New View of Mouse Genome Finds Many Similarities, Differences with Human Genome
|Building on years of mouse and gene regulation studies, an international group of researchers has developed a resource that can help scientists better understand how similarities and differences between mice and humans are written in their genomes.
Looking across evolutionary time and the genomic landscapes of humans and mice, an international group of researchers has found powerful clues to why certain processes and systems in the mouse—such as the immune system, metabolism and stress response—are so different from those in people. Building on years of mouse and gene regulation studies, they have developed a resource that can help scientists better understand how similarities and differences between mice and humans are written in their genomes.
Their findings—reported by the mouse ENCODE Consortium online Nov. 19 (and in print Nov. 20) in four papers in Nature and in several other publications—examine the genetic and biochemical programs involved in regulating mouse and human genomes. The scientists found that, in general, the systems that are used to control gene activity have many similarities in mice and humans and have been conserved, or continued, through evolutionary time.
The results may offer insights into gene regulation and other systems important to mammalian biology. They also provide new information to determine when the mouse is an appropriate model to study human biology and disease and may help to explain some of its limitations.
“In general, the gene regulation machinery and networks are conserved in mouse and human, but the details differ quite a bit,” noted co-senior author Dr. Michael Snyder of Stanford University. “By understanding the differences, we can understand how and when the mouse model can best be used.”
Mitral Valve Repair Following Heart Attack May Offer Patients Little To No Benefit
Routinely adding mitral valve repair to coronary artery bypass graft surgery for heart attack patients may not be warranted in patients with moderate mitral valve damage, according to an NIH-funded study. Patients treated with both procedures versus the bypass graft alone showed no differences at 1 year in recovery from structural damage to the heart’s left ventricle, nor in secondary measures such as heart failure, stroke, functional status or quality of life.
The results of the Surgical Interventions for Moderate Ischemic Mitral Regurgitation study, supported by NHLBI, were presented Nov. 18 at the American Heart Association scientific sessions in Chicago and published simultaneously in the New England Journal of Medicine.
About 1 million Americans suffer heart attacks each year. Of these, about half are left with functional damage to the mitral valve due to the injury and changes to the heart muscle. This damage can result in leaks, causing a backflow of blood accompanied by symptoms such as shortness of breath, abnormal fatigue and excess blood in the lungs.
Doctors typically treat heart attack patients with this condition, called ischemic mitral regurgitation, by performing coronary artery bypass graft surgery, sometimes adding a procedure to repair the leaky mitral valve. The study is the first large-scale randomized clinical trial to assess whether adding the repair procedure leads to a measurable benefit for patients.
NIH-Sponsored Study Identifies Superior Drug Regimen for Preventing Mother-to-Child HIV Transmission
For HIV-infected women in good immune health, taking a three-drug regimen during pregnancy prevents mother-to-child HIV transmission more effectively than taking one drug during pregnancy, another during labor and two more after giving birth, an international clinical trial has found.
The ongoing PROMISE (Promoting Maternal-Infant Survival Everywhere study also has found that one triple-drug regimen for preventing mother-to-child transmission may be safer than another for women and their babies.
These findings provide further support for World Health Organization guidelines for preventing mother-to-child HIV transmission, according to the researchers. The findings were reported Nov. 4 during a review of PROMISE study data by an independent data and safety monitoring board.
“We now have the gold standard of evidence—data from a randomized clinical trial—supporting a three-drug regimen as the preferred approach for preventing HIV transmission from an infected mother to her baby during pregnancy and delivery,” said NIAID director Dr. Anthony Fauci. “This is another important step in our efforts to define the best approaches toward the goal of eliminating mother-to-child HIV transmission globally.”