cross) generation and the three parental strains mentioned above. The SSCP typing results for amplification of these DNAs with the Mobp primers can be seen in Fig. 1. These data were then entered into a Genelink analysis program (Montagutelli 1988) containing the N2 typing data for each anchor marker utilized in the generation of these lines. The segregation pattern implicated Chr 9 alone. A EUCIB subset panel of 8 DNAs was selected from the Mbx database, and SSCP typing was carried out. The recombination events between anchor markers for these DNAs had been well characterized and subdivided Chr 9 into four regions. The segregation pattern observed for Mobp (Table 1) implicated the region