Fig. 5. Chromosomal location of microsatellite markers selected for analysis of phenotypic pools in the first level screen. Marker positions were obtained from the microsatellite map distributed by the MIT mouse genome database. All SSLP markers colored in both black and gray are employed in the N2 analysis. Black markers represent a heterozygous (B6/CBA) and gray markers represent a homozygous (B6/B6) allele in the N2 male. Black SSLP markers representing heterozygous (B6/CBA) allele are used in the N3 mapping analysis.