Genetic mapping of the polycystic kidney gene, pcy, on mouse chromosome 9

The murine polycystic kidney disease gene, pcy, is an autosomal recessive trait located on chromosome 9. To determine the genetic locus of pcy, 222 intraspecific backcross mice were obtained by mating C57BL/6FG-pcy and Mus molossinus. Restriction fragment length polymorphism analysis of 70 of the 222 backcross progeny showed that pcy, dilute coat color (d), and cholecystokinin (Cck) were located in the order d--pcy--Cck from the centromere. Simple sequence repeat length polymorphism analysis of DNA of all 222 backcross mice was carried out using four markers which were located near the central regions of d and Cck. One and eight recombinations were detected between D9Mit24 and pcy and between D9Mit16 and pcy, respectively. However, no recombinant was observed among pcy, D9Mit14, and D9Mit148. These findings strongly suggest that D9Mit14 and D9Mit148 are located near the pcy gene and are good markers for chromosomal walking to this gene.