Spotted Pups from two Solid Parents

[Moon Breeze]

I didn't think this was possible, but it happened and I'm incredibly curious to know how the genetics happened on this one. 

Mom: Nerthis, Solid Nutmeg with genes aa CC DD ee PP UwUw 
Breeding History: three previous litters with two different fathers, all solid colored pups 

Dad: Loki, Solid Burmese with genes aa c[hm]c[hm] DD Ee P* UwUw
Breeding History: five previous litters with two different mothers, all solid pups except when paired with a spotted mother

There were five pups with this litter born on 6/26/2015 and with their peach fuzz coming in, I have two with clearly white spotting! What kind of Sp gene would each gerbil need to produce spotting from two solid parents?

[betty]

Have you got any pictures of the spots - as Schimmel pups sometimes have just a single forehead spot?

[betty]

Also the numbers of pups in the litters could help as pups in earlier litters could have been spotted but passed early on... Just trying to rule out all the obvious things first. Very interesting otherwise.


FYI - I have had 2 spotted parents have all solid pups in one litter of 4 - and I have also had spotted pups from a Spotted CP Agouti with barely any visible spotting herself... (we could only tell afterwards from her toenails)...

[Shooting Star]

There is no known recessive spotting gene in gerbils. At least one parent *must* be spotted to produce spotted pups. Does either of your parents have clear nails?