Rapid communication: Microsatellites isolated from BAC clones containing v-akt1 murine thymoma viral oncogene homolog 1 and bradykinin receptor B2 assigned to sheep chromosome 18 by linkage analysis.

Genus and Species. Ovis aries. Locus. Ovine DNA segment OarTMR1 associated with ovine v-akt1 murine thymoma viral oncogene homolog 1 (AKT1) and ovine DNA segment OB2 associated with ovine bradykinin receptor B2 (BDKRB2). Source and Description of Primers. Primers for AKT1 (GenBank accession no. AF207873) were obtained from Scott Fahrenkrug, USDA-MARC, Clay Center, Nebraska, and were sent to Daniel Vaiman, INRA-Jouy, France, to isolate two positive clones from an ovine BAC library that had an average insert size of 123 kb (Vaiman et al., 1999). The procedure of Munroe et al. (1994) was used to identify microsatellite repeats in these clones and primers were designed for an AC-repeat designated OarTMR1. Primers (OarTMR1 forward: 5′-GCCGCTGGTTCCTCCTCCA-3′ and OarTMR1 reverse: 5′-CAGAGCCCTGCGTCCATCTT CT-3′; GenBank accession no. AF224742) were used to amplify the DNA microsatellite OarTMR1. Primers for BDKRB2 (GenBank accession no. AF207860) were designed and used by Scott Fahrenkrug, USDA-MARC, Clay Center, Nebraska, to isolate the DNA microsatellite OB2 (GenBank accession no. AF207876) from a positive clone from an ovine BAC library with an average insert size of 103 kb (Gill et al., 1999). Primers (OB2 forward: 5′-CTGCCCGATCCTTCTGCTT-3′ and OB2 reverse: 5′-AAAGGGGCAGATTCAGTATCCA-3′) were used to amplify the DNA microsatellite OB2. Method of Detection. Standard PCR conditions were used to amplify both microsatellites, using 33P-labeled reverse primers, Gibco BRL Taq DNA polymerase and buffers (Life Technologies, Grand Island, NY), and 2 mM MgCl2 in a touchdown procedure (Crawford et al., 1995). The PCR products were separated by standard high-voltage electrophoresis in 6% polyacrylamide gels and visualized by autoradiography on Kodak (Rochester, NY) XAR5 x-ray film.