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They discovered that a number of genomic regions, or loci, haveundergone changes in genes that underlie this genetically complexcharacteristic. They also discovered many new genes that play arole in the regulation of body weight, which can lead to obesity. The Plön-based researchers obtained mouse lines that have beenspecifically selected for extreme body weight for 25 years. Themice, which have been bred for over 150 generations, belong toseven different strains and now weigh two to four times more thanmice of normal weight. The Max Planck scientists were able toidentify a total of 67 loci on the genome that had changed in theheavy mice. The different strains have become so similar in theseregions as a result of the extreme artificial selection pressure,that the genomes of the heavier but unrelated animals were moresimilar at these loci than with their closely related sibling mousestrains of those with normal weight. This clearly indicates thatthese loci are involved in the regulation of body weight. The discovered loci regulate, among other things, energy balance,metabolic processes and growth. The Gpr133 gene, which is expressed in the adrenal gland, is a novel gene andpresumably controls body weight through the release of hormones.The second identified gene, Gpr10, which is active in thehypothalamus in the brain, was found to influence appetite andmetabolic rates. Accordingly, the team has also identified genesfor the regulation of fat cells and for taste and olfactoryperception that can affect body weight. Moreover, many of theregions discovered coincide with loci on the human genome thatinfluence body weight. "These genes probably also determinebody weight in humans, because size and body weight are suchtightly linked processes. This evolutionary connection serves as anice confirmation," says Frank Chan from the Max PlanckInstitute for Evolutionary Biology. Interestingly, the genome of mouse populations living in the wildon remote islands, shaped by natural selection, have also changedin similar ways to the animals bred in the laboratory. For example,on the Faroe Islands and St Kilda off the coast of Scotland, micepopulations have evolved to be among the largest mice in the world.The researchers have found that island mice retained littlevariation specifically at the same genomic loci that changed in theheavy laboratory-bred animal strains. These telltale signs suggestthat artificial selection in the laboratory changes the same lociin the genome as natural selection. Thus, when complex characteristics must adapt to alteredenvironmental conditions, selection affects many responsible genessimultaneously. These then change in parallel and contribute tovarying extents to the organism's capacity for adaptation. In thisway, the genetic basis of complex traits can be decoded throughparallel selection. I am an expert from bottle-dispenserpump.com, while we provides the quality product, such as Lotion Dispenser Pump , Shampoo Dispenser Pump Manufacturer, Bottle Dispenser Pump,and more.
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