Below you will find two examples of contributions to plant and animal genome projects in which Wageningen UR researchers are involved.
Genes to take the itch away
Tail and mane eczema can drive horses crazy. Insect bites cause an itchy rash that is almost impossible to treat. While rubbing against posts and fences may provide temporary relief, it ultimately makes the itching worse. Wageningen researchers collected genetic information from hundreds of horses and ponies in the hopes of developing a test that can help horse breeders combat this disease.
Anouk Schurink collected information from 280 Friesian horses, 200 Shetland ponies and 146 Icelandic horses. Half of these animals suffered from tail and mane disease and the other half showed no symptoms. Schurink had demonstrated in previous studies that sensitivity to eczema is genetic. Some horses are simply prone to it while others are not. By comparing the genetic information of vulnerable and resistant horses, Schurink hopes to discover the genes that determine this sensitivity. This is no easy feat. 'We now know that lots of genes are involved, but it's hard to narrow them down. This is probably because each individual gene has a minimal effect on tail and mane eczema. Rather, it is the sum of all these effects that determines the likelihood of a horse or pony developing this disease.'
Nevertheless, Schurink hopes to one day develop a test that will help horse breeders determine how sensitive their animals are to eczema. 'We'll know if this is possible next year.' The disease can be reduced by breeding less sensitive animals.
This research study on tail and mane eczema is being conducted as part of the European research programme Horsegene, which includes an international database that researchers currently studying horse DNA can use to indicate the diseases, features and horse breeds they are currently working on. In addition to improving collaboration between researchers, Schurink believes the database will add further impetus to research on genetic diseases and other horse characteristics. The database will be presented this week during the international Plant & Animal Genome Conference in San Diego.
Distant cousin reveals secret to potato tubers
Wageningen researchers discovered the genome of a distant cousin of the potato and the tomato. This discovery makes it easier for plant breeders to find interesting characteristics in the wild plant varieties of these crops.
Anyone who's seen a field of flowering potato plants can tell that Solanum etuberosum is related to the potato. The dark purple flowers of this species are shaped like the flowers of our very own Dutch Eigenheimer potato.
Several species that are related to our tomato and potato can be found in South and Central America. These species are a treasure trove for plant breeders looking for genes that can help improve resistance to disease and drought. Solanum etuberosum is an interesting member of this family, as it resembles the potato but does not grow tubers. This species may help researchers understand the genes involved in growing potato tubers and can help potato breeders create new potato varieties in the long term.
Genetic information from other members of the Solanum genus may also shed light on how these plants produce toxins. Modern ware potatoes contain small traces of the toxin glycoalkaloid. This chemical compound is mainly found in the green parts of potato tubers. Other members of the Solanum genus produce large quantities of this substance. In order to gain a better understanding of the genes involved in the production of toxins, the researchers plan to examine the DNA sequence of another relative: Solanum cardiophyllum. This species does not produce toxins and the tubers are used for food in Mexico.
Researcher Lidija Berke will present the DNA information for Solanum etuberosum this week at the international Plant & Animal Genome Conference in San Diego. She expects that her colleagues will be particularly interested in the familial relationship between Solanum etuberosum, the tomato and the potato. 'This relationship was unclear for a long time. Some people thought etuberosum was a potato species that grows in the wild and doesn't produce tubers. We found other genetic differences between this plant and the potato. The species shares the same links to a potato as to a tomato and is therefore interesting to breeders of both crops.'