#A-maize-ing double life of a genomeearly maize farmers selected for genes that improved the harvesting of sunlight a new detailed study of how plants use'doubles'of their genomes reveals.
They then traced how maize evolved to use these'copied'genes to cope with the pressures of domestication
They discovered that these copied genes were vital to optimizing photosynthesis in maize leaves and that early farmers selecting for them'fuelled'the transformation of maize into a high-yield crop.
'Although whole genome duplication events are widespread in plants finding evidence of exactly how plants use this new'toolbox'of copied genes is said very difficult Dr Steve Kelly of Oxford university's Department of Plant sciences
and after'of the associated genetic changes but with maize we can chart how these gene copies were acquired first then put to work
'Understanding the complete trajectory of duplication and how copied genes can transform a plant is relevant for current efforts to increase the photosynthetic efficiency of crops such as the C4 Rice Project c4rice. irri. org/.
and shows how human selection has sculpted'copies of genes to create one of the world's staple food sources.'
#Novel gene for salt tolerance found in wild soybeana team of researchers from The Chinese University of Hong kong BGI
and other institutes have identified a gene of wild soybean linked to salt tolerance with implication for improving this important crop to grow in saline soil.
Among the lost genes some may play important roles for the adaptation to different environments.
In this study scientists used wild soybean as a resource for investigating the valuable genes that adapt to certain environmental conditions They sequenced
and their previous germplasm re-sequencing data the team discovered a novel ion transporter gene Gmchx1
During the following rapid gain-of-function tests the gene Gmchx1 was conferred its function on salt tolerance
The authors assumed that the elimination of Gmchx1 in salt-sensitive germplasms may be an example of negative selection against a stress tolerance gene in unstressed environments.
The expression of stress tolerance genes may be an energy burden on the plant if the functions of these genes are required not.
Through this study researchers developed an efficient strategy using the combination of whole-genome de novo sequencing high-density-marker QTL mapping by re-sequencing and functional analyses
which could greatly enhance the efficiency of uncovering QTLS and genes for beneficial traits in crop breeding.
Lichtenberg's study focused on stingless bees--including two from the genus Trigona that recruit nestmates to food sources with chemically distinct pheromones--that compete with one another for similar food sources.
In a paper published in this weekâ##s early online edition of Nature they report the discovery of a new genetic pathway in plants made up of four genes from three different gene families that control the density
and genes by which CO2 represses stomatal pore developmentâ#says Schroeder. Working in a tiny mustard plant called Arabidopsis which is used as a genetic model
and shares many of the same genes as other plants and crops he and his team of biologists discovered that the proteins encoded by the four genes they discovered repress the development of stomata at elevated CO2 levels.
and genes have the potential to address a wide range of critical agricultural problems in the future including the limited availability of water for crops the need to increase water use efficiency in lawns as well as crops
After introducing a gene from oregano the transformed maize plants released E-Î-caryophyllene constantly.
In some cases the virus incorporated part of a cow gene or another virus in the part of the genome in which most mutations take place Chase explains.
#Boron tolerance discovery for higher wheat yieldsaustralian scientists have identified the genes in wheat that control tolerance to a significant yield-limiting soil condition found around the globe--boron toxicity.
Published in the journal Nature today the identification of boron tolerance genes in wheat DNA is expected to help plant breeders more rapidly advance new varieties for increased wheat yields to help feed the growing world population.
Our identification of the genes and their variants responsible for this adaptation to boron toxicity means that we now have molecular markers that can be used in breeding programs to select lines for boron tolerance with 100%accuracy.
The wheat genome is very large with about six times the number of genes as humans.
This complexity has meant that genes controlling yield and adaptation to environmental stresses have remained extremely challenging to identify.
In this study the researchers tracked these specific boron tolerance genes from wild wheats grown by the world's earliest farmers in the Mediterranean region through wheat lines brought into Australia more than a century ago to current day
They found a distinct pattern of gene variant distribution that was correlated to the levels of boron in soils from different geographical regions.
and the knowledge to select for the right variants of the tolerance gene needed to do the job in specific environments says Dr Sutton.
The bitter perception is highly complex according to Hayes with 25 known bitter receptor genes. It's also not destiny.
Dracaena a genus consisting of approximately 40 different species including the widely recognized lucky bamboo is among the most frequently imported group of ornamentals to enter the U s. for domestic sale and eventual export to Canada.
and XY karyotypes for female and male whipworm respectively but in this study researchers found no evidence for A y chromosome among the male-specific scaffolds suggesting that the sex chromosomes were the smallest chromosomal pair
and masculinizing developmental genes respectively. According to the authors this is the first time they observed such results in a metazoan.
Scott says that the gene construct responsible for lethality in antibiotic-free diets is female-specific Interestingly
and unexpectedly the genetically modified female larvae containing the tetracycline lethality genes also took on a crimson color due to overexpression of the linked red fluorescent protein marker gene.
Overexpression of the gene responsible for the reliance on tetracycline also seems to overexpress this marker gene Scott says.
In the study the researchers showed that the tetracycline gene construct also works in Drosophila the fruit fly lab rat of the insect world that is a distant cousin of the sheep blowfly.
Scientists at the University of Basel have identified a gene regulatory switch that was key to evolutionary adaption of limbs in ungulates.
To this aim they compared the activity of genes in mouse and cattle embryos which control the development of fingers and toes during embryonic development.
in mouse embryos the so-called Hox gene transcription factors are distributed asymmetrically in the limb buds which is crucial to the correct patterning of the distal skeleton.
what inactivation of the Patched1 gene regulatory switch. We assume that it is the result of progressive evolution as this switch degenerated in cattle
It follows that Arion is unresolved very genus from a taxonomic point of view. But looking into the genes of the slugs yielded even more insights.
Shared mutations in the genetic information of different individuals indicate relationships between them. On the basis of this we created a phylogenetic tree
and three variants of a gene encoding an important methane-forming reaction that were involved in elevated methane yields.
and methanogen abundance across sheep were rather subtle the team reported that the expression levels of genes involved in methane production varied more substantially across sheep suggesting differential gene regulation perhaps controlled by hydrogen concentration in the rumen
and quantify major genes specific for E coli O157. Developing a method to detect E coli before it can potentially contaminate the food supply benefits the beef industry by preventing costly recalls
The novelty of this test is that it targets four genes Nagaraja said. We are constantly working on finding better
#Discovery of bud-break gene could lead to trees adapted for a changing climatescientists have confirmed the function of a gene that controls the awakening of trees from winter dormancy a critical factor in their ability to adjust to environmental changes
While other researchers have identified genes involved in producing the first green leaves of spring the discovery of a master regulator in poplar trees (Populus species) could eventually lead to breeding plants that are adapted better for warmer climates.
No one has isolated ever a controlling gene for this timing in a wild plant outside of Arabidopsis a small flowering plant related to mustard
This is the first time a gene that controls the timing of bud break in trees has been identified. The timings of annual cycles--when trees open their leaves
Strauss called the confirmation of the bud-break gene --which scientists named EBB1 for short--a first step in developing the ability to engineer adaptability into trees in the future.
They developed modified trees that overproduced EBB1 genes and emerged from dormancy earlier in the year.
Strauss and Busov a former postdoctoral researcher at Oregon State led efforts to identify the genes responsible.
EBB1 also plays a role in suppressing genes that prepare trees for dormancy in the fall
Altogether they found nearly 1000 other poplar genes whose activity is affected by EBB1. It's unlikely that plant breeders will use the finding any time soon Strauss said.
Breeders tend to rely on large clusters of genes that are associated with specific traits such as hardiness tree shape or flowering.
However as more genes of this kind are identified the opportunity to breed or engineer trees adapted to extreme conditions will grow.
Advantages Amplifies multiple genes simultaneously requires no cold chain built-in gel loading dye which facilitates the loading of PCR products directly onto the agaose gel without addition of sample loading buffer easy to follow steps minimises handling
Combing through the 36000-plus genes found in Eucalyptus (nearly twice as many as in the human genome) the researchers homed in on those that may influence the production of secondary cell wall material that can be processed for pulp paper biomaterials and bioenergy applications.
The eucalyptus team identified genes encoding 18 final enzymatic steps for the production of cellulose
and expression in woody tissues we defined a core set of genes as well as novel lignin-building candidates that are expressed highly in the development of xylem--the woody tissue that helps channel water throughout the plant
The team's detailed analysis of the Eucalyptus genome revealed an ancient whole-genome duplication event estimated to have occurred about 110 million years ago as well as an unusually high proportion of genes in tandem duplicate arrays.
and suggest that Eucalyptus may have followed an evolutionary path that highlighted specific genes for woody biomass production.
By comparison Eucalyptus has three times the number of tandem repeat genes present in poplar the first tree sequenced (by the DOE JGI and published on the cover of the journal Science in 2006.
An additional finding by the team was sequenced that among plants to date Eucalyptus showed the highest diversity of genes for specialized metabolites such as terpenes.
By having a library of these genes that control the synthesis of terpenes we are able to dissect which genes produce specific terpenes;
The extensive catalog of genes contributed by the team will allow breeders to adapt Eucalyptus trees for sustainable energy production in regions such as the U s. Southeast where it cannot currently be grown.
This means that the chromosome sets are totted up. The chromosomes are then able to find their suitable partner during meiosis a type of cell division that produces an organism's reproductive cells.
This allows the plants to stay fertile and a new species is generated. Examples for such a combination of two genomes called allopolyploidy are found abundantly in both wild plants and crops like wheat rapeseed and cotton.
or recombination of genetic material--so-called horizontal gene transfer--between the grafted plants. In our previous work we were able to prove that
contrary to the generally accepted dogma there is horizontal gene transfer of chloroplast genes at the contact zone between grafted plants.
The researchers introduced resistance genes against two different antibiotics into nuclear genomes of the tobacco species Nicotiana tabacum and Nicotiana glauca
so that only cells containing both resistance genes and thus DNA from both species should survive.
To determine if the acquired double resistance is due to the transfer of single genes or the transfer of the entire genetic material the researchers counted the chromosomes in the nuclei of the resistant plants.
If complete genomes were transferred the new plants would contain the sum of the chromosome numbers of the two species. Indeed we found 72 chromosomes in the resistant plants Ralph Bock explains 72 is the sum of the 24 N. glauca
chromosomes and the 48 N. tabacum chromosomes. Thus plantlets generated from the graft junction contained the genetic information of both species. We managed to produce allopolyploid plants without sexual reproduction Sandra Stegemann joint first author of the study is pleased to say.
When the scientists grew their new plants in the greenhouse it became obvious that they combined characteristics of both progenitor species
It could happen with new plant-breeding toolsince the first plant genome sequence was obtained for the plant Arabidopsis in 2000 scientists have sequenced gene everything from cannabis to castor bean.
University of Florida scientists were part of a research team that this week unveiled a new tool that will help all plant scientists label (annotate in researcher parlance) genes far more quickly
In documenting genome sequences scientists must sort through millions of bits of genetic code to identify what function each gene is responsible for (such as telling a plant how tall to grow
because with 20000 to 30000 genes in a typical plant scientists can't possibly conduct experiments to find out what each and every gene is responsible for.
In this study the team was able to piece together the biological process that leads to the production of new bone by studying the offspring of mice lacking the Gastric Intrinsic factor gene
The team then compared sequences from pooled populations representing these regions finding only a small fraction of shared genes.
They found dense clusters of genes related to disease resistance within the chromosomes. They also identified a handful of genes involved in moving nitrogen around.
This information could be beneficial for farmers practicing the intercropping system known as milpa wherein beans
They found evidence of synteny in which a gene in one species is present in another.
Citrus has incestuous genes he told the audience. Nothing is pure. Story Source: The above story is provided based on materials by DOE/Joint Genome Institute.
This breakthrough study from the Twell Laboratory at the University of Leicester published in the academic journal The Plant Cell has found a pair of genes called DAZ1
'--so that DUO1 and the DAZ1/DAZ2 genes work in tandem to control a gene network that ensures a pair of fertile sperm is made inside each pollen grain.
Interestingly DAZ1 and DAZ2 perform their role by cooperating with a well-known'repressor'protein called TOPLESS that acts as a brake on unwanted gene activity that would otherwise halt sperm and seed production.
and DAZ2 has the potential to be applied in the development of new plant breeding techniques to prevent the unwanted passing of genes
--or'horizontal gene transfer'--between crops or from crops to wild species. This new knowledge also generates genetic tools
#Gene study shows how sheep first separated from goatsscientists have cracked the genetic code of sheep to reveal how they became a distinct species from goats around four million years ago.
The research identifies the genes that give sheep their fleece and uncovers features of their digestive system
This team--the International Sheep Genomics Consortium--compared the sheep's genes with those of other animals--including humans cattle goats and pigs.
The analysis identifies several genes that are associated with wool production. It also reveals genes that underpin the evolution of the rumen--a specialised chamber of the stomach that breaks down plant material to make it ready for digestion.
This collaborative study involving 26 research institutions in eight different countries was led by researchers from the Commonwealth Scientific and Industrial Research Organisation Australia;
which genes are expressed in a spectrum of 40 different tissues. The study is published today in the journal Science.
which disrupts a cell wall remodeling process critical for the greening bacteriumâ##s survival inside a citrus tree. â#oeas a consequence of the chemical treatment several genes were expressed not
The research group performed a comparative analysis of DNA sequence variation of land planarian by means of a nuclear and a mitochondrial gene.
It provides new avenues to discover resistance genes and helps explain the mechanisms of repeated emergence of this disease which to this day is still the most costly potato pathogen in the world.
This should allow us to make significant headway in finding additional genes that provide resistance to P. infestans.
Gene sequencing technology used by this research group helped pin down the Toluca Valley as the ancestral hot spot. The P. infestans pathogen co-evolved there hundreds of years ago with plants that were distant cousins of modern potatoes
Since different potato varieties plants and pathogens have been co-evolving there for hundreds of years it offers some of the best hope to discover genes that provide some type of resistance.
In their study reported in BMC Plant Biology the researchers used gene sequencing techniques to identify 11 naturally occurring bacteria isolated from rice plants grown in the field in California.
#What can plants reveal about gene flow? That its an important evolutionary forcea plant breeder discovers his experimental crops have been contaminated with genes from a neighboring field.
New nasty weeds sometimes evolve directly from natural crosses between domesticated species and their wild relatives.
They illustrate the important role of gene flow among populations and its potential consequences. Although gene flow was recognized by a few scientists as a significant evolutionary force as early as the 1940s its relative role in maintaining a species'genetic integrity
and/or its diversity has been debated over the decades vacillating from trivial to critical. So how much gene flow is there between plant populations?
How important is gene flow for maintaining a species'identity and diversity and what are the implications of these processes for evolution conservation of endangered species invasiveness
or unintentional gene flow from domesticated crops to wild relatives? Norman Ellstrand a plant geneticist at the University of California Riverside is interested in many aspects regarding gene flow especially in applied plant biology
and has spent more than 25 years considering the possibility and potential impacts of unintended gene flow from genetically engineered crops.
As part of the American Journal of Botany's Centennial Review series Ellstrand reviews the history of gene flow focusing on plants
and provides evidence for its importance as an evolutionary force. Selection mutation gene flow and genetic drift are the four mechanisms that lead to biological evolution or a change in allele frequencies in a population over time.
Just how important are each of these forces relative to each other? Interestingly Ellstrand points out that evolutionary biologists'view on the importance of gene flow has waxed
and waned over the last century. Although it was seen first in the 1940s to be the evolutionary glue that held species together
and thus a significant evolutionary force a few decades later when quantitative data on gene flow in plant populations began being collected this view changed as evidence seemed to indicate that gene flow was not all that significant.
Not only was intraspecific gene flow among populations seen to be minimal at that time but somewhat incongruously interspecific hybridization or the movement of genes among species was seen to be a much larger force in evolution than intraspecific allele movement.
At the time the main concern for plant breeders was pollen movement between different strains of crops
--if a variety of sweet corn was contaminated by pollen from a popcorn variety then the resulting hybrid offspring would produce seeds that were unusable for market purposes
When I first started doing plant paternity studies in the 1980s Ellstrand comments our lab assumed that gene flow was limited.
And the paradigm of limited gene flow in plants began to crumble. Indeed one of the amazing things that parentage studies revealed is just how far genes could flow from hundreds to thousands of meters in some cases.
In one extraordinary case a study found that the nearest possible paternal sire of an individual fig tree was 85 km away!
but changes in allele patterns over time and thus the effects of evolution on populations can be seen in the genetic information.
despite the initial skepticism about the importance of gene flow modern empirical and theoretical research using up-to-date molecular
and DNA techniques have shown us not only how surprisingly far the flow of genes between distant plant populations can be
but also that the flow of alleles among populations is just as important if not more so in some cases as natural selection.
Indeed even just a low level of gene flow between populations can counter opposing forces of mutation genetic drift and selection.
Just like selection gene flow is one of the evolutionary forces--and a potentially important one notes Ellstrand.
And plants are suited very well for studies on gene flow because individuals are stationary yet pollen
However an important caveat that Ellstrand reports in his review is that the relative importance of gene flow can vary tremendously among species
and among populations and can be as low as no gene flow at all to very high rates of gene flow.
This review paper tells the story of gene flow's rise to respect among plant evolutionary biologists he concludes a fact that hasn't yet penetrated biology in general that is still mired in selection/adaptation-only thinking.
#Understanding disease resistance genes in crops to secure future food productiona new understanding as to how plants defend themselves against some pathogens that cause crop diseases is proposed by researchers from the University of Hertfordshire to help scientists
The second line of defense is referred to as effector-triggered immunity (ETI) this is based on the detection of disease pathogens by the plant's genes--there is a relationship between the gene in the host plant and the gene in the pathogen.
Through our research we discovered that defense against extracellular pathogens (ETD) involves different plant genes from those involved in the defense against intracellular pathogens.
We identified some specific resistance genes that code for receptor-like proteis (RLPS) and described how they operated against the pathogens.
This new understanding of plant defense through ETD suggests different operations of specific resistance genes
which both copies of the gene encoding Galt (galactosyltransferase) the enzyme responsible for placing the Gal molecule on the cell surface were knocked out.
California U s a. This tiny shrimp the smallest in the genus was identified from among specimens originally collected from a cave on that island of romance sunny Santa catalina off the coast of Southern California.
Part of a marine family known as skeleton shrimp only distantly related to the ones some humans love to dip in cocktail sauce this crustacean is the first of its genus to be reported in the northeastern Pacific.
The emergence of resistant pink bollworm in India provided the researchers an opportunity to test the hypothesis that insects in the field would evolve resistance to Bt toxin by the same genetic mechanism found previously in the lab. In the lab strains the scientists had identified mutations in a gene
if field-resistant pink bollworm from India harbored these same changes in the cadherin gene Fabrick said.
He said that by collaborating with Indian scientists we discovered that the same cadherin gene is associated with the resistance in India
and in 2004 Kang's group reported that mice transgenic for a c. elegans gene called fat-1 converted omega-6s into omega-3s in their tissues.
The current study describes how crossbreeding the fat-1 mouse with another strain transgenic for the c. elegans gene fat-2
which converts monosaturated fats into omega-6s can produce mice expressing both c. elegans genes.
The crossbreeding protocol produces four different strains within the same litter--Omega mice that express both fat-1 and fat-2 strains that express only one of the c. elegans genes
and weeds affect each other's gene response Clay and a team of two research associates and a soils expert planted plots of velvetleaf alone corn with velvetleaf and corn kept weed-free.
In addition specific genes that influenced photosynthesis and other important plant responses differed in expression. Another study compared the corn's growth and yield in response to weeds lack of nitrogen or shade.
In all cases Clay and Horvath found that genes were expressed differentially compared with nonstressed plants.
When grown with weeds genes that control the major facets of the corn plant's metabolism were decreased
The genes never recovered says Clay even after the weeds were removed. The impact is long term she adds
The genes of the water-stressed corn on the top of the hill were regulated down in terms of phosphorus uptake Clay explains.
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