While this thread seems to be concentrating on 'kveik' yeasts at the moment, I thought I'd go back to the original question (ale yeast for lagers?) and bring up some interesting information about one of the commonly used homebrew lager strains: WLP800.
WLP800 is supposedly a lager yeast, and the Pilsner Urquell strain. Interestingly, this strain was included in a recent genome sequencing study (
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4825664/) by an Australian research group, and they found that WLP800 is actually not a lager yeast (
Saccharomyces pastorianus (
Saccharomyces cerevisiae x
Saccharomyces eubayanus)) at all, but rather a 'pure'
S. cerevisiae strain. So users of WLP800 have all along been brewing with an ale yeast when they've been making lagers. Whether this is the same strain that is used for Pilsner Urquell or not is unclear and a completely different question.
White Labs and the Verstrepen lab published their own genome sequencing study (
https://www.ncbi.nlm.nih.gov/pubmed/27610566) last year as well, and in it they looked at the geno- and phenotypes of 157
S. cerevisiae strains. Unfortunately, the strain names are encoded and it is unclear what strain numbers correspond to what White Labs strains. I've done some decoding (for more information you can visit my blog; see signature) of a number of the strains in the study using sequence data of White Labs strains from other studies (including the Australian one mentioned above), and WLP800 seems to be included as Beer087. Interestingly, Beer087 seems to be closely related to Beer073, a strain which appears to be WLP320 American Hefe (not confirmed by DNA evidence, but other evidence suggests this; again check the blog). According to the publication, Beer087/WLP800 and Beer073/WLP320 are not only genetically similar, but they also seem phenotypically very similar (e.g. very similar ester profiles and growth temperature ranges). This would suggest that you can make a nice lager with WLP320 as well (especially if you use the lower temperatures that are normally used with WLP800).
Sorry for the long post, but hopefully someone found it interesting.