The unikonts have a triple-gene fusion that is lacking in the bikonts. The three genes that are fused together in the unikonts but not bacteria or bikonts encode enzymes for synthesis of the pyrimidinenucleotides: carbamoyl phosphate synthase, dihydroorotase, aspartate carbamoyltransferase (Cavalier-Smith 2006). This must have involved a double fusion, a rare pair of events, supporting the shared ancestry of Opisthokonta and Amoebozoa.
The unikonts have a single centriole (Cavalier-Smith, 2002, 2006). Some unikonts have two centrioles but their origins are developmentally different than in the bikonts, indicating convergent evolution (Cavalier-Smith 2006).
Cavalier-Smith, Thomas (2006). "Protist phylogeny and the high-level classification of Protozoa". European Journal of Protistology39 (4): 338-348. ISSN0932-4739.
Stechmann, Alexandra; Cavalier-Smith, Thomas (2003). "The root of the eukaryote tree pinpointed". Current Biology13 (17): R665-R666. doi:10.1016/S0960-9822(03)00602-X. ISSN0960-9822.