As you know that plants rely on structures called chloroplasts within their cells to carry out photosynthesis—the process used to capture energy from sunlight by converting carbon dioxide from the air into sugars. During times of stress such as drought, though, the same reaction can also generate substances known as reactive oxygen species, which are toxic to plants and cause them to become damaged or even die.
With the population growth, increasingly shortage of natural resources and the treat of climate change, to develop crops that can survive sub-optimal growing conditions seems Researchers from Oxford University has found a gene that helps plants to remain healthy during times of stress.
According to Professor Paul Jarvis, from the Oxford University's Department of Plant Sciences, the development of chloroplasts is controlled by the presence of a gene known as SP1, which governs the passage of the proteins involved in photosynthesis through the chloroplast's outer membrane. It is suspected that the gene might use this ability to help plants survive in hostile conditions.
The researcher team led by Professor Jarvis wanted to find out if SP1 helped plants to remain healthy by limiting the production of the toxic compounds made during photosynthesis in harsh conditions and has carried out experiments to investigate the idea. Theyworked with three versions of a cress plant known as Arabidopsis thaliana: the naturally occurring wild type, a mutant plant lacking SP1, and an engineered plant that over-expressed SP1. The results indicated that SP1 was responsible for the resilience.
Another set of experiments was carried out to establish how SP1 works at a molecular level. The results demonstrated that SP1 reduces the production of toxic compounds by limiting photosynthesis in times of stress, making plants less likely to suffer serious or fatal damage.
"All plants have the SP1 gene,' explains Professor Jarvis." Now it's just a question of getting plants to over-express it so that they can survive in adverse conditions.'
The researchers are working with more plants to see whether the findings can be used in a wider variety of plants. Hope that the SP1 technology can benefit the improvement of the crop output all around the world.
Read more:http://www.cusabio.com/catalog-9-1.html
2015年9月22日星期二
Use customized protein-based sensor to detect viral infection
Biological engineers from MIT have developed a modular system of proteins which can detect a particular DNA sequence in a cell and then give a response like cell death. According to the researchers, the system can be customized to detect any DNA sequence in a mammalian cell and kill cancer cells or cells infected with a virus.
"There is a range of applications for which this could be important," says James Collins, the Termeer Professor of Medical Engineering and Science in MIT's Department of Biological Engineering and Institute of Medical Engineering and Science (IMES). "This allows you to readily design constructs that enable a programmed cell to both detect DNA and act on that detection, with a report system and/or a respond system."
The technology is based on a type of DNA-binding proteins known as zinc fingers. These proteins can be designed to recognize any DNA sequence.
"The technologies are out there to engineer proteins to bind to virtually any DNA sequence that you want," says Shimyn Slomovic, an IMES postdoc and the paper's lead author. "This is used in many ways, but not so much for detection. We felt that there was a lot of potential in harnessing this designable DNA-binding technology for detection."
The researchers needed to link zinc fingers's DNA-binding capability with a consequence-either turning on a fluorescent protein to reveal that the target DNA is present or generating another type of action inside the cell. To create the new system, they exploited a type of protein known as an "intein" and split it into two pieces. The split protein pieces are called "exteins". They only become functional once the intein removes itself while rejoining the two halves.
They decided to divide an intein in two and then attach each portion to a split extein half and a zinc finger protein. The zinc finger proteins are engineered to recognize adjacent DNA sequences within the targeted gene, so if they both find their sequences, the inteins line up and are then cut out, allowing the extein halves to rejoin and form a functional protein. The extein protein is a transcription factor designed to turn on any gene the researchers want.
The researchers also deployed this system to kill cells by linking detection of the DNA target to production of an enzyme called NTR. This enzyme activates a harmless drug precursor called CB 1954, which the researchers added to the petri dish where the cells were growing. When activated by NTR, CB 1954 kills the cells.
There will be more versions in the future which bind to DNA sequences found in cancerous genes and then produce transcription factors that would activate the cells' own programmed cell death pathways. This protein-based sensor can be of great significance.
Read more:http://www.cusabio.com/catalog-13-1.html
"There is a range of applications for which this could be important," says James Collins, the Termeer Professor of Medical Engineering and Science in MIT's Department of Biological Engineering and Institute of Medical Engineering and Science (IMES). "This allows you to readily design constructs that enable a programmed cell to both detect DNA and act on that detection, with a report system and/or a respond system."
The technology is based on a type of DNA-binding proteins known as zinc fingers. These proteins can be designed to recognize any DNA sequence.
"The technologies are out there to engineer proteins to bind to virtually any DNA sequence that you want," says Shimyn Slomovic, an IMES postdoc and the paper's lead author. "This is used in many ways, but not so much for detection. We felt that there was a lot of potential in harnessing this designable DNA-binding technology for detection."
The researchers needed to link zinc fingers's DNA-binding capability with a consequence-either turning on a fluorescent protein to reveal that the target DNA is present or generating another type of action inside the cell. To create the new system, they exploited a type of protein known as an "intein" and split it into two pieces. The split protein pieces are called "exteins". They only become functional once the intein removes itself while rejoining the two halves.
They decided to divide an intein in two and then attach each portion to a split extein half and a zinc finger protein. The zinc finger proteins are engineered to recognize adjacent DNA sequences within the targeted gene, so if they both find their sequences, the inteins line up and are then cut out, allowing the extein halves to rejoin and form a functional protein. The extein protein is a transcription factor designed to turn on any gene the researchers want.
The researchers also deployed this system to kill cells by linking detection of the DNA target to production of an enzyme called NTR. This enzyme activates a harmless drug precursor called CB 1954, which the researchers added to the petri dish where the cells were growing. When activated by NTR, CB 1954 kills the cells.
There will be more versions in the future which bind to DNA sequences found in cancerous genes and then produce transcription factors that would activate the cells' own programmed cell death pathways. This protein-based sensor can be of great significance.
Read more:http://www.cusabio.com/catalog-13-1.html
2015年9月21日星期一
DNA sequencing device helps to treat UTIs
A new research from the University of East Anglia suggest that a new DNA sequencing device can treat Urinary tract infections (UTIs) more quickly and efficiently. This device is called MinION. It was used to perform nanopore sequencing to characterise bacteria from urine samples four times more quickly than using traditional methods of culturing bacteria.
The method can also detect antibiotic resistance, which improve the efficiency of treatment and stewardship of diminishing antibiotic reserves.
Urinary tract infections are among the most common reasons for prescribing antibiotics. Most are mild and only affect the lower urinary tract, but a few are more troublesome. These 'ascending' UTIs cause a growing burden of hospitalisations, mostly of elderly patients. Infection spills into the bloodstream, leading to a condition called urosepsis, which can be fatal.
Antibiotics are vital, and it must be given urgently especially when bacteria has entered the bloodstream. But unfortunately it takes two days to grow the bacteria in the lab and test which antibiotics kill them.
The research team used a new small DNA sequencing device called Nanopore MinION from Oxford Nanopore Technologies to investigate UTIs quickly - without culturing the bacteria.
The device is about the size of a USB stick. It could detect the bacteria in heavily infected urine and provide its DNA sequence in just 12 hours, which is too much faster than conventional microbiology. This technology is rapid and capable not only of identifying the bacteria in UTIs, but also detecting drug-resistance at the point of clinical need.
There are still more limitations to be overcome. This method currently only works with heavily-infected urine and can't yet predict those resistances that arise by mutation. But as the study is still going on and the technology is developing, more can be achieved.
Read more:http://about.cusabio.com/m-185.html
The method can also detect antibiotic resistance, which improve the efficiency of treatment and stewardship of diminishing antibiotic reserves.
Urinary tract infections are among the most common reasons for prescribing antibiotics. Most are mild and only affect the lower urinary tract, but a few are more troublesome. These 'ascending' UTIs cause a growing burden of hospitalisations, mostly of elderly patients. Infection spills into the bloodstream, leading to a condition called urosepsis, which can be fatal.
Antibiotics are vital, and it must be given urgently especially when bacteria has entered the bloodstream. But unfortunately it takes two days to grow the bacteria in the lab and test which antibiotics kill them.
The research team used a new small DNA sequencing device called Nanopore MinION from Oxford Nanopore Technologies to investigate UTIs quickly - without culturing the bacteria.
The device is about the size of a USB stick. It could detect the bacteria in heavily infected urine and provide its DNA sequence in just 12 hours, which is too much faster than conventional microbiology. This technology is rapid and capable not only of identifying the bacteria in UTIs, but also detecting drug-resistance at the point of clinical need.
There are still more limitations to be overcome. This method currently only works with heavily-infected urine and can't yet predict those resistances that arise by mutation. But as the study is still going on and the technology is developing, more can be achieved.
Read more:http://about.cusabio.com/m-185.html
Evolutionary tree covering 2.3 million species released
Through cooperating whole heartedly of eleven institutions, a first draft of the "tree of life" for about 2.3 million species of animals, plants, fungi and microbes has been released. It depicts the relationships among living things as they diverged from one another over time, tracing back to the beginning of life on Earth more than 3.5 billion years ago.
There are so many smaller trees published over these years, but this is the first time that all of those results are combined into a single tree that covers all of life. It is available online at https://tree.opentreeoflife.org as a digital resource. You can browse, download, use or edit it for free. You can also find it in an article appearing Sept. 18 in the Proceedings of the National Academy of Sciences.
Evolutionary trees are not just for figuring out whether aardvarks are more closely related to moles or manatees, or pinpointing a slime mold's closest cousins, they are also helpful to discover new drugs, increase crop and livestock yields, and trace the origins and spread of infectious diseases and so on.
"As important as showing what we do know about relationships, this first tree of life is also important in revealing what we don't know," said co-author Douglas Soltis of the University of Florida.
The team is also developing software that can enable researchers to log on, update and revise the tree as new data come in for the species remaining to be named or discovered. It is quite important to share data for those works which are already-published or newly-published. Only by sharing can you improve. A few years ago no one was optimistic about the goal of huge trees, but now this Version 1.0. “tree of life” is just online for everyone. It is the starting point.
Read more:http://www.cusabio.com/catalog-9-1.html
There are so many smaller trees published over these years, but this is the first time that all of those results are combined into a single tree that covers all of life. It is available online at https://tree.opentreeoflife.org as a digital resource. You can browse, download, use or edit it for free. You can also find it in an article appearing Sept. 18 in the Proceedings of the National Academy of Sciences.
Evolutionary trees are not just for figuring out whether aardvarks are more closely related to moles or manatees, or pinpointing a slime mold's closest cousins, they are also helpful to discover new drugs, increase crop and livestock yields, and trace the origins and spread of infectious diseases and so on.
"As important as showing what we do know about relationships, this first tree of life is also important in revealing what we don't know," said co-author Douglas Soltis of the University of Florida.
The team is also developing software that can enable researchers to log on, update and revise the tree as new data come in for the species remaining to be named or discovered. It is quite important to share data for those works which are already-published or newly-published. Only by sharing can you improve. A few years ago no one was optimistic about the goal of huge trees, but now this Version 1.0. “tree of life” is just online for everyone. It is the starting point.
Read more:http://www.cusabio.com/catalog-9-1.html
2015年9月18日星期五
Scientists find a mechanism which slows down brain stem cell aging
Recently scientists from the University of Zurich have identified a novel mechanism of how neural stem cells stay relatively free of aging-induced damage. A diffusion barrier regulates the sorting of damaged proteins during cell division. As we know that neural stem cells generate new neurons throughout life in the mammalian brain. But the potential for regeneration in the brain dramatically declines with age. The mechanism just found is of great significance.
Yeast are useful for making wine, bread and brewing beer. At the same time, they are also a good model for neural stem cells in the mammalian brain. It was known that with every division cellular aging factors are asymmetrically distributed between the mother and the daughter cell, allowing for rejuvenation and full life span of the daughter independent of the age of the mother cell. The presence of a diffusion barrier that restricts movement of molecules from one side to the other side of the cell during cell division is partially responsible for that.
To dispose age, Sebastian Jessberger of the Brain Research Institute led a group of scientists to conduct a research and the results showed that also the stem cells of the adult mouse brain asymmetrically segregate aging factors between the mother and the daughter cells. It is a diffusion barrier in the endoplasmic reticulum that is responsible. The barrier keeps the stem cells relatively clean by preventing retention of damaged proteins in the stem cell daughter cell.
Scientists found that the strength of the barrier weakens with advancing age. The weakening leads to reduced asymmetry of damaged protein segregation with increasing age of the stem cell. This is supposed to be a mechanism related to the reduced regeneration capacity in the aged brain for stem cells that retain larger amounts of damaged proteins require longer for the next cell division.
The discovery of the new mechanism is an exciting thing. It is our first step to understand the molecular constituents and the worth of the barrier for stem cell division in the brain. And what remains to be explore is whether the barrier is established in all somatic stem cells of the body.The answer may help finding new way of target age-dependent alterations of stem cell activity in human disease.
Read more:http://www.cusabio.com/catalog-13-1.html
Yeast are useful for making wine, bread and brewing beer. At the same time, they are also a good model for neural stem cells in the mammalian brain. It was known that with every division cellular aging factors are asymmetrically distributed between the mother and the daughter cell, allowing for rejuvenation and full life span of the daughter independent of the age of the mother cell. The presence of a diffusion barrier that restricts movement of molecules from one side to the other side of the cell during cell division is partially responsible for that.
To dispose age, Sebastian Jessberger of the Brain Research Institute led a group of scientists to conduct a research and the results showed that also the stem cells of the adult mouse brain asymmetrically segregate aging factors between the mother and the daughter cells. It is a diffusion barrier in the endoplasmic reticulum that is responsible. The barrier keeps the stem cells relatively clean by preventing retention of damaged proteins in the stem cell daughter cell.
Scientists found that the strength of the barrier weakens with advancing age. The weakening leads to reduced asymmetry of damaged protein segregation with increasing age of the stem cell. This is supposed to be a mechanism related to the reduced regeneration capacity in the aged brain for stem cells that retain larger amounts of damaged proteins require longer for the next cell division.
The discovery of the new mechanism is an exciting thing. It is our first step to understand the molecular constituents and the worth of the barrier for stem cell division in the brain. And what remains to be explore is whether the barrier is established in all somatic stem cells of the body.The answer may help finding new way of target age-dependent alterations of stem cell activity in human disease.
Read more:http://www.cusabio.com/catalog-13-1.html
New butterflies naturally produced by gene transfer been discovered
Research teams from two universities have discovered that genes originating from parasitic wasps are present in the genomes of many butterflies. These genes were acquired through a wasp-associated virus that integrates into DNA. Wasp genes have now been domesticated and likely play a role in in protecting butterflies against other pathogenic viruses.
The study reveals that butterflies constitute naturally produced GMOs (Genetically Modified Organisms) during the course of evolution, including the Monarch, an iconic species for naturalists and well-known for its spectacular migrations. The findings highlight that the genes introduced in GM insects can be transferred between distant species.
Braconid wasps lay their eggs inside caterpillars inject bracovirus to circumvent the caterpillars' immune response to reproduce. The bracoviruses injected can integrate into the DNA of parasitized caterpillars and control caterpillar development to enable them to be the host.
In the genomes of several species of butterfly and moth, including the famous Monarch, the silkworm and insect pests like the Fall Armyworm and the Beet Armyworm, Bracovirus genes can be found. The identified integrated genes are not only remnants. The results suggest that they play a protective role against other viruses present in nature. What's more, the genes harboured by bracoviruses is not limited to viral genes, some of them originated from the wasp. For instance, in armyworm species, a group of genes transferred was more closely related to genes from hymenoptera, including the honey bee, rather than lepidoptera.
The results suggest the risk that GM-parasitoid wasps are produced, as genes artificially introduced into wasp species used for biological control could be transferred into the genomes of the targeted pests. Production of GM wasps expressing insecticide resistance for biological control of pests, may lead to involuntary transmission of this resistance to the herbivorous insects.
The results of the research led by teams from the University of Valencia and the University of Tours were published in PLOS Genetics on the 17th of September 2015. You can get more information about the GM problem.
Read more:http://about.cusabio.com/m-177.html
The study reveals that butterflies constitute naturally produced GMOs (Genetically Modified Organisms) during the course of evolution, including the Monarch, an iconic species for naturalists and well-known for its spectacular migrations. The findings highlight that the genes introduced in GM insects can be transferred between distant species.
Braconid wasps lay their eggs inside caterpillars inject bracovirus to circumvent the caterpillars' immune response to reproduce. The bracoviruses injected can integrate into the DNA of parasitized caterpillars and control caterpillar development to enable them to be the host.
In the genomes of several species of butterfly and moth, including the famous Monarch, the silkworm and insect pests like the Fall Armyworm and the Beet Armyworm, Bracovirus genes can be found. The identified integrated genes are not only remnants. The results suggest that they play a protective role against other viruses present in nature. What's more, the genes harboured by bracoviruses is not limited to viral genes, some of them originated from the wasp. For instance, in armyworm species, a group of genes transferred was more closely related to genes from hymenoptera, including the honey bee, rather than lepidoptera.
The results suggest the risk that GM-parasitoid wasps are produced, as genes artificially introduced into wasp species used for biological control could be transferred into the genomes of the targeted pests. Production of GM wasps expressing insecticide resistance for biological control of pests, may lead to involuntary transmission of this resistance to the herbivorous insects.
The results of the research led by teams from the University of Valencia and the University of Tours were published in PLOS Genetics on the 17th of September 2015. You can get more information about the GM problem.
Read more:http://about.cusabio.com/m-177.html
2015年9月17日星期四
Why bats frequently contact with infectious disease but seldom being infected?
New research concludes that the bat's immune system works in a fundamentally different way from other animals. The research about mastiff bats was conducted by scientists from the Max Planck Institute for Ornithology. It can also help fighting against viral diseases that can be transmitted from animals to humans.
There are very little researches has been conducted about bats'immune system till now. Researchers mentioned above are now trying to bridge this gap. Their findings show the difference between the immune system of bats and other animals. The bats seem to be able to fight off the pathogens without becoming ill themselves. But what makes their immune system so special?
The scientists studied the immune responses of Pallas's mastiff bats (Molossus molossus) in Panama. Those bats live a specific life: during the day they reduce their energy consumption in their roosts in order to save energy. During this period, the bats rest motionless and their body temperature drops. They come to life only at sunset when the mastiff bats set out for the hunt. Then their body temperature rises to more than 40 degrees Celsius as their muscles need to work to keep flying.
However, the high temperature could activate the immune response against pathogens as a type of daily fever. On the contrary, the daily slowdown in their metabolic rate could also inhibit the proliferation of existing pathogens in the body.
The researchers administered a lipopolysaccharide (LPS) to the bats to test the hypothesis. LPS is a compound which is harmless in itself and made up of lipid and sugar components. It is also found on the outer membrane of many pathogens, then the bat's immune system assumes a bacterial attack and switches to defence mode.
However, the daily temperature fluctuations turned out to remain unchanged even after the administration of LPS. The material therefore does not trigger a fever in the bats. What's more, the number of white blood cells in the blood, which is an indicator of the strength of the immune defence, did not increase. But the bats did lose a significant amount of mass within 24 hours meaning that the bats mobilise energy reserves for the immune defence decrease.
The findings indicate that the bats' immune system is switched on but works in a different way. Know more about the difference can help us learn more about the danger of human diseases.
Read more:http://about.cusabio.com/m-190.html
There are very little researches has been conducted about bats'immune system till now. Researchers mentioned above are now trying to bridge this gap. Their findings show the difference between the immune system of bats and other animals. The bats seem to be able to fight off the pathogens without becoming ill themselves. But what makes their immune system so special?
The scientists studied the immune responses of Pallas's mastiff bats (Molossus molossus) in Panama. Those bats live a specific life: during the day they reduce their energy consumption in their roosts in order to save energy. During this period, the bats rest motionless and their body temperature drops. They come to life only at sunset when the mastiff bats set out for the hunt. Then their body temperature rises to more than 40 degrees Celsius as their muscles need to work to keep flying.
However, the high temperature could activate the immune response against pathogens as a type of daily fever. On the contrary, the daily slowdown in their metabolic rate could also inhibit the proliferation of existing pathogens in the body.
The researchers administered a lipopolysaccharide (LPS) to the bats to test the hypothesis. LPS is a compound which is harmless in itself and made up of lipid and sugar components. It is also found on the outer membrane of many pathogens, then the bat's immune system assumes a bacterial attack and switches to defence mode.
However, the daily temperature fluctuations turned out to remain unchanged even after the administration of LPS. The material therefore does not trigger a fever in the bats. What's more, the number of white blood cells in the blood, which is an indicator of the strength of the immune defence, did not increase. But the bats did lose a significant amount of mass within 24 hours meaning that the bats mobilise energy reserves for the immune defence decrease.
The findings indicate that the bats' immune system is switched on but works in a different way. Know more about the difference can help us learn more about the danger of human diseases.
Read more:http://about.cusabio.com/m-190.html
订阅：
博文 (Atom)