Fig. 2.

PCR identification of the hr allele. This shows the reverse image of an ethidium bromide-stained agarose gel of PCR products that identify the retroviral insertion in the Hr locus described for the hr allele. Primers employed were 5′-CAAGCCTTATTCGAACTAAC-3′ located within the retroviral insertion and 5′-AGATTTAACACAGGTGCTAG-3′ located in mouse genomic DNA. The presence of the 439 bp specific band in genomic DNA from SKH1 outbred and SKHIN inbred mice indicates that they carry the hr hypomorphic allele. The band was absent when C57BL/6 DNA was used in the reaction. We confirmed by direct sequencing that the PCR product contained retroviral sequences. The arrow indicates the position of the 400 basepair DNA size standard.