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Acquired traits can be inherited via small RNAs

Acquired traits can be inherited via small RNAs
Columbia University Medical Center (CUMC) researchers have found the first direct evidence that an acquired trait can be inherited without any DNA involvement. The findings suggest that Lamarck, whose theory of evolution was eclipsed by Darwin's, may not have been entirely wrong. The study is slated to appear in the Dec. 9 issue of Cell. "In our study, roundworms that developed resistance to a virus were able to pass along that immunity to their progeny for many consecutive generations," reported lead author Oded Rechavi, PhD, associate research scientist in biochemistry and molecular biophysics at CUMC. In an early theory of evolution, Jean Baptiste Larmarck (1744-1829) proposed that species evolve when individuals adapt to their environment and transmit those acquired traits to their offspring. However, some evidence suggests that acquired traits can be inherited. Dr. RNAi is triggered by doubled-stranded RNA (dsRNA), which is not found in healthy cells.

Long non-coding RNA prevents the death of maturing red blood cells A long non-coding RNA (lncRNA) regulates programmed cell death during one of the final stages of red blood cell differentiation, according to Whitehead Institute researchers. This is the first time a lncRNA has been found to play a role in red blood cell development and the first time a lncRNA has been shown to affect programmed cell death. "Programmed cell death, or apoptosis, is very important, particularly in the hematopoietic (blood forming) system, where inhibition of cell death leads to leukemias," says Whitehead Institute Founding Member Harvey Lodish, who is also a professor of biology and a professor of bioengineering at MIT. "We know a lot about the genes and proteins that regulate apoptosis, but this is the first example of a non-coding RNA that plays a role in blood cells. And if an upregulated lncRNA is associated with cancer-cell survival, it may represent a new avenue of attack for therapeutics. LncRNAs were first identified in the 1980s.

Mechanisms cells use to remove bits of RNA from DNA strands When RNA component units called ribonucleotides become embedded in genomic DNA, which contains the complete genetic data for an organism, they can cause problems for cells. It is known that ribonucleotides in DNA can potentially distort the DNA double helix, resulting in genomic instability and altered DNA metabolism, but not much is known about the fate of these ribonucleotides. A new study provides a mechanistic explanation of how ribonucleotides embedded in genomic DNA are recognized and removed from cells. "We believe this is the first study to show that cells utilize independent repair pathways to remove mispaired ribonucleotides embedded in chromosomal DNA, which can be sources of genetic modification if not removed," said Francesca Storici, an assistant professor in the School of Biology at the Georgia Institute of Technology. The findings were reported Dec. 4, 2011 in the advance online publication of the journal Nature Structural & Molecular Biology.

Synthetic RNA lessens severity of fatal disease A team of University of Missouri researchers have found that targeting a synthetic molecule to a specific gene could help the severity of the disease Spinal Muscular Atrophy (SMA) -- the leading genetic cause of infantile death in the world. "When we introduced synthetic RNA into mice that carry the genes responsible for SMA, the disease's severity was significantly lowered," said Chris Lorson, researcher at the Bond Life Sciences Center and professor in the Department of Veterinary Pathobiology and the Department of Molecular Microbiology and Immunology. "The mice that receive synthetic RNA gain more weight, live longer, and had improvements in motor skills. These results are very exciting." SMA is a rare genetic disease that is inherited by one in 6,000 children, who often die young because there is no cure. While the results are promising, Lorson notes additional research is needed before synthetic RNA could be used on humans for SMA.

Cancer drug cisplatin found to bind like glue in cellular RNA An anti-cancer drug used extensively in chemotherapy binds pervasively to RNA -- up to 20-fold more than it does to DNA, a surprise finding that suggests new targeting approaches might be useful, according to University of Oregon researchers. Medical researchers have long known that cisplatin, a platinum compound used to fight tumors in nearly 70 percent of all human cancers, attaches to DNA. Its attachment to RNA had been assumed to be a fleeting thing, says UO chemist Victoria J. DeRose, who decided to take a closer look due to recent discoveries of critical RNA-based cell processes. "We're looking at RNA as a new drug target," she said. The National Institutes of Health- and UO-funded research is detailed in a paper placed online ahead of regular publication in ACS Chemical Biology, a journal of the American Chemical Society. The researchers applied cisplatin to rapidly dividing and RNA-rich yeast cells (Saccharomyces cerevisiae, a much-used eukaryotic model organism in biology).

Computer assisted design (CAD) for RNA The computer assisted design (CAD) tools that made it possible to fabricate integrated circuits with millions of transistors may soon be coming to the biological sciences. Researchers at the U.S. Department of Energy (DOE)'s Joint BioEnergy Institute (JBEI) have developed CAD-type models and simulations for RNA molecules that make it possible to engineer biological components or "RNA devices" for controlling genetic expression in microbes. This holds enormous potential for microbial-based sustainable production of advanced biofuels, biodegradable plastics, therapeutic drugs and a host of other goods now derived from petrochemicals. "Because biological systems exhibit functional complexity at multiple scales, a big question has been whether effective design tools can be created to increase the sizes and complexities of the microbial systems we engineer to meet specific needs," says Jay Keasling, director of JBEI and a world authority on synthetic biology and metabolic engineering.

Built-in 'self-destruct timer' causes ultimate death of messenger RNA in cells Researchers at Albert Einstein College of Medicine of Yeshiva University have discovered the first known mechanism by which cells control the survival of messenger RNA (mRNA) -- arguably biology's most important molecule. The findings pertain to mRNAs that help regulate cell division and could therefore have implications for reversing cancer's out-of-control cell division. The research was recently described in the journal Cell. "The fate of the mRNA molecules we studied resembles a Greek tragedy," said the study's senior author, Robert Singer, Ph.D., co-director of the Gruss Lipper Biophotonics Center and professor and co-chair of anatomy and structural biology at Einstein. Directions for making proteins are encoded in the DNA sequences of genes, which reside on chromosomes in the nucleus of each cell. In their search for such a mechanism, Dr. While these observations pertain to yeast cells, Dr.

A radar for ADAR: Altered gene tracks RNA editing in neurons Jan. 4, 2012 — RNA editing is a key step in gene expression. Scientists at Brown University report in Nature Methods that they have engineered a gene capable of visually displaying the activity of the key enzyme ADAR in living fruit flies. To track what they can't see, pilots look to the green glow of the radar screen. Now biologists monitoring gene expression, individual variation, and disease have a glowing green indicator of their own: Brown University biologists have developed a "radar" for tracking ADAR, a crucial enzyme for editing RNA in the nervous system. The advance gives scientists a way to view when and where ADAR is active in a living animal and how much of it is operating. In experiments in fruit flies described in the journal Nature Methods , the researchers show surprising degrees of individual variation in ADAR's RNA editing activity in the learning and memory centers of the brains of individual flies. A reporter of an editor A versatile new tool? Story Source:

Simpler times: Did an earlier genetic molecule predate DNA and RNA? In the chemistry of the living world, a pair of nucleic acids -- DNA and RNA -- reign supreme. As carrier molecules of the genetic code, they provide all organisms with a mechanism for faithfully reproducing themselves as well as generating the myriad proteins vital to living systems. Yet according to John Chaput, a researcher at the Center for Evolutionary Medicine and Informatics, at Arizona State University's Biodesign Institute®, it may not always have been so. Chaput and other researchers studying the first tentative flickering of life on earth have investigated various alternatives to familiar genetic molecules. One approach to identifying molecules that may have acted as genetic precursors to RNA and DNA is to examine other nucleic acids that differ slightly in their chemical composition, yet still possess critical properties of self-assembly and replication as well as the ability to fold into shapes useful for biological function.

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