[Correlation between morphological and genetic differentiation in Cuban hutia (Rodentia, Capromyinae): species fragmentation on the area and the problem of excessive taxonomic status problem].

The work attempts to explain the previously discovered phenomenon of excessive taxonomic status of the species and subspecies of Cuban hutias relative to their protein genetic divergence. The reasons underlying the fragmentary distribution of the species belonging to the family Capromyidae over the Antilles and Bahamas is also considered. Samples of four geographically distant hutia (genera Capromys and Mysateles) populations inhabiting different biotypes were assessed according to 32 allozyme loci. It has been demonstrated that the interpopulation and subspecies differentiation in the gene frequencies in these genera is very low. As for the pattern of polymorphism (Shannon?s measure), the populations and subspecies within these genera are well differentiated and adequate to their morphological differentiation. This suggests that the genetic divergence pattern of hutias in post-Pleistocene was predominantly determined by selection on the background of a relatively rapid formation of multiple morphotypes. It is assumed that the evolution within the family Capromyidae in the earlier and the later periods was associated with the geomorphological and climatic events in the history of the Earth. This standpoint provides for explaining the phenomena of both the excessive taxonomic status of the Cuban Capromyinae and the fragmentary distribution of these species over the Antilles and Bahamas, amazing at a first glance.

[Origin of the house mice (superspecies complex Mus musculus sensu lato) from the Transcaucasian region: A new look at dispersal routes and evolution]. / Proiskhozhdenie domovykh myshei Zakavkaz'ia (nadvidovoi kompleks Mus musculus). Novyi vzgliad na puti ikh rasseleniia i évoliutsiiu.

We analyzed our results and literature evidence on variability of nuclear protein genes in 39 populations of eight synanthropic and wild species of house mice (superspecies complexes Mus musculus and M. spicilegus) from Transcaucasia, Eastern and Western Europe, Near and Middle East, Central, South, and East Asia, and Cuba. These data were for the first time ever combined into a single database by unification of nomenclature of 21 loci examined by different authors in 39 populations. Analysis of geographical allele distribution have shown that populations of domestic Transcaucasian mice are close to Indo-Pakistani populations of form oriental of the species M. castaneus, which preserved a high level of ancestral polymorphism. We concluded that a very heterogeneous, rich gene pool of house mice from Transcaucasia could not develop only by secondary contacts of differentiated M. musculus s. str. and M. domesticus forms, since it is similar to the ancestral gene pool of the superspecies complexes M. musculus and M. spicilegus. In this context, unique characteristics of some Central Asian populations were examined; these populations may have served as a "transit station" in the dispersal of synanthropic house mice forms. We suggest that the Transcaucasian populations are genealogically closely related to an early Near East form of M. musculus, which, as M. domesticus and M. castaneus, split from the common ancestor and preserved nondifferentiated pool of ancestral alleles of protein genes. This hypothesis admits the involvement of differentiated species M. musculus s. str. and M. domesticus in the ultimate formation of the gene pool of Transcaucasian house mice. Apparently, these populations resulted from alternation and (or) "overlapping" of different evolutionary processes. A scenario suggesting that hybrid events having occurred in Transcaucasia at different times, were "superposed" on the gene pool of the ancient autochtonous population of house mice from this region seems most plausible. Analysis of allozyme variability in the modern Transcaucasian Mus populations could not always distinguish between ancestral polymorphism and hybridization consequences.

[Effect of enterally administrated oxygenated water on electrical activity of the small intestine in early postoperative period in rats]. / Vliianie oksigenirovannoi vody, vvedennoi énteral'no, na élektricheskuiu aktivnost' tonkoi kishki krys v rannem posleoperatsionnom periode.

The effect of oxygen, structurally-binded with water (oxygen water), on electrical activity of rat jejunum in early postoperative period. It was shown, that in contrast to effect of 0.9% NaCl, there is normalization of electrical activity parameters (frequency and slow wave amplitude) of jejunum in early postoperative period under the influence of oxygen water.

[Genetic differences and similarities in the introduced population of European beaver (Castor fiber L., 1785) in the Kirov and Novosibirsk regions of Russia]. / Geneticheskoe razlichie i skhodstvo introdutsirovannykh populiatsii evropeiskogo bobra (Castor fiber L., 1758) Kirovskoi i Novosibirskoi oblastei Rossii.

Potential factors were analyzed that affected the formation of gene pools of two introduced beaver populations founded in the 1940s-1950s by releasing beavers from Voronezh oblast and Belarus into rivers of the Kirov and Novosibirsk oblasts. The populations from these two regions were shown to differ in four allozyme loci (Ahd-2, Gpi, Es-5, and Dia-2). Within Kirov oblast, the samples from three tributaries of the Vyatka River differed in three other loci (Ck-1, Gp-9, and Trf). It is suggested that these features of the allele distribution at these loci are explained by the history of the introduced populations, hybridization between beavers from Voronezh oblast and Belarus, and founder effect during the subsequent artificial and spontaneous migration. Generally, genetic differences between the populations in all studied loci were very small: D = 0.02 between populations from different regions and D = 0.01 between populations from the tributaries of third-order rivers of the Kirov oblast. At the same time, disequilibrium was detected for ten polymorphic loci in the combined sample from the populations of Kirov oblast, which indicates the existence of interpopulation heterogeneity at the level of local populations of fourth- and fifth-order rivers. The unexpected finding of a genetic similarity between one studied individual of Tuvinian beaver subspecies (Castor fiber tuvinicus) and C. f. orientoeuropeas was recorded.

[Analysis of allozyme variability in populations of three species of brush-haired mice of species Lophuromys (Rodentia, Muridae) from the Bale Mountains National Park in Ethiopia]. / Analiz allozimnoi izmenchivosti v populiatsiiakh trekh vidov zhestkovolosykh myshei roda Lophuromys (Rodentia, Muridae) natsional'nogo parka bale Efiopii.

Allozyme variability was examined in populations of three endemic species of the species complex Lophuromys flavopunctatus sensu lato: L. chrysopus, L. brevicaudus, and L. melanonyx. These species substitute each other in adjacent latitudinal belts of the Bale Massif in Ethiopia. A deficit of heterozygotes at several loci was found in most samples of all species studied. Moreover, the samples included animals homozygous for two or three minor alleles and heterozygous for alleles that are rare and unique for the given species. It is suggested that the Bale Massif are inhabited by numerous genetically isolated populations of each Lophuromys species, which exchange genes at an extremely low rate. Genotypic disequilibrium observed in most samples is explained by the fact that most sampling localities comprise ranges of two and more micropopulations. In our view, microgeographic subdivision of the populations is caused by recurrent fragmentation of habitats during the Pleistocene glaciation of the Bale Massif and subsequent prolonged isolation of local populations. Gene drift accompanying these processes resulted in high genetic differentiation of the local populations, which probably persisted until the present. Geographical isolation of the Bale Massif, its uniquely diverse ecological conditions, and extraordinary allozyme structure of the Lophuromys populations suggest that these populations represent remnants or direct descendants of relic local populations.

[High allozyme variation in populations of three spiny rat species from Upper Amazonia: association with ecology and evolution]. / Vysokaia allozimnaia izmenchivost' v populiatsiiakh trskh vidov shchetinistykh krys Verkhnei Amazonii: sviaz' s ékologiei i i évoliutsiei.

The allozyme variation in three spiny rat species of the genus Proechimys from Upper Amazonia was studied in relation to their ecology and evolution. The ecological environmental factors and biotopic distribution of species were analyzed. The unusually high allozyme variation was found in P. simonsi and P. sp. (2n = 34) inhabiting native forest biotopes. A relatively low allozyme variation in P. brevicauda was assumed to be associated with eurybiotic properties and the ability of this species to adapt to anthropogenic biotopes. Data on chromosome homeology and reconstruction of chromosome rearrangements in six spiny rat species were correlated with allozyme variation. The results suggested that chromosome rearrangements played the major role in evolution of the spiny rat species, and that the reorganization of the P. brevicauda genome was not random. P. simonsi and P. sp. (2n = 34), which live in native forest biotopes and carry an excessive genomik "informational load", were assumed to be highly susceptible to any novel external factors. These species are potentially able to produce new chromosome forms and are most significantly affected by deforestation.

[Genotypic variability in populations of the mound-builder mouse Mus spicilegus Pet., 1882, at various life cycle stages]. / Genotipicheskaia izmenchivost' v populiatsiikh kurganchikovykh myshei Mus specilegus Peteny, 1882 na razlichnykh fazakh zhiznennogo tsikla.

Genotypic variability in two Moldovian populations of moundbuilder mice Mus spicilegus Pet. was examined at different stages of their life cycle--at the beginning of overwintering in mounds and in the middle of summer in agrocenoses. Thirty allozymes were assayed. Significant differences in allele frequencies and heterozygosity between overwintered and mice born in the year of the experiment were recorded only for Idh-1. This fact was related to the presence of differential mortality among overwintered mice in the populations by the middle of summer. The increase in heterozygosity for Idh-1 in the populations occurred because of "old" mice that lived until the middle of summer, at which point they still have not contributed to the gene pool of the population. The genetic effect of the annual separation of generations of mound-builder mice due to their overwintering in mounds is analyzed. Overwintering has a bottleneck effect on the population. The relatively low genetic variability in mound-builder-mice populations is considered with regard to their biological and ecological features. Based on obtained data, a conclusion on the high genetic stability of moundbuilder-mice populations during their entire life cycle is made.

[Chromosome arrangements and cytogenetic differentiation of two species of African mice of the genus Mus (Rodentia, Muridae)]. / Khromosomnye nabory i tsitogeneticheskaia differentsiatsiia dvukh vidov Afrikanskikh myshei roda Mus (Rodentia, Muridae).

Karyotypes of two African mouse species, Mus mahomet, 2n = 36, NFa = 34 (34A + XA + YA) and Mus sp. A, 2n = 34, NFa = 32 (32A + XA + YA), from five localities of the Bale Mountains National Park, Ethiopia, were analyzed. In both species all autosomes contained C-positive pericentromeric blocks. In M. mahomet, heterochromatin blocks of different chromosomes varied in size. In addition, the X chromosomes of both species contained a pericentromeric block and showed more intensive staining throughout the chromosome. The Y chromosome was two times larger in Mus sp. A than in M. mahomet and C-positive in both species. Comparative analysis of G-banding patterns revealed a similarity with respect to nine autosomes and the X chromosome. Autosome 1 of Mus sp. A was demonstrated to result from centromere-telomere fusion of two M. mahomet acrocentrics. The other five autosomes represent different linkage groups determining a specificity of the karyotypes. The karyotypes of M. mahomet and Mus sp. A were also compared with that of M. musculus. The evolution of M. mahomet and Mus sp. A karyotypes was shown to have involved structural rearrangements in 10 and 12 autosomes, respectively. The high karyological divergence confirmed molecular phylogenetic data. The cytogenetic differences T of M. musculus C from M. mahomet and Mus sp. A are high enough to different genera.

[Karyological differentiation of three species of coarse-haired mice of the genus Lophuromys (Murinae, Rodentia) from the Bale Mountain National Part in Ethiopia]. / Kariologicheskaia differeentsiatsiia trekh vidov zhestkovolosykh myshei roda Lophuromys (Murinae, Rodentia) natsional'nogo parka Bale, Efiopiia.

Three karyotypically differentiated species of harsh-furred mice, Lophuromys melanonyx (2n = 60, NFa = 90; 24m,sm + 8st + 26a + Xm + Ya), Lophuromys sp. A (2n = 54, NFa = 60; 8m,sm + 44a + Xa + Ya), and Lophuromys sp. B (2n = 68, NFa = 78; 8m,sm + 4st + 54a + Xst + Ya), were found at the Bale Mountains National Park, Ethiopia. Comparative analysis of chromosomes showed that G-banding patterns of 2 to 17 chromosome banding patterns or chromosome arms were identical in all species. Apparently, the formation of the studied species was associated with their independent karyotypic divergence during early evolution. The results obtained indicate that the rate of karyotypic alterations is not associated with the degree of morphological differentiation in this group of species.

[Karyotypes and chromosomal differentiation of two species of the genus Tachyoryctes (Rodentia, Tachyoryctinae) from Ethiopia]. / Kariotipy i khromosomnaia differentsiatsiia dvukh vidov roda Tachyoryctes (Rodentia, Tachyoryctinae) iz Efiopii.

Karyotypes of two species of genus Tachyoryctes from four localities in the Bale Mountains National Park, Ethiopia, were analyzed. T. splendens has 2n = 48, NFa = 65-86. Variations of the autosome arm number are determined by different numbers of autosomes with additional heterochromatin arms (7-17). Karyological analysis indicated that the cytogenetic structures of T. splendens from the localities studied was unique, which might result from formation of the karyotypes optimal for the given habitats. T. macrocephalus has 2n = 50, NFa = 62. A high conservatism of the number and size of C-positive heterochromatin blocks reflects the extreme specialization of T. macrocephalus endemic for the Bale province and occupying a limited ecological niche. Homology of G-banding patterns of several chromosomes and chromosome arms demonstrated that karyotypes of T. splendens and T. macrocephalus were formed from the common ancestral karyotype through different rearrangements in some chromosomes.

[Population-genetic variability of the house mouse Mus musculus L. 1758 S. stricto from the western, central, and southeastern area of species range]. / Populiatsionno-geneticheskaia izmenchivost' domovykh myshei Mus musculus L. 1758 S. stricto iz zapadnoi, tsentral'noi i iogo-vostochnoi chastei areala vida.

Allozyme variation in nine populations of the house mouse Mus musculus L. s. str. was examined. Twenty-five out of 34 analyzed loci were shown to be polymorphic. Estimates of genetic variation were obtained for separate populations and for population groups classified according to their habitat. Populations from Moldova and Tadzhikistan displayed the lowest and highest amounts of allozyme variation, respectively. Variation in town populations was significantly greater than in rural ones. This can be explained by active human-induced migration of mice into towns. All Central Asian populations showed high levels of genic diversity, which is presumably related to their proximity to ancient centers of mice expansion. Allelic distributions in the populations were analyzed.

[Allozyme variability of the European bean Castor fiber 1758 (Castoridae, Rodentia) from the Voronezh State Nature Reserve]. / Allozimnaia izmenchivost' evropeiskogo bobra Castor fiber 1758 (Castoridae, Rodentia) iz voronezhskogo gosudarstvennogo zapovednika.

Electrophoretic methods were used to study protein products of 32 gene loci in the blood of European and Canadian beavers held in captivity at the Voronezh State Nature Reserve. In the studied samples, the levels of polymorphism and average heterozygosity exceeded the average values of corresponding indices determined for beavers that inhabit temperate zones. To what extent the studied samples represent the state of the gene pool of parental populations is discussed. A comparison between allozyme spectra of samples of European and Canadian beavers revealed many coinciding polymorphic loci, on the one hand, and pronounced genetic divergence of these species, on the other.