Genes For Alcohol Consumption Identified

Researchers from the Department of Experimental Psychology at the University of Bristol, in collaboration with colleagues from the University of Oxford, found that the amount of beer, wine and other alcoholic drinks that people regularly consume, and possibly an individual's susceptibility to addiction, may be related to differences in genetic make-up.
Lead researcher Dr Marcus Munafò, at the Department of Experimental Psychology, University of Bristol, said: "Our study suggests that there's a genetic basis to certain kinds of behaviour, including alcohol consumption, which may be important in influencing whether people are at an increased risk of alcohol dependence. Understanding genetic influences on behaviour is important if we are to understand why some people are more likely to become addicted than others."
The scientists analysed data from almost a thousand people who gave detailed information on their drinking habits. The research focused on a key gene that controls chemical signalling in the brain. Different versions of this gene may affect the balance and effect of signalling molecules and in turn help to shape individual drinking habits.
Scientists do not know precisely why particular genetic variants may influence behaviour, but they do have a few clues. They found that one particular genetic variant – a version of the dopamine D2 receptor gene (DRD2) - was strongly associated with alcohol consumption.
The DRD2 gene appears to influence the 'high' that people derive from drugs such as alcohol. People without this variant might derive less pleasure from alcohol, and may therefore drink less.
The large-scale study, published in The Pharmacogenomics Journal [March 2005], provides evidence that particular human genes can influence behaviour. It is being hailed as an important advance in understanding why some of us drink more than others, and why some people might be more vulnerable to alcohol dependence.

Drunken Fruit Flies Help Scientists Find Potential Drug Target For Alcoholism

fruit flies have helped researchers from North Carolina State and Boston universities identify entire networks of genes -- also present in humans -- that play a key role in alcohol drinking behavior.

This discovery, published in the October 2009 print issue of the journal Genetics, provides a crucial explanation of why some people seem to tolerate alcohol better than others, as well as a potential target for drugs aimed at preventing or eliminating alcoholism. In addition, this discovery sheds new light on many of the negative side effects of drinking, such as liver damage.
"Translational studies, like this one, in which discoveries from model organisms can be applied to insights in human biology, can make us understand the balance between nature and nurture, why we behave the way we do, for better or worse, and what makes us tick," said Robert Anholt, a Professor of Biology and Genetics at North Carolina State University, Director of the W. M. Keck Center for Behavioral Biology, and one of the senior scientists involved in the work.
To make this discovery, Anholt and colleagues first measured the amount of time it took for the fruit flies to lose postural control after exposure to alcohol. At the same time, changes in the expression of all the flies' genes were recorded. Using statistical methods to identify genes that work together, the scientists were able to pinpoint specific genes that played a crucial role in adaptation relating to alcohol exposure. Armed with this information about fruit flies, the scientists set out to determine if the same genes contribute to alcohol drinking habits in humans. Indeed they do: expression of the human counterpart of a critical gene in fruit flies could be directly tied to alcohol consumption in humans.
"From a scientific point-of-view, research like this is almost intoxicating," said Mark Johnston, Editor-in-Chief of the journal Genetics. "We've known for a while now that genetics played a role in alcohol consumption, but now, we actually know some of the genes that are involved. As a result of this work, we have a potential drug target for curing this insidious condition."

Thanks to a technique known as genetic mapping, Cornell University scientists have for the first time located genetic factors that allow significant increases in yields of rice grown by poor farmers trying to produce crops in hardscrabble conditions.

The researchers' breakthrough has been to use genetic maps to identify regions of chromosomes containing genes that control traits such as grains per plant, disease resistance and earliness. These genes are identified in a wild ancestor of rice and then introgressed, or "spliced," into domesticated, popular varieties of rice. In this case, the genes were introduced into a variety of upland rice, widely grown in unfavorable conditions such as on mountain slopes. As a result, the yield of the domesticated rice has been increased.
"The ability to use modern molecular techniques to improve yield and disease resistance of varieties grown by poor farmers under adverse conditions is as important as using this technology in the high-production areas of the world," says Susan R. McCouch, Cornell assistant professor of plant breeding.
McCouch presented the results of this plant-breeding achievement today at the annual meeting of the American Association for the Advancement of Science. Her talk, "Molecular Breeding and Genetic Resources," was part of a panel discussion on "Accelerating Crop Evolution for Greater Production and Better Biodiversity Conservation."
McCouch noted that she and her colleague, Steven D. Tanksley, Cornell Liberty Hyde Bailey Professor of Plant Breeding, have been able to unlock the genetic potential of domesticated rice varieties. Looking specifically at rice and tomatoes, the two researchers systematically mapped the genes of those plants, looking for specific loci, or genes, known as quantitative trait locus, or QTLs, which could be used to boost production.
This follows Cornell research reported two years ago on introgressing high-yield production genes from wild rice varieties into domesticated varieties grown under favorable, bread-basket conditions as a way to improve yields.
"Our latest work shows that the strategy to boost yields in domesticated varieties from genes in wild varieties is likely to work with any existing variety," said McCouch. "Whatever the baseline is that we're working from, we have shown that we can expand our concept and detect improved production performance. And, at the same time, we can broaden the genetic base of these plants."
Agricultural practices of the past century, McCouch noted, have led researchers to be victims of their own success. Modern plant-breeding techniques, she said, have been successful in developing high-yielding rice and tomatoes, but the crossing and re-crossing of close plant relatives has resulted in a "genetic bottleneck." Paradoxically this could result in reducing plant production and render plants more vulnerable to pests and disease.
However, said McCouch, "the upland varieties of rice have very interesting genetics" that could be exploited by farmers far from the regions where they are adapted. In countries like Brazil, she noted, the less productive yet sturdy upland varieties of rice thrive on subsisdence farms in acidic soils and even in areas prone to disease. She said that these traits could be valuable elsewhere, particularly in Asian countries, where boosting rice production is critical to keeping up with the needs of burgeoning populations.

Gene For Resistance To Parasitic 'Witchweed'

The parasitic flowering plant Striga, or "witchweed," attacks the roots of host plants, draining needed water and nutrients and leaving them unable to grow and produce any grains. Witchweed is endemic throughout sub-Saharan Africa, causing crop losses that surpass hundreds of millions of dollars annually and exacerbating food shortages in the region.

Among the crops heavily parasitized by witchweed is black-eyed pea, known in Africa as "cowpea" or "niebe" in Francophone countries.
About 80 percent of the world's cowpea crop is grown in sub-Saharan Africa, mostly by subsistence farmers who lack the resources to purchase expensive herbicides and fertilizers. In this region, cowpea is the primary protein source for millions of people, who consume the entire plant – the pea for soups, stews and breads, the leaves as fresh greens, the stems as hay and fodder for cattle.
As the use of cowpea expanded over time, so did the prevalence of Striga gesnerioides, the type of witchweed adapted to parasitize it. Today, witchweed is so virulent that farmers in this semi-arid region must relocate their cowpea crop to new soil every few years.
Now, scientists at the University of Virginia have identified a gene in cowpea that confers resistance to witchweed attack. This discovery will help researchers better understand how some plants can resist Striga, while others, such as corn and sorghum, are susceptible.
The findings are presented in the Aug. 28 issue of the journal Science.
"Discovery of this resistance gene is not only important for improving cowpea, but may help us develop strategies for improving resistance to Striga in other affected crops," said Michael P.Timko, the U.Va. biology professor who led the study.
Currently there are no natural sources of Striga resistance in corn or sorghum, both of which are major cereal grains in the African diet.
"Making plants durably resistant to Striga could have a significant impact on food security for Africa," Timko said.
In recent years, he and other scientists have sequenced the cowpea genome and are using this information to develop cowpea plants with multiple improved agronomic traits.
"It is now possible for us to identify all possible genes for Striga resistance in cowpeas, as well as resistance to other cowpea pathogens," Timko said. "We may even eventually breed a more drought-resistant plant and varieties that have higher levels and a better balance of nutrients. We've reached a point where we can manipulate this plant for the good of millions of people."
Timko's approach is to improve the performance of plants by identifying genes that control key characteristics, and then using selective breeding to emphasize those traits.
While he is finding success breeding parasite-resistant hybrids, there are at least seven different races of Striga, each capable of adapting to changing varieties of cowpeas.
"We are trying to create a plant that is resistant across the board," he said. "Striga is hyper-virulent. This is warfare between the cowpea plant and its parasite, and we keep trying to stay ahead of the enemy."

What is Genetic Engineering?

Genetic engineering is a laboratory technique used by scientists to change the DNA of living organisms.
DNA is the blueprint for the individuality of an organism. The organism relies upon the information stored in its DNA for the management of every biochemical process. The life, growth and unique features of the organism depend on its DNA. The segments of DNA which have been associated with specific features or functions of an organism are called genes.
Molecular biologists have discovered many enzymes which change the structure of DNA in living organisms. Some of these enzymes can cut and join strands of DNA. Using such enzymes, scientists learned to cut specific genes from DNA and to build customized DNA using these genes. They also learned about vectors, strands of DNA such as viruses, which can infect a cell and insert themselves into its DNA.
With this knowledge, scientists started to build vectors which incorporated genes of their choosing and used the new vectors to insert these genes into the DNA of living organisms. Genetic engineers believe they can improve the foods we eat by doing this. For example, tomatoes are sensitive to frost. This shortens their growing season. Fish, on the other hand, survive in very cold water. Scientists identified a particular gene which enables a flounder to resist cold and used the technology of genetic engineering to insert this 'anti-freeze' gene into a tomato. This makes it possible to extend the growing season of the tomato.
At first glance, this might look exciting to some people. Deeper consideration reveals serious dangers.

General information about disorders that run in families

What does it mean if a disorder seems to run in my family?

A particular disorder might be described as “running in a family” if more than one person in the family has the condition. Some disorders that affect multiple family members are caused by gene mutations, which can be inherited (passed down from parent to child). Other conditions that appear to run in families are not caused by mutations in single genes. Instead, environmental factors such as dietary habits or a combination of genetic and environmental factors are responsible for these disorders.

It is not always easy to determine whether a condition in a family is inherited. A genetics professional can use a person’s family history (a record of health information about a person’s immediate and extended family) to help determine whether a disorder has a genetic component. He or she will ask about the health of people from several generations of the family, usually first-, second-, and third-degree relatives

Degrees of relationship
Examples

First-degree relatives
Parents, children, brothers, and sisters

Second-degree relatives
Grandparents, aunts and uncles, nieces and nephews, and grandchildren

Third-degree relatives
First cousins