DNA

DNA Molecules Used To Assemble Nanoparticles

University of Michigan researchers have developed a faster, more efficient way to produce a wide variety of nanoparticle drug delivery systems, using DNA molecules to bind the particles together. Nanometer-scaled dendrimers can be assembled in many configurations by using attached lengths of single-stranded DNA molecules, which naturally bind to other DNA strands in a highly specific fash...

Viral DNA sequence a possible trigger for breast cancer

A small sequence of DNA in the envelope (Env) protein of a mouse breast tumor virus (called MMTV) can transform breast cells into cancer cells, according to a study by Katz et al. in the February 7 issue of The Journal of Experimental Medicine. The ability of this motif to transform cells single-handedly suggests that viral infection may be an important and previously unrecognized trigger for bre...

Deficient DNA Repair Capacity Associated With Increased Risk Of Breast Cancer

Deficiencies in the ability of cells to repair damaged DNA are associated with an increased risk of breast cancer, according to a new study in the January 19 issue of the Journal of the National Cancer Institute. is the system of defenses designed to protect the integrity of the genome. Studies have suggested that deficiency...

Novel technology detects human DNA mutations

Researchers at today reported unprecedented benefits in the company's technology for the medical analysis of human DNA. genotyping...

Dinosaur DNA? New Patent Covers Degraded DNA recovery

The US Patent Office issued Patent # 6,872,552, "A Method of Reconstituting Nucleic Acid Molecules" today to Burt D. Ensley, Ph.D, Chairman of MatrixDesign, and CEO of DermaPlus, Inc. The patent covers methods for recovering and reconstituting genes from "degraded" DNA samples, and could allow scientists to reassemble everything from prehistoric, extinct animals to unsolved crime scenes. "...

Mitochondrial DNA mutations play significant role in prostate cancer

Mutations in mitochondrial DNA (mtDNA) playan important role in the development of prostate cancer, according toresearch by scientists at Emory University School of Medicine and theUniversity of California, Irvine. The findings are published onlinethis week in the Proceedings of the National Academy of Sciences(PNAS). Mitochondrial DNA, which is separate from nuclear DNA, is foundin the hun...

Color-blind method opens new doors in DNA sequencing

A "color-blind" method of fluorescence detection developed by researchers at Baylor College of Medicine (BCM) and Rice University could open new doors that would take DNA sequencing to the patient's bedside, the doctor's office and even the scene of a crime or a battlefield. "We could eventually do direct detection of a DNA sequence from native DNA" without manipulation now performed in th...

Papers of DNA Pioneer and Nobel Laureate Francis Crick Added to National Library of Medicine’s Profiles in Science Web Site

The National Library of Medicine, a part of the National Institutes of Health, is proud to present an extensive selection from the papers of one of the twentieth century’s greatest scientists, Francis Crick, on its Profiles in Science Web site. Don't miss Crick's This la...

DNA Recombination and Repair—A New Twist to RecA Function

Molecular motors harness the energy of ATP (or GTP, a related energy currency) and transform it into mechanical force. Well-known examples of motors include myosin and dynein, proteins that use ATP to ferry intracellular cargo along fibers made of actin or tubulin proteins. The ATP-dependent assembly of actin or tubulin fibers itself can work as a motor: for instance, the march of white blood cel...

Circles Of DNA Might Help Predict Success Of Stem Cell Transplantation

Measuring the quantity of a certain type of immune cell DNA in the blood could help physicians predict whether a bone marrow stem cell transplant will successfully restore a population of infection-fighting cells called T lymphocytes in a child. This research, by investigators at St. Jude Children's Research Hospital, is published in the journal Blood. This finding could help physicians p...

Study of genomic DNA leads to new advances in cancer diagnostics

Researchers at the University of Illinois at Chicago have identified a method of assessing the malignant potential of cells based on the sensitivity of cellular DNA to enzyme digestion. The article by Andrew J. Maniotis et al., "Chromatin sensitivity to Alu I restriction enzyme decreases with malignancy and is regulated by the extracellular matrix and cytoskeleton," appears in the April 2005 issu...

Unexpressed But Indispensable -- The DNA Sequences That Control Development

Amidst the hoopla over the exact number of genes we have in our genome—more than a fruitfly, fewer than a rice plant—a more fundamental genetic truth has often been obscured. The expression of 20,000?0,000 genes is under the control of an uncounted host of non-coding sequences, which bind transcription factors and thereby regulate when and where genes are expressed. Unlike coding sequences, whose...

Bioelectronic ‘signatures?hold key to DNA mutations

A new method to identify DNA mutations may shepherd in an era of small, portable, electronic devices for the rapid screening and identification of genes that harbor disease. Joseph Wang, director of the Center for Bioelectronics and Biosensors at the Biodesign Institute at ASU, led a team effort that successfully merged work in the fields of biosensors, electronics, and nanotechnology to...

New understanding of DNA repair may pave way to cancer treatments

A Burnham Institute study has found that a protein known for its role in gene regulation has another important function, that of initiating DNA repair. The study, published in the May 27th edition of Molecular Cell, points to new targets for treatment of cancer. Ze'ev Ronai, Ph.D., Director of the Institute's Signal Transduction Program, and his colleagues found that the protein ATF2 ("Ac...

Insight into DNA's 'weakest links' may yield clues to cancer biology

The chromosomes of mammals, including humans, contain regions that are particularly prone to breaking under conditions of stress and in cancer. Now, new research by geneticists at Duke University Medical Center finds that yeast cells also contain such weak links in DNA and begins to reveal the molecular characteristics of these links that might help to explain them. The findings, publishe...

Basis for DNA ejection from single phage particles

Studying phage, a primitive class of virus that infects bacteria by injecting its genomic DNA into host cells, researchers have gained insight into the driving force behind this poorly understood injection process, which has been proposed in the past to occur through the release of pressure accumulated within the viral particle itself. Almost all phages (also known as bacteriophages) are f...

Doing a spin with DNA

A Dutch led international team of researchers has unravelled how nature releases the torque built up in DNA at the molecular level. The researchers from Delft University of Technology, the Ecole Normale Supérieure in Paris and the Sloan-Kettering institute in New York published their findings in the 31 March 2005 issue of Nature. An artistic impression of the enzyme at work is featured on the cov...

Unchecked DNA replication drives earliest steps toward cancer

Although not widely appreciated as a disease of the genes, cancer is always rooted in genetic errors or problems in gene regulation. Scientists have identified some of the first genetic triggers for cancer as mutations in specific oncogenes or tumor suppressor genes. Full-blown tumors and metastatic cancers, however, often exhibit many genetic mutations, sometimes dozens in a given tumor. An impo...

Purdue researchers use enzyme to clip 'DNA wires'

Researchers at Purdue University have attached magnetic "nanoparticles" to DNA and then cut these "DNA wires" into pieces, offering the promise of creating low-cost, self-assembling devices for future computers. Findings are detailed in a paper published online in February in the Journal of the American Chemical Society. The paper was written by Purdue graduate student Joseph M. Kinsella...

Chemical Engineer Kao Explores Antibiotic Synthesis With DNA Chips

Ask Assistant Professor of Chemical Engineering Camilla Kao to describe a bacterium, and she'll compare it to a factory capable of producing antibiotics, immunosuppressants and anti-cancer drugs that no chemist can synthesize. Bacteria normally produce antibiotics to inhibit other bacterial strains competing for resources. Pharmaceutical companies exploit this property to manufacture drugs, but t...

DNA constraints control structure of attached macromolecules

A new method for manipulating macromolecules has been developed by researchers at the University of Illinois at Urbana-Champaign. The technique uses double-stranded DNA to direct the behavior of other molecules. In previous DNA nanotechnology efforts, duplex DNA has been used as a static lattice to construct geometrical objects in three dimensions. Instead of manipulating DNA alone into s...

High fidelity keeps human DNA assembly line humming

Scientists at Michigan State University have made a major discovery on the inner workings of genetic coding, mapping out mechanisms of one of life's most elemental functions: RNA synthesis. Their work has crucial implications for how a normal cell forms a tumor and how a virus runs amok. Behind th...

New miniaturised chip dramatically reduces time taken for DNA analysis

A team of researchers at the Universitat Autònoma de Barcelona has developed new miniature sensors for analysing DNA. The sensors have the same size and thickness as a fingernail and reduce the time needed to identify DNA chains to several minutes or a few hours, depending on each chain. These sensors can be applied to many different tasks, ranging from paternity tests and identifying people to d...

Ancient DNA helps clarify the origins of two extinct New World horse species

The Patagonian Hippidion horse genus and North American stilt-legged horses have found a new place on the evolutionary tree, according to a new article in the open access journal PLoS Biology. In the paper, Jaco Weinstock, Alan Cooper, and colleagues use ancient DNA to argue that the Hippidion genus is younger than previously thought and that American stilt-legged horses were American endemics, n...

Recombinant DNA technology may enable oral, rather than injectable, delivery of protein drugs

Transferrin, a plasma protein found in blood, can be fused with large, protein-based drugs such as granulocyte colony-stimulating factor (G-CSF) to create a new oral compound that is capable of surviving the journey through the gastrointestinal (GI) tract and then able to cross over into the bloodstream to be used by the body, according to research from the University of Southern California Schoo...

IMF Launches World’s First DNA Database for Myeloma Patients

A biologist at Washington University in St. Louis has shown that for some fish species, females prefer males with larger sexual organs, and actually choose them for mating. That does not exclude males with an average-sized sex organ, called a gonopodium. These fish out-compete the larger-endowed males in a predator-laden environment because they have a faster burst speed than the males with large...

Big differences in duplicated DNA distinguish chimp and human genomes

A study comparing the genomes of both humans and chimpanzees has found that much of the genetic difference between the two species came about in events called segmental duplications, in which segments of genetic code are copied many times in the genome. The study appears as a companion article to the draft sequence of the chimpanzee genome published in the Sept. 1 issue of the journal Nature....

Brown-Harvard team solves mobile DNA's surgical sleight-of-hand

In a clever bit of biology called site-specific recombination, DNA can travel inside an organism, or into another organism, and perform a sort of grafting surgery that allows it to insert its chromosome into a chromosome of the target cell. The process is important because mobile DNA can carry genes that cause drug resistance or transmit viruses that cause disease or tumors that result in certain...

Self-assembled DNA buckyballs for drug delivery

DNA isn't just for storing genetic codes any more. Since DNA can polymerize -- linking many molecules together into larger structures -- scientists have been using it as a nanoscale building material, constructing geometric shapes and even working mechanical devices. Now Cornell University researchers have made DNA buckyballs -- tiny geodesic spheres that could be used for drug delivery an...

Virginia Tech group adds tools to DNA-targeted anti-cancer drugs

Chemistry and biology researchers at Virginia Tech have enhanced the abilities of the molecules they are creating to deliver killing blows to cancer cells. The man-made molecular complexes enter cancer cells and, when signaled, deliver killing medicine or cause the cell to change. The new supermolecules have more units that will absorb light - providing more control over the range of light freque...

Major advance made on DNA structure

Oregon State University researchers have made significant new advances in determining the structure of all possible DNA sequences ?a discovery that in one sense takes up where Watson and Crick left off, after outlining in 1953 the double-helical structure of this biological blueprint for life. One of the fundamental problems in biochemistry is to predict the structure of a molecule from it...

Using computers and DNA to count bacteria

Don't call them the Dirt Doctors, or Sultans of Soil, they're just clever Lab guys. A team from Los Alamos National Laboratory has a paper in this week's Science Magazine with a new way to count bugs in dirt. Bacteria, that is, in the highly complex world beneath our feet. "Computational Improvements Reveal Great Bacterial Diversity and High Metal Toxicity in Soil," by Jason Gans, Murray W...

New Look at DNA Hints at Origin of UV Damage

Researchers at Duke University Medical Center have identified a previously unknown family of virulence factors that make the bacterium responsible for the plague especially efficient at killing its host. In the process, the team not only demonstrated that the use of the common roundworm is a valid model for studying the virulence of Yersinia pestis, the bacterium that causes plague. They a...

Scientists track stealth DNA elements in primate evolution

Louisiana State University scientists in the Department of Biological Sciences have unraveled the details of a 25-million-year-old evolutionary process in the human genome. Specific DNA sequences that appear to have persisted in a latent state for long periods of time may not be simply lying dormant. Instead, the researchers say that these elements have played a crucial role in human evolution by...

Drawing with DNA: 'Bioart' illuminates genomics

On any given day, tens of thousands of biologists around the globe run DNA sequences of unknown function through a lightning-fast online algorithm called BLAST ?typically submitting 200 to 400 base pairs, or "letters" of genetic code, to be matched against the billions of letters for known genes. Searching for similarities that can shed light on functional or evolutionary relationships, scientist...

New mitochondrial DNA gene chip may be early cancer diagnosis tool

A pilot study at the National Institute of Standards and Technology (NIST), in support of the National Cancer Institute's Early Detection Research Network (EDRN), has validated the measurement accuracy of new techniques that use mitochondrial DNA as an early indicator for certain types of cancer. Additional results suggest that a relatively simple diagnostic test using a DNA microarray "chip" cou...

Scientists find new way to manipulate DNA

Polymers, large molecules comprised of chains of repeating structures, are used in everything from the coatings on walls of ships and pipes to reduce flow drag to gene therapy. But long polymer chains are subject to breakage, called scission, and a new study by the University of Michigan shows that as it turns out, much of what scientists previously thought about why polymers break whe...

Few clues about African ancestry to be found in mitochondrial DNA

Mitochondrial DNA may not hold the key to your origins after all. A study published today in the open access journal BMC Biology reveals that fewer than 10% of African American mitochondrial DNA sequences analysed can be matched to mitochondrial DNA from one single African ethnic group. There has been a growing interest in the use of mitochondrial DNA to trace maternal ancestries, and several com...

Genetic study of Neanderthal DNA reveals early split between humans and Neanderthals

In the most thorough study to date of the Neanderthal genome, scientists suggest an early human-Neanderthal split. The two species have a common ancestry, say the authors, but do not share much else after evolving their separate ways. The study, published in this week's issue of Science, also finds no evidence of genetic admixture between Neanderthals and humans. The study helps to explain...

Novel mechanism for DNA replication discovered

Mount Sinai School of Medicine researchers first to discover that a protein can provide the coding information for DNA replicationSince the discovery of the structure of DNA by James Watson and Francis Crick in 1953, the paradigm for DNA replication has stated that the DNA itself codes for the appropriate pairings for replication. In other words, if a guanine base is on the original strand...