Olsen said favored gene variants (alleles) that are relatively insensitive to background effects and highly responsive to selection.
Only a subset of the genes in the wild population would have produced reliably a favored trait regardless of the crop variety into
Over the past 20 years researchers have begun to identify the genes that control some of the most important domestication traits no easy task in the days before rapid sequencing
because they had to start with plant traits and work back to unknown genes. This work showed that many domestication traits were under the control of single genes.
For example the gene teosinte branched1 (tb1) converts highly branched teosinte plants into single stalks of corn.
But the seeming importance of single genes could have been an artifact of the method used to identify domestication genes which required the researcher to pick candidate genes
and perhaps prematurely narrow the search overlooking indirect genetic effects. Little is known about the underlying genetics of domestication Olsen said.
The new work examines the possibility that two indirect effects--the influence of the genetic background on the expression of a gene (called epistasis)
and the effects of the environment on the expression of genes--might have slowed the selection of plants with the desired traits.
or linked to genes that underlie this trait a major one called QTL 1 and a minor one called QTL2.
The domestication genes in other words tended to be ones that would produce the same result even if they were introduced into a different crop variety.
When a teosinte plant with a wild tb1 gene is backcrossed repeatedly with maize it produces highly branched plants in uncrowded growing conditions
plants with the domesticated tb1 gene allele are unbranched whether or not they are crowded. Unlike companion-animal breeders early farmers seem to have selected domestication-gene alleles that are insensitive to genetic background and to the environment.
This process would have been slow unrewarding and difficult to understand because the effects of gene variants on the plant weren't stable.
But once sensitive alleles had been replaced with robust ones breeders would have been able to exert strong selection pressure on plant traits shaping them much more easily than before
#Synthetic gene circuits pump up cell signals in study of neurodegenerative diseasessynthetic genetic circuitry created by researchers at Rice university is helping them see for the first time how to regulate cell mechanisms that degrade the misfolded proteins implicated in Parkinson's Huntington
or genes that can increase proteasomal activity she said. This will help us rationally design compounds
The scientists introduced into mice the gene that codes for the normal bank vole prion protein thereby generating mice that express bank vole Prp but not mouse Prp.
Researchers had tried previously to tackle this problem by reducing the quantity of lignin in trees by suppressing genes
but there are ways to ensure that the genes do not spread to the forest. These techniques include growing crops away from native stands
introducing genes to make both the male and female trees or plants sterile; and harvesting trees before they reach reproductive maturity.
When crossing parent plants for example breeders often like to track the genes underlying their trait of interest such as resistance to a pathogen.
That's because pinpointing offspring that carry the right genes is often faster and easier than examining plants for the trait itself.
But sometimes so many genes contribute to a single trait that figuring out which genes are involved in the first place becomes onerous.
This is where Hoekenga thinks his style of research and analysis might one day help. We're trying to describe at the biochemical level what might be responsible for a trait.
The sequences provide researchers access to 96 percent of all peanut genes in their genomic context providing the molecular map needed to more quickly breed drought-and disease-resistant lower-input and higher-yielding
Being able to see the two separate structural elements also will aid future gene marker development-the determination of links between a gene's presence and a physical characteristic of the plant.
#Genes identified that could lead to tough, disease-resistant varieties of riceas Earth's human population marches toward 9 billion the need for hardy new varieties of grain crops has never been greater.
Now researchers at Michigan Technological University have identified a set of genes that could be key to the development of the next generation of super rice.
A meta-data analysis by biologist Ramakrishna Wusirika and Phd student Rafi Shaik has uncovered more than 1000 genes in rice that appear to play key roles in managing its response to two different kinds
Traditionally scientists have believed that different sets of genes regulated plants'responses to biotic and abiotic stress.
However Wusirika and Shaik discovered that 1377 of the approximately 3800 genes involved in rice's stress response played a role in both types stress.
These are the genes we think are involved in the cross talk between biotic and abiotic stesses said Wusirika.
About 70 percent of those master genes are co-expressive--they turn on under both kinds of stress.
The scientists looked at the genes'response to five abiotic stresses--drought heavy metal contamination salt cold and nutrient deprivation--and five biotic stresses--bacteria fungus insect predation weed
A total of 196 genes showed a wide range of expressions to these stresses. The top genes are likely candidates for developing a rice variety with broad stress-range tolerance Wusirika said.
Next they would like to test their findings. We want to do experimental analysis to see if five or 10 of the genes work as predicted he said.
Their study is described in the paper Machine learning Approaches Distinguish Multiple Stress Conditions using Stress-Resposive Genes
and Identify Candidate Genes for Broad Resistance in Rice published in the January edition of Plant Physiology.
Story Source: The above story is provided based on materials by Michigan Technological University. The original article was written by Marcia Goodrich.
what we saw was an inhibition of a marker gene in the lungs after a few weeks indicating an inhibition of metastasis
#Instrument built to study effects of genes, environment on plant traitslet's say plant scientists want to develop new lines of corn that will better tolerate long stretches of hot dry weather.
It contained additional four virulence genes making it extremely invasive and ultimately caused 14 cases resulting in 5 deaths.
and validate genes from the P450 detoxification enzyme superfamily which are expressed highly in the adult females from the area.
The new work reveals that two members of the P450 gene superfamily in particular are expressed highly in resistant Tiassalã mosquitoes:
When these genes were transplanted into Drosophila resistance to pyrethroids and carbamates was generated in otherwise susceptible fly strains..
These genes are familiar candidates to LSTM researchers who have documented previously their links with pyrethroid and DDT resistance.
This new research shows how specific P450 genes can engender resistance across insecticides with entirely different modes of action:
whereas carbamates and organophosphates target the neurotransmitter Acetylcholinesterase encoded by the gene ACE-1. This is where Tiassalã mosquitoes yielded another surprise contributing to their exceptionally high carbamate resistance.
A well-known single nucleotide resistance mutation at the ACE-1 gene is near ubiquitous in the population
However from application of a newly-developed qpcr diagnostic it was found that the ACE-1 gene was duplicated in some individuals with those resistant to carbamate much more likely to have duplicated additional copies of the resistant ACE-1 allele.
The genome also revealed the location of genes that may be involved in fighting off pathogens which will help scientists understand more about disease resistance in pines.
By looking at how genes were expressed the molecular biologist narrowed the possibilities from thousands of genes to 608 then to 47 and eventually to three.
These genes are functional in both resistant and susceptible varieties. How they respond to regulations triggered by the fungal infection makes the difference he says.
That's why normal gene cloning didn't work. Resistance to the disease is controlled by the chemical pathways of two growth hormones jasmonate
Two of the three genes are involved directly in the chemical pathways Yen explains. How the third one is involved we still do not know
In the resistant wheat the key resistance gene may delay this chain of reactions until the host tissue is too hard for the disease to develop Yen explains.
Most of the genes had come from a poultry virus that had existed in china for many years
and two genes probably came from a wild bird isolate he says. We felt a major knowledge gap in the outbreak was that we didn't know which poultry species was maintaining the virus
Some of these earlier studies had traced the genetic origin of this trait in Europeans to a particular mutation that regulates the expression of the gene that codes for lactase.
To look for genetic variations among the populations'abilities to digest milk the team sequenced three genomic regions thought to influence the activity of the lactase-encoding LCT gene in 819 Africans from 63 different populations and 154 non
The research provides a new approach integrating knowledge of genes proteins plant chemical compounds and engineering modeling to understand how plants make products
They analyzed RNA interference (RNAI) a method that uses genetic material to silence specific genes--in this case genes known to give insect pests an advantage.
The team targeted two genes that are regulated differently in rotation-resistant and non-resistant rootworms. The first Dvrs5 codes for an enzyme that helps the rootworms digest plant proteins.
These genes have been found to play a role in rootworm resistance to crop rotation. The team looked at how treatment with RNAI
The researchers were surprised to find that the RNAI targeting the gene att1 had no effect
This does not represent an immediate concern for RNAI technology the researchers said as they tested genes that are unlikely to be used in commercial crops.
The findings suggest that targeting a single gene to control a pest species is not the best strategy Spencer said.
We now know that disrupting a particular target gene may enhance undesirable pest characteristic such as rotation resistance
The researchers identified a de novo gene mutation--one that occurs for the first time in a member of a family--in a gene called GRIN2A.
The discovery required an analysis of the patient's genetic makeup in search of the one gene that changed setting this detrimental series of events in motion.
Pierson added that many other genes have been associated with several forms of epilepsy in infancy but only few other instances of early-onset epileptic encephalopathy involved the GRIN2A gene.
The GRIN2A gene influences electrochemical events that affect the flow and strength of electrical impulses in the brain.
Having identified the de novo gene defect the researchers conducted laboratory experiments to confirm the resulting protein dysfunction and its effects on electrical-regulating mechanisms.
We then performed lab studies with several drugs that were approved already by the Food and Drug Administration and which we thought might block the seizure activity.
Our results suggest that children with early-onset epileptic encephalopathy should undergo evaluation for similar gene variants with the possibility of using memantine
and their ideas--an international postal system organized agriculture research and meritocracy-based civil service among other things--shaped national borders languages cultures and human gene pools
It was shown also that a higher saturated fat intake was associated with an increased risk of dementia among those carrying a genetic risk factor of Alzheimer's disease the epsilon 4 variant of the apolipoprotein E (Apoe) gene.
Most of the yield increases are the result of breeders selecting better combinations of genes that can allow plants to take sunlight and produce more seed from that sunlight.
We don't know what genes breeders are selecting that are resulting in these increases for example where in that pathway from the sunlight hitting the canopy to producing seed where this occurs.
Bt genes have been engineered into a variety of crops to control insect pests. Since farmers began planting Bt crops in 1996 with 70 million hectares planted in the United states in 2012 there have been only three clear-cut cases in agriculture of resistance in caterpillars
To delay or prevent insect pests from evolving resistance to Bt crops the U s. Environmental protection agency promotes the use of multiple Bt genes in plants
and the practice of growing refuges of non-Bt plants that serve as a reservoir for insects with Bt susceptible genes. â#oeour paper argues there is another factor involved:
because they are known to be free of cattle genes and represent bison that existed on the Great plains for thousands of years.
Texas A&m University scientists are working to map the genes controlling drought and heat tolerance in recent varieties.
and ultimately clone the genes controlling drought and heat tolerance for molecular studies and deployment of these genes in other crops she said.
Joining Zhang on the project are Dr. Hongbin Zhang Texas A&m professor of plant genomics and systems biology and director of the Laboratory for Plant Genomics and Molecular genetics;
This research will use high-throughput site-associated DNA sequencing to map the genes controlling drought
and heat tolerant genes but also develop a platform for mapping genes controlling several other biotic and abiotic stress tolerances such as aphid resistance and low phosphorus tolerance both
The drought and heat tolerant genes once defined and cloned will significantly advance understanding of the molecular basis underlying plant tolerances to these stresses Zhang said.
The researchers led by Dr Charles Wondji used a wide range of methods to narrow down how the resistance works finding a single mutation in the GSTE2 gene which makes insects break down DDT
They have shown also that this gene makes insects resistant to pyrethroids raising the concern that GSTE2 gene could protect mosquitoes against the major insecticides used in public health.
The spread of resistance genes could hold back efforts to prevent the disease. The authors say that knowing how resistance works will help to develop tests
and stop these genes from spreading amongst mosquito populations. Charles Wondji said:''We found a population of mosquitoes fully resistant to DDT (no mortality
They identified the GSTE2 gene as being upregulated--producing a lot of protein--in Benin mosquitoes. They found that a single mutation (L119f) changed a non-resistant version of the GSTE2 gene to a DDT resistant version.
They designed a DNA-based diagnostic test for this type of resistance (metabolic resistance) and confirmed that this mutation was found in mosquitoes from other areas of the world with DDT resistance
X-ray crystallography of the protein coded by the gene illustrated exactly how the mutation conferred resistance by opening up the'active site'where DDT molecules bind to the protein so more can be broken down.
They also introduced the gene into fruit flies (Drosophila melanogaster) and found they became resistant to DDT
and later with sugarcane the team introduced genes that boost natural oil production in the plant.
The introduced gene from a South american wild relative of potato triggers the plant's natural defense mechanisms by enabling it to recognize the pathogen.
Cultivated potatoes possess around 750 resistance genes but in most varieties late blight is able to elude them.
and by the time a gene is introduced successfully into a cultivated variety the late blight pathogen may already have evolved the ability to overcome it said Professor Jonathan Jones from The Sainsbury Laboratory.
The Sainsbury Laboratory is continuing to identify multiple blight resistance genes that will difficult for blight to simultaneously overcome.
Their research will allow resistance genes to be prioritized that will be more difficult for the pathogen to evade.
and experiment with multiple resistance genes. By combining understanding of resistance genes with knowledge of the pathogen they hope to develop Desiree
and Maris Piper varieties that can completely thwart attacks from late blight. Story Source: The above story is provided based on materials by Norwich Bioscience Institutes.
Genetic diversity can be measured in a number of ways by looking at the number of different variants in a gene in a population for instance
S. polyrhiza turns out to have one of the smallest known plant genomes at about 158 million base pairs and fewer than 20000 protein-encoding genes.
The most surprising find was insight into the molecular basis for genes involved in maturation--a forever-young lifestyle said senior author Joachim Messing director of the Waksman Institute of Microbiology at Rutgers University.
S. polyrhiza had fewer genes to promote and more genes to repress the switch from juvenile to mature growth.
Because of the reduction in neoteny there is an arrest in development and differentiation of organs. So this arrest allowed us to uncover regulatory networks that are required for differentiation
which genes were preserved over time and which were not. Many of the genes responsible for cellulose and lignin production in land dwelling plants were missing
and there were fewer copies of those that were present. Genes for another compound related to cell walls called expansins which are involved with cell wall
and root growth were reduced also. Genes for starch production on the other hand were retained and are used probably for creating starch-filled turions specialized buds produced by aquatic plants for overwintering enabling them sink to the bottom of ponds
and revive in warmer weather. Moreover despite the reduced number of total genes S. polyrhiza has more copies of genes for enzymes involved in nitrogen absorption and metabolism than in other plants.
This is probably linked to the plant's ability to utilize excess nitrogen in contaminated waters.
Understanding which genes produce which traits will allow researchers to create new varieties of duckweed with enhanced biofuel traits such as increased reduction of cellulose or increased starch or even higher lipid production.
The team analyzed a dataset with more than 80000 gene sequences representing the global diversity of the Influenza a virus
What we're finding is that the avian virus has an extremely shallow history in most genes not much older than the invention of the telephone Worobey explained.
According to Worobey the newly generated evolutionary trees show a global replacement of the genes in the avian flu virus coinciding closely with the horse flu outbreak
Ever since the influenza pandemic of 1918 it has not been possible to narrow down even to a hemisphere the geographic origins of any of the genes of the pandemic virus. Our study changes that Worobey said.
Instead the genetic diversity across the whole avian virus gene pool in domestic and wild birds often appears to trace back to earlier outbreaks of the virus in domestic birds Worobey explained.
In contrast a male benefit from ensuring that only his sperm is used to fertilize the female's eggs thereby passing only his genes on to the next generation.
In a recent issue of Nature the researchers reported on a particular gene sequence that allows Bacteroidetes to carry out this function.
They show that about 92 per cent of the population harbors bacteria with a variant of the gene sequence according to a survey of public genome data from 250 adult humans.
The team used the latest gene identification techniques to compare the genes of healthy and infected female Holstein-friesians.
Differences between cattle in their genes is not the only factor in determining whether the animal will get bovine TB or not;
When applied Meja initiates a process of gene activity affiliated with the biosynthesis of glucosinolates (GS)
However during this process Meja also signals a network of genes that lead to plant decay by inducing the release of ethylene Juvik explained.
#Wasps use ancient aggression genes to create social groupsaggression-causing genes appeared early in animal evolution
If these mean genes keep their roles in different animals and in different contexts then perhaps model organisms--such as bees and mice--can provide insights into the biological basis of aggression in all animals including humans the researchers said.
This is one of the first investigations to utilize large datasets consisting of thousands of different genes to ask
whether there are shared genes relating to similar forms of behavior across a very wide range of animals said Amy Toth assistant professor of ecology evolution and organismal biology Iowa State.
and mice and found a few genes that are associated consistently with aggression. This suggests that even after hundreds of millions of years of evolution some genes may retain their ancestral roles in similar forms of behavior like aggression.
The team investigated the expression of aggression genes in the brains and ovaries of paper wasps--Polistes metricus.
Specifically they looked at wasps belonging to different castes including dominant colony-founding queens subordinate colony-founding queens established queens dominant workers and subordinate workers.
We found that in wasps which are primitively social insects aggression genes control the establishment of an individual's dominance over a group said Christina Grozinger professor of entomology and director of the Center for Pollinator Research Penn State.
In contrast in honey bees which are advanced social insects aggression genes control altruistic defensive behavior--for example
In solitary species like fruit flies and mice the same set of aggression genes controls fighting between males over territory.
So the same genes are involved in aggression across species but are now being used in different ways by different organisms.
because they share some of the same genes that regulate aggression behaviors even if those behaviors are now quite different.
In addition to learning that aggression genes are shared among organisms the team also found that these genes are extremely sensitive to the external environment.
We found that the most important influence on expression of genes in the brains of paper wasps was external factors such as the season
Everyone agrees that both nature--including genes and physiology--and nurture--including diet environment and social interactions--contribute to the likelihood that an individual will behave in a certain way
But our results show that the external environment plays a much greater role in regulating expression of genes in the brain
which they will manipulate the expression of single genes to see how they affect behavior.
if we ramp up expression of one of the genes involved in aggression Toth said.
This type of question allows us to go beyond correlation between the gene and the behavior and address causation.
Does the gene of interest actually cause aggressive behavior? Grozinger added If there are hyper-aggressive wasps
Funded by the Grains Research & development Corporation Professor Oliver and his team in conjunction with independent research provider Kalyx Australia have demonstrated that by taking away disease-sensitivity genes from the wheat germplasm
They compared cultivars with disease-sensitivity genes to cultivars that lacked these particular genes and were able to show that the cultivars lacking the gene showed no yield loss and in some instances increased yields in the presence of disease.
From this the team were able to conclude if a sensitivity gene was eliminated there would be associated minimal risks
and it would be a safe and straightforward strategy for improving disease resistance. Professor Oliver said this research had never been done before as direct mapping for disease resistance had led not to useful molecular markers.
and relatively susceptible parents before doing the QTL (quantitative disease-resistance gene) mapping. But as disease resistance is multifactorial due to the several effector reactions the QTL mapping was always a bit fuzzy
and distribution over hosts involved investigating 484'18s rrna genes'the fragments of RNA responsible for protein synthesis.'Our most important discovery is that ciliates are extremely diverse'says evolution biologist Johannes Hackstein.'
APEC may also provide a reservoir for virulence genes that may be acquired by human strains. Many types of bacteria produce extracellular surface fibers like ECP enabling them to adhere to one another as well as to various surfaces.
The new research demonstrates--for the first time--the prevalence of ecpa a gene coding for a major structural subunit of ECP in a majority APEC sequences examined.
Deletion of ECP-related genes was shown to reduce biofilm production. Finally the study attempted to evaluate APEC virulence in baby chicks using strains with deleted ECP genes.
Results show a reduction in virulence. In fact the potential for colonization among the ECP deletion strains was reduced particularly in the bloodstream.
although the gene of ECP was found in a large number of APEC these bacteria express this gene differently
Elucidating how the expression of some genes is turned on or off by different factors will help us understand how these bacteria cause disease.
To demonstrate the utility of the protocol Avanesyan successfully amplified the DNA of a noncoding region of a plant chloroplast gene
and director of movement disorders at UCLA. Bronstein said the team also found that people with a common genetic variant of the ALDH2 gene are particularly sensitive to the effects of ALDH-inhibiting pesticides
Then the researchers found that those participants in the epidemiologic study with a genetic variant in the ALDH gene were increased at risk of Parkinson's when exposed to these pesticides.
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