| Bottom up genomic analysis generates many, small, expressed sequence tagged sites (ESTS). These ultrashort segments do not lend themselves to physical mapping of the genome using conventional in-situ hybridization. Their small size prevents adequate visualization of signal location on the chromosomes, even when using fluorescent tags.; DISC-PCR is a technique that uses the power of the polymerase chain reaction to amplify these short segments while incorporating a biologic tag to the product for microscopic detection and visualization.; This technique was used to map eight, type I genetic loci to their respective sub-chromosomal regions. Placental/Endometrial, type II aromatase P (CYP 19) was mapped to porcine chromosome 1, FLPter 0.6. Two, SLA sites (DQβ and TNFα) were mapped to porcine chromosome 7 at FLPter 0.4 and 0.3 respectively supporting that the SLA complex spans the centromere. Fucosyltransferase 1, (Fut1) maps to porcine chromosome 6, at FLPter 0.4. Superoxide dismutase (SOD1) maps to FLPter 0.4–0.5 on the p arm of porcine chromosome 9. Syntenic variances between SSC 13 and HSA 3 were detected by mapping the order of cholecystokinin (CCK), mucin (muc4), and myxovirus resistance gene, (Mx1) to FLPter 0.2, 0.4, and 1.0 respectively on porcine chromosome 13.; The technique was modified at pre-PCR, PCR, and post-PCR detection steps. Post-PCR detection steps were the most rewarding, supporting that a more sensitive detection scheme could reveal signal that had likely been present but not detected using other or original means. |
