DNSSEC between two topologically disjoint domains - ?

[lejeczek]

hi everyone,

I want to ask if it's possible setup and if so then how,
IPA's DNSes forward directly to each other (let be only two
or however many you might have) while those IPAs "fqdn" are
"disconnected" - and all this without disabling DNSSEC? In
most basic example: private.dom <=> domain.priv

many thanks, L.