Posted By: GliderFun
Inbreeding and line breeding in sugar gliders - 01/22/13 04:20 PM
I was looking for a discussion about this but couldn't find one.
I was hoping to start a discussion about this to see why inbreeding is bad and why it's not done in gliders.
Please add input. If speculating or hypothesizing, please STATE that. If you have scientific evidence, please cite.
Here is my understanding
I breed mice and rats. Inbreeding is done extensively to strengthen the lines and ensure you are selling PURE healthy lines.
The basis of this is, breed one pair of mice a couple times and get healthy litters,
Breed the babies back to dad and get some babies with a genetic deformity. Test with mom and get none. With that, you will KNOW that dad carries a hidden recessive trait for that deformity.
Breed the same babies back to mom and get zero genetic deformities.
Then, take those babies and breed them back to mom again. Still clear of any genetic deformities? Great, now breed them to mom one more time or go directly to breeding to each other for several generations.
Pair the male and female mice from that litter 1.1 and produce litters.
To TEST to see if any of those offspring carry that same genetic defect, breed back to the KNOWN carrier (AKA Dad).
If several litters show clean, cull those test litters and continue working with the clean line.
You've successfully eliminated a dangerous genetic deformity that out-crossing COULD have hidden for GENERATIONS AND GENERATIONS.
I've seen this done, done this type of breeding myself, and know that it works. Additionally, I believe (though I can't find the article anymore) that this is how lab rats and mice came around. They were selectively bred for large litters and elimination of genetic deformities to create pure lines to work with in a lab.
Now, I understand with mice and rats you are able to do this a lot more and a lot better due to the high production rate, where-as, with gliders, producing 4-6 babies a year or less, makes it hard.
Couple that with the reproductive age of 1 year for females and it makes it A LOT HARDER to do the same with gliders.
But, since gliders can produce for quite a few years (and have a much longer lifespan than that of a mouse or rat), you MAY be able to accomplish the same thing if you work toward it and plan things accordingly.
I have seen the kinship chart on gliders (though I don't know what scientific research was done to create that chart, so if anyone has cited experiments I'd love to see the reports on those experiments )
My concern is, how do we know there isn't some horrible genetic disease lurking in the recessives of our gliders that hasn't been expressed yet, but after years of out crossing, now every line has been exposed to this genetic disease and after years of work on a line, it pops up?
There's no guarantee that the recessive would show up first, second, or third time breeding to another WITH that recessive, but that doesn't mean it doesn't carry that gene. (look at breeding a leu to a het, you could breed them 4 times and still not get any leus, though statistically you would get 50% leus. It doesn't always happen that way!)
Now it's back to the drawing board and you need to scrap years of out-crossing in order to try something different to produce healthy animals.
Here's an experiment you can easily do at home to describe breeding hets to leus and the 50% leu baby thing.
Take a quarter. Flip it 10 times. How many heads and how many tails? was it exactly 50%? Try it 20 times, 50 times, 100 times?
I went 25 times almost all heads.
This helps people understand the recessive thing more.
ANYWAY, I know inbreeding within this community is a "NO NO" and I hope I'm not BEHEADED and thrown to the sharks for posing this question and having a slight difference of opinion, but I'd like to discuss this since I think it's important to the future of our gliders and the lines.
We have only been breeding gliders for around 20-30 years, so our knowledge of these animals is VERY little and limited. I think we have a lot to learn and posing questions like this will better help our understanding and maybe get us thinking some more.
Look at all the information we are discrediting every day on Glider Central Fact or Fiction. Look how many times the appropriate and best diet has changed.
I was hoping to start a discussion about this to see why inbreeding is bad and why it's not done in gliders.
Please add input. If speculating or hypothesizing, please STATE that. If you have scientific evidence, please cite.
Here is my understanding
I breed mice and rats. Inbreeding is done extensively to strengthen the lines and ensure you are selling PURE healthy lines.
The basis of this is, breed one pair of mice a couple times and get healthy litters,
Breed the babies back to dad and get some babies with a genetic deformity. Test with mom and get none. With that, you will KNOW that dad carries a hidden recessive trait for that deformity.
Breed the same babies back to mom and get zero genetic deformities.
Then, take those babies and breed them back to mom again. Still clear of any genetic deformities? Great, now breed them to mom one more time or go directly to breeding to each other for several generations.
Pair the male and female mice from that litter 1.1 and produce litters.
To TEST to see if any of those offspring carry that same genetic defect, breed back to the KNOWN carrier (AKA Dad).
If several litters show clean, cull those test litters and continue working with the clean line.
You've successfully eliminated a dangerous genetic deformity that out-crossing COULD have hidden for GENERATIONS AND GENERATIONS.
I've seen this done, done this type of breeding myself, and know that it works. Additionally, I believe (though I can't find the article anymore) that this is how lab rats and mice came around. They were selectively bred for large litters and elimination of genetic deformities to create pure lines to work with in a lab.
Now, I understand with mice and rats you are able to do this a lot more and a lot better due to the high production rate, where-as, with gliders, producing 4-6 babies a year or less, makes it hard.
Couple that with the reproductive age of 1 year for females and it makes it A LOT HARDER to do the same with gliders.
But, since gliders can produce for quite a few years (and have a much longer lifespan than that of a mouse or rat), you MAY be able to accomplish the same thing if you work toward it and plan things accordingly.
I have seen the kinship chart on gliders (though I don't know what scientific research was done to create that chart, so if anyone has cited experiments I'd love to see the reports on those experiments )
My concern is, how do we know there isn't some horrible genetic disease lurking in the recessives of our gliders that hasn't been expressed yet, but after years of out crossing, now every line has been exposed to this genetic disease and after years of work on a line, it pops up?
There's no guarantee that the recessive would show up first, second, or third time breeding to another WITH that recessive, but that doesn't mean it doesn't carry that gene. (look at breeding a leu to a het, you could breed them 4 times and still not get any leus, though statistically you would get 50% leus. It doesn't always happen that way!)
Now it's back to the drawing board and you need to scrap years of out-crossing in order to try something different to produce healthy animals.
Here's an experiment you can easily do at home to describe breeding hets to leus and the 50% leu baby thing.
Take a quarter. Flip it 10 times. How many heads and how many tails? was it exactly 50%? Try it 20 times, 50 times, 100 times?
I went 25 times almost all heads.
This helps people understand the recessive thing more.
ANYWAY, I know inbreeding within this community is a "NO NO" and I hope I'm not BEHEADED and thrown to the sharks for posing this question and having a slight difference of opinion, but I'd like to discuss this since I think it's important to the future of our gliders and the lines.
We have only been breeding gliders for around 20-30 years, so our knowledge of these animals is VERY little and limited. I think we have a lot to learn and posing questions like this will better help our understanding and maybe get us thinking some more.
Look at all the information we are discrediting every day on Glider Central Fact or Fiction. Look how many times the appropriate and best diet has changed.