Category Archives: DNA

Deoxyribonucleic Acid (DNA) What is DNA? We all know that elephants only give birth to little elephants, giraffes to giraffes, dogs to dogs and so on for every type of living creature. But why is this so? The answer lies in a molecule called deoxyribonucleic acid (DNA), which contains the biological instructions that make each species unique. DNA, along with the instructions it contains, is passed from adult organisms to their offspring during reproduction. Top of page DNA is found inside a special area of the cell called the nucleus. Because the cell is very small, and because organisms have many DNA molecules per cell, each DNA molecule must be tightly packaged. This packaged form of the DNA is called a chromosome. During DNA replication, DNA unwinds so it can be copied. At other times in the cell cycle, DNA also unwinds so that its instructions can be used to make proteins and for other biological processes. But during cell division, DNA is in its compact chromosome form to enable transfer to new cells. Researchers refer to DNA found in the cell's nucleus as nuclear DNA. An organism's complete set of nuclear DNA is called its genome. Besides the DNA … Continue reading →

DNA, short for deoxyribonucleic acid, is the molecule that contains the genetic code of organisms. This includes animals, plants, protists, archaea and bacteria. DNA is in each cell in the organism and tells cells what proteins to make. Mostly, these proteins are enzymes. DNA is inherited by children from their parents. This is why children share traits with their parents, such as skin, hair and eye color. The DNA in a person is a combination of the DNA from each of their parents. Part of an organism's DNA is "non-coding DNA" sequences. They do not code for protein sequences. Some noncoding DNA is transcribed into non-coding RNA molecules, such as transfer RNA, ribosomal RNA, and regulatory RNAs). Other sequences are not transcribed at all, or give rise to RNA of unknown function. The amount of non-coding DNA varies greatly among species. For example, over 98% of the human genome is non-coding DNA,[1] while only about 2% of a typical bacterial genome is non-coding DNA. Viruses use either DNA or RNA to infect organisms.[2] The genome replication of most DNA viruses takes place in the cell's nucleus, whereas RNA viruses usually replicate in the cytoplasm. DNA has a double helix shape, … Continue reading →

DNA robots crawl across a surface made of DNA. DNA-based nanotechnology has been around for more than 30 years, but it really took off in 2006, when DNA origami was featured on the cover of Nature. This form of origami, the folding of DNA into 2D and 3D shapes,was more of an art form back then, but scientists are now using the approach to construct nanoscale robots. The basic principle of DNA origami is that a long, single-stranded DNA molecule will fold into a predefined shape through the base-pairing of short segments called staples. All thats required is to ensure that each staple can find a complementary match to base-pair with at the right location elsewhere in the molecule. This approach can be used to create both 2D and 3D structures. The idea behind the new work is that a DNA origami robot can be programmed to have a specific function based on a key, which can be a protein, a drug, or even another robot. Once the right key and the right robot find each other, the key drives a conformational (structural) change in the robot. The new shape causes the robot to perform a programmed function, such as … Continue reading →

FACE OF THE FUTURE: Dr Dennis McNevin is part of a team developing DNA tests that can draw exact pictures of suspects. Photo: Jeffrey Chan Australian police and researchers are developing a ground-breaking test that will help them identify suspects based on the DNA evidence they leave behind. It is set to change the way police use DNA evidence. Officers may soon be able to use a single strand of hair from a crime scene to pinpoint whether a suspect has a cleft chin, how many moles they have and whether or not they are bald. The University of Canberra's Dennis McNevin is working on the four-year project set to finish at the end of next year and called ''From Genotype to Phenotype: Molecular Photofitting'', with Victoria Police, the Australian Federal Police and the Queensland Institute of Medical Research. He said Australian police now used DNA evidence to link an existing suspect to a crime scene, but eventually research might lead to their using DNA to create photofit images of potential suspects. Victoria Police forensic officer Runa Daniel, who is working on the project with her colleague Roland van Oorschot, said the research could be used in the absence of … Continue reading →

James P. Eaton, of Palatine, Ill., right, was arrested Saturday in Chicago. He was being held in Racine County Jail on $1 million bail on charges of first-degree intentional homicide and hiding a corpse in connection to the 1997 death of Amber Creek, a 14-year-old from Palatine, Ill. (Courtesy: Racine County Sheriff) RACINE, Wis. Authorities in Wisconsin and Oklahoma used DNA and fingerprint analysis to connect an Illinois man to the cold-case slaying of a teenage runaway whose battered body was found in a Wisconsin marsh in 1997, the Racine County sheriff said Tuesday. James P. Eaton of Palatine, Ill., was arrested Saturday in Chicago. He was being held in Racine County Jail on $1 million bail on charges of first-degree intentional homicide and hiding a corpse, Sheriff Chris Schmaling said. No court date was scheduled for Tuesday. Schmaling didn't know whether Eaton has an attorney. "This is a day that we have been waiting more than 17 years to arrive," Schmaling said at a news conference. Eaton is suspected in connection with the slaying of Amber Creek, a 14-year-old from Palatine, Ill. She had run away from a state-operated juvenile shelter in Chicago on Jan. 23, 1997. She then … Continue reading →

Authorities tailed a man for several days and used DNA from a cigarette he tossed away at a train station to connect him to the cold-case slaying of a teenage runaway whose body was found in a marsh in 1997, a sheriff in southeastern Wisconsin said Tuesday. James P. Eaton, 36, of Palatine, Ill., was arrested Saturday in Chicago after investigators conducting the surveillance were able to recover the partially used cigarette, Racine County Sheriff Chris Schmaling said. Eaton has been charged with first-degree intentional homicide and hiding a corpse. He was being held in Racine County Jail on Tuesday on $1 million bail, and Schmaling didn't know whether Eaton has an attorney. No court date was scheduled for Tuesday, "This is a day that we have been waiting more than 17 years to arrive," Schmaling said at a news conference. Eaton is suspected in connection with the slaying of Amber Creek, a 14-year-old from Palatine, Ill. She had run away from a state-operated juvenile shelter in Chicago on Jan. 23, 1997. She was last seen leaving a motel party in Rolling Meadows, Ill., and getting into a luxury car that had a placard reading "mayor." The driver was described … Continue reading →

HOUSTON (AP) An analysis of Houston police sexual assault kits, which at one time went years without being tested, has resulted in DNA evidence that implicated a prison inmate in multiple assaults dating to 1992, police officials said. Texas prison system records show 43-year-old Herman Ray Whitfield on Wednesday was in the Byrd Unit in Huntsville, serving time for kidnapping. Police announced Tuesday that Whitfield has been charged with aggravated sexual assault of a child and three counts of aggravated sexual assault. The outcome came as part of DNA evidence testing on an extensive backlog of police sexual assault kits. The attacks happened from 1992 to 1994, and again from 2006 to 2009, in bushes, on trails and at vacant properties, authorities said, adding that they believe others were attacked. Whitfield was convicted of kidnapping in 1995, paroled in 2006 and returned to prison in 2009 for a parole violation. Online prison records don't list an attorney for him. "He was very violent in his assaults," Sgt. John Colburn said of the 6-foot-3 Whitfield. "He choked his victims and would display a weapon or let them know he had one." The announcement comes a year after two independent labs began … Continue reading →

UT Southwestern Medical Center researchers have demonstrated in both cancer cell lines and in mice that blocking critical DNA repair mechanisms could improve the effectiveness of radiation therapy for highly fatal brain tumors called glioblastomas. Radiation therapy causes double-strand breaks in DNA that must be repaired for tumors to keep growing. Scientists have long theorized that if they could find a way to block repairs from being made, they could prevent tumors from growing or at least slow down the growth, thereby extending patients' survival. Blocking DNA repair is a particularly attractive strategy for treating glioblastomas, as these tumors are highly resistant to radiation therapy. In a study, UT Southwestern researchers demonstrated that the theory actually works in the context of glioblastomas. "This work is informative because the findings show that blocking the repair of DNA double-strand breaks could be a viable option for improving radiation therapy of glioblastomas," said Dr. Sandeep Burma, Associate Professor of Radiation Oncology in the division of Molecular Radiation Biology at UT Southwestern. His lab works on understanding basic mechanisms by which DNA breaks are repaired, with the translational objective of improving cancer therapy with DNA damaging agents. Recent research from his lab has demonstrated … Continue reading →

FRIDAY, April 4, 2014 (HealthDay News) -- A new DNA test can identify prostate cancer patients at high risk for a return of their cancer, researchers say. The test uses DNA from biopsy (tissue) samples taken before patients undergo surgery or radiation therapy for their cancer. The test is about 80 percent accurate in predicting which men have a high or low risk of their cancer returning within two years, according to the study. The findings are scheduled for presentation Saturday at a meeting of the European Society for Radiotherapy and Oncology in Vienna. Surgery and targeted radiation therapy are the main treatments for cancer that's confined to the prostate. However, cancer returns in 30 percent to 50 percent of patients because its spread outside the prostate was undetected during the initial treatment, said study author Robert Bristow. He is a clinician-scientist at the Princess Margaret Cancer Center in Toronto and a professor at the University of Toronto. "Men who fail treatment within two years may be at the highest risk of dying from their prostate cancer," he said in a society news release. "Existing methods for identifying high-risk patients are imperfect, so new tests are required that are better … Continue reading →

There were large protests this morning at the home of BJP leader Arun Jaitley, who has been accused by the Aam Aadmi Party or AAP of offering its members bribes to bring down the Delhi government led by Arvind Kejriwal. There were large protests this morning at the home of BJP leader Arun Jaitley, who has been accused by the Aam Aadmi Party or AAP of offering its members bribes to bring down the Delhi government led by Arvind Kejriwal. AAP has offered no evidence in support of its allegations. Mr Jaitley has dismissed the charges as baseless. "Rubbish claims by AAP. AAP's alternative politics includes a fundamental right to falsehood and lies," Mr had Jaitley. And also called them a party full of lies. While AAP claimed that Congress and BJP were trying to pay bribes to topple AAP government. Two groups of protesters battled outside Mr Jaitley's home today, with workers of his BJP countering slogan-shouting AAP members and holding up banners against Mr Kejriwal. Both the groups are staging a protest amidst heavy police barricading. Mr Kejriwal heads a minority government. Yesterday, one of his 27 lawmakers, Madan Lal, told reporters that he had been approached by … Continue reading →