Researchers almost doubled the lifespan of yeast cells by genetically rewiring the circuit that controls aging in a new proof-of-concept study.
What the human genome is lacking compared with the genomes of other primates might have been as crucial to the development of humankind as what has been added during our evolutionary history, according to a new study led by researchers at Yale and the Broad Institute of MIT and Harvard.
The new findings, published April 28 in the journal Science, fill an important gap in what is known about historical changes to the human genome. While a revolution in the capacity to collect data from genomes of different species has allowed scientists to identify additions that are specific to the human genome —such as a gene that was critical for humans to develop the ability to speak—less attention has been paid to what’s missing in the human genome.
For the new study researchers used an even deeper genomic dive into primate DNA to show that the loss of about 10,000 bits of genetic information—most as small as a few base pairs of DNA—over the course of our evolutionary history differentiate humans from chimpanzees, our closest primate relative. Some of those “deleted” pieces of genetic information are closely related to genes involved in neuronal and cognitive functions, including one associated with the formation of cells in the developing brain.
A team of researchers at the Broad Institute of MIT and Harvard has developed a new approach to next-generation sequencing that detects genetic mutations within single molecules of DNA.
The method, called Concatenating Original Duplex for Error Correction (CODEC), makes next-generation sequencing about 1,000 times more accurate and opens up the possibility of a range of applications including detecting tiny numbers of cancer mutations in blood samples, monitoring cancer during and after treatment, and identifying mutations underlying rare diseases, all at relatively low cost. The study appears today in Nature Genetics.
“The beauty of this approach is that it’s not an overhaul of how sequencing is done,” said Viktor Adalsteinsson, senior author on the study and director of the Gerstner Center for Cancer Diagnostics and leader of the Blood Biopsy Team at the Broad. “It’s not something that requires new instrumentation or capital investment —it’s a simple set of steps added into existing sample preparation workflows to improve the accuracy of DNA sequencing.”
Why do some people live lawful lives, while others gravitate toward repeated criminal behavior? Do people choose to be moral or immoral, or is morality simply a genetically inherited function of the brain? Research suggests that psychopathy as a biological condition explained by defective neural circuits that mediate empathy, but what does that mean when neuroscience is used as evidence in criminal court? How can understanding neuroscience give us an insight into the actions and behaviors of our political leaders?
Forensic psychiatrist Dr. Octavio Choi https://med.stanford.edu/profiles/ochoi will explore how emerging neuroscience challenges long-held assumptions underlying the basis—and punishment—of criminal behavior.
Protein-coding sequence differences have failed to fully explain the evolution of multiple mammalian phenotypes. This suggests that these phenotypes have evolved at least in part through changes in gene expression, meaning that their differences across species may be caused by differences in genome sequence at enhancer regions that control gene expression in specific tissues and cell types. Yet the enhancers involved in phenotype evolution are largely unknown. Sequence conservation–based approaches for identifying such enhancers are limited because enhancer activity can be conserved even when the individual nucleotides within the sequence are poorly conserved. This is due to an overwhelming number of cases where nucleotides turn over at a high rate, but a similar combination of transcription factor binding sites and other sequence features can be maintained across millions of years of evolution, allowing the function of the enhancer to be conserved in a particular cell type or tissue. Experimentally measuring the function of orthologous enhancers across dozens of species is currently infeasible, but new machine learning methods make it possible to make reliable sequence-based predictions of enhancer function across species in specific tissues and cell types.
Using Zoonomia’s data, researchers have also constructed a phylogenetic tree that estimates when each mammalian species diverged from its ancestors5. This analysis lends support to the hypothesis that mammals had already started evolutionarily diverging before Earth was struck by the asteroid that killed the dinosaurs about 65 million years ago — but that they diverged much more rapidly afterwards.
Only the beginning
The Zoonomia Project is just one of dozens of efforts to sequence animal genomes. Another large effort is the Vertebrate Genomes Project (VGP), which aims to generate genomes for roughly all 71,000 living vertebrate species, which include mammals, reptiles, fish, birds and amphibians. Although the two projects are independent of one another, many researchers are a part of both, says Haussler, who is a trustee of the VGP.
New research offers a path toward transplants that can fix damage from a heart attack without causing life-threatening arrhythmias.
People typically think of food as calories, energy and sustenance. However, the latest evidence suggests that food also “talks” to our genome, which is the genetic blueprint that directs the way the body functions down to the cellular level.
This communication between food and genes may affect your health, physiology and longevity. The idea that food delivers important messages to an animal’s genome is the focus of a field known as nutrigenomics. This is a discipline still in its infancy, and many questions remain cloaked in mystery. Yet already, we researchers have learned a great deal about how food components affect the genome.
I am a molecular biologist who researches the interactions among food, genes and brains in the effort to better understand how food messages affect our biology. The efforts of scientists to decipher this transmission of information could one day result in healthier and happier lives for all of us. But until then, has unmasked at least one important fact: Our relationship with food is far more intimate than we ever imagined.
A lightweight structure made of rubber and metal layers can provide an object with underwater acoustic stealth over a broad frequency range.
An acoustic “cloak” could hide an underwater object from detection by sonar devices or by echolocating marine animals. Much like camouflage clothing allows figures to fade into a background, acoustic camouflage can make an object indistinguishable from the surrounding water. Underwater acoustic cloaks have previously been demonstrated, but they typically work over a narrow range of frequencies or are too bulky to be practical. Now Hao-Wen Dong at the Beijing Institute of Technology and colleagues demonstrate a lightweight, broadband cloak made of a thin shell of layered material. The cloak achieves acoustic stealth by both blocking the reflection of sonar pings off the surface and preventing the escape of sound generated from within the cloaked object [1].
Dong and colleagues designed a 4-cm-thick structure—combining an outer rubber layer and a “metamaterial” made of porous aluminum—which covered a steel plate. Using a genetic algorithm, they optimized the metamaterial’s elastic properties to tailor the interaction with underwater sound waves. Specifically, the metamaterial converts impinging longitudinal sound waves, which can travel long distances underwater, to transverse sound waves, which cannot propagate through water. These transverse waves get trapped in the rubber layer, where they get absorbed, eliminating reflected and transmitted waves simultaneously. The researchers built and tested a prototype cloak, confirming that it behaved as predicted. In particular, it absorbed 80% of the energy of incoming sound waves while offering 100-fold attenuation of acoustic noise produced on the side of the steel plate.
Over the past 100 million years, mammals have adapted to nearly every environment on Earth. Scientists with the Zoonomia Project have been cataloging the diversity in mammalian genomes by comparing DNA sequences from 240 species that exist today, from the aardvark and the African savanna elephant to the yellow-spotted rock hyrax and the zebu.
This week, in several papers in a special issue of Science, the Zoonomia team has demonstrated how comparative genomics can not only shed light on how certain species achieve extraordinary feats, but also help scientists better understand the parts of our genome that are functional and how they might influence health and disease.
In the new studies, the researchers identified regions of the genomes, sometimes just single letters of DNA, that are most conserved, or unchanged, across mammalian species and millions of years of evolution—regions that are likely biologically important. They also found part of the genetic basis for uncommon mammalian traits such as the ability to hibernate or sniff out faint scents from miles away. And they pinpointed species that may be particularly susceptible to extinction, as well as genetic variants that are more likely to play causal roles in rare and common human diseases.
