genes
dr. dolittle | September 15, 2017 Photo of sea sponges by Steve Rupp, National Science Foundation via Wikimedia Commons
Through the course of evolution vertebrates have apparently lost their gene-encoded viral defense mechanisms. These ancient defenses allow plants and insects to silence the expression of certain genes by using what is known as RNA interference. This natural defense system can be manipulated to create genetically modified crops that resist certain infections. However, a new study by researchers from the University of Leuven in Belgium examined over 40 organisms in search of a specific family of proteins…
dr. dolittle | November 3, 2016Mitochondria produce more than just ATP
Anatomy of a mitochondrion from Wikimedia Commons
Pinchas Cohen from the University of California - Davis presented data showing that mitochondria produce more than just ATP. They also make several peptides that can each affect our physiology. Some help cells respond to insulin better, some help with weight, some regulate cell metabolism. What is even more impressive is that some of these peptides have been shown to slow down the development of atherosclerosis or Alzheimer's, and some even help prevent side effects from chemotherapy in animals. Maybe…
jhalper | January 7, 2016
Why does infection with bacteria or viruses make you feel sick? Prof. Guy Shakhar and Dr. Keren Shakhar have proposed that your symptoms are not just a byproduct of your body’s attempt to get rid of the infection. It is your genes’ way of ensuring they are passed down. The long and short of their argument is that the malaise, loss of appetite and lethargy are all ways of isolating you from your social group – so that your kin, who carry many of your genes, are not infected as well.
That means we share an evolutionary adaptation with such organisms as bees that go off to die far from the hive…
jhalper | January 3, 2016Cells that “spit” out their contents and messenger RNA that is not so swift at delivering its message. Those are two brand new stories on our new and improved website. Check it out and let us know what you think.
The first story arose from a simple question: How do secretory cells – those that produce copious amounts of such substances as tears, saliva or all those bodily fluids – manage to get their contents out of the cell? Cells are walled all the way around; they don’t really have doors for letting things the size of a drop of fluid out. Instead, they use the vesicle system – small globes…
jhalper | October 27, 2015 Metastatic melanoma tumors. Left exhibits low or absent expression of RASA2 and reduced survival, typical of about 35% of patients. The sample on the right exhibits high RASA2 expression and increased survival
Rates of melanoma are increasing, even as the rates of other common cancers are decreasing. According to the Melanoma Research Alliance, it is the most common cancer diagnosis in young adults 25-29 years old in the United States, the second most common cancer in young people 15-29, and its incidence has tripled in the last 30 years.
What are we doing about it? The Weizmann Institute’…
jhalper | August 31, 2015
One day in the future, we may be treating our ailments with microbiotic combinations designed specifically to correct imbalances in our personal microbiomes. We’ll bring our prescriptions on rewritable paper and pay using shimmery optical chips embedded in our cell phone cases or maybe our jewelry. Or we’ll be waiting in our doctor’s office for a simple test of our microbiogenome to see if a light-based nanoparticle delivery treatment is working, while watching iridescent optical displays that change as we move...
These future scenarios (and many more) are all imaginary, but they are…
jhalper | June 16, 2015When Dr. Jakub Abramson was a 14-year-old boy in the former Czechoslovakia, he asked his father what was the best place to do science. His father took the question seriously and, after some consideration, answered “the Weizmann Institute of
Dr. Jakub Abramson
Science.” Since that day, says Abramson, he knew he was bound for the Institute. “It’s just that the science I was interested in back then involved blowing things up,” he says.
Today, Abramson is more interested in exploding the common wisdom about autoimmune diseases. His lab at the Weizmann Institute has produced two new papers –…
jhalper | April 26, 2015Foreigner or native-born? Your immune system discriminates between them, as do those of bacteria. Yes indeed, bacteria do have immune systems – pretty complex ones at that. And like any useful immune system, the bacterial ones must have a good technique for distinguishing “foreign” from “self.”
You may even have heard of the bacterial immune system: It’s called CRISPR, and it’s used in biology research around the world for DNA engineering and genome editing. CRISPR normally inserts short DNA sequences taken from phages – viruses that invade bacteria – into special slots called spacers within…
dr. dolittle | July 23, 2014
Like Aesop's fable, rats have another reason to be envious of elephants. Elephants also have significantly more genes that can detect different smells (i.e. olfactory receptor genes) than other super-sniffers like rats and dogs. In fact, compared to 13 other species, African elephants have 1,948 genes related to smell putting them ahead of the previous record holder, rats that only have about half as many genes. Primates have much fewer with only 296-396 of these olfactory receptor genes. Interestingly, the common ancestor of mammals had 781 olfactory genes, meaning that primates have lost…
milhayser | March 23, 2014For the first time, researchers have transformed induced pluripotent stem cells (iPSCs) into specialized bladder cells. Meanwhile the development of iPSCs from normal cells has been shown to depend on two proteins necessary for the induction of a glycolytic state. In order to make iPSCs, researchers have previously needed to collect significant amounts of skin, bone marrow, or blood from a donor, but researchers have demonstrated a new method that requires only a single drop of blood. In the future, you may be able to prick your finger, send a drop of blood to the lab, and have them grow a…
dr. dolittle | December 3, 2013 Image of a great white shark from Wikimedia Commons.
Dr. Michael Stanhope from Cornell University has discovered that great white sharks actually share more proteins involved in metabolism and biochemistry in common with humans than zebrafish, a common fish model used in biomedical research. They made this discovery by sequencing the transcriptome of a heart isolated from a great white shark. I find it fascinating that sharks have more proteins in common with mammals than with bony fish, even though sharks and bony fish are not very closely related.
Source:
Cornell University Press
jhalper | November 25, 2013More science-themed haikus. I seem to keep writing them because we tend to put out three “mini press releases” at a time (a relic of the days when they were printed on two sides of a fold-up page and mailed). So I could pick just one to blog about, or I could try to fit all three into one post (which tends to get muddled when it is on subjects as varied as physics, neurobiology and genetics). Or else I can leave these little breadcrumbs inviting you to follow them back to our website, where the fuller explanation awaits (or, from there, you can follow the links in the releases to get to the…
jhalper | October 31, 2013In the future, stem cells created from our own skin cells will be used to renew damaged organs or grow new ones. We know this promise has often been made before, but the latest research in the lab of Dr. Jacob (Yaqub) Hanna is producing some solid findings that may make you believe in the possibility.
Just a little over a month ago, we reported that Hanna and his group had discovered a “brake” that keeps our cells from easily reverting to an embryonic-stem-cell-like state (induced pluripotent stem cells, or iPS cells). Removing that brake enabled them to ramp up the conversion process – in…
milhayser | October 1, 2013On Pharyngula, PZ Myers says that cancer, unlike an infectious bacterium or virus, is not the product of millions of years of evolution. Instead, PZ writes, “Cancer misuses and perverts existing processes in your cells to send them out of control.” But what causes cancer? Well, it happens about 20,000 times a day in your body. Luckily, it is almost always repaired. It is the mutation of DNA during cell division. Just one base out of place, and suddenly the gene that made a protein to tightly regulate cell division is making a protein that encourages the cell to divide continually. Depending…
jhalper | September 29, 2013Cancer, we are told, is a disease of the genes. It originates in mutations in the DNA. But a paper published by a Weizmann Institute group in Cell Reports flips that idea sideways by about 90 degrees: For at least some types of the disease, the healthy, non-mutated version of a gene is no less of a driving force behind the development of cancer than its mutated form.
Prof. Yoram Groner, who led the research, describes the situation as a “balance of terror.” Until now, researchers have assumed that, when a mutation causes cancer it becomes dominant in the cell, overriding the second copy of…
jhalper | September 19, 2013First, there was the great hope of induced pluripotent stem cells (iPSCs), and then there was the inevitable letdown. When the announcement came, in 2006, that simple adult skin cells could be reprogrammed – reverted back to an embryonic stem cell state by the addition of just four genes – it seemed like an almost magical solution to the problems of using stem cells from embryos. But then some studies started to find that the reprogramming process was not perfect – iPSCs were similar, but not identical, to the cells from early embryos. More critically, only about 1% of the cells treated with…
jhalper | July 30, 2013Since the haiku post was well received, and since we have another three pieces online today – each on a different finding and each interesting in its own right – I have decided to return to the haiku format. Among other things, there is something quite satisfying about distilling complex scientific findings down to 17 little syllables – like writing the perfect tweet, but more so.
In any case, follow the links to read more:
A burst of enzymes:
A transcription traffic jam
Watch for gene speed bumps
Genetics can rid
The poison from potatoes
Or add it elsewhere
image: Thinkstock
To raise…
jhalper | February 24, 2013Another advance in cancer research is featured on our website this week. Among other things, this one highlights the dangers of assuming causation from correlation. Prof. Dov Zipori and his team were looking at adult stem cells in the bone marrow. These hold a lot of potential for treating many kinds of disease but, like many kinds of stem cells, there is a risk of these cells differentiating into cancer instead of the intended normal tissue replacement. The idea was to find a marker that could tell which cells were more likely to turn cancerous, thus making the use of these stem cells safer…
jhalper | January 17, 2013Does your face reveal what’s in your heart? It might – even more than you know. Take, for instance, a common group of birth defects – forms of a disorder called DiGeorge syndrome. Around one in 4000 is born with this syndrome, which arises from a deletion of a short segment of chromosome 22. Among other problems, this deletion nearly always involves deformations in both the face and the heart.
Sculpture: Igor Mitoraj
The Institute’s Prof. Eldad Tzahor had already shown that face and heart go together: Very early on in the developing embryo, the progenitor cells that will become heart…
jhalper | July 17, 2012We were just getting used to the idea of our digestive tract as an ecosystem. There are 10 times as many bacteria in our gut as there are cells in our bodies, and the ecological balance between the different types might affect everything from our tendency to gain weight to our general health and susceptibility to various diseases.
Now, a Weizmann Institute researcher has exposed a whole new layer of this ecosystem: the viruses – called phages – that infect our gut bacteria.
Dr. Rotem Sorek and his team identified hundreds of these phages in the human gut. They were able to find them thanks to…