It has been shown that a major gene, called RN, is responsible for the RTN technological yield, a meat quality porcine trait. Experimental families informative for the segregation of RN gene were constituted from animals belonging to the Laconie composite line. We have previously mapped the RN gene to Chromosome (Chr) 15 (Milan et al. Genet. Sel. Evol. 27, 195-199, 1995). A Chr 15 map was established with 16 markers. The RN gene was found to be located between markers Sw120 and Sw936, at 2 cM from Sw936 (LOD = 38.1). In addition, by localizing Sw936 at 15q21-22 using DISC-PCR, we also located RN on the physical map.