LINKAGE GROUPS OF PROTEIN-CODING GENES IN WESTERN PALEARCTIC WATER FROGS REVEAL EXTENSIVE EVOLUTIONARY CONSERVATION

Among progeny of a hybrid (Rana shqiperica X R. lessonae) X R lessonae , 14 of 22 loci form four linkage groups (LGs): (1) mitochondrial aspa rtate aminotransferase, carbonate dehydratase-2, esterase 4, peptidase D; (2) mannosephosphate isomerase, lactate dehydrogenase-B, sex, hexo kinase-1, peptidase B; (3) albumin, fructose-biphosphatnse-1, guanine deaminase; (4) mitochondrial superoxide dismutase, cytosolic malic enz yme xanthine oxidase. Fructose-biphosphate aldolase-2 and cytosolic as partate aminotransferase possibly form a fifth LG. Mitochondrial aconi tate hydratase, alpha-glucosidase, glyceraldehyde-3-phosphate dehydrog enase, phosphogluconate dehydrogenase, and phosphoglucomutase-2 are un linked to other loci. All testable linkages (among eight loci of LGs 1 , 2, 3, and 4) are shared with eastern Palearctic water frogs. Includi ng published data, 44 protein loci can be assigned to 10 of the 13 chr omosomes in Holarctic Rana. Of testable pairs among 18 protein loci, a greement between Palearctic and Nearctic Rana is complete (125 unlinke d, 14 linked pairs among 14 loci of five syntenies), and Holarctic Ran a and Xenopus laevis are highly concordant (125 shared nonlinkages, 13 shared linkages, three differences). Several Rana syntenies occur in mammals and fish. Many syntenies apparently have persisted for 60-140 x 10(6) years (frogs), some even for 350-400 x 10(6) years (mammals an d teleosts).