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Mini-Brain Study Shows How Environmental Risk Factors Can Amplify Genetic Risks for Autism

Summary: Using human stem cells to develop a brain organoid model, researchers were able to show exposure to a common pesticide synergizes with an autism-linked gene mutation. The study provides clear evidence that genetics and environment may combine to disrupt neurodevelopment.

Source: Johns Hopkins University.

Researchers at Johns Hopkins Bloomberg School of Public Health have shown in a brain organoid study that exposure to a common pesticide synergizes with a frequent autism-linked gene mutation.

Researchers Create New CRISPR Genetic Tools to Help Contain Mosquito Disease Transmission

University of California San Diego scientists have now developed several genetic editing tools that help pave the way to an eventual gene drive designed to stop Culex mosquitoes from spreading disease. Gene drives are designed to spread modified genes, in this case those that disable the ability to transmit pathogens, throughout the targeted wild population.


Genetics toolkit targets less researched Culex mosquitoes, which transmit West Nile virus and avian malaria.

Since the onset of the CRISPR genetic editing revolution, scientists have been working to leverage the technology in the development of gene drives that target pathogen-spreading mosquitoes such as Anopheles and Aedes species, which spread malaria, dengue, and other life-threatening diseases.

Much less genetic engineering has been devoted to Culex genus mosquitoes, which spread devastating afflictions stemming from West Nile virus—the leading cause of mosquito-borne disease in the continental United States—as well as other viruses such as the Japanese encephalitis virus (JEV) and the pathogen causing avian malaria, a threat to Hawaiian birds.

How a Common Fungus May Contribute to Digestive Issues

The team plans to keep studying whether vaccines could help alleviate IBD symptoms, which tend to stay dormant then flare up. They also hope to find similar ways to nudge a dysfunctional gut microbiome back into balance.


The connection between gut bacteria and our overall health has been well studied in recent years. And while many of the specifics of this relationship are still unknown, it’s clear that a balanced microbiome with the right mix of bacteria helps maintain many of our regular bodily functions; conversely, the wrong mix of bacteria might help cause or signal the emergence of illness. But bacteria are only one type of microbe, and there’s been less work studying the many viruses and fungi that inhabit our body.

This new research was conducted by scientists from the University of Utah Health, who were curious if fungi were relevant to the development of inflammatory bowel disease (IBD), which includes Crohn’s. IBD is a complicated disorder, thought to have several contributing factors, including genetics. But recent research has suggested that certain species of fungi and yeast (the single celled version of fungi) could be one of these risk factors, including a common fungi in our gut called Candida albicans.

In experiments with mice, the team noticed that a functioning immune system seemed to interact with C. albicans. The yeast has the uncanny ability to switch between different forms of growth. It can remain a ball-like single-celled organism, or it can turn into a multicellular form, decked out with hyphae, a common branch-like structure found in most other fungi, that allows it to invade the tissues of our body to keep growing. The team found evidence that antibodies specific to C. albicans didn’t outright try to kill it—instead, they kept the yeast from turning into this more invasive form. But once the yeast was allowed to grow unfettered, the mice became sick with IBD-like symptoms, which can include diarrhea, intense cramps, and weight loss.

Gene editing ‘blocks virus transmission’ in human cells

“Once the virus is recognised, the CRISPR enzyme is activated and chops up the virus,” she said.


Paris (AFP)

Scientists have used CRISPR gene-editing technology to successfully block the transmission of the SARS-CoV-2 virus in infected human cells, according to research released Tuesday that could pave the way for Covid-19 treatments.

Writing in the journal Nature Communications, researchers in Australia said the tool was effective against viral transmissions in lab tests, adding that they hoped to begin animal trials soon.

Memory Making Involves Extensive DNA Breaking

If you want to learn, then you have to break some things.


Summary: Brain cells snap DNA in more places and in more cell types than previously realized in order to express genes for learning and memory.

Source: Picower Institute for Learning and Memory

The urgency to remember a dangerous experience requires the brain to make a series of potentially dangerous moves: Neurons and other brain cells snap open their DNA in numerous locations—more than previously realized, according to a new study—to provide quick access to genetic instructions for the mechanisms of memory storage.

The extent of these DNA double-strand breaks (DSBs) in multiple key brain regions is surprising and concerning, said study senior author Li-Huei Tsai, Picower Professor of Neuroscience at MIT and director of The Picower Institute for Learning and Memory, because while the breaks are routinely repaired, that process may become more flawed and fragile with age. Tsai’s lab has shown that lingering DSBs are associated with neurodegeneration and cognitive decline and that repair mechanisms can falter.

Scientists Discover That Mating Can Cause Epigenetic Changes That Last for 300 Generations

University of Maryland scientists discover that match matters: The right combination of parents in nematode worms can turn a gene off indefinitely.

Evidence suggests that what happens in one generation — diet, toxin exposure, trauma, fear — can have lasting effects on future generations. Scientists believe these effects result from epigenetic changes that occur in response to the environment and turn genes on or off without altering the genome or DNA sequence.

But how these changes are passed down through generations has not been understood, in part, because scientists have not had a simple way to study the phenomenon. A new study by researchers at the University of Maryland provides a potential tool for unraveling the mystery of how experiences can cause inheritable changes to an animal’s biology. By mating nematode worms, they produced permanent epigenetic changes that lasted for more than 300 generations. The research was published on July 9, 2021, in the journal Nature Communications.

Researchers discover new genetic driver of autism and other developmental disorders

Using CRISPR-Cas9, the researchers subsequently removed the one copy of the Ndn gene from the 15q dup mouse model to generate mice with a normalized genomic copy number for this gene (15q dupΔNdn mouse). Using this model, they demonstrated that the abnormalities observed in 15q dup mice (abnormal spine turnover rate and decreased inhibitory synaptic input) could be ameliorated.


A research group including Kobe University’s Professor TAKUMI Toru (also a Senior Visiting Scientist at RIKEN Center for Biosystems Dynamics Research) and Assistant Professor TAMADA Kota, both of the Physiology Division in the Graduate School of Medicine, has revealed a causal gene (Necdin, NDN) in autism model mice that have the chromosomal abnormality called copy number variation.

The researchers hope to illuminate the NDN gene’s molecular mechanism in order to contribute towards the creation of new treatment strategies for developmental disorders including autism.

These research results were published in Nature Communications on July 1, 2021.

Off-Patent Osteoporosis Drug Also Found to Extend Lifespan

Zoledronate is a biophosphonate, a drug used to strengthen bones and reduce the risk of osteoporosis-related bone fractures. It is well-absorbed into the bones, so it only needs to be administered through infusion once a year.

A 2010 study had found that people who were given zoledronate after experiencing hip fractures showed slightly reduced all-cause mortality compared to a control group. Patients who took the drug were at significantly lower risk for heart arrhythmias and pneumonia.

As this is a drug that is already being given to people, the choice to go back to genetically modified fruit flies, a much simpler model of aging, may seem counterintuitive. The team chose to test these insects for two principal reasons. The first is that Drosophila flies are a common subject of studies on basic aging pathways, which the researchers wished to explore. The second is simpler: Drosophila flies lack bones, making the bone-affecting properties of zoledronate irrelevant to the study.

Match matters: The right combination of parents can turn a gene off indefinitely

Evidence suggests that what happens in one generation—diet, toxin exposure, trauma, fear—can have lasting effects on future generations. Scientists believe these effects result from epigenetic changes that occur in response to the environment and turn genes on or off without altering the genome or DNA sequence.

But how these changes are passed down through generations has not been understood, in part, because scientists have not had a simple way to study the phenomenon. A new study by researchers at the University of Maryland provides a potential tool for unraveling the mystery of how experiences can cause inheritable changes to an animal’s biology. By mating nematode worms, they produced permanent epigenetic changes that lasted for more than 300 generations. The research was published on July 9, 2021, in the journal Nature Communications.

“There’s a lot of interest in heritable epigenetics,” said Antony Jose, associate professor of cell biology and molecular genetics at UMD and senior author of the study. “But getting clear answers is difficult. For instance, if I’m on some diet today, how does that affect my children and grandchildren and so on? No one knows, because so many different variables are involved. But we’ve found this very simple method, through mating, to turn off a for multiple generations. And that gives us a huge opportunity to study how these stable epigenetic changes occur.”