A brief history of statistical developments in animal breeding 2 - use of genomics in animal breeding practice

Published on January 31, 2017   33 min

Other Talks in the Series: Statistical Genetics

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0:00
Hello, this is Daniel Gianola from the University of Wisconsin-Madison and Technical University of Munich, Germany. And I will start discussing the second part of the presentation concentrating on the impact of "Genomics in Animal Breeding".
0:16
So now we're about to enter the genomic era, but until we actually had a massive number of molecular markers, we were using linear models, using phenotypes and pairing research inputs. But in the mean time, the Edinburgh school kept working on the basic foundations of quantitative genetics. And I would like to mention Alan Robertson and William Hill from the University of Edinburgh that did considerable work on the quantitative genetics of small populations. What would be the fate of favorable alleles in the selection process? And what would be the probability of fixation? That's the first formula. And then we have a series of curves that show the chance of fixation of recessive alleles as a function of population size and selection intensity. So we were working with this sort of black box, blind statistical models, but at the same time there were persons such as Hill and Robertson working on the underlying theory that we would need at some point. And the time came when genomics began to be applied in animal and plant breeding.
1:32
Let me state briefly what the genomic era has meant from an animal breeding perspective.
1:39
First, let's talk about genomic data and more specifically about one type of genomic data that I already mentioned, called the SNPs. So in this diagram, we have randomly grown individuals with a pair of chromosomes, one and two. And here you see the double helixes. And if you observe the sequential basis, these letters A's, T's, C's, and G's. You see that the two chromosomes are the same except in that part, it's a SNP, where in one chromosome, we have a C paired with G, whereas, in the other chromosome we have a T paired with A. And that is called a polymorphism in the population. And millions of such polymorphisms have been discovered. This gave the impetus to the idea that perhaps we should use all the genomic variability in prediction models.

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A brief history of statistical developments in animal breeding 2 - use of genomics in animal breeding practice

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