“…The juxtaposition of 45S and 5S fluorescent-based signals in dividing cells or interphase nuclei, as observed by FISH, has traditionally been used as putative evidence for the linkage of 45S and 5S rRNA genes in plants. In seed plants, FISH colocalization of both multigene families has been observed not only in the Asteraceae (García et al, 2010), but also in other unrelated angiosperm lineages such as Tulipa (Mizuochi et al, 2007), Rhoeo (Golczyk et al, 2005), Linum (Muravenko et al, 2004), Silene (Široký et al, 2001), Brassica (Snowdon et al, 2000;Hasterok et al, 2001), as well as in a couple of gymnosperm genera: Ginkgo (Nakao et al, 2005) and Podocarpus (Murray et al, 2002). However, given the shortcomings of the axialresolution detection limits of classical FISH (between 2000 and 10 000 kb; Figueroa and Bass, 2010), such molecular cytogenetic methods could generate crude estimates or visual artifacts concerning the organization of the 45S and 5S rDNA families in plants.…”