Genetic Material

Call it the case of the missing genetic material. No one knows exactly what causes melanoma, the deadliest form of skin cancer, but researchers have identified something called a microRNA that may provide some clues to detecting and treating the disease. A team at the Sanford Burnham Medical Research Institute in Orlando, Fla., has discovered that microRNA211 appears in healthy skin pigment cells but not in melanoma cells. "It's disappearing, so it has something to do with the cancer," research team leader Dr. Ranjan Perera said in an Orlando Sentinel story . "If it is present in normal skin — and in benign tumors — we know it is not melanoma.

It's not often that the Department of Homeland Security makes it into a science blog, but this is an unusual week. The department announced this week that it has developed the first vaccine for foot-and-mouth disease that can be manufactured and licensed in the United States and that could be used in the event of an outbreak of the disease in this country. "This is the biggest news in [foot-and-mouth disease] research in the last 50 years," said veterinarian Lawrence Barrett, director of the department's high-containment Plum Island Animal Disease Center on the tip of Long Island, N.Y. The licensed vaccine is effective against only one strain of the virus, but vaccines against the other strains are already in development.

Scientists have deciphered all the genetic material of the germ that causes typhus fever. Ironically, the finding gives new evidence that the lethal microbe shares an evolutionary history with an important component of healthy cells. The work defined the 1.1 million building blocks that make up the genetic code for Rickettsia prowazekii. The germ is spread by lice and causes epidemics of typhus fever, which differs from typhoid fever, and is blamed for millions of deaths after each world war.

Call it the case of the missing genetic material. No one knows exactly what causes melanoma, the deadliest form of skin cancer, but researchers have identified something called a microRNA that may provide some clues to detecting and treating the disease. A team at the Sanford Burnham Medical Research Institute in Orlando, Fla., has discovered that microRNA211 appears in healthy skin pigment cells but not in melanoma cells. "It's disappearing, so it has something to do with the cancer," research team leader Dr. Ranjan Perera said in an Orlando Sentinel story . "If it is present in normal skin — and in benign tumors — we know it is not melanoma.

Scientists have linked two eye diseases to genetic defects in the powerhouses of cells, providing further evidence that damage to such genetic material may cause a variety of illnesses. Emory University researchers in Atlanta reported that they had confirmed that a previously identified flaw in the mitochondrial DNA of cells is to blame for Leber's hereditary optic neuropathy, a rare inherited disease that causes blindness. In the same issue of the New England Journal of Medicine, another scientific team last week linked damage to the same kind of genetic material to a disorder called progressive external ophthalmoplegia, which weakens eye muscles.

Re "Beefy Biotech Wonder Saved From Slaughter," Jan. 17: Herman, the genetically engineered bull, has been saved from the slaughterhouse. Herman is reportedly the first bull to carry a human gene, so he's special. But one day this may become routine. As the slaughterhouse doors swing open for unwanted transgenic livestock, we are faced with difficult questions. Should canned meat containing human genetic material be so labeled? Yes, so cannibals will know which brand to buy. No, because there are no religious proscriptions against eating transhuman foods.

Modern techniques of genetic engineering are "powerful and safe" and no more dangerous than selective breeding techniques used for thousands of years, said a report from the council of the National Academy of Sciences. A recombinant DNA modified organism "is like a breeder's new variety of flower," said the report by a committee of five experts.

British scientists have mapped the genetic material of a common soil bacterium in an achievement that could combat the growing problem of "super-bugs"--bacteria resistant to the most powerful antibiotics. The bacterium, Streptomyces coelicolor, and its relatives already produce two-thirds of natural antibiotics such as tetracycline and erythromycin.

Scientists have discovered a genetic abnormality that apparently causes the most common adult form of muscular dystrophy, a discovery that could help research into developing a treatment. The finding also should allow better diagnosis of the inherited condition, called myotonic dystrophy, prenatally or before symptoms appear in later life, experts said. Early diagnosis is important because symptoms may not appear until after a person has had children, unwittingly passing along the flawed gene.

A genetic accident in a single mosquito apparently led to the ability of some mosquitoes around the world to resist a class of insecticides, French researchers reported last week in the journal Nature. The finding may have important implications for programs that use insecticides to control mosquitoes that spread disease. The study investigated why mosquitoes called Culex pipiens can often resist organophosphate insecticides.

State lawmakers concerned that police are failing to analyze crucial DNA evidence in rape and sexual assault crimes approved legislation last week requiring law enforcement agencies to keep detailed records of all genetic material gathered in such cases. The bill, which won support from all but one state senator, now goes to Gov. Arnold Schwarzenegger for his approval or veto. Victims of rape or sexual assault who contact authorities are typically taken to a hospital where semen, saliva or other genetic material left by the assailant is collected and packaged for use by police in their investigations.

Molecular biologist J. Craig Venter's announcement last week sounded like something out of a science-fiction film (or a Michael Crichton thriller): His team created living bacteria cells from genetic material designed by computer and assembled in a laboratory. Venter didn't exactly pull a Dr. Frankenstein — bacteria aren't complex organisms, and Venter's team didn't start completely from scratch. Still, his feat raises difficult questions about the expanding boundaries of science and the nature of life.

A new study eases fears that the pandemic H1N1 influenza virus will recombine with seasonal flu to mutate into a more lethal form. The study, reported in the online journal PLoS Currents, shows that the pandemic virus, commonly known as swine flu, grows much faster than seasonal flu viruses and is thus less likely to exchange genetic material with them. Virologist Daniel Perez of the University of Maryland and his colleagues grew the virus in ferrets, which are considered the best animal model for influenza because their respiratory system is very similar to that of humans.

A small amount of genetic material matching Phil Spector's DNA profile was found on Lana Clarkson's left breast, a courtroom expert testified Tuesday. But his genetic profile was not detected on the revolver used to shoot the actress, a Los Angeles County criminalist testified in the murder trial of the legendary record producer. Sheriff's criminalist Steve Renteria also said DNA matching Lana Clarkson's genetic markers was found in Spector's groin area.

A private lab used by prosecutors in the Duke University lacrosse rape case failed to disclose that it had found DNA from unidentified males in samples taken from the accuser's body and underwear, according to a defense motion filed Wednesday. The DNA did not match samples taken from three Duke lacrosse players charged with raping an exotic dancer during an off-campus party March 14.

She was just 17 when a stranger raped her in a dark alley near the downtown Riverside bus depot, authorities say. On Monday, seven years later, she took the witness stand and stared at the man charged with the crime. Darryl Joseph Tavie faces rape, kidnapping and robbery charges and is the first person in Riverside County to be identified through a DNA match in the California Department of Justice's Cold Hit program.

Researchers at Amgen Inc. of Thousand Oaks have developed an effective new method of inserting new genetic information into chicken eggs so that it will be passed on to succeeding generations. One benefit of the development may be a new path to production of genetically engineered drugs.

As her mother slipped into the disoriented world of Alzheimer's disease, Oleta Toliver poured herself into a project that offered hope. She began turning up at nursing homes, church groups and family reunions near her Texas home, trying to coax Alzheimer's patients and their families to donate DNA to Texas Tech University. Most families were eager to help.

A nonprofit group that says it promotes forests by cloning America's biggest and oldest trees arrived in eastern California Tuesday to claim a crown jewel. In a stealth operation with the cooperation of the U.S. Forest Service, the tree advocates ventured into California's White Mountains to the home of Methuselah, a 4,768-year-old bristlecone pine recognized as the oldest known living tree.