RESISTANCE TO LEISHMANIA-MAJOR IS LINKED TO THE H2 REGION ON CHROMOSOME-17 AND TO CHROMOSOME-9

In Leishmaniasis, as in many infectious diseases, clinical manifestati ons are determined by the interaction between the genetics of the host and of the parasite. Here we describe studies mapping two loci contro lling resistance to murine cutaneous leishmaniasis. Mice infected with L. major show marked genetic differences in disease manifestations: B ALB/c mice are susceptible, exhibiting enlarging lesions that progress to systemic disease and death, whereas C57BL/6 are resistant, develop ing small, self-healing lesions. F2 animals from a C57BL/6 x BALB/c cr oss showed a continuous distribution of lesion score. Quantitative tra it loci (QTL) have been mapped after a non-parametric QTL analysis on a genome-wide scan on 199 animals. QTLs identified were confirmed in a second cross of 271 animals. Linkage was confirmed to a chromosome 9 locus (D9Mit67-D9Mit71) and to a region including the H2 locus on chro mosome 17. These have been named lmr2 and lmr1, respectively.