PCR-screening of YAC contig between markers D10S191 and D10S548. (A) The inferred position of the cubilin gene (designatedCUB) between D10S1661 and WI-5445. The individual YACs and their genetic marker content (x) are arranged essentially as in the Whitehead WC10.1 contig. (B) Agarose gels aligned to the individual YAC clones, with CUB-specific PCR fragments corresponding to YACs 956a7 and 917b1. The bottom lane is genomic test DNA. The incorrectly sized PCR fragment in lane 721g12 is scored as negative (see text).