introducing new traits in the Gene Pool - Page 2

Chris,

Of course i would do it.  My main concern is finding a male to breed to.  Most of the ones i have seen work and what I would consider worthy are not titled, or have not shown that they have the ability to pass on their genes to their progeny.   One showline breeder i know has done this.  They refer to the pups as "half breeds".     How far has the split gone that breeding dogs of the same breed and we call them Half breeds? 

I think you would have an easier time finding "working" homes willing to give it a try than show.  As i stated earlier (or in another thread) working people seem to have more of an open mind when it comes to trying new things.   Most of the working dogs that have some show in them you will find it a little further back.  Could be the same reason, maybe they had  a hard time finding homes for their pups.

I find it funny that in a world were you can purchase  shepadoddle, labadoddles, and every other combination of dogs just for the sake of having a "rare" breed, so many would have a hard time with a cross breed of  what most would call "true" working dogs.  To bad we dont have more records of all the dog breeds used to create the german shepherd in the first place.  That would be some interesting reading, or better yet, what if they had dna records 100 years ago.  

Would i cross breed a shepherd with a malinois or dutch shepherd, or etc, etc?  Dont know.  Havent done it yet.   Makes one wonder what would cause the greater stink,, crossbreeding or really tight linebreeding like 1-2?

Just some things to think about.

john

yea it is all about the selection, bringing a specific trait to your breeding program could be very easy if the trait you seek is controlled by only one gene, but usually that's not the case.  in fact i think that most behavioral traits are produced by 'modifying genes'  -  i guess you could imagine them as 'gene clusters' - i.e. a few genes group together and modify/influence each other - so it may take a few generations to 'set' the trait fully with any kind of consistency.  but from what i've been reading radical change (for the good or the bad) in any breeding program can be done in as little as ten years. i don't believe any trait that has existed is ever truly lost but rather it is either diluted (modified by other genes) or buried but can be retrieved with the right selection & breeding process as well as providing environmental influences that cultivating the same trait.  so i think one would need to have a keen eye, good attention to detail and lots of patience but it can be done <g>

 

Selective breeding is definitley not a quick fix and it might be a lot more prudent to obtain  breeding stock that already exhibits the desirable trait/s rather than trying to breed it into a line that is missing it. It can be done, but you may well need to produce a lot more puppies to do it than you would if you had a brood bitch with all or at the least most of characteristics you are wanting and then breed her to a male with like characteristics. Like begets like.

i ran across this article thought it might help answer your questions - below is the first portion the rest you can find at this link - hth - http://www.vin.com/proceedings/Proceedings.plx?CID=TUFTSBG2003&PID=5114&O=Generic

As breeders, you engage in genetic "experiments" each time you plan a mating. The type of mating selected should coincide with your goals. Outbreeding brings together two animals less related than the average for the breed. This promotes more heterozygosity, and usually more variation in a litter. A reason to outbreed would be to bring in new genes or traits that your breeding stock does not possess. Outbreeding can also mask the expression of recessive genes, and allow their propagation in the carrier state.

Linebreeding attempts to concentrate the genes of a specific ancestor or ancestors through their appearance multiple times in a pedigree. The ancestor should appear behind more than one offspring in the sire and dam's pedigree. Otherwise you are only linebreeding on the single offspring. A linebreeding may produce an offspring with magnificent qualities. However, if those qualities are not present in any of the ancestors that have been linebred on, the individual may have a wonderful show career, but it may not breed true. Careful selection of mates is important, but careful selection of offspring from the resultant litter is also important to fulfill your genetic goals. Without this, you are reducing your chances of concentrating the genes of the linebred ancestor.

Inbreeding significantly increases homozygosity, and therefore uniformity in litters. Inbreeding can cause the expression of both beneficial and detrimental recessive genes through pairing up. Inbreeding cannot change, or create undesirable genes. It only exposes them through homozygosity. Inbreeding can also exacerbate a tendency toward disorders controlled by multiple genes, such as hip dysplasia and congenital heart anomalies. Unless you have prior knowledge of what milder linebreeding on the common ancestors has produced, inbreeding may expose the offspring (and buyers) to extraordinary risk of genetic defects. Research has shown that inbreeding depression, or diminished health and viability through inbreeding is directly related to the amount of detrimental recessive genes present. Some lines can thrive with inbreeding, and some cannot.

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To introduce a non-existing trait, I think the easiest method would be by gene manipulation in a lab.  Many genes are "universal" throughout the breeds, but a particular allelic type has been purged.  For example, in one study, the missing allele for black in a mouse population was inserted into the already present Agouti-locus of mice to produce black mice.