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She blinded me with science!
Messenger RNA molecules (in red) during cell division. (Credit: Image courtesy of Albert Einstein College of Medicine)“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. “Their lifespans are determined at the moment of their birth.” The study was carried out in yeast cells using advanced microscope technology developed previously by Dr. Singer that has allowed scientists, for the first time, to observe single molecules in single cells in real time.
When genes are transcribed, a part of the gene called the promoter region has the job of switching on the gene so that DNA will be copied into mRNA. The Einstein scientists found that the promoter regions of the SWI5 and CLB2 genes do something else as well: they recruit a protein called Dbf2p, which jumps onto mRNA molecules as they’re being synthesized.
These mRNAs — transcribed from the SWI5 and CLB2 genes and bearing the Dbf2p protein — make their journey from the nucleus into the cytoplasm. Here a protein called Dbf20p joins Dbf2p aboard the mRNA molecules — and the two proteins together call for the molecules’ precipitous decay.
“Our findings indicate that genes making proteins whose levels must be carefully controlled contain promoter regions that sentence their mRNA molecules to death even as the mRNA is being born,” said Dr. Singer. “The promoter regions do that by ‘marking’ the newly made mRNA with the protein Dbf2p — the common factor between mRNA synthesis and its ultimate decay. Dbf2p stays attached to the mRNA from its birth and then, responding to a signal indicating that no more protein should be made, orders mRNA’s destruction.”
Chimera monkeys created in U.S. lab by fusing up to six different embryos
U.S. researchers said Thursday they have created the world’s first genetically modified monkeys by fusing cells from up to six different embryos, in what could be a big advance for medical research.
Until now, rodents have been the primary creatures used to make chimeras, a lab animal produced by combining two or more fertilized eggs or early embryos together.
Scientists have long been able to create “knock-out” mice with certain genes deleted in order to study a host of ailments and remedies, including obesity, heart disease, anxiety, diabetes and Parkinson’s disease.
Attempts to do the same with more complicated primates have failed in the past, but scientists in the western state of Oregon succeeded by altering the method used to make mice. (Photo: AFP/Oregon Health & Science University)
(via openscience)
Stressed yeast cells frantically reshuffle their chromosomes in a desperate last bid to find a combination that survives. This “panic” response enables them to rapidly evolve resistance to drugs.
The discovery might also apply to cancer, because cancer cells often have abnormal numbers and arrangements of chromosomes. Understanding one of the mechanisms by which cancers develop resistance to drugs could in turn open up new ways to combat cancer.
The key panic button driving the reshuffling is heat-shock protein 90 (Hsp90), which normally ensures that chromosomes are faithfully copied when cells divide and multiply. When Hsp90 is knocked out, the chromosomes get completely reshuffled. That’s normally a disaster, but in a desperate situation it’s a potential lifeline.
The range of color variation in Golden Retrievers.
One of each, please.
Absolutely beautiful paper-quilted anatomical cross-sections by artist Lisa Nilsson, reminiscent of Yulia Brodskaya’s work.
Love everything about this.
Colourful cancer cells snag micro-photography prize.
An ovarian cancer researcher found the beauty in a horrific disease to win the 2011 IN Cell Analyzer Image Competition. Geoffrey Grandjean from the MD Anderson Cancer Center in Houston, Texas captured this image of human cancer cells to win the prize.
The cells’ kaleidoscope of colours come from stains that show DNA in red and microtubules in green. Images of this type help the researchers identify areas to attack in cancer therapies.
This image will be shown off with the other category winners on the big screen in New York’s Times Square on April 20-22. If you can’t make it to the Big Apple this spring, you can still check out all the winners in GE Healthcare’s online gallery.
Ovarian cancer cells have also been made to fluoresce to help doctors remove them more accurately.
nybg:
WARNING: Science Content. Sorry—I’ve always wanted to steal a page from the Mythbusters’ playbook. —MN
Animal? Plant? Actually It’s Both!
Many animals transform themselves almost beyond recognition in the course of their lives. Caterpillars become butterflies and tadpoles become frogs, and if we couldn’t watch them do so we might not even suspect that the two stages were the same creature. Spectacular as these shifts are, they are only shape-shifting. A tadpole and a frog are both animals, so both must take in food from their surroundings. Not so Mesodinium chamaeleon. This newly discovered single-celled organism is a unique mixture of animal and plant.
