Comparative autosomal linkage in mammals: genetics of esterases in Mus musculus and Rattus norvegicus

Abstract

Recombination between Esterase 4 and Esterase 2 in the rat was not observed in 278 backcross offspring. Es 4 is thus included within the 'esterase cluster' in Linkage group V. A new map of this region was constructed and the relationship of the four esterase loci was found to be: Es 4 (9.6 ± 1.6 cM) Es 2, Es 4 (1.5 ± 0.7 cM) Es 3. Homology of this region with a region of Linkage Group XVIII (Chromosome 8) of the mouse was proposed on the basis of tissue distribution, subcellular localization and response of enzymes to inhibitors. Specifically, rat Es 1 was suggested as the homolog of mouse Es 2, rat Es 2 as the homolog of mouse Es 1, and rat Es 4 as the homolog of mouse Es 6. An autosomal segment comprising at least 15 cM of the rat and mouse genomes appears to have remained relatively intact with respect to genetic content during rodent speciation. In addition, a new polymorphism for mouse esterase was described. The locus was designated Esterase 10 (Es 10) and proposed as the mouse homolog of human Esterase D. Linkage of Es 10 with nucleoside phosphorylase 1 (Np 1) on Chromosome 14 was established.