Fig. 1. Schematic representation of the Y chromosome of Drosophila melanogaster. From top to bottom: cytological localization of satellite DNAs (Bonaccorsi and Lohe, 1991; Lohe et al., 1993), Y chromosome diagram showing N-banding and Hoechst 33258 banding (Pimpinelli et al., 1976; Gatti and Pimpinelli, 1992), cytological localization of transposable elements (Pimpinelli et al., 1995; Berloco et al., 2005), Y chromosome diagram showing the cytological localization and organization of the fertility factors (Gatti and Pimpinelli, 1992), other genetic elements mapping on the Y chromosome (Gatti and Pimpinelli, 1992; Russell and Kaiser, 1993; Gepner and Hays, 1993; Carvalho et al., 2000; Carvalho et al., 2001).