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PubMed1995

Gastrointestinal helminths from the endangered Hualapai vole, Microtus mogollonensis hualpaiensis (Rodentia: Cricetidae).

The Hualapai vole (Microtus mogollonensis haulpaiensis) is an endangered rodent occurring in northwestern Arizona. Helmiths were examined from 47 voles collected from 9 localities in northwestern Arizona. A toal of 375 helminths was collected, including 2 species of cestodes Anoplocephaloides troeschi and Paranoplocephala macrocephala, and 1 cecal nematode Syphacia obvelata. Pinworms were the most common helminth, but prevalence and abundance varied among localities. Comparison of the pinworms we found with the types of S. obvelata and Syphacia nigeriana indicate that those in M. m. hualpaiensis were S. obvelata.

Animals↗
PubMedDate not supplied

[A taxonomic interpretation of the morphological variability exemplified by common voles (Microtus s. lato, Rodentia)].

An analysis of variability of the crown pattern of the first lower molars in gray voles has indicated the existence of two trends in its transformation, the "pitimoid" and the "ratticepoid" ones. The first trend is characteristic of Microtus, whereas the second one is found in Alexandromys. These taxa differ also by diploid chromosome numbers. This regular pattern of variability is discussed from the taxonomic standpoint.

Animals↗
PubMed1995

[Molecular-genetic typing of three representatives of the transpalearctic species of forest and field mice (Apodemus, Muridae, Rodentia)].

The genomes of three species of wood mouse (Apodemus falzfeini and A. ponticus from the Caucasus and A. argenteus from Japan) were compared by means of restriction analysis of nuclear DNA. The species are differentiated from each other and from previously studies species. Each species has its species-specific features. Within the genus Apodemus, A. ponticus is most closely related to the European species A. sylvaticus and A. flavicollis. A. falzfeini has a peculiar type of restriction with EcoR I (specific for dispersed repeats) and Hind III (specific for satDNA). The genome of this species contains three families of EcoR I repeats previously found in various species (European and Asian) of wood mouse and Hind III components characteristic of both wood and field mice. A. argenteus differs from all other forms of Apodemus, the genome of which contains the 375-bp Hind III satellite, by the presence of a EcoR I satDNA fraction consisting of 240-bp repeating units.

Animals↗
PubMed1995

[Nucleolus organizer regions and B-chromosomes of field mice (Mammalia, Rodentia, Apodemus)].

Distribution of nucleolus organizer regions (NORs) in karyotypes was studied in 10 species of wood mice, including Apodemus flavicollis, A. sylvaticus, A. uralensis (= A. microps), A. fulvipectus (= A. falzfeini), A. ponticus, A. hyrcanicus, A. mystacinus, A. agrarius, A. peninsulae, and A. speciosus. Peculiarities of NOR location in karyotypes can be used in interspecific diagnostics of wood mice. Intraspecific polymorphism of A. sylvaticus, A. agrarius, and A. peninsulae in terms of the number of NORs and their localization in chromosomes can serve as evidence for karyological differentiation in certain populations of these species. The minimum number of active NORs in mice of the genus Apodemus is two to four. Two A. flavicollis wood mice with karyotypes containing one small acrocentric B-chromosome (2n = 49) were identified among animals captured in Estonia. In A. peninsulae, B-chromosomes were found among animals captured in the following regions: the vicinity of Kyzyl (one mouse with 17 microchromosomes, 2n = 65); the vicinity of Birakan (two mice with one metacentric chromosome each, 2n = 49); and in the Ussuri Nature Reserve (one mouse with five B-chromosomes, including three metacentric and two dotlike chromosomes; 2n = 65). In the latter animal, the presence of NORs on two metacentric B-chromosomes was revealed; this is the first case of identification of active NORs on extra chromosomes of mammals.

Animals↗
PubMedDate not supplied

[Heterochromatin of the rat-like hamster Tscherskia triton de Winton (Rodentia, Cricetinae), II].

Differential staining of rat-like hamster chromosomes revealed: 1) C- and G-banding of chromosomes depending upon the Giemsa solvent (distilled H2O and phosphate buffer correspondingly) in case of ordinary staining; 2) dependence of C-banding pattern on the C-method; 3) different resistance of C-bands to trypsin action; 4) dependence of Q-bands on the fluorochroms employed (A, 33258 H, AO), the second non-fluorescent (A, 33258 H) near-centrometric heterochromatic region is brilliantly fluorescing when AO is employed; 5) heterogeneity of C-, G- and Q-bands, i.e. similarly stained region, may differ in their structural-functional peculiarities.

Animals↗
PubMedDate not supplied

[An analysis of isometric reflections in morphology exemplified by the mandible of the rat (Rattus, Rodentia)].

Individual, age, sex, and species differences of morphological shape is treated as a result of general shape formation process. It is assumed that mutual reflections of these differences could be described by continuous and discontinuous transformations. The first type of these reflects equilibrium properties of shape formation, while the second type reflects its non-equilibrium properties. Equilibrium process is strongly canalized and is able to generate quite limited diversity of shapes. Contrary to this, non-equilibrium process can generate a lot of different shapes, as it destroys canalized relations between characters. Idea of equilibrium process provides a background for formulation of null hypothesis about anticipated relations between characters. Statistically significant deviations from these relations allow to recognize characters that mark areas of possibly non-equilibrium transformations. Analysis of localizations of all such characters allows to formulate more meaningful hypothesis about shape transformations for a particular morphological object. Some easily available statistical methods of recognizing characters that reflect either continuous of discontinuous transformations are exposed using mandible of three rat species as an example. It is shown that discontinuous transformations are located mainly in the same areas of mandible in all modes of inter-reflections. Characters (linear measurements between morphometric landmarks) with continuous inter-reflections describe transformations of general shape of the mandible. Characters with discontinuous inter-reflections mark boundaries between functional blocks and areas with the heaviest dynamic loads.

Aging↗
PubMed1993

Divergence of two families of repeated DNA in wood and field mice of the genus Apodemus (Muridae, Rodentia).

The nDNA of six species of a wood and field mice of the genus Apodemus (2n = 48): peninsulae, sylvaticus, flavicollis, microps, speciosus, agrarius, grey rat Rattus norvegicus as well, and house mouse Mus musculus were studied using EcoRI and HindIII restriction endonucleases with an agarose and polyacrylamide gel electrophoresis and a microdensitometry. It is shown for dispersed sequences that a quarter of 1.85 kb EcoRI genus specific family of repeated DNA is constant but a quarter of 1.35 kb EcoRI repeats, which are specific for more large taxon unit, is variable. The HindIII satDNA of the various species differs in the length of monomer, size of more representative multimer and digestion of the monomers by the same endonuclease of restriction; HindIII satDNA quantity correlates with 1.35 kb EcoRI repeat content. Some nonidentified components are found in Apodemus genomes. The possible ways evaluation of the repetitive DNA are briefly discussed. It was supposed that the evolutionary age of the wood mice is directly proportional to the length of HindIII multimer and inversely proportional to the amount of HIndIII satDNA with a 1.35 kb EcoRI repeats.

Animals↗
PubMed1993

[Differentiation of GC-rich restriction sites in the highly repeated DNA in Apodemus (Muridae, Rodentia].

nDNAs of six species of wood and field mice of the genus Apodemus (peninsulae, flavicolis, microps, speciosus, and agrarius), grey rat Rattus norvegicus as well, and house mouse Mus musculus were digested with restriction endonucleases (MspI (CCGG), BspRI (GGCC) and MvaI (CCA/TGG). Two highly representative satellites are found in A.peninsulae (8%) and M.musculus (20%) genomes using BspRI and MvaI. The length of restriction fragments of these components are equal to n x 30 and n x 230 nb, respectively. Based on the results of PDRF of nDNA in rodent interspecies, genetic distances are estimated and phylogenetic tree reconstructed. Among wood mice examined A.sylvaticus and A.flavicollos are most closely related, A.peninsulae is more diverged. Field mouse has approx. equal differences from the european and asian species of wood mice. A middle value of genetic distances is about 7.12% in Apodemus genus, 12.69 and 13.2% between Apodemus with M.musculus and R.norvegicus, respectively.

Animals↗
PubMed1995

Normal hematologic values of various age groups of Calomys callosus (Rodentia Cricetidae).

Hematologic values for Calomys callosus, a wild rodent, were established. Males and females from a colony raised in Animal Housing of the Institute of Tropical Medicine of São Paulo were examined individually. For the red blood cell series, the number of erythrocytes, hemoglobin concentration, hematocrit, and platelet and reticulocyte numbers were measured. All values except hemoglobin concentration were slightly higher in aged animals than in young animals. The white blood cell series had a predominance of lymphocytes, with no age-associated changes.

Aging↗
PubMed1995

High-resolution G-banding of chromosomes in Microtus subarvalis (Rodentia, Arvicolidae)

Karyotypes of six females and four males of the East European vole (Microtus subarvalis) were prepared from spleen cell cultures. G-banding of early metaphase chromosomes has allowed us to distinguish 488 bands in the haploid set of chromosomes of M. subarvalis. Based on the detailed study of chromosomes at various levels of condensation, an idiogram has been built up for the chromosomes of the East European vole.

Animals↗
PubMedDate not supplied

[The genetic links and species affiliation of the field mouse (Rodentia, Muridae, Sylvaemus) from the Pamir-Alai].

Analysis of variation in 30 presumptive biochemical loci in Sylvaemus sylvaticus pallipes from Tadjikistan was carried out with reference to the geographically closely related species S. uralensis. The data obtained support the genetic identity of pallipes, on the one hand, and suggest a rather low level of genetic divergence (D'Nei = 0.154, Pfd = 13) from an ancestral taxon, on the other hand. Analysis of genetic variation of diagnostic morphological features suggests that pallipes is the most extreme form of geographic population series of the uralensis species group. Both genetic and morphometric data suggest that S. pallipes is an allospecies of the uralensis species complex.

Alleles↗
PubMed1996

[Comparative cytogenetics of three species of South American field hamsters of the genus Akodon (Rodentia, Cricetidae)].

A karyological analysis of three species of South American field mice of the genus Akodon from four different localities of the Department of Tarija, Bolivian Republic, was performed. In Akodon simulator, 2n = 40 - 42, NFa = 42. The variation of the diploid number is caused by a polymorphism of the Robertsonian type involving six pairs of acrocentric chromosomes. Five variants of karyotypes were revealed. The chromosome set of A. sp. has 2n = 36, NFa = 40; in A. toba, 2n = 42 - 43, NFa = 44 - 46. The variation of the diploid number and the number of autosomal arms is caused by the polymorphism of the first autosomal pair. A comparative karyological analysis of A. simulator, A. sp., and A. toba revealed a high level of similarity of all karyotypic elements. Fifteen autosomal pairs of these three species have identical G-banding patterns; the others are involved in formation of larger chromosomes, representing one possible combination of the same chromosomal material. The set of rearrangements is limited only to tandem chromosome fusions.

Animals↗