By Carol Beuchat PhD
Do you REALLY need to take a genetics course to be a dog breeder?
In the "good ol' days" probably not, but dogs are in a bit of a bind right now. Decades of breeding in closed gene pools (because of closed stud books) means that our once healthy breeds have lost genetic diversity and concentrated the nasty mutations, with the result that it takes some serious match-making and a wad of cash for DNA tests to produce healthy puppies, and still you could be unlucky. Trying to purge the gene pool of the mutations is doomed to fail, so breeders will need to start breeding in a way that allows mutations to remain in the gene pool without causing trouble. This is something breeders of other domestic animals figured out how to do long ago out of necessity, because if they don't have healthy animals they can't stay in business. But dog breeding has lagged far behind, and we have some catching up to do.
In the "good ol' days" probably not, but dogs are in a bit of a bind right now. Decades of breeding in closed gene pools (because of closed stud books) means that our once healthy breeds have lost genetic diversity and concentrated the nasty mutations, with the result that it takes some serious match-making and a wad of cash for DNA tests to produce healthy puppies, and still you could be unlucky. Trying to purge the gene pool of the mutations is doomed to fail, so breeders will need to start breeding in a way that allows mutations to remain in the gene pool without causing trouble. This is something breeders of other domestic animals figured out how to do long ago out of necessity, because if they don't have healthy animals they can't stay in business. But dog breeding has lagged far behind, and we have some catching up to do.
| If you're not sure what you need to know that you don't already, have a look at this paper published this week about the genetics of Bullmastiffs in Australia (Mortlock et al 2016). This might not be your breed, but you should have a look at it anyway, because sooner or later there will be a paper like this for your breed and you're going to need to understand it. Here's what Mortlock and colleagues have to say: "Management and preservation of genomic diversity in dog breeds is a major objective for maintaining health...Concerns about the potential effects of inbreeding and reduced diversity on health and welfare within breeds, has also led to a call for improved genetic management practices. Hence, managing diversity has become a major focus for dog breeders and oversight authorities. National breed clubs are now assessing methods for evaluating genomic diversity to inform breeding decisions and reduce the incidence of disease, while maintaining positive breed traits and diversity." (Mortlock et al 2016) |  |
How many of you reading this are involved in using assessments of genomic diversity to inform breeding decisions? Or if you aren't, is your breed club doing this? According to the canine geneticists and veterinarians, this is what we need to be doing, and if we could have a show of hands I suspect we would find that mostly we are not. But this definitely will be in your future and there will be a learning curve, so if you're not on it already now is a good time to take a little peek at what lies ahead.
Take a quick look at this list of the tools you will be using to understand the genetics of your breed in the not-too-distant future: inbreeding coefficient, effective population size, effective number of founders, effective number of ancestors, relationship coefficient, kinship coefficient, single nucleotide polymorphisms (SNP), multi-locus heterozygosity, Hardy-Weinberg, linkage-disequilibrium, and runs of homozygosity. These are not obscure scientific terms; they are as fundamental to population genetics as dominant and recessive are to Mendelian genetics. If you continue to breed for very long, these terms will be rolling off your tongue and part of your standard vocabulary when you're planning for your next litter.
My point is that The Future is here. There are more and more papers like this one coming out, which is terrific for dog breeders. This is information you can use to solve genetic problems in your breed and plan breeding strategies that will produce the healthier dogs in the future. If you're a lucky Bullmastiff breeder, you should grab a copy of this paper and sit down with your fellow breeders to absorb the gold mine of information. If this isn't your breed, you will still benefit from reading this because the tools and concepts will be the same for all breeds.
And I'll put in a little plug here, and remind you that ICB teaches courses designed for dog breeders that are a great place to start the next phase of your education as a breeder. (See the info below.)
What was the bottom line for Bullmastiffs?
My point is that The Future is here. There are more and more papers like this one coming out, which is terrific for dog breeders. This is information you can use to solve genetic problems in your breed and plan breeding strategies that will produce the healthier dogs in the future. If you're a lucky Bullmastiff breeder, you should grab a copy of this paper and sit down with your fellow breeders to absorb the gold mine of information. If this isn't your breed, you will still benefit from reading this because the tools and concepts will be the same for all breeds.
And I'll put in a little plug here, and remind you that ICB teaches courses designed for dog breeders that are a great place to start the next phase of your education as a breeder. (See the info below.)
What was the bottom line for Bullmastiffs?
"...Bullmastiffs generally have a level of genetic diversity that is mid-range when compared with other breeds, but a relatively low effective population size, and a rate of inbreeding that slightly greater than that the level required for avoiding the effects of inbreeding depression. This evaluation provides information that may influence decisions to maintain genetic diversity within the breed. Any decisions that affect the breed as a whole would be most effectively implemented through the collaborative efforts of breed clubs that maintain data records of registered dogs, and can provide information to their members. There are many examples where breed clubs have implemented registration policies and provided the best available advice to reduce the incidence of inherited diseases and deleterious alleles, and promote breed health...The results of the present study show evidence of ancestral inbreeding in Bullmastiffs, and unequal founder contributions during breed establishment. A relatively small effective population size may be improved by utilising the available genetic diversity in systematic manner."
Mortlock S-A, MS Khatkar, & P Williamson. 2016. Comparative analysis of genome diversity in Bullmastiff dogs. PLoS ONE | DOI:10.1371/journal.pone.0147941 January 29, 2016. (download pdf)
| Ready to learn? You can learn about effective founders, Hardy-Weinberg, kinship coefficients, and all the rest in the ICB course Managing Genetics for the Future. The next class starts Monday, 1 February. Learn more about the course and sign up HERE. |  |
Check out
ICB's online courses
*******************
Coming up NEXT -
Managing Genetics for the Future
Next class starts
1 February 2016
Sign up now!
***************************************
Visit our Facebook Groups
ICB Institute of Canine Biology
...the latest canine news and research
ICB Breeding for the Future
...the science of dog breeding
ICB's online courses
*******************
Coming up NEXT -
Managing Genetics for the Future
Next class starts
1 February 2016
Sign up now!
***************************************
Visit our Facebook Groups
ICB Institute of Canine Biology
...the latest canine news and research
ICB Breeding for the Future
...the science of dog breeding
