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PubMedDate not supplied

[Small wild mammals and arboviruses in Italy].

In 1980 and 1981, sera of 256 small wild mammals (rodentia, insectivora, carnivora) were collected in Piemonte and Southern Italy. They were then tested for antibody against 12 arboviruses by haemagglutination inhibition and complement fixation tests. In the North of the country, 42.8% of sera were found positive against Tahyna or Sicilian Sandfly fever viruses. In the Southern provinces, 44.3% of sera reacted with Bhanja, West Nile or other flaviviruses, Tahyna, Sicilian Sandfly fever and Arumowot viruses. These results lead to suspect the possible role of some small mammals (muridae, Clethrionomys glareolus, Talpa caeca, Talpa romana) in circulating these arboviruses in Italy.

Animal Population Groups↗
PubMed1978

Comparative aspects of circadian rhythms in homeotherms, re-entrainment after phase shifts of the zeitgeber.

Re-entrainment of circadian activity of 3 avian species (Fringillidae: Fringilla coelebs, Carduelis chloris, Pyrrhula pyrrhula) and 4 mammalian species (Rodentia: Eutamias sibiricus, Funambulus pennanti, Glis glis, Mesocricetus auratus), subjected to 12:12 h light-dark (LD) cycles as zeitgeber, was studied after shifting the LD cycle by different amounts (hours) and in different directions (advances and delays). The properties of the zeitgeber were changed by varying light intensity during dark-time (ID) and/or light-time (IL). After 6 and 9-h advance and delay shifts of the LD cycle, the 3 species of finches similarly re-entrained their activity rhythms in the direction of the shifted zeitgeber. After 10.5 and 12-h shifts, the majority of individuals re-entrained by delay phase shifts of the rhythms. After two successive 6-h advance or delay shifts (resulting in inversion of the LD cycle) most finches responded by advances. Generally, the time needed for re-entrainment of 2/3 of the full shift (2/3 tr) in finches dependend on: (a) the direction of the phase shift ('asymmetry effect'), and (b) the phase-angle difference between onset of activity and light-on (psio) before the shift. After 12-h shifts, species-specific differences in the direction of re-entrainment and in the slope of the relationship between 2/3 tr and psio were found. In two rodents, the nocturnal golden hamster and the diurnal Siberian chipmunk, the direction of re-entrainment following inversion of the LD cycle depended on psio. In both species, 2/3 tr after inversion of the zeitgeber was significantly longer than in the common dormouse. In chipmunks, changes in 2/3 tr were correlated with changes in psio due to systematic variation of the zeitgeber properties (range and/or mean level). After 6-h phase shifts, the 'asymmetry effect' was opposite in the two nocturnal rodents, the hamster and the dormouse. It is suggested that the time course (direction and rate) of re-entrainment was influenced by differences in the characteristics of the circadian systems and their responses ('sensitivity') to light changes in the various species of birds and mammals.

Animals↗
PubMed1980

Fungi from interior organs of free-living small mammals in Czechoslovakia and Yugoslavia.

A total of 308 fungi was isolated from interior organs (lungs, spleen, liver) of 529 small mammals belonging to 21 species, 7 families and 3 orders (Insectivora, Chiroptera, Rodentia), some of these being potentially pathogenic to vertebrates (e.g. Aspergillus flavus, A. fumigatus, Geotrichum candidum, Mucor pusillus, Rhizopus arrhizus). In one vole (Microtus arvalis) captured in South Moravia, adiaspiromycosis (Emmonsia crescens) was demonstrated. Comparison of mycoflora of hair and that of interior organs of wild small mammals revealed that out of the total number of isolates the following fungi were represented in a higher proportion from visceral organs than from the hair: Aspergillus (A. amstelodami, A. flavus, A. repens), Aureobasidium (A. pullulans), Candida, Cladosporium (C. herbarum), Cryptococcus, Fusarium, Gliocladium (G. deliquescens), Helminthosporium, Kloeckera, Mucor (M. fragilis, M. hiemalis, M. pusillus), Paecilomyces marquandii, Penicillium (P. purpurogenum), Phoma, Rhizopus arrhizus, Scopulariopsis (S. candida, S. koningii) and Torulopsis.

Animals↗
PubMed1976

A comparative survey of the mast cells of the mammalian brain.

A search for mast cells has been made in the brains of 18 mammalian species in 13 families in the orders Insectivora, Primates, Rodentia and Carnivora. In the larger animals, only the diencephalon and olfactory bulbs were examined. Mast cells were identified by virtue of their heparin-containing granules, which are stained by Alcian blue 8GX and, metachromatically, by toluidine blue 0. Within the cerebral parenchyma, mast cells were confined to the dorsal diencephalon of Erinaceus europaeus (hedgehog), Tupaia glis (tree-shrew) and Nycticebus coucang (slow loris). Some cells were next to capillaries; others were not. Mast cells were sometimes found, though rarely, in the intracerebral perivascular connective tissue leptomeninges and choroid plexuses of some of the other species examined. It is concluded that pericapillary cells (pericytes), which have been called mast cells by some investigators, are not in fact mast cells since there is no evidence for the presence of heparin. The functions of mast cells in the brain are unknown.

Animals↗
PubMed1993

Occurrence and prevalence of bot flies, Metacuterebra apicalis (Diptera: Cuterebridae), in rodents of cerrado from central Brazil.

The occurrence and prevalence of Metacuterebra apicalis (Diptera: Cuterebridae) in natural populations of Oryzomys subflavus, Bolomys lasiurus, and Thalpomys cerradensis (Rodentia: Muridae) from August 1990 to July 1992 in the cerrado, a common savanna-like vegetation type of central Brazil, are reported. An increase in bot infection in the 3 rodent species between October 1991 and July 1992 without correlation to precipitation was detected. The prevalence was lower than in neotropical forest formations. Mean intensity was 1.3 bots (range 1-2) for T. cerradensis and 1 bot for B. lasiurus and O. subflavus. This is the first record of T. cerradensis as host of bot flies.

Animals↗
PubMed1977

Haemaphysalis (allophysalis) danieli, sp. n. (ixodoidea: ixodidae), female and tentatively associated immature stages from high mountains of northern Pakistan and Afghanistan.

Haemaphysalis (Allophysalis) danieli sp. n. is described from a female taken from alpine vegetation in Swat, Pakistan. Fifty-one nymphal and larval ticks tentatively associated with this taxon are from hamsters, field mice, voles, and marmots (Rodentia), Cricetulus migratorius, Apodemus flavicollis, alticola roylei, and Marmota caudata, and from pikas (Lagomorpha), Ochotona roylei, in Gilgit and Hazara districts of Pakistan and in Badakhashan Province of Afghanistan. Collecting localities are in the western Himalayan mountain complex between 2,310 and 4,000 m altitude and between 35degrees08' and 36degrees23' N and 71degrees51' and 74degrees02' E. This species is most closely related to the mountain-inhabiting H. (A9Y pospelovashtromae Hoogstraal of southern USSR and Mongolia and H. (A.) garhwalensis Dhanda and Bhat of northern India and Nepal.

Afghanistan↗
PubMedDate not supplied

[The flea fauna of small mammals in Kostroma Province].

There were 22 species of fleas recorded on different Rodentia and Insectivora in Kostroma Province. The flea species M. turbidus, M. penicilliger, M. walkeri, C. agyrtes, C. uncinatus, P. sylvatica dominate on the rodents, and the species C. bisoctodentatus, P. soricis, P. kohauti, D. dasycnema dominate on the insectivores.

Animals↗
PubMed1996

On Physaloptera sibirica Petrow et Gorbunow, 1931 (Nematoda: Physalopteridae) parasitizing Iberian mammals.

Faunistic and morphological study of Physaloptera sibirica PETROW et GORBUNOW, 1931 (Nematoda: Physalopteridae), a nematode isolated in Spain from three mammal species: red fox, Vulpes vulpes (LINNAEUS, 1758) (Carnivora: Canidae), eurasian badger, Meles meles (LINNAEUS, 1758) (Carnivora: Mustelidae), and garden dormouse, Eliomys quercinus (LINNAEUS, 1766) (Rodentia: Myoxidae) in the Iberian Peninsula. Morphological features of cephalic and caudal regions of males are presented for the first time by SEM (scanning electron microscopy).

Animals↗
PubMed1995

Clinical aspects of rodent dental anatomy.

The order Rodentia is vast, encompassing a large number of species with significant anatomical variations developed during natural adaptation to differing habitats. Many veterinarians have little knowledge of the anatomy of species other than the commoner domestic large herbivores and small carnivores. Clinicians require a basic knowledge of the relevant anatomy of species they are likely to be asked to treat. This article provides sufficient working knowledge of the oral and dental anatomy of those rodents commonly kept as pets to enable veterinarians to interpret clinical and radiographic findings when investigating suspected dental disease.

Animals↗
PubMed1998

Collagenase 1 and collagenase 3 expression in a guinea pig model of osteoarthritis.

OBJECTIVE: To analyze the in vivo compartmental expression of collagenases 1 and 3 (MMP-1 and MMP-13) in the Hartley guinea pig model of spontaneously occurring osteoarthritis (OA) for the purpose of elucidating their roles in the pathogenesis of OA. METHODS: Competitive reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry quantification of messenger RNA (mRNA) and protein levels in medial and lateral tibial cartilage obtained from the knee joints of 2-month-old (no OA) and 12-month-old (OA) guinea pigs. RESULTS: The patterns of mRNA expression of collagenases 1 and 3 varied with the age of the animal and the compartment of the knee. We also found focal areas of collagenase 1 and collagenase 3 proteins localized to the extracellular matrix of OA lesion sites, coincident with three-quarter/one-quarter collagen cleavage. Collagenase 3 protein was also abundant throughout the medial tibial cartilage of 2-month-old animals. CONCLUSION: This represents the first description of bona fide collagenase 1 in a rodent species. Recent evidence, however, based on analysis of mitochondrial DNA homologies, suggests that the guinea pig is not a member of the order Rodentia and may be more closely allied with lagomorphs. This taxonomic controversy leaves open to question the issue of the expression of collagenase 1 in other rodents, such as mice and rats. The presence of active collagenases 1 and 3 at OA lesion sites is consistent with an important role of these enzymes in the cartilage degradation of OA in guinea pigs. The expression of collagenase 3 in medial tibial cartilage from 2-month-old guinea pigs may signify a role of this enzyme in cartilage remodeling with growth and development, or it may represent an early molecular manifestation of OA.

Animals↗
PubMed2005

Gas chromatographic quantification of free D-amino acids in higher vertebrates.

D-amino acids were determined in brain, body fluids (urine, blood coagulate, serum, plasma) and faeces of animals belonging to nine out of 11 taxonomic orders of vertebrates (Artiodactyla, Aves, Carnivora, Lagomorpha, Marsupalia, Osteichthyes, Primates, Rodentia, Tubilidentata). Free amino acids were isolated by means of cation exchangers and converted into volatile N(O)-perfluoroacylamino acid propyl esters. Derivatives of amino acids were separated into D- and L-enantiomers using Chirasil-L-Val capillary columns and detected by selected ion monitoring mass spectrometry. Quantification of amino acids was achieved by comparison of analytes with amino acid standards using L-norleucine as internal standard. Large relative amounts of D-serine were determined in brains of mammals but not of birds. In body fluids the D-enantiomers of most proteinogenic L-amino acids were detected, largest absolute and relative amounts were found in urine. Therein quantities of D-Ala and D-Ser exceeded 50% relative to the L-enantiomers in many instances. Feeding animals with diet fortified with DL-Met resulted in excretion of almost racemic Met in urine. D-Amino acids were also abundant in faeces of rodents. The data confirm that d-amino acids are common in body fluids and certain tissues of vertebrates.

Amino Acids↗
PubMed1991

Expression of cytochrome P-450lpr is developmentally regulated and limited to house fly.

Expression of house fly cytochrome P-450lpr was examined using immunoblotting in male and female adult LPR house flies, mixed sex adult house flies at 12 different ages, larvae, and pupae. P-450lpr was expressed in both male and female adult house flies. P-4501pr was clearly present in all adult stages examined, was barely detectable in pupae, and could not be detected in larvae. Thus, cytochrome P-450lpr is developmentally regulated and present in both sexes of house fly. Expression of cytochrome P-450, immunologically homologous to house fly cytochrome P-4501pr, was examined in other species using immunoblot analysis. Eleven animal species were tested in the orders Diptera, Hymenoptera, Lepidoptera, Orthoptera, Acari, and Rodentia, using microsomes in some species from both induced and noninduced animals or insecticide-resistant and susceptible strains. P-450lpr appears to be restricted to house flies, as none of these species contained cytochrome P-450 that reacted with antiserum to cytochrome P-450lpr.

Animals↗
PubMed1983

Growth and reproduction of two species of Akodon and their hybrids.

Growth and reproduction of Akodon molinae (A.m.), A. dolores (A.d.) (Rodentia: Cricetidae), and their hybrids are described. A.d. showed less fertility under animal room conditions, fewer "successful" matings, similar litter sizes, and an altered sex proportion as compared to A.m.; A.d. ovulatory index is supposed to be higher than mean litter size. X-linked lethal gene(s) and chromosome polymorphisms are possible causes of these variations. Interspecific crosses showed a marked seasonal (summer) tendency in parturitions. Intraspecific matings also produced young during winter. F1 hybrids showed a reversed tendency, while F2 matings returned to the parental pattern. A.d. male X A.m. female and F1 crosses presented larger litter sizes than the other pairings. A.m. exhibited sexual differences in weight after 60 days of age. A.d. and F1 hybrids did not show significant differences in weight of both sexes at any age. A.m. males and females were heavier than A.d. individuals except 12 months after birth. F1 hybrids born to A.m. male were heavier at birth than the A.d. female s interspecific offspring, and may be interpreted as a maternal influence of the A.m. females. Hybrids were heavier than their parents at birth and some of them were also heavier at 21 days, and probably is due to pseudoheterosis. The comparison of body measurements between sexes of both species did not give conclusive results. A.m. females were larger than females of A.d. Males of both species showed similar total lengths; A.m. males had larger body lengths and shorter tails. Body measurements were not related to weight variations. However, differences in weight and measurements between sexes appeared simultaneously at 2-6 months. This probably reflected the attainment of maturity.

Animals↗
PubMed2002

Sequence and expression analysis of deer mouse interferon-gamma, interleukin-10, tumor necrosis factor, and lymphotoxin-alpha.

Deer mice (Peromyscus maniculatus) are the principal host species of Sin Nombre (SN) virus, the primary etiologic agent of hantavirus cardiopulmonary syndrome in North America. The disease is a cytokine-mediated immunopathology characterized by pulmonary mononuclear infiltrates without discernible viral pathology. Infected deer mice remain life-long carriers and virus is found in many organs, including the lungs, but without pathology. It is unclear how deer mice respond to SN virus because no tools exist to examine the immune response in infected animals. As an initial step in examining host responses to SN virus, we have cloned partial cDNAs of deer mouse interferon-gamma (IFN-gamma), interleukin-10 (IL-10), tumor necrosis factor (TNF) and lymphotoxin-alpha (LTalpha). IL-10, TNF and LTalpha sequences are highly conserved compared to orthologs of other mammalian species, while IFN-gamma is substantially less conserved. Phylogenetic analyses indicate that the amino acid sequences of IFN-gamma and TNF may be useful in resolving relationships at the subfamily level within the rodent family Muridae. While all four sets of analyses were able to reconstruct clade Rodentia, they were not able to resolve the relationships among the mammalian orders represented in this study. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis of concanavalin A-stimulated splenocytes determined that maximal IFN-gamma and TNF expression occurred rapidly while IL-10 and LTalpha expression was maximal at 24 h.

Amino Acid Sequence↗
PubMed2001

The cluster of BTN genes in the extended major histocompatibility complex.

We sequenced the 170-kb cluster of BTN genes in the extended major histocompatibility complex region, 4 Mb telomeric of human leukocyte antigen class I genes, at 6p22.1. The cluster consists of seven genes belonging to the expanding B7/butyrophilin-like group, a subset of the immunoglobulin gene superfamily. The main complex is composed of six genes, from two subfamilies, BTN2 and BTN3, arranged in pairs. This alternating pattern must have evolved by duplications of an original block of two genes, one from each subfamily. The sequences from the two subfamilies share approximately 50% amino acid identity. By analysis of repeat elements within each block, these duplications may be dated to approximately 100 million years ago, at about the time of the branching of the Rodentia and Primate lineages. The single BTN1A1 (butyrophilin) gene was positioned approximately 25 kb centromeric to the cluster. Each gene covers approximately 12 kb and consists of seven (BTN2 subfamily) or nine (BTN3 subfamily) coding exons. The predicted leader sequence, immunoglobulin-like IgV (variable)/IgC (constant) ectodomains, and the predicted transmembrane domain are encoded on separate exons and are separated from a B30.2 domain by a variable number of very short exons, 21 and 27 nucleotides in length. BTN transcripts were detected in all tissues examined. Alternative splicing, involving particularly the carboxyl-terminal B30.2 domain, was a notable feature. Most transcripts of BTN2 subfamily genes contained this domain, whereas BTN3 genes did not. Using immunofluorescence, we showed surface expression of BTN-green fluorescent protein fusions in mammalian cell transfectants.

Alternative Splicing↗
PubMed1996

A congruence study of molecular and morphological data for eutherian mammals.

The four orders of eutherian mammals which are traditionally placed in the superorder Archonta [Chiroptera (microbats and megabats), Dermoptera (flying lemurs), Primates (primates), and Scandentia (tree shrews)] are among the best-studied taxa of their infraclass from both the molecular and morphological perspectives. Nevertheless, the ordinal relationships of archontans remain unresolved. While morphological studies favor their monophyly, molecular investigations do not. To evaluate these opposing conclusions, parsimony analyses were conducted with three separate sets of DNA sequences from both the nuclear and mitochondrial genomes and one file of morphological data for archontans and other eutherian mammals. Statistical tests of character support and ordinal branching pattern differences documented that the three sets of DNA sequences and their results were homogeneous and congruent, thereby allowing for the combination of these data into one large matrix for further phylogenetic analysis. In contrast, these same tests revealed that the combined sequence and morphological files and their topologies were in strong conflict. Archontan monophyly was supported by the morphological evidence, but this arrangement was strongly rejected by the combined DNA sequences that favored instead a grouping of Dermoptera, Primates, and Scandentia with Lagomorpha (rabbits) and Rodentia (rodents). Resolution of these significant differences will require further evaluations about the homologies and evolutionary properties of the molecular and morphological characters and about the appropriateness of the chosen phylogenetic methods, as well as the incorporation of new comparative data from both sources.

Animals↗
PubMed1998

Higher taxonomic relationships among extant mammals based on morphology, with selected comparisons of results from molecular data.

Until a few decades ago, phylogenetic relationships among placental orders were ambiguous and usually depicted to radiate as an unresolved "bush." Resolution of this bush by various workers has been progressing slowly, but with promising results corroborated by nondental, dental, and molecular characters. In this study we continue to seek resolution. A total of 258 nondental and 2 dental characters was analyzed by PAUP and MacClade on 39 vertebrate taxa (3 reptiles, 1 nonmammalian therapsid, and 35 mammals; 20 of the mammals are extant and 15 are extinct) to study higher taxonomic relationships with emphasis on Placentalia (Eutheria). About two-thirds of the characters are osteological, the rest concern soft tissues, including myological but excluding molecular characters (most are our data, the rest are from the literature). Cladistic analysis included all 39 taxa (fossil taxa help to evaluate polarities of characters) and all characters were given equal weight. Extant Mammalia are divided into Prototheria and Theria, the latter into Marsupialia and Placentalia. Placentalia comprises Xenarthra and Epitheria. Within Epitheria, Lipotyphla and Preptotheria (emended) are sister-taxa. Preptotherian taxa group into: ungulate-related taxa and various nonungulates. The former include Carnivora, Pholidota, Tubulidentata, Artiodactyla, Cetacea, Perissodactyla, Hyracoidea, Proboscidea, and Sirenia. A possible association to embrace Lagomorpha, Rodentia, Macroscelidea, Scandentia, Primates, Chiroptera, and Dermoptera is suggested. Significant differences between our findings and those of recent investigators include the dissociation of Pholidota from Xenarthra and the plesiomorphous position of Lipotyphla within Epitheria. Congruence between morphological and molecular results is closer than previously reported.

Animals↗
PubMed1983

Aberrant sex chromosome mechanisms in mammals. Evolutionary aspects.

There are a number of mammalian species with complicated or unknown mechanisms for sex determination. The literature is reviewed with special reference to the origin and evolution of the sex chromosome mechanisms in three species of monotremes and in the following species of rodents: the creeping vole (Microtus oregoni), the mole vole (Ellobius lutescens), the Amami spinous country rat (Tokudaia osimensis), the wood lemming (Myopus schisticolor), the varying lemming (Dicrostonyx torquatus), South American field mice (Akodon sp.), and the short-tailed bandicoot rat (Nesokia indica). Although this is a heterogeneous group with regard to their sex chromosomes, it is striking that among placental mammals only one order, Rodentia, and only two of its subfamilies, Microtinae and Murinae, are represented. Various reasons for this are discussed. Some of these species have proven to be excellent models for studies of fundamental processes involved in sex determination.

Animals↗