Would it be a problem to breed two Mosaics? That might sound like a stupid question but I know that in some breeds of dogs that have the merle/dapple coloring, you shouldn't breed two merle/dapples. I heard it causes health problems, blindness, and pups that are deaf or go deaf within the first year.
Are there any times that you can't breed when using the same morph?

Other than the potential for inbreeding, (be very careful about your lineages) I don't know of any genetic problems that could result.

I think the only reason people don't breed mosaic to mosaic is that you don't have to breed them together to get more mosaics. It's financially friendlier to breed a mosaic to a standard.

Just be sure that two potential mates' lines are far enough apart so that you don't inbreed.

That is what popped into my head at first but I just wanted to be sure. Do you know the percentage of joeys in each litter that turn out to be mosaic with standard/mosaic vs mosaic/mosaic?

There isn't anyway to tell you that answer.

I have a mo/wfb pair that has had 4 joeys, 2 mosaic, 2 wfb. Some mosaics have mos almost every time, some rarely.

Ok, thank you for the answers.

As Dancing said, there is no way to guarantee any outcomes but your odds would depend on whether the mosaic (or mosaics if you are using two) have one or two copies of the mosaic gene. Generally, your odds using one mosaic parent would be 50% chance that each baby would be a Mosaic but if you used two mosaics your odds should be 75% chance that each baby will be a Mosaic. Those odds do depend on whether or not the Mosaic(s) in the pair carry one or two copies of the gene though but unless the mosaic parent is the offspring of two mosaics itself then it would only carry one copy and those odds would apply.

Many people make the mistake of seeing the odds as half the babies should be Mosaic or look at the punnett square as showing that a certain number out of every 4 babies should be a specific morph but that is incorrect. if the odds are 50% or the punnett square shows 2 out of 4 babies as a specific morph you should be looking at that as meaning that EACH AND EVERY baby that is produced has those same odds. Its not that half the babies should be mosaic, its that every single Joey has a 50% chance of being mosaic and that is why you cannot predict a specific ratio for the babies.

If you would like me to outline the odds in much greater detail according to whether or not the parents have one or two copies let me know but unless it is specifically requested I will keep it simple.

So in reality, each joey from a mosaic would have a 50/50 chance of being mosaic? Why does a mosaic/mosaic pairing only have a 75% chance? Wouldn't the odds be doubled when you double the gene given from the parents?
If the mosaic didn't come from a mosaic/mosaic pairing, that means he only passes half mosaic genes?
Sorry, my brain is a little fried lately. I just got home from seeing my new baby niece (2 days old) and I haven't gotten much sleep the past couple days so it's taking a little while for me to absorb.

Each glider has 2 alleles. If you had 2 gliders who each had one mosaic gene and one normal gene then you have a 25% chance of getting a normal Joey, a 25% chance of getting a mosaic Joey with 2 mosaic genes, and a 50% chance of getting a mosaic with one mosaic gene and a normal gene. The only way you could guarantee that all joeys are mosaic is if you had one parent who had both mosaic genes, mated with a standard grey or any other color. And the only way to get this mosaic with 2 mosaic genes is to breed 2 mosaics together.

Right on Shannon!!


Here is a punnet square diagram to help you out a bit...

If each Glider has 2 alleles that make up each trait and the allele for normal is NN and the allele for Mosaic is lowercase m then

If you paired a normal NN with a mosaic that had one mosaic allele and one normal allele Mm then you would get 50% chance for normal babies NM and 50% chance for mosaics with one mosaic allele Nm, otherwise known as heterozygous mosaic (they are NOT hets FOR mosaic, they are Mosaics with ONE morph allele which is referred to as heterozygous state)

M m

N NM Nm

N NM Nm


If you paired two Mosaics together that both carried only one Mosaic allele then you would get 25% chance for normal MM, 50% chance for mosaics with one mosaic allele Mm, and 25% chance for mosaics that carry two copies of the mosaic gene and are known as homozygous because they carry a pair of the mutant gene. The heterozygous mosaics that only carry one gene can produce both normals and mosaics but the mosaics that are homozygous and possess two copies of the mutant gene can only pass on the mutant gene meaning they will only produce mosaics. This is similar to what is being called the super WFB that only produces WFB offspring.

M m

M MM Mm

m Mm mm


If you paired a mosaic with two copies of the mosaic gene with a mosaic with only one copy you would get all mosaic babies and 50% would carry one copy and 50% would carry two copies.

m m

M Mm Mm

m mm mm


If you paired two mosaics together that both carry two copies of the gene all the offspring would carry two copies of the gene.

It gets pretty confusing but it can be figured out pretty easily. The odds don't just double though simply because both parents are the same morph. Just to be clear though, there are NO hets FOR mosaic, there are only mosaics that have one or two copies of the mutant gene. There is no such thing as a standard grey that carries the mosaic gene. Also, there is absolutely no way to tell visually between a mosaic with one copy of the gene and a mosaic with two copies of the gene. You would know for sure what its genotypic makeup is only be breeding it out OR if only one parent is a mosaic and that parent had only one mosaic parent itself.

Ok, I think I have it figured out now. It is pretty confusing but I've read over your posts for 30 minutes. You would need to pair two mosaics with at least one parents having two copies of the gene to ensure all mosaic babies?
Please be easy on me! lol I'm entirely new to the entire genetic side of morphs but it fascinates me.

You could either pair two mosaics, with at least one of them having two copies of the gene OR you could use one mosaic but it would have to be a homozygous mosaic (possess two copies). You are starting to catch on!! Don't worry I know it can be extremely overwhelming but eventually it will start to get much easier to figure out. I just wanted to mention though, myself along with many other breeders don't recommend breeding mosaic to mosaic generation after generation because it limits the genetic variation and along with a homozygous mosaic you will also greatly increase the chances of genetic flaws, just wanted to mention that as a general caution to anyone

I have it now. Thanks so much. I'm still a long way away from actually breeding a mosaic but I just wanted to dip my feet so I could get all the info on genetics I could before I even started to think about breeding.