"Orthologous" refers to genes that are similar in different species and descended from a common ancestral gene. These genes usually perform similar functions in the different species, despite some differences in their DNA sequences. Full definition
Using data from the National Center for Integrative Biomedical Informatics (NCIBI)'s MiMI: (Michigan Molecular Interactions) which contains data from IntAct, DIP, BIND and others, we identified conserved and predicted novel protein - protein interactions (interologs or interologues) in human, mouse, fly, worm, and yeast based on interaction of orthologous proteins found in the other organisms. (ccri.uthscsa.edu)
Inferring nonneutral evolution from human - chimp - mouse orthologous gene trios. (nielsenlab.org)
It is important to realise that the ancestral element - based approach has its limits, as orthologous sequences between species have the potential to diverge beyond recognition. (journals.plos.org)