“…Upon the mapping of the Y chromosome on the phylogeny proposed by Lindblad-Toh et al, (2005), it is observed as a bi-armed chromosome in the Canis clade and the genera Otocyon and Nyctereutes. Both Canis familiaris (Linnaeus, 1758) and the two Nyctereutes procyonoides subspecies have a Y chromosome whose short arms are not heterochromatic, and are the only species in the family presenting nucleolar organizer regions in this chromosome (Mäkinen et al, 1986;Pieńkowska and Świtoński, 1998;Switonski et al, 2003). Both characteristics could be the result of a pericentric inversion and transposition events, respectively.…”