Berkeley Lab Researchers Produce First Step-by-Step Look at Transcription Initiation
Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have achieved a major advance in understanding how genetic information is transcribed from DNA to RNA by providing the first step-by-step look at the biomolecular machinery that reads the human genome.
“We’ve provided a series of snapshots that shows how the genome is read one gene at a time,” says biophysicist Eva Nogales who led this research. “For the genetic code to be transcribed into messenger RNA, the DNA double helix has to be opened and the strand of gene sequences has to be properly positioned so that RNA polymerase, the enzyme that catalyzes transcription, knows where the gene starts. The electron microscopy images we produced show how this is done.” (more…)
Decoded genome reveals secrets of pigeon traits and origins
Scientists have decoded the genetic blueprint of the rock pigeon, unlocking secrets about pigeons’ Middle East origins, feral pigeons’ kinship with escaped racing birds and how mutations give pigeons traits like feather head crests.
“Birds are a huge part of life on Earth, but we know surprisingly little about their genetics,” says Michael Shapiro, one of the study’s two principal authors and a biologist at the University of Utah. (more…)
The Encyclopedia of DNA Elements (ENCODE) project is the effort of hundreds of scientists to describe the workings of the human genome. Their research, outlined in 30 papers published in multiple journals Sept. 5, has confirmed our genome is far more complex than originally thought. Regions that contain instructions for making proteins, which carry out life’s functions, account for only about 1 percent of our genome. ENCODE has shed light on the other 99%. Almost 80 percent of the genome is biochemically active, much of it involved in some sort of regulation of genes. Vast regions of our DNA once considered “junk” contain some 400,000 regulators called enhancers, which play a key role activating or silencing genes despite residing far away from the gene itself. Yale University researchers played a key role ENCODE, helping to author 9 of the 30 papers published in four journals on Sept. 5. Some of their work is described below.
The massive Encyclopedia of DNA Elements (ENCODE) unveiled Sept. 5 reveals a human genome vastly more rich and complex than envisioned even a decade ago. In a key supporting paper published in the journal Nature, the lab of Yale’s Mark Gerstein, the Albert L. Williams Professor of Biomedical Informatics, has found order amidst the seeming chaos of trillions of potential molecular interactions. (more…)
*New analytical method approaches the unstudied 99% of the human genome*
WASHINGTON, D.C., – 02 Nov 2011: Evolutionary history shows that human populations likely originated in Africa, and the Genographic Project, the most extensive survey of human population genetic data to date, suggests where they went next. A study by the Project finds that modern humans migrated out of Africa via a southern route through Arabia, rather than a northern route by way of Egypt. These findings will be highlighted today at a conference at the National Geographic Society.
National Geographic and IBM’s Genographic Project scientific consortium have developed a new analytical method that traces the relationship between genetic sequences from patterns of recombination – the process by which molecules of DNA are broken up and recombine to form new pairs. Ninety-nine percent of the human genome goes through this shuffling process as DNA is being transmitted from one generation to the next. These genomic regions have been largely unexplored to understand the history of human migration. (more…)
Baltimore, MD — The human genome shares several peculiarities with the DNA of just about every other plant and animal. Our genetic blueprint contains numerous entities known as transposons, or “jumping genes,” which have the ability to move from place to place on the chromosomes within a cell.
An astounding 50% of human DNA comprises both active transposon elements and the decaying remains of former transposons that were active thousands to millions of years ago before becoming damaged and immobile. If all of this mobile and formerly mobile DNA were not mysterious enough, every time a plant, animal or human cell prepares to divide, the chromosome regions richest in transposon-derived sequences, even elements long deceased, are among the last to duplicate. The reason for their delayed duplication, if there is one, has eluded biologists for more than 50 years. (more…)
