Polymorphism in Pg-1 (urinary pepsinogen-1) locus in the rat and its linkage analysis

Cramer (1981) reported that Pg-1 (urinary pepsinogen) in the rat was loosely linked with albinism in the linkage group I. We performed a three point test on the loci of pg-1, c, and Hbb. We could reconfirm that pg-1 was autosomal trait with two co-dominant alleles of pg-1a and pg-1b. But in progeny of ((WF X IS) X WF) backcross, pg-1 was linked to neither c nor Hbb, while a close linkage between c and Hbb was detected. Also pg-1 was not linked to Mup-1 (LG II), a (LG IV), Es-3 (LG V), and h (LG VI). pg-1 will be one of the most valuable genetic markers of the rats, since pg-1 was highly polymorphic among inbred strains of rats, and not linked to LG I, II, IV, V, and VI.