“…FISH is a rapid and reliable technique for chromosome identifi cation, gene mapping, localisation of gene expression, and analysis of chromosome rearrangements in a wide variety of genomes. Different probes have already been applied successfully to species of the genus Crassostrea: telomeric sequences (Guo, Allen, 1997;Cross et al, 2005), satellite DNA (Clabby et al, 1996;, simple sequence repeats (Cross et al, 2005;Bouilly et al, 2008), ribosomal RNA genes (Zhang et al, 1999;Xu et al, 2001;Cross et al, 2003Cross et al, , 2005Wang et al, 2004Wang et al, , 2005a, and bacteriophage P1 clones (Wang et al, 2005b). DNA sequences of nuclear and mitochondrial genes (Boudry et al, 2003;Reese et al, 2008), including repetitive satellite DNA sequences (López-Flores et al, 2004) have been variously used to examine the phylogenetic relationships between oysters.…”