Lifeboat Foundation

Over the last 60 years, scientists have been able to observe how and when genetic information was replicated, determining the existence a “replication timing program,” a process that controls when and in what order segments of DNA replicate. However, scientists still cannot explain why such a specific timing sequence exists. In a study published today in Science, Dr. David Gilbert and his team have answered this 60-year-old question.

“Why would cells care about the order in which they replicate DNA?” asked lead scientist Dr. Gilbert. “After all—all cells need to replicate all their DNA. Our hypothesis has been that it’s not just DNA that replicates, but all of the regulatory molecules that read the DNA replicate as well.” Dr. Gilbert further hypothesized that there might be a purpose behind the replication timing program and process because “mother nature would not squander this opportunity to control how the DNA is read.”

“The time at which you replicate provides an ideal time at which to choose whether to maintain all the regulatory factors and continue with the same functional interpretation of the information in DNA or change it to elicit new functions,” explains Dr. Gilbert.

Males may have shorter lifespans than females due to repetitive sections of the Y chromosome that create toxic effects as males get older. These new findings appear in a study by Doris Bachtrog of the University of California, Berkeley published April 22 in PLOS Genetics.

In humans and other species with XY sex chromosomes, females often live longer than males. One possible explanation for this disparity may be repetitive sequences within the genome. While both males and females carry these repeat sequences, scientists have suspected that the large number of repeats on the Y chromosome may create a “toxic y effect” that shortens males’ lives. To test this idea, Bachtrog studied male fruit flies from the species Drosophila miranda, which have about twice as much repetitive DNA as females and a shorter lifespan. They showed that when the DNA is in its tightly packed form inside the cells of young male flies, the repeat sections are turned off. But as the flies age, the DNA assumes a looser form that can activate the repeat sections, resulting in toxic side effects.

The new study demonstrates that Y chromosomes that are rich in repeats are a genomic liability for males. The findings also support a more general link between repeat DNA and aging, which currently, is poorly understood. Previous studies in fruit flies have shown that when repeat sections become active, they impair memory, shorten the lifespan and cause DNA damage. This damage likely contributes to aging’s physiological effects, but more research will be needed to uncover the mechanisms underlying repeat DNA’s toxic effects.

Cystic fibrosis is diagnosed in infants by use of sweat testing as elevated chloride concentrations in sweat are indicative of cystic fibrosis. The current approach can have poor sensitivity and require repeated testing. Toward the goal of developing a noninvasive, simple test for cystic fibrosis, Ray et al. devised an adhesive microfluidic device, or “sweat sticker,” to capture and analyze sweat in real time with colorimetric readout. Benchtop testing and validation in patients with cystic fibrosis showed that smartphone imaging of sweat stickers adhered to the skin could monitor sweat chloride concentrations. Results support further testing of the sweat stickers in larger studies.

The concentration of chloride in sweat remains the most robust biomarker for confirmatory diagnosis of cystic fibrosis (CF), a common life-shortening genetic disorder.

Telomeres are large nucleoproteins structures that cap the ends of chromosomes in eukaryotic cells. When a cell divides, a small portion of the telomere is lost due to the inherently incomplete process of genome replication. If left unchecked, over time the telomeres will reach a critically short length and the cell will face genomic instability, deterioration or death. To offset this shortening, an essential enzyme called telomerase rebuilds the telomeres by synthesizing new telomeric DNA repeats at chromosome ends. Kelly Nguyen’s group, in the LMB’s Structural Studies Division, has solved the first complete atomic model of this enzyme and discovered a histone dimer as novel telomerase subunits.

Telomeres act as a barrier to protect the genetic information from progressive degradation arising from incomplete DNA replication. Additionally, telomeres distinguish the natural chromosome ends from DNA double-strand breaks, thereby avoiding an illicit DNA damage response and preventing intrachromosomal fusion. This makes telomeres essential for the preservation of genome and chromosome stability. In previous research, Kelly had discovered the architecture and composition of human telomerase holoenzyme at 8 Å (Ångströms) resolution using cryo-EM. However, to understand the molecular mechanism governing telomerase mediated telomere maintenance, a high-resolution structure of the complex was required.

To conduct this study, Kelly’s group, in collaboration with Kathleen Collins at the University of California, Berkeley, and Rhiju Das at Stanford University, prepared telomerase by extracting it from cultured human cells, before imaging using cryo-EM—resulting in the collection of almost 44000 images. This data was analyzed using RELION—a complex computer program developed at the LMB—in order to achieve the 3.4−3.8 Å structure of telomerase. From this Kelly and members of her group, George Ghanim, Adam Fountain, and Marike van Roon, were able to build the first complete atomic model of telomerase, with 12 protein subunits and telomerase RNA. By completing the structure to such a high resolution, the group was not only able to illuminate how common RNA and protein motifs work together, but also to highlight new interactions.

No fossils necessary.

Scientists have achieved a breakthrough they’re comparing to the moon landing: sequencing a full ancient genome from soil samples.

How’s that on par with humans touching down on the lunar surface? Well, the research team from the University of Copenhagen found the entire genetic code of an ancient bear species without obtaining it from fossils, marking the very first time scientists have found genes outside the fossil record. And by gathering the DNA from the soil, these researchers gathered a bunch of examples, rather than just one single specimen’s genome.

Continue reading “In ‘Moon Landing of Genomics,’ Scientists Sequence Ancient DNA From Dirt” »

Summary: Betaine, a dietary supplement extracted from sweet beets, reduces behavioral symptoms of schizophrenia in mice with genetic risk factors for the disorder. The supplement may help protect proteins that build the cellular skeletons of neurons.

Source: University of Tokyo.

A simple dietary supplement reduces behavioral symptoms in mice with a genetic mutation that causes schizophrenia. After additional experiments, including visualizing the fluorescently stained dancing edge of immature brain cells, researchers concluded that the supplement likely protects proteins that build neurons’ cellular skeletons.

One in 17 people will suffer from a rare disease at some time in their lives. Most of these rare diseases have a genetic cause and often affect children, but proving which gene change causes a disease is a huge challenge.

Scientists have discovered a new genetic disease, which causes some children’s brains to develop abnormally, resulting in delayed intellectual development and often early onset cataracts.

The majority of patients with the condition, which is so new it doesn’t have a name yet, were also microcephalic, a birth defect where a baby’s head is smaller than expected when compared to babies of the same sex and age.

Continue reading “Strange New Genetic Disease Discovered That Causes Children’s Brains to Develop Abnormally” »

There are several key technologies converging on an inevitable effect, namely a dramatic, explosive increase in human population. Currently around 40% of Earth’s total land area is dedicated to agricultural production to feed seven billion people, but, interestingly, while the human population will increase, the land area required to sustain this population will decrease, approaching zero land area to sustain a trillion human lives. In this era, bulk elements such as gold will have no value, since they will be so easy to produce by fusion separation of elements from bulk rock. Instead, value will be attached to biological material and, most importantly, new technologies themselves.

The several key emerging technologies that make this state of affairs unstoppable are listed along with aspects of their impact:

1) Most important is fusion energy, an unlimited, scalable energy, with no special fuel required to sustain it. This will allow nearly all agriculture to be contained in underground “vertical farm” buildings, extending thousands of feet downwards. Cheap artificially-lighted, climate-controlled environments will allow the maximum efficiency for all food crops. Thus, agriculture will take up close to zero surface area, largely produced underground on Earth or the Moon.

Continue reading “Approaching a Singularity, When The Number of Humans Alive Will Equal The Number Who Have Ever Died” »

Oral treatment with a bacterial protein known as colonization factor antigen I (CFA/I) fimbriae, from Escherichia coli bacteria, has been shown to protect against several autoimmune diseases, including arthritis and type 1 diabetes. Another bacteria, called Lactococcus lactis, was recently adapted to express CFA/I fimbriae. These bacteria were shown to effectively suppress inflammation by the induction of regulatory T-cells (Tregs) — which are negative regulators of the immune system, meaning they work to shut down excessive inflammatory responses.

Oral treatment with a molecule produced by bacteria, called colonization factor antigen I, can reduce or halt the progression of Sjögren’s syndrome, a mouse study suggests.

Researchers believe these findings provide the basis for future testing in patients with Sjögren’s.

Continue reading “Bacterial Molecule Can Slow Sjögren’s Progression, Preclinical Study Suggests” »