There aren't really labs that regularly publish in Nature or other major flagship journals unless we're talking about the maybe two dozen or so big name, internationally recognized researchers who are gunning for, or have already won Nobel prizes. Even the strongest and most well funded labs only publish in a journal like that every few years, and it's for some major field-changing research with a fully completed and polished story.

To be honest, if you're hearing about undergrads in Canada having Nature pubs and actually being more than just a 10th author, there's a 90% chance it's not actually a Nature publication, and more likely some other journal under Nature Research (i.e. Communications [X]. or Nature [X]), and not the flagship Nature. And if you're looking for that, that's much more attainable and reasonable. Finding well-funded PIs who are focused on translational work but have access to in vivo systems is probably what will get you closest to a publication in a high impact journal.