PIG MICROSATELLITES ISOLATED FROM COSMIDS REVEALING POLYMORPHISM AND LOCALIZED ON CHROMOSOMES

One of the most widely studied simple sequences in the mammalian genom e is the (TG)(n) dinucleotide sequence. Because these microsatellites are highly polymorphic, we chose to study microsatellites from cosmids to provide genetic markers for the porcine genome. After screening a porcine cosmid library with a (CA)(10) probe, 20 cosmids containing mi crosatellites were subcloned and 17 microsatellites identified by sequ encing. Oligonucleotide primers flanking the repeat were designed for seven (TG)(n) microsatellites with n > 14. These seven microsatellites revealed polymorphism and were regionally assigned to chromosomes by fluorescent in situ hybridization of initial cosmids. These seven loci will be useful for both the construction of the genetic map and as la ndmark loci on the physical map of the porcine genome.