I am using MEGA 6 to build a phylogenetic tree using five genes. They were already aligned separatelly using MUSCLE, but now I don't know how to continue....
You should concatenate your sequences from the two genes. You can use DnaSP software to do so. Then export the concatenated file from DnaSP in FASTA or MEGA format.
Please note that your two FASTA files to be concatenated must have the same number of sequences and in the same order.
DnaSP will generates the concatenated data file that you should use in MEGA.
Well, so what if the sequences of different genes we put into MrBayes or PAUP softwares into different partions, does it work the same as concatenated datasets?