Hi Katie,
PartitionFinder will tell you which partitions should be analyzed
with different evolutionary models (like HKY versus GTR+Gamma etc.),
but assuming that all partitions evolved under the same tree
topology. In your case, I suggest that you use your 11 genes
separately as 11 different loci in BUCKY, because BUCKy assumes that
each locus is recombination-free (same tree topology for all sites
within the locus), and that different loci are unlinked. These
assumptions are probably reasonable for your 11 genes. But they are
probably not met for your 4 partitions, as one or more partition is
probably spanning 2 or more genes, with possible recombination
within that partition. So the BUCKy analysis on genes would be best.
If PartitionFinder suggests splitting a gene into 3 partitions, for
example based on codon position, then it is best to analyze this
gene as a single locus, but let MrBayes use the 3 partitions at that
locus (MrBayes assumes that the same tree topology is shared by all
3 partitions at that locus). Then later you can combine all the
MrBayes results from a bunch of genes to run BUCKy.
I hope that answered your question!
Cecile.