FIG. 1.

Isolation of a YAC carrying the Gr gene. (A) Structure of the unmodified YAC YGR4 and the shortened YAC YGR290. The position of the Gr gene on the YAC and its exon-intron structure (enlarged) is indicated. (B) Restriction analysis of YGR4 by digestion with the rare-cutting enzymes SfiI and NotI, PFGE, and Southern blotting with probes for GR exons 2 and 8. Alignment of fragments is shown in panel A. (C) PFGE and Southern blot analysis of YACs obtained after B1 fragmentation. The position of the original YAC YGR4 and its shortened derivative YGR290 are indicated by an arrow.