GENETIC-MAPPING OF THE POLYCYSTIC KIDNEY GENE, PCY, ON MOUSE CHROMOSOME-9

The murine polycystic kidney disease gene, pcy, is an autosomal recess ive trait located on chromosome 9. To determine the genetic locus of p cy, 222 intraspecific backcross mice were obtained by mating C57BL/6FG -pcy and Mus molossinus. Restriction fragment length polymorphism anal ysis of 70 of the 222 backcross progeny showed that pcy, dilute coat c olor (d), and cholecystokinin (Cck) were located in the order d-pcy-Cc k from the centromere. Simple sequence repeat length polymorphism anal ysis of DNA of all 222 backcross mice was carried out using four marke rs which were located near the central regions of d and Cck. One and e ight recombinations were detected between D9Mit24 and pcy and between D9Mit16 and pcy, respectively. However, no recombinant was observed am ong pcy, D9Mit14, and D9Mit148. These findings strongly suggest that D 9Mit14 and D9Mit148 are located near the pcy gene and are good markers for chromosomal walking to this gene.