A colour/genes question for Pod. (Though anyone can look!)

Just wondering if you can help me. I'm looking into Sires for Isla's pups and have tried my best to work out what colours would occur if she was mated to a Liver and White.

My understanding is that Black is dominant, so have tried my best to work it out myself, but wondered if you could give me your thoughts instead?

Isla is Black and White, both her parents were B/W but her litter consisted of 3 B/W and 2 L/W.

I think I have an idea of what would result from Isla being mated to a Liver, but I'd like to see what the expert thinks first!

Thanks to all that attempt this!

In Dalmatians where you get the same two colour variants, liver is a recessive gene; a dog may be black dominant (B) or not (b). We would always get all liver in a liver to liver mating, but Deccy's dad is black, mother liver and the litter was mixed. However, you can breed black to black and still get some liver, although I never managed it!
If you know any Dally people with Patches Silverstone's book of the breed (Dalmatians Today) there is a chapter where this is explained very well although mostly above my head I'm afraid!

My Poppy is blue roan - from an all blue dad line, she was mated to a blue roan dog, they had 6 pups 2 of which were orange, the stud dog owner, who is very good in predicting colours, was completely shocked that she produced 2 orange, there was definitely no chance of her being mated by another dog as we don't have dogs only bitches.

Genetics can be very confusing

I'm assuming Isla is a ESS! As she had L/W siblings this means that both her parents carry the Liver gene (bb) she therefore has a 50% chance herself of carrying the Liver gene. However, mating her to a Liver dog would mean that each puppy has a 50% chance of being either B/W or L/W if she carries the Liver gene.
Does that make sense?
Becky

Yes, the above (inc Deccy's post) is correct except that Isla has a 66.6% chance of carrying liver not 50%. It would be 50% if just one parent was a carrier but we know both parent are as Mahooli has explained.

Mated to a liver & white......if she is carrier (Bb) then each pup born has a 50:50 chance of being black or liver (as above) but you also have to consider tricolour which is carried as a recessive to solid.

This is on the K locus, which makes it a bit more confusing, because this gene has the effect of disguising the A locus pattern but what it boils down to is that, if both parents carry the 'potential' for tricolour (Kk), then each pup born has a 25% chance of this. This will turn a black & white or a liver & white into a black tri or liver tri.

If she doesn't carry liver or tri, then you will just get black & whites whatever you mate her to.

ps: also assuming Isla is an ESS

The orange colour is carried on a different locus to black/liver... it's the E gene. ee is the recessive that produces red/golden/orange/lemon in Cockers and many other gundog breeds.

Black is dominant over orange, so any black or blue roan (or B&T and tri) dog has the chance of carrying orange/red.

Poppy is obviously Ee and also the blue roan sire too, both carriers of orange/red.

Pod, you never cease to amaze me with your knowledge of genetics. How do you carry all that info and knowledge around in your head without your brain going into overload?
I will be definately consulting you 'the oracle' very soon as I too will having a type of 'colour crisis' when I breed from Maelona!

How can it be 66.6% chance? As both parents carry liver that means they are Bb (ignoring the parti gene and tan pointing gene which are separate)
so that means you get 25% BB 50% Bb and 25% bb, where does the 66.6 come from?
Becky

Ok, I'll try to explain, bear with me

The ratio from two carrier parents is - 1:2:1 which is -

25% BB (black) 50% Bb (black) 25% bb (liver)

Now you can discount the livers because we can see them. Isla is black, so she is definitely not bb.

We are left with the blacks in the ratio of 2:1 which equates to 2/3 Bb and 1/3 BB which is 66.6r:33.3r.

Does that make sense?

Yikes, I'm no expert TW, you should read some of the genetics list I go to