Schematic representation of the hop-1 and sel-12 loci in wild-type (+) and deletion-containing animals. Solid boxes represent coding sequences, open boxes represent 3′ untranslated sequences, and lines represent extragenic sequences (6, 7). (A) F1, F2, R1, and R2 denote the approximate locations of the nested PCR primers used to identify the nr2003 deletion. The extent of the nr2003 deletion is indicated by the gap. (B) Primers used to identify the nr2011 deletion are designated as in A. The extent of the nr2011 deletion is indicated by the gap. See text for deletion endpoints.