genetic variation

(University of Michigan Health System) Anyone who has ever tried smoking probably remembers that first cigarette vividly.

Now, a new study links those first experiences with smoking, and the likelihood that a person is currently a smoker, to a particular genetic variation.

The finding may help explain the path that leads from that first cigarette to lifelong smoking.

A genetic variation which evolved to protect people of African descent against malaria has now been shown to increase their susceptibility to HIV infection by up to 40 percent, according to new research.

Conversely, the same variation also appears to prolong survival of those infected with HIV by approximately two years.

Major Histocompatibility Complex (MHC) genes produce proteins that are crucial in fighting pathogen assault.

Researchers characterized genetic variation and detected more than one MHC class II locus in a tailed amphibian. Unlike mammals, not much has been known until now about the immune defense of amphibians.

(Henry M. Jackson Foundation for the Advancement of Military Medicine) A review article in the New England Journal of Medicine explores the genetic variation of HIV-1 and its implications for preventing and treating the disease.

Francine McCutchan, Ph.D., a researcher with the US Military HIV Research Program, co-authored the article, which appeared in the April 10, 2008 edition.

Genetic variation in the DNA of mitochondria -- the "power plants" of cells -- contributes to a person's risk of developing age-related macular degeneration, investigators report.

The study is the first to examine the mitochondrial genome for changes associated with AMD, the leading cause of blindness in Caucasians over age 50.

Whole-organ maps that superimpose genetic information over the terrain of cancerous bladders chart the molecular journey from normal cell to invasive cancer.

By geographically relating an organ's varied tissues -- normal, precancerous and malignant -- to their underlying genetic variation or regulation, the team also identified a crucial new category of genes that launches the process of cancer development.

Scientists are embarking on a study to index the useful genetic variation of more than 2,000 accessions in the Agricultural Research Service, USDA, grape germplasm collection.

A genetic variation, found predominantly in African Americans, protects some people with heart failure, enabling them to live longer than expected.

Researchers found that the genetic variation acts just like beta-blockers, a class of drugs used to treat chronic heart failure.

The researchers say their discovery adds to the accumulating evidence that genetic differences contribute to the way people respond to medications.

A genetic variation, found predominantly in African Americans, protects some people with heart failure, enabling them to live longer than expected.

Researchers found that the genetic variation acts just like beta-blockers, a class of drugs used to treat chronic heart failure.

The researchers say their discovery adds to the accumulating evidence that genetic differences contribute to the way people respond to medications.

The productivity and biodiversity of an ecosystem is significantly affected by the rate at which organisms move between different parts of the ecosystem.

When there is little or no dispersal, populations of species that remain in harsh areas of an ecosystem are unable to adapt to their environment due to a low population size and lack of genetic variation.

Conversely, when there is too much dispersal in an ecosystem, species evolve to be 'generalists' that can survive in many habitats, but fail to thrive in any given one.