Does IIS 7.5 use a separate "AppDomain" for each subdomain?

Within an IIS worker process, separate sites (i.e. domains) run in their own app domain.

I have a site example.com which has a wildcard DNS record (i.e. *.example.com pointed to an IP.) Will processing for a subdomain resource z.example.com be isolated into a separate appdomain from handling of requests for www.abc.com? I think the answer must be yes, but can't find anything definitive