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ScienceDaily_2014 17872.txt

#Genetic testing to produce more offspringthe Fleckvieh is breed a of cattle that originated in the Alpine region. A robust animal it is now found on every continent with an estimated worldwide population of around 40 million. In Germany there are approximately 1 million Fleckvieh dairy cows: Their genomes can be traced back to a small number of key ancestors explains Prof. Ruedi Fries Chair of Animal breeding at TUM. With artificial insemination male breeding animals can produce more than one hundred thousand offspring. Infertility caused by a single gene This practice is fraught with risk however: If the genetic make-up of any animal contains an unidentified defect this characteristic will be passed on to future generations. TUM researchers have discovered now that a mutation in the TMEM95 gene on cattle chromosome 19 makes bulls effectively infertile with a success rate for insemination of less than 2 percent. Otherwise the animals are perfectly healthy and normal points out Dr. Hubert Pausch lead author of the study. The characteristic only manifests itself if bulls inherit the mutation from both the male and female side i e. they are homozygous for the defective gene. It is only in this case that the animals should be excluded from breeding. Routine genetic testing for all breeding bulls has been underway since August 2012. Findings of interest for human medicineas part of their study the researchers compared the genome of 40 subfertile animals with 8000 breeding bulls with normal fertility levels. They discovered that the genetic defect can be traced back to one Fleckvieh animal born in 1966. The TMEM95 gene encodes a protein on the surface of the sperm heads. The protein probably mediates the binding process between the sperm and egg cells. If it is missing fertilization will not occur. Our findings indicate that genetic defects in TMEM95 could also cause infertility in men elaborates Pausch. During their investigation of the sperm of infertile breeding bulls the TUM scientists collaborated with Prof. Sabine KÃ lle and Dr. Matthias Trottmann from Munich's Ludwig Maximilian University. Trottmann helps couples with infertility problems. Genetic analysis for healthier animalsscientists have been systematically studying the cattle genome since 2009. Unlike in humans a small number of loci explain a large proportion of characteristics. This allows the genetic profile of breeding bulls to be mapped in detail --and individual weaknesses can be taken into account for breeding says Pausch. Fries adds: Genetic analysis highlights the undesirable characteristics and also the diseases that animals pass on. With this knowledge we can not only improve yield and quality but also improve animal health by identifying pathogenic gene variants and ensuring that they are passed not on to future animals. One example is a genetic defect which causes a blood clotting malfunction in the homozygous state. Story Source: The above story is provided based on materials by Technische Universitaet Muenchen. Note: Materials may be edited for content and length. Journal Reference n

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