The MEGA format allows you to assign different taxa to groups in a sequence as well as to distance data files. In this case, the name of the group is written in a set of curly brackets following the taxa name. The group name can be attached to the taxa name using an underscore or just can be appended. It is important to note that there should be no spaces between the taxa name and group name. (Note that the groups of taxa can also be defined interactively through a dialog box.) In the following, we show an example in which human and mouse are designated as the members of the group Mammal and chicken belongs to group Aves.
!Gene=FirstGene Domain=Exon1 Property=Coding;
#Human_{Mammal} ATGGTTTCTAGTCAGGTCACCATGATAGGTCTCAAT
#Mouse_{Mammal} ATGGTTTCTAGTCAGGTCACCATGATAGGTCCCAAT
#Chicken_{Aves} ATGGTTTCTAGTCAGCTCACCATGATAGGTCTCAAT
!Gene=SecondGene Domain=Intron Property=Noncoding;
#Human ATTCCCAGGGAATTCCCGGGGGGTTTAAGGCCCCTTTAAAGAAAGAT
#Mouse GTAGCGCGCGTCGTCAGAGCTCCCAAGGGTAGCAGTCACAGAAAGAT
#Chicken GTAAAAAAAAAAGTCAGAGCTCCCCCCAATATATATCACAGAAAGAT
!Gene=ThirdGene Domain=Exon2 Property=Coding;
#Human ATCTGCTCTCGAGTACTGATACAAATGACTTCTGCGTACAACTGA
#Mouse ATCTGATCTCGTGTGCTGGTACGAATGATTTCTGCGTTCAACTGA
#Chicken ATCTGCTCTCGAGTACTGCTACCAATGACTTCTGCGTACAACTGA