a vertebrate animal that shares an evolutionary ancestor with humans ~400 million years ago.

Dr Ozren Bogdanovic and his team discovered that unusually high levels of DNA repeats of the sequence ‘TGCT’ in the zebrafish genome undergo a modification called methylation, which may change the shape or activity of the surrounding DNA. The study, published in Nucleic Acids Research and conducted in collaboration with Queen Mary University of London, could lead to the development of new experimental models for studying how DNA modifications impact human development and disease.

“We’ve revealed a new form of DNA methylation in zebrafish at TGCT repeats, and crucially, the enzyme that makes the modification,” says Dr Bogdanovic, who heads the Developmental Epigenomics Lab at Garvan and Senior Research Fellow at the School of Biotechnology

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Enzymatic photocaging for the study of gene regulation through DNA methylation — ScienceDaily

The addition and removal of methyl groups on DNA plays an important role in gene regulation. In order to study these mechanisms more precisely, a German team has developed a new method by which specific methylation sites can be blocked and then unblocked at a precise time through irradiation with light (photocaging). As reported in the journal Angewandte Chemie, the required regent is produced enzymatically, in situ.

Although they look very different and serve completely different functions, all cells in our body have identical DNA. However, they do not use the same genes. Certain genes are turned on and others off, depending on the type of cell and the moment in time. The “switches” are chemical changes in the building blocks of the DNA. These changes are called epigenetic modifications. One significant regulation mechanism is methylation and demethylation, meaning the attachment and removal of a methyl group (-CH(3)). The

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DNA Technology Could Help Investigators In Prince George’s County Reopen Cold Cases : NPR

Prince George’s County will reopen cold cases with the help of DNA technology.

National Cancer Institute/Unsplash


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A $470,000 grant to use new DNA technology could be the answer to solving cold cases in Prince George’s County.

The county was one of 10 in the nation to receive the three-year-long grant from the Department of Justice. The grant will allow the county to reopen cases, some going as far back as 1979, using forensic genetic genealogy — an investigative tool comparing and analyzing DNA samples from crime scenes and popular genealogy websites like 23andMe and Family Tree. The county’s State’s Attorney Aisha Braveboy’s office was the recipient of the grant.

“This is a process that holds great promise for achieving justice and bringing closure for victims of cold case crimes and their loved ones,” Braveboy said in a statement. “It’s important for the community

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Scientists regenerate skin with stem cells to see how DNA defects in kids cause cancer

Scientists regenerate skin with stem cells to see how DNA defects in kids cause cancer
Shown are microscopic images of human epidermis with pluripotent stem cells derived from donated skin cells. The images on the left are epidermis from a healthy control subject, the images at right being from a person with Fanconi anemia. The colorful confocal images (bottom) offer a more superficial view that does not reveal differences between control and FA samples. The black and white electron microscopic images, with 1,000-fold greater magnification, do reveal defects in the FA epidermis. Researchers studying Fanconi anemia-related skin disease and cancer report new data in Cell Stem Cell. Credit: Cincinnati Children’s

Physicians and scientists at Cincinnati Children’s Hospital Medical Center used new stem cell technology to regenerate and study living patient-specific skin in the lab, giving them a precise close up view of how inherited DNA defects cause skin damage and deadly squamous cell carcinoma in children and young adults with Fanconi anemia (FA).

Reporting

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A repetitive DNA sequence that causes health risks when it malfunctions can now be watched inside living cells using a synthetic tool — ScienceDaily

A new synthetic probe offers a safe and straightforward approach for visualizing chromosome tips in living cells. The probe was designed by scientists at the Institute for Integrated Cell-Material Science (iCeMS) and colleagues at Kyoto University, and could advance research into aging and a wide range of diseases, including cancers. The details were published in the Journal of the American Chemical Society.

“Chromosome ends are constantly at risk of degradation and fusion, so they are protected by structures called telomeres, which are made of long repeating DNA sequences and bound proteins,” says iCeMS chemical biologist Hiroshi Sugiyama, who led the study. “If telomeres malfunction, they are unable to maintain chromosome stability, which can lead to diseases such as cancer. Also, telomeres normally shorten with each cell division until they reach their limit, causing cell death.”

Visualizing telomeres, especially their physical arrangements in real-time, is important for understanding their relevance

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Prince George’s will use DNA registries to solve cold cases through new DOJ grant

Prince George’s County is one of 10 jurisdictions across the country that will receive a $470,000 grant from the Justice Department to reopen cold cases using forensic genetic genealogy — a new investigative technique that draws on privately curated DNA databases from popular genealogy websites to compare with samples collected from crimes.

The funding could help investigators reopen as many as 60 cold cases over the next three years, Prince George’s prosecutors and police said at a news conference Thursday.

“This is just another area where we’re going to make a big difference in Prince George’s County,” county State’s Attorney Aisha Braveboy said.

There are more than 600 cases of serious and violent crimes in the county in which DNA was collected from the scene but the sample did not generate a match in the FBI’s Combined DNA Index System, often referred to as CODIS.

The leads ran out,

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A key to the mystery of fast-evolving genes was found in ‘junk DNA’

A long-standing puzzle in evolution is why new genes — ones that seem to arise out of nowhere — can quickly take over functions essential for an organism’s survival.

A new study in fruit flies may help solve that puzzle. It shows that some new genes quickly become crucial because they regulate a type of DNA called heterochromatin. Once considered “junk DNA,” heterochromatin actually performs many important jobs, including acting like a tightly guarded prison: It locks up “bad actor” genes, preventing them from turning on and doing damage.

Heterochromatin is also one of the fastest-changing bits of DNA in the body, so the genes that regulate it have to adapt quickly just to keep up, evolutionary biologist Harmit Malik at the Fred Hutchinson Cancer Research Center in Seattle and his colleagues report online November 10 in eLife.

“The work is a milestone,” said Manyuan Long, an evolutionary biologist

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Genetic code evolution and Darwin’s evolution theory should consider DNA an ‘energy code’

Genetic code evolution and Darwin's evolution theory should consider DNA an 'energy code'
Three conformations of the DNA double helix: A (left), B (center) and left-handed Z (right). Credit: David S. Goodsell and RCSB PDB

Darwin’s theory of evolution should be expanded to include consideration of a DNA stability “energy code”—so-called “molecular Darwinism”—to further account for the long-term survival of species’ characteristics on Earth, according to Rutgers scientists.


The iconic genetic code can be viewed as an “energy code” that evolved by following the laws of thermodynamics (flow of energy), causing its evolution to culminate in a nearly singular code for all living species, according to the Rutgers co-authored study in the journal Quarterly Reviews of Biophysics.

“These revelations matter because they provide entirely new ways of analyzing the human genome and the genome of any living species, the blueprints of life,” said senior author Kenneth J. Breslauer, Linus C. Pauling Distinguished University Professor in the Department of Chemistry and Chemical Biology

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1989 rape, murder of 16-year-old Kansas City girl solved with new DNA technology

The same technology that helped crack the Golden State Killer case has been used to solve a 30-year-old Kansas City cold case.

Fawn Cox, then 16, was found dead in her Missouri bedroom on July 26, 1989, raped and strangled. Her sister, Felisa, told KCTV that Fawn had gotten home from work at Worlds of Fun after 11 p.m. and went straight to sleep.

When Fawn’s alarm went off this morning, she never woke up. Her mother and sister found her dead in her bed.

“I went over to shake her, ‘Come on! Get up!’ But she had been gone for a while,” Felisa said.



a person posing for the camera: Fawn Cox was murdered in 1989.


© Kansas City Police Department
Fawn Cox was murdered in 1989.

Fawn Cox was murdered in 1989. (Kansas City Police Department/)

Three teenagers were arrested for Fawn’s murder, but the charges were dropped after the case fell apart.

Then the case went cold until new

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Scientists Sequence DNA Of 240 Mammals

An international team of scientists has sequenced the genomes of 240 species of mammals. 

Their publicly available dataset, which contains genomes of mammals ranging from the bumblebee bat to the black rhinoceros, including many endangered species, is the largest and most comprehensive of its kind generated to date. These data will help scientists learn which genetic mutations cause human diseases like cancer. 

The Zoonomia Project has analyzed the genomes of mammals over about 110 million years of evolution. A paper about the dataset is published in Nature.

“The core idea for the project was to develop and use this data to help human geneticists figure out which mutations cause disease,” Kerstin Lindblad-Toh, a senior co-author of the study and a professor in comparative genomics at Uppsala University, said in a news release.

Scientists can

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