** Authors ** Salvador Capella-Gutierrez. Comparative Genomics Group. Bioinformatics and Genomics Department. Centre for Genomic Regulation. Barcelona, Spain. e-mail: scapella _at_ crg.es Toni Gabaldón. Comparative Genomics Group. Bioinformatics and Genomics Department. Centre for Genomic Regulation. Barcelona, Spain. e-mail: tgabaldon _at_ crg.es ** Authors (until trimAl v1.1) ** Jose Ma. Silla-Martínez. e-mail: josilma1 _at_ gmail.com