http___metro-portal.hr_genetske-pogreske-koliko-ih-nam-roditelji-proslijede_60349_1.xml
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Rutherford Mansfield: Family genetic research reveals the speed of human evolution rwrc: A team of researchers have discovered that, on average, thirty mutations are transmitted from each parent to their child, revising previous estimations and revolutionizing the timescale we use to calculate the number of generations separating us from other species. “Your genome, or genetic code, is made up of six billion pieces of information, called nucleotides,” explained co-lead author Philip Awadalla of the University of Montreal’s Faculty of Medicine and Director of CARTaGENE. “Three billion come from each parent, and based on indirect evolutionary studies, we had previously estimated that parents would contribute an average of 100-200 mistakes in these pieces of information to their child. Our genetic study, the first of its kind, shows that actually much fewer mistakes – or mutations – are made.” Awadalla published the study with co-author Matt Hurles of the Wellcome Trust Sanger Institute in Nature Genetics on June 12, 2011. As mutations play a key role in the evolutionary process, geneticists will now revise the number of generations separating us from genetic relatives such as apes. “In principle, evolution is happening a third as slowly as previously thought,” Awadalla said. The researchers made the discovery by looking at the complete genomes of two families – a mother, father and their child. In another first, the findings enabled the team to determine whether men contribute more mutations to their offspring than women. The theory is that because mistakes are made during cell division and DNA replication, and males produces many millions more gametes (sperm) than women (eggs), more mutations would come from men compared to women. In one of their families, men contributed six times as many genetic errors to their children. However, the research also showed a wide variation between families. “We saw that the number of mutations from the male was less than the number of mutations from the female in one of the families,” Awadalla explained. “This doesn’t mean that we’re throwing the theory out the window, it simply means that the mutation rate is extremely variable from individual to individual, or even that some people have mechanisms that reduce the likelihood of mutations.” He also noted that this finding would have important implications for research that attempts to tie specific genetic mutations to diseases. Researchers will need to undertake further studies with more families to better understand just how variable the individual mutation rate is. “We also need to be looking at other kinds of mutations, such as structural variations within our genetic code,” Awadalla said. About the study : Conrad DF et al. (2011) Variation in genome-wide mutation rates within and between human families. Nature Genetics, published online 12 June 2011. Image: This image is courtesy of Vecer, the third largest newspaper in Slovenia. They ran it to accompany their story about this research, entitled Evolucija človeštva kot kaže počasnejša od predvidevanj. Great to hear my blog inspires you. You’ll love zoology. I think you might be right about the peacock. What’s interesting is (so far as I know) the albino gene is either on or off. I’m really quite confused by that picture still, especially how it seems the albino portion is almost exactly split in the middle of it’s body. Also albino animals tend to have a lot of genetic problems - the albino gene accounts for more than just colouration. We’re left wondering if this peacock has genetic problems associated with albinism or not. Centennial Theme by One by Four Studio. Powered by Tumblr.
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Genetske pogreške - koliko ih nam roditelji proslijede Novo istraživanje međunarodnog tima genetičara pokazalo je da se u našem genetskom kodu nalazi najmanje 60 novih mutacija u odnosu na roditelje Kada roditelji prenose gene na svoju djecu obično se u genetički kod provuče oko 60 pogrešaka, tvrdi se u novom istraživanju. Bila koja od tih genetskih mutacija može biti ključni razlog za to kako se određena osoba ponaša u usporedbi s roditeljima. Na kraju, sve te mutacije su u osnovi pokretačka snaga evolucije. Šezdeset mutacija možda zvuči kao velika brojka, ali prema riječima međunarodnog tima genetičara koji stoje iza istraživanja, to je manje nego što se dosad mislilo. „Dosada smo vjerovali kako roditelji na dijete prenesu između 100 i 200 genetskih pogrešaka", kazao je u službenom priopćenju Phillip Awadalla, genetičar sa Sveučilišta Montreal, koji je jedan od voditelja projekta. „Naše genetsko istraživanje, inače prvo te vrste, dokazalo je da dolazi do manje pogrešaka ili mutacija", dodao je. U prijevodu to znači da je ljudska evolucija puno sporija nego što se prije mislilo. Istraživači su analizirali kompletne genetske sljedove dvaju obitelji koji su prikupljeni još ranije u sklopu „Projekta 1.000 genoma". Oni su tražili nove mutacije prisutne u dječjoj DNK koje nisu postojale u roditeljskim genomima. „Poput vrlo malene igle u plastu sijena", rekao je Awadalla, pronađena je tek jedna mutacija na svakih 100 milijuna slova DNK. Osim toga, broj mutacija koji je došao od oca i majke drastično je različit. U jednoj obitelji za čak 92 posto mutacija kriv je otac, dok je u drugoj obitelji 64 posto mutacija došlo s majčine strane. „To nam je bilo iznenađenje. Većina ljudi bi očekivala da u svim obiteljima većina mutacija dolazi s očeve strane zbog dodatnog broja kopiranja genoma što je potrebno radi stvaranja sperme za razliku od jajašca", objasnio je u kontekstu ove priče Matt Hurles iz Instituta Wellcome Trust Sanger iz Ujedinjenog Kraljevstva dodavši kako su potrebne daljnje analize da bi se objasnila ta neujednačenost. Najnovije tehnike i algoritmi razvijeni za ovo istraživanje, o kojem se pisalo u časopisu New Genetics, mogli bi se iskoristiti za buduća istraživanja i pronalaženje odgovora na dodatna pitanja poput toga kako i do koje mjere roditeljska dob utječe na broj prenesenih mutacija ili kako na stopu mutacija utječu određeni okolišni čimbenici.