Изучение генетической структуры роруояции монгольского сурка и некоторые проблемы чумы. A study on population genetic structure of Mongolian marmot and some problems of plague [ Izoutchenie genetitcheskoï strouktoury popoulyatsii Mongol'skogo sourka i nekeotorye problemy tchoumy. Une étude de la structure génétique de la population de marmotte de Mongolie et quelques problèmes liés à la peste].

Résumé

from serum proteins of Mongolian marmots were observed. The blood serum protein - haptoglobulin (Hp) of the Mongolian marmots with 3 hereditary phenotypes determined by HpS and HpF alleles, the Transferrin (Tf with 6 phenotypes, by TfK, TfL and TfM alleles, the Post-albumin (Pa) 6 phenotypes, by PaA, PaB and PaC alleles and the Albumen (Al) 3 phenotypes, by AlA and AlB alleles were observed and confirmed. The mean frequencies of the observed alleles for Mongolian marmots are shown in the table. The mean heterozygosity of marmot populations for 4 polymorphic loci was 25.56% within 24.0-27.1% range. The means of inbreeding in marmot population were FIT=4.56%, FIS=2.84% and FST=1.68%. The F-statistics or genetic differentiation was ranged from 0.009928-0.021314. We selected and studied 3 populations of Mongolian marmot which are geographically isolated and differed with respect to the prevalence of plague: high intensity plague focus, non-intensity and free from plague. These populations were almost identical by frequencies of alleles in the Hp, Pa and Al loci (l = 0.9967 ± 0.001), but were differed by frequencies of alleles in the transferrin’s locus (l = 0.9361 ± 0.05). The genetic distances (Nei’s distance: D) of marmot populations geographically remote from each other were 0.0022-0.0192, and we found a correlation between genetic and geographic distances (r = 0.977). The marmot population within high intensity of plague clearly differed from the 2 populations in areas of non-intensity and free of plague in their population genetic structure (D = 0.0157-0.0192). The D coefficient was very low between the populations in non-intensity plague areas and populations free of plague (D = 0.0022). The high rate of genetic differentiation (0.021314) and the observed heterozygosity lower than expected (Ho = 25.5 < Hc = 29.7%) were observed in the population within the intensity plague area. Although these populations were differentiated from each other, the observed genetic distances between marmot populations could not be determined at the subspecies level. Plague epizootic influence on marmot population structure was studied for 5 years in the Gobi-Altain Tonkhil sum’s focus. Prior to initiation of the plague epizootic, the genetic structure of the marmot population (Ho = 0.2583 < Hc = 0.2883), population subdivided into many small groups, high inbreeding rates (FST= 0.062320, FIS= 0.042750), and the population susceptible to natural selection. Following infection of the population by plague, HpS, TfM, TfK and AlB allelic frequencies decreased and frequencies of the TfL, AlB, HpF alleles increased. Among the polymorphic hereditary systems studied, intense selection during the epizootic acted most strongly on the transferrin locus (S = 0.545). The TfL gene frequency increased 1.7 times, and both TfK and TfM gene frequencies decreased (selection rate of booth alleles STfK = 0.67, STfM = 0.56) during the plague epizootic. After the epizootic, the FIS disappeared from the population (FIS = -0.077585), the FST decreased 2 times (FST = 0.030214), heterozygosity was increased by 15.8% (Ho = 0.2992, Hc = 0.2684), and population survival abilities (or average fitness in relation to selection) improved.