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1

Functional skeletal morphology and its implications for locomotory behavior among three genera of myosoricine shrews (Mammalia: Eulipotyphla: Soricidae).  

PubMed

Myosoricinae is a small clade of shrews (Mammalia, Eulipotyphla, Soricidae) that is currently restricted to the African continent. Individual species have limited distributions that are often associated with higher elevations. Although the majority of species in the subfamily are considered ambulatory in their locomotory behavior, species of the myosoricine genus Surdisorex are known to be semifossorial. To better characterize variation in locomotory behaviors among myosoricines, we calculated 32 morphological indices from skeletal measurements from nine species representing all three genera that comprise the subfamily (i.e., Congosorex, Myosorex, Surdisorex) and compared them to indices calculated for two species with well-documented locomotory behaviors: the ambulatory talpid Uropsilus soricipes and the semifossorial talpid Neurotrichus gibbsii. We summarized the 22 most complete morphological variables by 1) calculating a mean percentile rank for each species and 2) using the first principal component from principal component analysis of the indices. The two methods yielded similar results and indicate grades of adaptations reflecting a range of potential locomotory behaviors from ambulatory to semifossorial that exceeds the range represented by the two talpids. Morphological variation reflecting grades of increased semifossoriality among myosoricine shrews is similar in many respects to that seen for soricines, but some features are unique to the Myosoricinae. J. Morphol. 276:550-563, 2015. © 2015 Wiley Periodicals, Inc. PMID:25678028

Woodman, Neal; Stabile, Frank A

2015-05-01

2

Can they dig it? Functional morphology and semifossoriality among small-eared shrews, genus Cryptotis (Mammalia, Soricidae)  

USGS Publications Warehouse

Small-eared shrews (Mammalia: Soricidae: Cryptotis), exhibit modifications of the forelimb skeleton that have been interpreted as adaptations for semifossoriality. Most species inhabit remote regions, however, and their locomotory and foraging behaviors remain mostly speculative. To better understand the morphological modifications in the absence of direct observations, we quantified variation in these species by measuring 151 individuals representing 18 species and populations of Cryptotis and two species of moles (Talpidae) for comparison. From our measurements, we calculated 22 indices, most of which have been used previously to characterize substrate use among rodents and other taxa. We analyzed the indices using 1) average percentile ranks, 2) principal components analysis, and 3) cluster analysis. From these analyses, we determined that three basic modes of substrate adaptation are present within Cryptotis: 1) a primarily terrestrial mode, with species that are capable of burrowing, but lack adaptations to increase digging efficiency, 2) a semifossorial mode, with species whose forelimbs bones show strong muscle attachment areas and increased mechanical advantage, and 3) an intermediate mode. In addition to identifying new morphological characters and contributing to our understanding of the functional morphology of soricids, these analyses provide additional insight into the ecology of the species of interest.

Woodman, Neal; Gaffney, Sarah A.

2014-01-01

3

Can they dig it? Functional morphology and semifossoriality among small-eared shrews, genus Cryptotis (Mammalia, Soricidae).  

PubMed

Small-eared shrews (Mammalia: Soricidae: Cryptotis), exhibit modifications of the forelimb skeleton that have been interpreted as adaptations for semifossoriality. Most species inhabit remote regions, however, and their locomotory and foraging behaviors remain mostly speculative. To better understand the morphological modifications in the absence of direct observations, we quantified variation in these species by measuring 151 individuals representing 18 species and populations of Cryptotis and two species of moles (Talpidae) for comparison. From our measurements, we calculated 22 indices, most of which have been used previously to characterize substrate use among rodents and other taxa. We analyzed the indices using 1) average percentile ranks, 2) principal components analysis, and 3) cluster analysis. From these analyses, we determined that three basic modes of substrate adaptation are present within Cryptotis: 1) a primarily terrestrial mode, with species that are capable of burrowing, but lack adaptations to increase digging efficiency, 2) a semifossorial mode, with species whose forelimbs bones show strong muscle attachment areas and increased mechanical advantage, and 3) an intermediate mode. In addition to identifying new morphological characters and contributing to our understanding of the functional morphology of soricids, these analyses provide additional insight into the ecology of the species of interest. PMID:24470078

Woodman, Neal; Gaffney, Sarah A

2014-07-01

4

Phylogeny and Evolution of African Shrews (Mammalia: Soricidae) Inferred from 16s rRNA Sequences  

Microsoft Academic Search

Current phylogenetic hypotheses on the African Crocidurinae (Soricidae) are based upon morpho-anatomical, karyological, and allozyme studies. The present study attempts to resolve the interrelationships among African Crocidurinae and their relationships to Eurasian Crocidurinae and to the subfamily Soricinae, on the basis of partial mitochondrial 16s rRNA sequences (549 bp). This is the first molecular study to include all but one

Sophie Quérouil; Rainer Hutterer; Patrick Barrière; Marc Colyn; Julian C. Kerbis Peterhans; Erik Verheyen

2001-01-01

5

Skeletal morphology of the forefoot in shrews (Mammalia: Soricidae) of the genus Cryptotis, as revealed by digital x-rays  

USGS Publications Warehouse

Variation in the forefoot skeleton of small-eared shrews (family Soricidae, genus Cryptotis) has been previously documented, but the paucity of available skeletons for most taxa makes assessment of the degrees of intraspecific and interspecific variation difficult. We used a digital X-ray system to extract images of the forefoot skeleton from 101 dried skins of eight taxa (seven species, including two subspecies of one species) of these shrews. Lengths and widths of each of the four bones of digit III were measured directly from the digital images, and we used these data to quantify variation within and among taxa. Analysis of the images and measurements showed that interspecific variation exceeds intraspecific variation. In fact, most taxa could be distinguished in multivariate and some bivariate plots. Our quantitative data helped us define a number of specific forefoot characters that we subsequently used to hypothesize evolutionary relationships among the taxa using the exhaustive search option in PAUP, a computer program for phylogenetic analysis. The resulting trees generally concur with previously published evolutionary hypotheses for small-eared shrews. Cryptotis meridensis, a taxon not previously examined in recent phylogenies, is rooted at the base of the branch leading to the C. mexicana group of species. The position of this species suggests that the mostly South American C. thomasi group shares an early ancestor with the C. mexicana group.

Woodman, N.; Morgan, J.J.P.

2005-01-01

6

At the foot of the shrew: manus morphology distinguishes closely-related Cryptotis goodwini and Cryptotis griseoventris (Mammalia: Soricidae) in Central America  

USGS Publications Warehouse

Small-eared shrews (Mammalia, Soricidae) of the New World genus Cryptotis are distributed from eastern North America to the northern Andes of South America. One well-defined clade in this genus is the Central American Cryptotis mexicana group, whose members are set off from other species in the genus by their variably broader fore feet and more elongate and broadened fore claws. Two species in the C. mexicana group, Cryptotis goodwini Jackson and Cryptotis griseoventris Jackson, inhabit highlands in Guatemala and southern Mexico and are presumed to be sister species whose primary distinguishing feature is the larger body size of C. goodwini. To better characterize these species and confirm the identification of recently-collected specimens, we obtained digital X-ray images of the manus from large series of dried skins of both species. Measurements of the metacarpals and phalanges successfully separated most specimens of C. goodwini and C. griseoventris. These measurements also show that the fore feet of C. griseoventris from Chiapas, Mexico, are morphologically distinct from those of members of the species inhabiting Guatemala. Univariate, bivariate, and multivariate analyses indicate that fore foot characters are more conservative within species of the C. mexicana group than are cranio-mandibular characters. Patterns of evolution of fore foot characters that superficially appear to be linear gradations are actually more complex, illustrating individual evolutionary trajectories.

Woodman, Neal; Stephens, Ryan B.

2010-01-01

7

Biogeographical and Evolutionary Relationships Among Central American Small-Eared Shrews of the Genus Cryptotis (Mammalia: Insectivora: Soricidae)  

E-print Network

Small-eared shrews of the genus Cryptotis have a distribution that extends from southernmost Ontario and across much of the eastern half of the United States south to the northern Andean highlands. The genus attains its ...

Woodman, Neal

1992-09-09

8

A new species of small-eared shrew from Colombia and Venezuela (Mammalia: Soricomorpha: Soricidae: Genus Cryptotis)  

USGS Publications Warehouse

Populations of small-eared shrews inhabiting the northern Cordillera Oriental of Colombia and adjoining Venezuelan highlands in the vicinity of Paramo de Tama have been referred alternatively to Cryptotis thomssi or Cryptotis meridensis. Morphological and morphometrical study of this population indicates that it belongs to neither taxon, but represents a distinct, previously unrecognized species. I describe this new species as Cryptotis tamensis and redescribe C. meridensis. Recognition of the population at Paramo de Tama as a separate taxon calls into question the identities of populations of shrews currently represented only by single specimens from Cerro Pintado in the Sierra de Perija, Colombia, and near El Junquito in the coastal highlands of Venezuela.

Woodman, N.

2002-01-01

9

A new small-eared shrew of the Cryptotis nigrescens-group from Colombia (Mammalia: Soricomorpha: Soricidae)  

USGS Publications Warehouse

Cryptotis colombiana Woodman & Timm, 1993 previously was known from few specimens from two isolated regions in the Cordillera Central and Cordillera Oriental of Colombia. Recent collecting in the northern Cordillera Central and review of older collections from the central Cordillera Oriental in the vicinity of Bogota yielded additional specimens that permit reevaluation of the two geographic populations of these small-eared shrews. Morphological and morphometrical studies indicate that the population inhabiting the Cordillera Oriental represents a distinct, previously unrecognized species that I describe herein as Cryptotis brachyonyx. Study of 54 specimens of shrews from the Cordillera Oriental in systematic collections in North America, South America, and Europe yielded only four specimens of the new species, all collected before 1926. The paucity of modern specimens suggests that C. brachyonyx may be extremely restricted in distribution, or possibly extinct.

Woodman, N.

2003-01-01

10

Relationships of basal metabolic rate, relative testis size and cycle length of spermatogenesis in shrews (Mammalia, Soricidae).  

PubMed

The aim of the present study was to determinate the cycle length of spermatogenesis in three species of shrew, Suncus murinus, Sorex coronatus and Sorex minutus, and to assess the relative influence of variation in basal metabolic rate (BMR) and mating system (level of sperm competition) on the observed rate of spermatogenesis, including data of shrew species studied before (Sorex araneus, Crocidura russula and Neomys fodiens). The dynamics of sperm production were determined by tracing 5-bromodeoxyuridine in the DNA of germ cells. As a continuous scaling of mating systems is not evident, the level of sperm competition was evaluated by the significantly correlated relative testis size (RTS). The cycle durations estimated by linear regression were 14.3 days (RTS 0.3%) in Suncus murinus, 9.0 days (RTS 0.5%) in Sorex coronatus and 8.5 days (RTS 2.8%) in Sorex minutus. In regression and multiple regression analyses including all six studied species of shrew, cycle length was significantly correlated with BMR (r2=0.73) and RTS (r2=0.77). Sperm competition as an ultimate factor obviously leads to a reduction in the time of spermatogenesis in order to increase sperm production. BMR may act in the same way, independently or as a proximate factor, revealed by the covariation, but other factors (related to testes size and thus to mating system) may also be involved. PMID:18402763

Parapanov, Roumen; Nusslé, Sébastien; Hausser, Jacques; Vogel, Peter

2008-01-01

11

Cycle length of spermatogenesis in shrews (mammalia: soricidae) with high and low metabolic rates and different mating systems.  

PubMed

The aim of the present study was to establish and compare the durations of the seminiferous epithelium cycles of the common shrew Sorex araneus, which is characterized by a high metabolic rate and multiple paternity, and the greater white-toothed shrew Crocidura russula, which is characterized by a low metabolic rate and a monogamous mating system. Twelve S. araneus males and fifteen C. russula males were injected intraperitoneally with 5-bromodeoxyuridine, and the testes were collected. For cycle length determinations, we applied the classical method of estimation and linear regression as a new method. With regard to variance, and even with a relatively small sample size, the new method seems to be more precise. In addition, the regression method allows the inference of information for every animal tested, enabling comparisons of different factors with cycle lengths. Our results show that not only increased testis size leads to increased sperm production, but it also reduces the duration of spermatogenesis. The calculated cycle lengths were 8.35 days for S. araneus and 12.12 days for C. russula. The data obtained in the present study provide the basis for future investigations into the effects of metabolic rate and mating systems on the speed of spermatogenesis. PMID:17267697

Parapanov, Roumen; Nusslé, Sébastien; Vogel, Peter

2007-05-01

12

Fossil shrews from Honduras and their significance for late glacial evolution in body size (Mammalia: Soricidae: Cryptotis)  

USGS Publications Warehouse

Our study of mammalian remains excavated in the 1940s from McGrew Cave, north of Copan, Honduras, yielded an assemblage of 29 taxa that probably accumulated predominantly as the result of predation by owls. Among the taxa present are three species of small-eared shrews, genus Cryptotis. One species, Cryptotis merriami, is relatively rare among the fossil remains. The other two shrews, Cryptotis goodwini and Cryptotis orophila, are abundant and exhibit morpho metrical variation distinguishing them from modern populations. Fossils of C. goodwini are distinctly and consistently smaller than modern members of the species. To quantify the size differences, we derived common measures of body size for fossil C. goodwini using regression models based on modern samples of shrews in the Cryptotis mexicana-group. Estimated mean length of head and body for the fossil sample is 72-79 mm, and estimated mean mass is 7.6-9.6 g. These numbers indicate that the fossil sample averaged 6-14% smaller in head and body length and 39-52% less in mass than the modern sample and that increases of 6-17% in head and body length and 65-108% in mass occurred to achieve the mean body size of the modern sample. Conservative estimates of fresh (wet) food intake based on mass indicate that such a size increase would require a 37-58% increase in daily food consumption. In contrast to C. goodwini, fossil C. orophila from the cave is not different in mean body size from modern samples. The fossil sample does, however, show slightly greater variation in size than is currently present throughout the modern geographical distribution of the taxon. Moreover, variation in some other dental and mandibular characters is more constrained, exhibiting a more direct relationship to overall size. Our study of these species indicates that North American shrews have not all been static in size through time, as suggested by some previous work with fossil soricids. Lack of stratigraphic control within the site and our failure to obtain reliable radiometric dates on remains restrict our opportunities to place the site in a firm temporal context. However, the morphometrical differences we document for fossil C. orophila and C. goodwini show them to be distinct from modern populations of these shrews. Some other species of fossil mammals from McGrew Cave exhibit distinct size changes of the magnitudes experienced by many northern North American and some Mexican mammals during the transition from late glacial to Holocene environmental conditions, and it is likely that at least some of the remains from the cave are late Pleistocene in age. One curious factor is that, whereas most mainland mammals that exhibit large-scale size shifts during the late glacial/postglacial transition experienced dwarfing, C. goodwini increased in size. The lack of clinal variation in modern C. goodwini supports the hypothesis that size evolution can result from local selection rather than from cline translocation. Models of size change in mammals indicate that increased size, such as that observed for C. goodwini, are a likely consequence of increased availability of resources and, thereby, a relaxation of selection during critical times of the year.

Woodman, N.; Croft, D.A.

2005-01-01

13

Distributional records of shrews (Mammalia, Soricomorpha, Soricidae) from Northern Central America with the first record of Sorex from Honduras  

USGS Publications Warehouse

Short term surveys for small mammals in Guatemala and Honduras during 1992–2009 provided important new records for 12 taxa of shrews from 24 localities. These locality records expand the known geographic distributions for five species and for the genus Sorex Linnaeus, 1758: the geographic range of Cryptotis goodwini Jackson, 1933, now includes the Sierra de las Minas, Guatemala, and several isolated highlands in western Honduras; the known distribution of Cryptotis mayensis (Merriam, 1901) is increased with the first definite modern record for this shrew from Guatemala; Cryptotis merriami Choate, 1970, is now known to occur in the Sierra de las Minas and the Sierra del Merendon, Guatemala, as well as the isolated Sierra de Omoa and Montana de La Muralla in Honduras, and its documented elevational range (600–1720 m) is expanded; records of Sorex veraepacis Alston, 1877, expand the known distribution of this species to include the Sierra de Yalijux, Guatemala; and discovery of Sorex salvini Merriam, 1897, at Celaque, Honduras (1825–3110 m), represents a considerable extension of the geographic range of the species, and it is the first record of the genus Sorex from Honduras. In addition, the first record of potential syntopy among C. goodwini, C merriami, and Cryptotis orophilus (J.A. Allen, 1895), is reported at an elevation of 1430 m in the Sierra de Celaque, Honduras. Information associated with these records contributes substantially to knowledge of habitat use, elevational distributions, reproductive patterns, diet, and parasites of the species encountered. General patterns include the first evidence that Neotropical species of soricids have smaller litters than their temperate congeners.

Woodman, Neal; Matson, John O.; McCarthy, Timothy J.; Eckerlin, Ralph P.; Bulmer, Walter; Ordonez-Garza, Nicte

2012-01-01

14

Histological description of seminiferous epithelium and cycle length of spermatogenesis in the water shrew Neomys fodiens (Mammalia: Soricidae).  

PubMed

Recently, we examined the spermatogenesis cycle length in two shrews species, Sorex araneus characterized by a very high metabolic rate and a polyandric mating system (sperm competition) resulting in a short cycle and Crocidura russula characterized by a much lower metabolic rate and a monogamous mating system showing a longer cycle. In this study, we investigated the spermatogenesis cycle in Neomys fodiens showing an intermediate metabolic rate. We described the stages of seminiferous epithelium according to the spermatid morphology method and we calculated the cycle length of spermatogenesis using incorporation of 5-bromodeoxyuridine into DNA of the germ cells. Twelve males were injected intraperitoneally with 5-bromodeoxyuridine, and the testes were collected. For cycle length determination, we applied a recently developed statistical method. The calculated cycle length is 8.69 days and the total duration of spermatogenesis based on 4.5 cycles is approximately 39.1 days, intermediate between the duration of spermatogenesis of S. araneus (37.6 days) and C. russula (54.5 days) and therefore congruent with both the metabolic rate hypothesis and the sperm competition hypothesis. Relative testes size of 1.4% of body mass indicates a promiscuous mating system. PMID:17629637

Parapanov, Roumen; Nusslé, Sébastien; Hausser, Jacques; Vogel, Peter

2008-08-01

15

This shrew is a jumping mouse (Mammalia, Dipodidae): Sorex dichrurus Rafinesque 1833 is a synonym of Zapus hudsonius (Zimmermann 1780)  

USGS Publications Warehouse

Constantine S. Rafinesque described Sorex dichrurus as a shrew in 1833, based on a specimen he found in a proprietary museum near Niagara Falls on the New York/Ontario border. The name subsequently has been ignored by the scientific community. By describing this specimen as a shrew and ascribing it to the genus Sorex, Rafinesque clearly indicated that his species should be considered a member of the taxonomic family now recognized as the Soricidae (Mammalia, Eulipotyphla). Yet, the description of the animal, and its comparison to ‘‘Gerbillus,’’ clearly identify it as a dipodid rodent, specifically Zapus hudsonius (Zimmermann, 1780); S. dichrurus should be treated as a junior subjective synonym of that taxon. Based on its type locality of Goat Island, New York, this name is also a junior synonym of the subspecies Z. hudsonius canadensis (Davies, 1798).

Woodman, Neal

2012-01-01

16

Phylogeographical footprints of the Strait of Gibraltar and Quaternary climatic fluctuations in the western Mediterranean: a case study with the greater white-toothed shrew, Crocidura russula (Mammalia: Soricidae)  

Microsoft Academic Search

We used mitochondrial cyt b sequences to investigate the phylogenetic relationships of Crocidura russula ( sensu lato ) populations across the Strait of Gibraltar, western Europe, Maghreb, and the Mediterranean and Atlantic islands. This revealed very low genetic divergence between European and Moroccan populations. The application of a molecular clock previously calibrated for shrews suggested that the separation of European

JEAN-FRANÇOIS COSSON; RAINER HUTTERER; ROLAND LIBOIS; MAURIZIO SARÀ; PETER VOGEL

17

The Stephen H. Long Expedition (1819?1820), Titian R. Peale?s field illustrations, and the lost holotypes of the North American shrews Sorex brevicaudus Say and Sorex parvus Say (Mammalia: Soricidae) from the Philadelphia Museum  

USGS Publications Warehouse

While encamped for the winter of 1819?1820 at Engineer Cantonment along the Missouri River in present-day eastern Nebraska, members of Major Stephen Harriman Long?s Expedition to the Rocky Mountains collected a number of animals that were previously unknown. Among the mammals were two soricids that were subsequently described by Thomas Say as Sorex brevicaudus (Northern Short-tailed Shrew, Blarina brevicauda) and Sorex parvus (Least Shrew, Cryptotis parvus). The holotypes of these species were deposited and placed on public exhibit in the Philadelphia Museum, the predominant North American systematic collection of the early nineteenth century. Like most private museums of that era, the Philadelphia Museum eventually went out of business, and its collections were dispersed and, for the most part, lost. Fortunately, Titian R. Peale made a detailed field sketch of the two specimens soon after their capture and subsequently executed a watercolor based on that sketch. In addition, an engraving of the holotypes was published in the decade following the discovery of the two species. Illustrations of holotypes are taxonomically useful when they depict diagnostic characters of species. They take on added taxonomic significance in the absence of the holotypes. In the cases of Sorex brevicaudus and Sorex parvus, pictures provide strong confirmation of the taxonomic identities of these two species, as well as recording the early history of the specimens.

Woodman, N.

2009-01-01

18

Phylogeographical footprints of the Strait of Gibraltar and Quaternary climatic fluctuations in the western Mediterranean: a case study with the greater white-toothed shrew, Crocidura russula (Mammalia: Soricidae).  

PubMed

We used mitochondrial cyt b sequences to investigate the phylogenetic relationships of Crocidura russula (sensu lato) populations across the Strait of Gibraltar, western Europe, Maghreb, and the Mediterranean and Atlantic islands. This revealed very low genetic divergence between European and Moroccan populations. The application of a molecular clock previously calibrated for shrews suggested that the separation of European from Moroccan lineages occurred less than 60 000 bp, which is at least 5 million years (Myr) after the reopening of the Strait of Gibraltar. This means that an overwater dispersal event was responsible for the observed phylogeographical structure. In contrast, genetic analyses revealed that Moroccan populations were highly distinct from Tunisian ones. According to the molecular clock, these populations separated about 2.2 million years ago (Ma), a time marked by sharp alternations of dry and humid climates in the Maghreb. The populations of the Mediterranean islands Ibiza, Pantelleria, and Sardinia were founded from Tunisian populations by overwater dispersal. In conclusion, overwater dispersal across the Strait of Gibraltar, probably assisted by humans, is possible for small terrestrial vertebrates. Moreover, as in Europe, Quaternary climatic fluctuations had a major effect on the phylogeographical structure of the Maghreb biota. PMID:15773942

Cosson, Jean-François; Hutterer, Rainer; Libois, Roland; Sarà, Maurizio; Taberlet, Pierre; Vogel, Peter

2005-04-01

19

Cornea, retina, and lens morphology in five Soricidae species (Soricomorpha: Mammalia).  

PubMed

We analyzed the cornea, retina, and lens of five species of Soricidae (pygmy shrew, Sorex minutus; common shrew, Sorex araneus; Millet's shrew, Sorex coronatus; water shrew, Neomys fodiens; greater white-toothed shrew, Crocidura russula) by light and electron microscopy. In all of these species, the corneal epithelium showed a dead cell layer, which may increase the refractive power of the cornea, thereby reducing the hypermetropy that would be expected in a small eye. Moreover, the anterior surface of the lens was more curved than the posterior, thus minimizing spherical aberrations. The thicker lens and its smaller radii of curvature indicated that Sorex species and N. fodiens have a higher refractive lens power than the most nocturnal species, C. russula. In addition, only in the retina cone inner segments of the most diurnal species (genus Sorex) did we find megamitochondria that might act as microlenses to enhance the efficiency of cones. In C. russula, the scarcity of cones and the relatively small yet abundant rod nuclei were found to be consistent with its habits. The flat lens and its more anterior arrangement, together with the lack of megamitochondria in the retina of C. russula, indicated that this species has less visual acuity than the other shrews studied here. PMID:19367448

Lluch, Sara; López-Fuster, María José; Ventura, Jacint

2009-12-01

20

Molecular phylogeny of short-tailed shrews, Blarina (Insectivora: Soricidae).  

PubMed

Phylogenetic relationships among the three described species of short-tailed shrews (genus Blarina) were inferred based on mitochondrial DNA sequences of 16S rRNA (506 bp) and cytochrome b (1137 bp) from 38 specimens representing B. brevicauda, B. hylophaga, and B. carolinensis, from across their range in North America. Phylogenetic analyses of both data sets combined followed tests showing lack of incongruence between these fragments. Analysis of substitution patterns indicated saturation of transitions at third codon positions in cytochrome b when Blarina sequences were compared to those of Sorex and Cryptotis, used as outgroups. Maximum-likelihood and weighted parsimony supported the monophyly of the genus and placed B. hylophaga as its basal branch, sister to B. brevicauda + B. carolinensis. Phylogeographic analysis revealed a significant partition between eastern and western populations of B. carolinensis and B. brevicauda, on either side of the Mississippi basin. These results are discussed in relation to cytogenetic, morphological, and fossil data. PMID:11820838

Brant, Sara V; Ortí, Guillermo

2002-02-01

21

Fine structure of the submandibular salivary gland of the venomous short-tailed shrew, Blarina brevicauda Say (Insectivora: Soricidae).  

PubMed

Adult male short-tailed shrews, Blarina brevicauda, (Insectivora: Soricidae) were trapped in Virginia and Pennsylvania, anesthetized, and perfused via the left ventricle of the heart with fixative. The submandibular glands were dissected free and prepared for transmission electron microscopy. The lobular, compound tubuloacinar glands had secretory endpieces consisting of seromucous acini and serous tubules connected to intercalated ducts, granular ducts, striated ducts, and excretory ducts. The general cytology of the submandibular gland of Blarina shared morphological characters with individuals in several other mammalian orders and yet differed in many ways from another Insectivore, the European hedgehog, Erinaceus europaeus. PMID:8398545

Carson, K A; Rose, R K

1993-01-01

22

First evidence of poisonous shrews with an envenomation apparatus  

Microsoft Academic Search

Herein, we report evidence of an envenomation apparatus (EA) in two different species of extinct “giant” shrews, Beremendia and an indeterminate soricine (Mammalia, Eulipotyphla, Soricidae), documented by very well preserved fossil specimens recovered\\u000a from two Early Pleistocene cave deposits of the Sierra de Atapuerca in Burgos, Spain. The two soricine taxa from Atapuerca\\u000a have evolved specialized teeth as EAs, which

Gloria Cuenca-Bescós; Juan Rofes

2007-01-01

23

Persistence and diversification of the Holarctic shrew, Sorex tundrensis (Family Soricidae), in response to  

E-print Network

communities. The tundra shrew and its sister species, the Tien Shan shrew (Sorex asper), exhibit strong timeframes deeper than the periodicity of Pleistocene glacial cycling. That some species such as the tundra are, to varying degrees, specialized for a cold climate, as exemplified by the tundra community

24

Recombination Map of the Common Shrew, Sorex araneus (Eulipotyphla, Mammalia)  

PubMed Central

The Eurasian common shrew (Sorex araneus L.) is characterized by spectacular chromosomal variation, both autosomal variation of the Robertsonian type and an XX/XY1Y2 system of sex determination. It is an important mammalian model of chromosomal and genome evolution as it is one of the few species with a complete genome sequence. Here we generate a high-precision cytological recombination map for the species, the third such map produced in mammals, following those for humans and house mice. We prepared synaptonemal complex (SC) spreads of meiotic chromosomes from 638 spermatocytes of 22 males of nine different Robertsonian karyotypes, identifying each autosome arm by differential DAPI staining. Altogether we mapped 13,983 recombination sites along 7095 individual autosomes, using immunolocalization of MLH1, a mismatch repair protein marking recombination sites. We estimated the total recombination length of the shrew genome as 1145 cM. The majority of bivalents showed a high recombination frequency near the telomeres and a low frequency near the centromeres. The distances between MLH1 foci were consistent with crossover interference both within chromosome arms and across the centromere in metacentric bivalents. The pattern of recombination along a chromosome arm was a function of its length, interference, and centromere and telomere effects. The specific DNA sequence must also be important because chromosome arms of the same length differed substantially in their recombination pattern. These features of recombination show great similarity with humans and mice and suggest generality among mammals. However, contrary to a widespread perception, the metacentric bivalent tu usually lacked an MLH1 focus on one of its chromosome arms, arguing against a minimum requirement of one chiasma per chromosome arm for correct segregation. With regard to autosomal chromosomal variation, the chromosomes showing Robertsonian polymorphism display MLH1 foci that become increasingly distal when comparing acrocentric homozygotes, heterozygotes, and metacentric homozygotes. Within the sex trivalent XY1Y2, the autosomal part of the complex behaves similarly to other autosomes. PMID:18245365

Borodin, Pavel M.; Karamysheva, Tatyana V.; Belonogova, Nadezhda M.; Torgasheva, Anna A.; Rubtsov, Nikolai B.; Searle, Jeremy B.

2008-01-01

25

Persistence and diversification of the Holarctic shrew, Sorex tundrensis (Family Soricidae), in response to climate change  

USGS Publications Warehouse

Environmental processes govern demography, species movements, community turnover and diversification and yet in many respects these dynamics are still poorly understood at high latitudes. We investigate the combined effects of climate change and geography through time for a widespread Holarctic shrew, Sorex tundrensis. We include a comprehensive suite of closely related outgroup taxa and three independent loci to explore phylogeographic structure and historical demography. We then explore the implications of these findings for other members of boreal communities. The tundra shrew and its sister species, the Tien Shan shrew (Sorex asper), exhibit strong geographic population structure across Siberia and into Beringia illustrating local centres of endemism that correspond to Late Pleistocene refugia. Ecological niche predictions for both current and historical distributions indicate a model of persistence through time despite dramatic climate change. Species tree estimation under a coalescent process suggests that isolation between populations has been maintained across timeframes deeper than the periodicity of Pleistocene glacial cycling. That some species such as the tundra shrew have a history of persistence largely independent of changing climate, whereas other boreal species shifted their ranges in response to climate change, highlights the dynamic processes of community assembly at high latitudes.

Hope, Andrew G.; Waltari, Eric; Fedorov, V.B.; Goropashnaya, A.V.; Talbot, Sandra; Cook, Joseph A.

2014-01-01

26

The maritime shrew, Sorex maritimensis (Insectivora: Soricidae): a newly recognized Canadian endemic  

Microsoft Academic Search

Previous morphological and cytological analyses have suggested that the arctic shrew (Sorex arcticus )a s currently recognized may be two distinct species. Specifically, those studies demonstrated considerable differentiation between the putative subspecies S. a. maritimensis and one or both of the other two subspecies, S. a. arcticus and S. a. laricorum. Phylogenetic analysis of 546 base pairs of cytochrome b

Donald T. Stewart; Neil D. Perry; Luca Fumagalli

2002-01-01

27

Persistence and diversification of the Holarctic shrew, Sorex tundrensis (Family Soricidae), in response to climate change  

USGS Publications Warehouse

Environmental processes govern demography, species movements, community turnover and diversification and yet in many respects these dynamics are still poorly understood at high latitudes. We investigate the combined effects of climate change and geography through time for a widespread Holarctic shrew, Sorex tundrensis. We include a comprehensive suite of closely related outgroup taxa and three independent loci to explore phylogeographic structure and historical demography. We then explore the implications of these findings for other members of boreal communities. The tundra shrew and its sister species, the Tien Shan shrew (Sorex asper), exhibit strong geographic population structure across Siberia and into Beringia illustrating local centres of endemism that correspond to Late Pleistocene refugia. Ecological niche predictions for both current and historical distributions indicate a model of persistence through time despite dramatic climate change. Species tree estimation under a coalescent process suggests that isolation between populations has been maintained across timeframes deeper than the periodicity of Pleistocene glacial cycling. That some species such as the tundra shrew have a history of persistence largely independent of changing climate, whereas other boreal species shifted their ranges in response to climate change, highlights the dynamic processes of community assembly at high latitudes. ?? 2011 Blackwell Publishing Ltd.

Hope, A.G.; Waltari, Eric; Fedorov, V.B.; Goropashnaya, A.V.; Talbot, S.L.; Cook, J.A.

2011-01-01

28

A new species of small-eared shrew (Mammalia, Eulipotyphla, Cryptotis) from the Lacandona rain forest, Mexico  

USGS Publications Warehouse

The diversity and distribution of mammals in the American tropics remain incompletely known. We describe a new species of small-eared shrew (Soricidae, Cryptotis) from the Lacandona rain forest, Chiapas, southern Mexico. The new species is distinguished from other species of Cryptotis on the basis of a unique combination of pelage coloration, size, dental, cranial, postcranial, and external characters, and genetic distances. It appears most closely related to species in the Cryptotis nigrescens species group, which occurs from southern Mexico to montane regions of Colombia. This discovery is particularly remarkable because the new species is from a low-elevation habitat (approximately 90 m), whereas most shrews in the region are restricted to higher elevations, typically > 1,000 m. The only known locality for the new shrew is in one of the last areas in southern Mexico where relatively undisturbed tropical vegetation is still found. The type locality is protected by the Mexican government as part of the Yaxchilán Archaeological Site on the border between Mexico and Guatemala.

Guevara, Lázaro; Sánchez-Cordero, Víctor; León-Paniagua, Livia; Woodman, Neal

2014-01-01

29

Helminth associations in white-toothed shrews Crocidura russula (Insectivora: Soricidae) from the Albufera Natural Park, Spain.  

PubMed

The helminths of 218 white-toothed shrews from 29 sites in 2 biotopes in the Albufera Natural Park (Valencia, Spain) were examined from July 1990 to August 1991. An association analysis of helminths occurring at a prevalence of more than 4% was carried out for 4 species of cestodes located in the intestine (Hymenolepis pistillum, H. scalaris, H. tiara, and Pseudhymenolepis redonica) and 3 species of nematodes (Pseudophysaloptera sp. located in the stomach, Stammerinema rhopocephala larvae in the intestine and abdominal cavity, and Porrocaecum sp. in the thoracic and abdominal cavities). Bivariate (species pairs) versus multivariate analyses (associations within the entire set of species) were performed of presence-absence and of quantitative records (influence of intensity on associations). The associations were evaluated with respect to the sex and age of the host and to the sampling date and sites. The host and environment played a limited role, and the major determinant of species assemblage was phylogenetic. Positive associations were found among both the cestodes and the nematodes, whereas negative associations were found between cestodes and nematodes. The type of life cycle was probably the second greatest determinant of species associations. Nematodes using shrews as a paratenic host or as their definitive host were both positively associated. PMID:15270101

Portolés, Enrique; Granel, Pedro; Esteban, J Guillermo; Cabaret, Jacques

2004-06-01

30

The identity of the enigmatic "Black Shrew" (Sorex niger Ord, 1815)  

USGS Publications Warehouse

The scientific name Sorex niger Ord, 1815 (Mammalia, Soricidae) was originally applied to a North American species that George Ord called the “Black Shrew.” The origin of the name “Black Shrew,” however, was obscure, and Samuel Rhoads subsequently wrote that the species represented by this name could not be determined. The names Sorex niger Ord and Black Shrew have since been mostly forgotten. Two of Ord's contemporaries, however, noted that Ord's use of these names probably alluded to Benjamin Smith Barton's Black Shrew, whose discovery near Philadelphia was announced by Barton in 1806. Examination of two unpublished illustrations of the Black Shrew made by Barton indicates that the animal depicted is Blarina brevicauda (Say, 1822). Had the connection between Ord's and Barton's names been made more clearly, one of the most common mammals in eastern North America would bear a different scientific name today. This connection also would have affected the validity of Sorex niger Horsfield, 1851. While Sorex niger Ord remains a nomen nudum, the animal it referenced can now be identified.

Woodman, Neal

2013-01-01

31

Quantitative cytoarchitecture of the liver of the shrew Crocidura russula (fam. Soricidae). Ultrastructural and morphometric comparison with rat liver.  

PubMed

The livers of two groups of the shrew Crocidura russula, kept under standardized physiological conditions, were investigated with electron microscopy and morphometry. The adaptations to the extremely high basal metabolism of these small mammals are reflected in the architectural characteristics of the hapatocytes, which, in comparison with those of the rat, show a smaller cell volume of the mononuclear hepatocytes (3,800 micrometers3), and increased number of cells per cm3 of liver tissue (250 X 10(6)), and a relative larger liver volume (4.85 ml per 100 g body weight). The ground substance is reduced by the other cell compartments to 4%. The volume density of the glycogen differs from 5-15% and the variation of the SER is from 10-20%. The RER (constant at about 35%) and the mitochondria (around 30%) form the main part of the cytoplasm of the hepatocyte. The mean volume of individual mitochondria amounts to 2.5 micrometers3. The chrondriome in the cell shows important numerical-volumetrical transformations, i.e, an increase in the individual volume of mitochondria correlating with a decrease in the number of the mitochondria per volume unit and vice versa. The adaptations to the high basal metabolism and the special conditions of life (short phases of activity, long resting times) are considered in relation to the possible functional activity of the megamitochondria. PMID:7105142

Durrer, H

1982-01-01

32

Geographic variation and evolutionary relationships among broad-clawed shrews of the Cryptotis goldmani–group (Mammalia: Insectivora: Soricidae)  

E-print Network

. James W. Bee (KU unpublished field cat- alog, 1954, 1955) recorded taking Sorex verae- pacis, Microtus guatemalensis, Peromyscus gua- temalensis, Reithrodontomys microdon, Reithro- dontomys sumichrasti, and Reithrodontomys ten- uirostris along..., Peromyscus levipes, Reithrodontomys fulvescens, Reithrodontomys mexicanus, R. sumichrasti, and Scotinomy tegui- na. Reproductive data for Cryptotis goodwini goodwini are lacking. Our inspection of study skins of males taken from 4 to 15 January (n = 6...

Woodman, Neal; Timm, Robert M.

1999-01-01

33

Taxonomy and evolutionary relationships of Phillips’ small-eared shrew, Cryptotis phillipsii (Schaldach, 1966), from Oaxaca, Mexico (Mammalia: Insectivora: Soricidae)  

E-print Network

mexi- cana, two Oryzomys chapmani, 12 Pero- myscus megalops, and one Reithrodonto- mys mexicanus. Nearby, "among & under rocks in an overgrown field," he collected a C. phillipsii with two Reithrodontomys megalotis, three R. sumichrasti, and one...

Woodman, Neal; Timm, Robert M.

2000-07-01

34

Phylogeography of the dusky shrew, Sorex monticolus (Insectivora, Soricidae): insight into deep and shallow history in northwestern North America.  

PubMed

Phylogenetic relationships among the dusky shrew (Sorexmonticolus) and eight related species (S. bairdi, S. bendirii, S. neomexicanus, S.ornatus, S. pacificus, S. palustris, S. sonomae and S.vagrans) were assessed using sequences from the mitochondrial cytochrome b gene (801 bp). Analyses using parsimony and maximum likelihood revealed significant molecular variation not reflected in previous morphological studies of these species. Conversely, three morphologically defined species (S.bairdi, S.neomexicanus and S.pacificus) were poorly differentiated. Sorexornatus and S.vagrans represented basal taxa for a more inclusive group that included: (i) a widespread Continental clade containing S.monticolus (Arizona to Alaska, including S. neomexicanus); (ii) a Coastal clade containing S.monticolus (Oregon to south-east Alaska, including S. bairdi and S. pacificus); (iii) the semiaquatic species (S. bendirii and S. palustris); and (iv) S.sonomae. Additional subdivision was observed within the Continental clade corresponding to populations from the northern and southern Rocky Mountains. Average uncorrected sequence divergence between the Coastal and Continental clades was 5.3% (range 4.5-6.2%), which exceeds many interspecific comparisons within this species complex and within the genus Sorex. Lack of resolution of internal nodes within topologies suggests a deep history of rapid diversification within this group. Late Pleistocene/Holocene glacial perturbations are reflected in the shallow phylogeographic structure within these clades in western North America. Our results suggest also that S. monticolus is not monophyletic under current taxonomic nomenclature. This perspective on phylogeographic history was developed within a growing comparative framework for other organisms in western North America. PMID:11380879

Demboski, J R; Cook, J A

2001-05-01

35

White-toothed shrews (Mammalia, Soricomorpha, Crocidura) of coastal islands of Vietnam  

PubMed Central

Abstract New findings of the white-toothed shrews (Crocidura spp.) from offshore islands of Vietnam are reported. The species identifications have been confirmed by the analysis of complete mitochondrial cytochrome b gene (1140 bp). Crocidura phuquocensis is the only species found in the Phu Quoc Island. Crocidura fuliginosa has been recorded from two islands of the Con Dao Archipelago (Con Son and Bai Canh). The occurrence of Crocidura fuliginosa in Vietnam has been genetically confirmed for the first time. Crocidura attenuata has been collected from the Cat Ba Island for the first time, and this finding corresponds well with the proposal that the species’ distribution is confined to the north and east of the Red River only. PMID:22855639

Abramov, Alexei V.; Bannikova, Anna A.; Rozhnov, Viatcheslav V.

2012-01-01

36

Taxonomic status and origin of the shrews (Soricidae) from the Canary islands inferred from a mtDNA comparison with the European Crocidura species.  

PubMed

European island shrews are either relicts of the endemic Pleistocene fauna, e.g.,. Crocidura zimmermanni, or were introduced from continental source populations. In order to clarify the taxonomic status and the origin of the two shrew species from the Canary islands, a 981bp fragment of cytochrome b gene was investigated in all European Crocidura species and compared with the Canary shrew (Crocidura canariensis) and the Osorio shrew (Crocidura osorio). The first shares its karyotype with the Sicilian shrew Crocidura sicula (2N=36), the second with the Greater white-toothed shrew Crocidura russula (2N=42), suggesting possible sister species relationships. Results confirm the monophyly of taxa sharing the same karyotype. Genetic distances between C. sicula and C. canariensis suggest a separation since 5 Myr. The first was probably isolated from the North African ancestor after the Messinian desiccation; the second arrived on the Canary islands by natural jump dispersal. Within the 2N=42 cluster, a first split separated an Eastern line (Tunisia) from a western line (Morocco/Europe) of C. russula. C. osorio clusters together with C. russula from Spain, indicating conspecificy. This suggests a recent introduction from Spain by human. PMID:12695091

Vogel, Peter; Cosson, Jean François; López Jurado, Luis F

2003-05-01

37

Short Report: Phylogenetically Distinct Hantaviruses in the Masked Shre w( Sorex cinereus) and Dusky Shrew (Sorex monticolus) in the United States  

Microsoft Academic Search

A limited search for hantaviruses in lung and liver tissues of Sorex shrews (family Soricidae, subfamily Soricinae) revealed phylogenetically distinct hantaviruses in the masked shrew (Sorex cinereus) from Minnesota and in the dusky shrew (Sorex monticolus) from New Mexico and Colorado. The discovery of these shrew-borne hantaviruses, named Ash River virus and Jemez Springs virus, respectively, challenges the long-held dogma

Satoru Arai; Shannon N. Bennett; Laarni Sumibcay; Joseph A. Cook; Jin-Won Song; Andrew Hope; Cheryl Parmenter; Vivek R. Nerurkar; Terry L. Yates; Richard Yanagihara

2008-01-01

38

[Respiratory function of blood and relative weight of certain organs in two species of shrew: Crocidura russula and Suncus etruscus (Soricidae mammals)].  

PubMed

A high oxygen capacity combined with a low oxygen affinity and a large Bohr effect achieve a high oxygen transport capacity in small shrews. The high metabolic rate (Suncus estruscus: 100 to 350 ml O2/kg. min) can be explained by the combination of the favorable blood parameters with a high relative heart weight (1,2% of body weight) and heart frequencies of 1,000 to 1,350 per minute. PMID:27314

Bartels, H; Bartels, R; Baumann, R; Fons, R; Jürgens, K D; Wright, P

1978-04-24

39

Coccidian parasites (Apicomplexa: Eimeriidae) from insectivores. III. Seven new species in shrews (Soricidae: Soricinae) from Canada, Japan, and the United States.  

PubMed

Since May 1979, 458 shrews (Blarina sp. and Sorex spp.) representing 20 species collected in Canada, Japan, and the United States were examined for coccidia; 110 (24%) had oocysts in their feces, including 8 of 21 (38%) B. brevicauda from Massachusetts, Ohio, Pennsylvania, and Vermont; 2 of 7 (29%) S. caecutiens from Hokkaido and Honshu; 14 of 63 (22%) S. cinereus from Colorado, New Mexico, Pennsylvania, Vermont, Manitoba, and Ontario; 3 of 7 (43%) S. fontinalis from Pennsylvania; 11 of 16 (69%) S. fumeus from Massachusetts, Minnesota, Pennsylvania, Vermont, and Ontario; 1 of 4 (25%) S. haydeni from Minnesota; 6 of 8 (75%) S. longirostris from Florida and Virginia; 1 of 2 (50%) S. ornatus from California; 5 of 12 (42%) S. pacificus from California and Oregon; 13 of 41 (32%) S. palustris from California, Colorado, and New Mexico; 1 of 2 (50%) S. tenellus from California; 11 of 105 (10%) S. trowbridgii from California, Oregon, and Washington; 10 of 48 (21%) S. unguiculatus from Hokkaido; and 24 of 112 (21%) S. vagrans from Arizona, California, Colorado, New Mexico, Oregon, and Washington. The following coccidians were identified from infected shrews: Eimeria brevicauda n. sp. from B. brevicauda; Eimeria fumeus n. sp. from S. fumeus, S. pacificus, S. unguiculatus, and S. vagrans; Eimeria inyoni n. sp. from S. tenellus; Eimeria palustris n. sp. from S. cinereus, S. fontinalis, S. fumeus, S. haydeni, S. longirostris, S. ornatus, S. pacificus, S. palustris, S. tenellus, S. trowbridgii, and S. vagrans; Eimeria vagrantis n. sp. from S. fumeus, S. trowbridgii, and S. vagrans; Isospora brevicauda n. sp. from B. brevicauda; and Isospora palustris n. sp. from S. pacificus, S. palustris, S. trowbridgii, S. unguiculatus, and S. vagrans. The world literature on coccidian parasites of shrews (16 eimerians and 3 isosporans exclusive of the 7 new species described here) is reviewed. PMID:3572649

Hertel, L A; Duszynski, D W

1987-02-01

40

Evolution of mtDNA D-loop sequences and their use in phylogenetic studies of shrews in the subgenus Otisorex (Sorex: Soricidae: Insectivora).  

PubMed

mtDNA D-loop sequences were examined in shrews of the genus Sorex. All specimens possessed an array of tandem repeats in which each repeat was 78 to 80 base pairs (bp) in length. Each specimen also possessed a 76-bp imperfect copy of the tandem repeats. Three observations are consistent with the tandem repeats being the product of concerted evolution: (1) the repeats are capable of forming secondary structures; (2) there was minimal sequence divergence between tandem repeats within individuals; and (3) although the tandem repeats and the imperfect repeat presumably arose due to a duplication event in an ancestor of the shrews, the imperfect repeat per se was not copied in any of the specimens observed. Interspecific homology can therefore be assumed for the imperfect repeat. Furthermore, given the apparent high rate of concerted evolution within a genome, tandem repeats in different individuals may be compared as though only a single copy were present. By including data from the imperfect repeat, the last tandem repeat, and the surrounding unique sequence cladistic and genetic distance approaches to phylogeny reconstruction indicated two sister groups within the subgenus Otisorex. One group was composed of Sorex fumeus and the S. cinereus species complex and the other group was composed of S. hoyi, S. monticolus, S. vagrans, and S. palustris. Resolution of relationships among recently evolved taxa demonstrated the usefulness of selected regions of the D-loop for molecular systematic studies. PMID:8025728

Stewart, D T; Baker, A J

1994-03-01

41

Maximal enzyme activities, and myoglobin and glutathione concentrations in heart, liver and skeletal muscle of the Northern Short-tailed shrew (Blarina brevicauda; Insectivora: Soricidae).  

PubMed

We measured the enzymes of glycolysis, Krebs Cycle, beta-oxidation and electron transport in the heart, liver and skeletal muscle of the Northern Short-tailed Shrew, Blarina brevicauda. Additionally, we measured the amount of myoglobin in skeletal and heart muscle as well as the concentration of glutathione in heart. The picture that emerges is of an aerobically well-endowed animal with constrained anaerobic capacity as indicated by small activities of glycolytic enzymes and creatine kinase. Lipid metabolism and amino acid transamination, as well as gluconeogenesis, are predominant in processing carbon resources and probably reflect the large contribution lipid and protein make to the diet of this carnivore. The citrate synthase activity is the largest of any reported value for vertebrate heart (250 U/g). The additional, very active cytochrome c oxidase activity (220 U/g) and large myoglobin concentrations (8 mg/g) in heart are clearly the underpinnings of the rapid metabolic rates reported for small insectivores. The potential for generation of reactive oxygen species must be great since the total glutathione concentration (165 mumol/g) is 300-fold greater in shrew hearts than in hearts of rats. PMID:15914053

Stewart, J M; Woods, A K; Blakely, J A

2005-07-01

42

Contraction parameters, myosin composition and metabolic enzymes of the skeletal muscles of the etruscan shrew Suncus etruscus and of the common European white-toothed shrew Crocidura russula (Insectivora: soricidae).  

PubMed

In the Etruscan shrew, the isometric twitch contraction times of extensor digitorum longus (EDL) and soleus muscles are shorter than in any other mammal, allowing these muscles to contract at outstandingly high contraction frequencies. This species has the highest mass-specific metabolic rate of all mammals and requires fast skeletal muscles not only for locomotion but also for effective heat production and for an extremely high ventilation rate. No differences could be detected in the fibre type pattern, the myosin heavy and light chain composition, or in the activity of the metabolic enzymes lactate dehydrogenase and citrate synthase of the two limb muscles, the EDL and the soleus, which in larger mammalian species exhibit distinct differences in contractile proteins and metabolic enzymes. All properties determined in EDL and soleus muscles of Suncus etruscus, as well as in the larger Crocidura russula, are typical for fast-oxidative fibres, and the same holds for several other skeletal muscles including the diaphragm muscle of S. etruscus. Nevertheless, the EDL and soleus muscles showed different mechanical properties in the two shrew species. Relaxation times and, in C. russula, time to peak force are shorter in the EDL than in the soleus muscle. This is in accordance with the time course of the Ca(2+) transients in these muscles. Such a result could be due to different parvalbumin concentrations, to a different volume fraction of the sarcoplasmic reticulum in the two muscles or to different Ca(2+)-ATPase activities. Alternatively, the lower content of cytosolic creatine kinase (CK) in the soleus compared with the EDL muscle could indicate that the observed difference in contraction times between these shrew muscles is due to the CK-controlled activity of their sarcoplasmic reticulum Ca(2+)-ATPase. PMID:10460733

Peters, T; Kubis, H P; Wetzel, P; Sender, S; Asmussen, G; Fons, R; Jürgens, K D

1999-09-01

43

Novel Hantavirus in the Flat-Skulled Shrew (Sorex roboratus)  

PubMed Central

Abstract Genetically distinct hantaviruses have been identified recently in multiple species of shrews (Order Soricomorpha, Family Soricidae) in Eurasia and North America. To corroborate decades-old reports of hantaviral antigens in shrews from Russia, archival liver and lung tissues from 4 Siberian large-toothed shrews (Sorex daphaenodon), 5 Eurasian least shrews (Sorex minutissimus), 12 flat-skulled shrews (Sorex roboratus), and 18 tundra shrews (Sorex tundrensis), captured in the Sakha Republic in northeastern Siberia during July and August 2006, were analyzed for hantavirus RNA by reverse transcription–polymerase chain reaction. A novel hantavirus, named Kenkeme virus, was detected in a flat-skulled shrew. Sequence analysis of the full-length S and partial M and L segments indicated that Kenkeme virus was genetically and phylogenetically distinct from Seewis virus harbored by the Eurasian common shrew (Sorex araneus), as well as all other rodent-, soricid-, and talpid-borne hantaviruses. PMID:20426682

Kang, Hae Ji; Arai, Satoru; Hope, Andrew G.; Cook, Joseph A.

2010-01-01

44

Hand development and sequence of ossification in the forelimb of the European shrew Crocidura russula (Soricidae) and comparisons across therian mammals  

PubMed Central

Hand development in the European shrew Crocidura russula is described, based on the examination of a cleared and double-stained ontogenetic series and histological sections of a c. 20-day-old embryo and a neonate. In the embryo all carpal elements are still mesenchymal condensations, and there are three more elements than in the adult stage: the ‘lunatum’, which fuses with the scaphoid around birth; a centrale, which either fuses with another carpal element or just disappears later in ontogeny; and the anlage of an element that later fuses with the radius. Carpal arrangement in the neonate and the adult is the same. In order to compare the relative timing of the onset of ossification in forelimb bones in C. russula with that of other therians, we built up two matrices of events based on two sets of data and used the event-pair method. In the first analysis, ossification of forelimb elements in general was examined, including that of the humerus, radius, ulna, the first carpal and metacarpal to ossify, and the phalanges of the third digit. The second analysis included each carpal, humerus, radius, ulna, the first metacarpal and the first phalanx to ossify. Some characters (= event–pairs) provide synapomorphies for some clades examined. There have been some shifts in the timing of ossification apparently not caused by ecological and/or environmental influences. In two species (Oryctolagus and Myotis), there is a tendency to start the ossification of the carpals relatively earlier than in all other species examined, the sauropsid outgroups included. PMID:15291793

Prochel, Jan; Vogel, Peter; Sánchez-Villagra, Marcelo R

2004-01-01

45

Hand development and sequence of ossification in the forelimb of the European shrew Crocidura russula (Soricidae) and comparisons across therian mammals.  

PubMed

Hand development in the European shrew Crocidura russula is described, based on the examination of a cleared and double-stained ontogenetic series and histological sections of a c. 20-day-old embryo and a neonate. In the embryo all carpal elements are still mesenchymal condensations, and there are three more elements than in the adult stage: the 'lunatum', which fuses with the scaphoid around birth; a centrale, which either fuses with another carpal element or just disappears later in ontogeny; and the anlage of an element that later fuses with the radius. Carpal arrangement in the neonate and the adult is the same. In order to compare the relative timing of the onset of ossification in forelimb bones in C. russula with that of other therians, we built up two matrices of events based on two sets of data and used the event-pair method. In the first analysis, ossification of forelimb elements in general was examined, including that of the humerus, radius, ulna, the first carpal and metacarpal to ossify, and the phalanges of the third digit. The second analysis included each carpal, humerus, radius, ulna, the first metacarpal and the first phalanx to ossify. Some characters (= event-pairs) provide synapomorphies for some clades examined. There have been some shifts in the timing of ossification apparently not caused by ecological and/or environmental influences. In two species (Oryctolagus and Myotis), there is a tendency to start the ossification of the carpals relatively earlier than in all other species examined, the sauropsid outgroups included. PMID:15291793

Prochel, Jan; Vogel, Peter; Sánchez-Villagra, Marcelo R

2004-08-01

46

Short Report: Phylogenetically Distinct Hantaviruses in the Masked Shrew (Sorex cinereus) and Dusky Shrew (Sorex monticolus) in the United States  

PubMed Central

A limited search for hantaviruses in lung and liver tissues of Sorex shrews (family Soricidae, subfamily Soricinae) revealed phylogenetically distinct hantaviruses in the masked shrew (Sorex cinereus) from Minnesota and in the dusky shrew (Sorex monticolus) from New Mexico and Colorado. The discovery of these shrew-borne hantaviruses, named Ash River virus and Jemez Springs virus, respectively, challenges the long-held dogma that rodents are the sole reservoir hosts and forces a re-examination of their co-evolutionary history. Also, studies now underway are aimed at clarifying the epizootiology and pathogenicity of these new members of the genus Hantavirus. PMID:18256444

Arai, Satoru; Bennett, Shannon N.; Sumibcay, Laarni; Cook, Joseph A.; Song, Jin-Won; Hope, Andrew; Parmenter, Cheryl; Nerurkar, Vivek R.; Yates, Terry L.; Yanagihara, Richard

2008-01-01

47

Phylogenetically distinct hantaviruses in the masked shrew (Sorex cinereus) and dusky shrew (Sorex monticolus) in the United States.  

PubMed

A limited search for hantaviruses in lung and liver tissues of Sorex shrews (family Soricidae, subfamily Soricinae) revealed phylogenetically distinct hantaviruses in the masked shrew (Sorex cinereus) from Minnesota and in the dusky shrew (Sorex monticolus) from New Mexico and Colorado. The discovery of these shrew-borne hantaviruses, named Ash River virus and Jemez Springs virus, respectively, challenges the long-held dogma that rodents are the sole reservoir hosts and forces a re-examination of their co-evolutionary history. Also, studies now underway are aimed at clarifying the epizootiology and pathogenicity of these new members of the genus Hantavirus. PMID:18256444

Arai, Satoru; Bennett, Shannon N; Sumibcay, Laarni; Cook, Joseph A; Song, Jin-Won; Hope, Andrew; Parmenter, Cheryl; Nerurkar, Vivek R; Yates, Terry L; Yanagihara, Richard

2008-02-01

48

Bones and genes: resolution problems in three Vietnamese species of Crocidura (Mammalia, Soricomorpha, Soricidae) and the description of an additional new species  

PubMed Central

Abstract Recent investigations of Southeast Asian white toothed shrews belonging to the genus Crocidura have revealed discrepancies between the results of morphological and molecular studies. The following study concerns three species of Crocidura occurring in Vietnam, namely Crocidura attenuata, Crocidura tanakae and Crocidura wuchihensis, and an undescribed fourth species revealed by molecular analysis. For many years Crocidura attenuata has been known to occur in Vietnam but, until very recently, the morphologically similar and comparably sized Crocidura tanakae was believed to be restricted to Taiwan. Following several molecular studies over the last few years, this species is now believed to be considerably more widespread and recognised as occuring also in Vietnam. The results of one of these recent molecular studies also revealed the presence of an undescribed species of Crocidura, similar in size and morphology to Crocidura wuchihensis, which is herein described. Data are provided on geographical variation in Vietnam and the problems of defining morphologically similar yet molecularly disparate species are discussed. PMID:23840165

Jenkins, Paulina D.; Abramov, Alexei V.; Bannikova, Anna A.; Rozhnov, Viatcheslav V.

2013-01-01

49

Muscle aging and oxidative stress in wild-caught shrews  

Microsoft Academic Search

Red-toothed shrews (Soricidae, subfamily Soricinae) are an intriguing model system to examine the free-radical theory of aging in wild mammals, given their short (<18months) lifespan and high mass-specific metabolic rates. As muscle performance underlies both foraging ability and predator avoidance, any age-related decline should be detrimental to fitness and survival. Muscle samples of water shrews (Sorex palustris) and sympatrically distributed

Allyson G. Hindle; John M. Lawler; Kevin L. Campbell; Markus Horning

2010-01-01

50

Development and characterization of 21 polymorphic microsatellite markers for the barren-ground shrew, Sorex ugyunak (Mammalia: Sorcidae), through next-generation sequencing, and cross-species amplification in the masked shrew, S. cinereus  

USGS Publications Warehouse

We used next generation shotgun sequencing to develop 21 novel microsatellite markers for the barren-ground shrew (Sorex ugyunak), which were polymorphic among individuals from northern Alaska. The loci displayed moderate allelic diversity (averaging 6.81 alleles per locus) and heterozygosity (averaging 70 %). Two loci deviated from Hardy–Weinberg equilibrium (HWE) due to heterozygote deficiency. While the population did not deviate from HWE overall, it showed significant linkage disequilibrium suggesting this population is not in mutation-drift equilibrium. Nineteen of 21 loci were polymorphic in masked shrews (S. cinereus) from interior Alaska and exhibited linkage equilibrium and HWE overall. All loci yielded sufficient variability for use in population studies.

Sonsthagen, S.A.; Sage, G.K.; Fowler, M.; Hope, A.G.; Cook, J.A.; Talbot, S.L.

2013-01-01

51

Muscle Aging and Oxidative Stress in Wild-Caught Shrews  

PubMed Central

Red-toothed shrews (Soricidae, subfamily Soricinae) are an intriguing model system to examine the free radical theory of aging in wild mammals, given their short (<18 month) lifespan and high mass-specific metabolic rates. As muscle performance underlies both foraging ability and predator avoidance, any age-related decline should be detrimental to fitness and survival. Muscle samples of water shrews (Sorex palustris) and sympatrically distributed short-tailed shrews (Blarina brevicauda) were therefore assessed for oxidative stress markers, protective antioxidant enzymes and apoptosis. Activity levels of catalase and glutathione peroxidase increased with age in both species. Similarly, Cu,Zn-superoxide dismutase isoform content was elevated significantly in older animals of both species (increases of 60% in the water shrew, 25% in the short-tailed shrew). Only one oxidative stress marker (lipid peroxidation) was age-elevated; the others were stable or declined (4-hydroxynonenal adducts and dihydroethidium oxidation). Glutathione peroxidase activity was significantly higher in the short-tailed shrew, while catalase activity was 2× higher in water shrews. Oxidative stress indicators were on average higher in short-tailed shrews. Apoptosis occurred in <1% of myocytes examined, and did not increase with age. Within the constraints of the sample size we found evidence of protection against elevated oxidative stress in wild-caught shrews. PMID:20109576

Hindle, Allyson G.; Lawler, John M.; Campbell, Kevin L.; Horning, Markus

2010-01-01

52

Muscle aging and oxidative stress in wild-caught shrews.  

PubMed

Red-toothed shrews (Soricidae, subfamily Soricinae) are an intriguing model system to examine the free-radical theory of aging in wild mammals, given their short (<18months) lifespan and high mass-specific metabolic rates. As muscle performance underlies both foraging ability and predator avoidance, any age-related decline should be detrimental to fitness and survival. Muscle samples of water shrews (Sorex palustris) and sympatrically distributed short-tailed shrews (Blarina brevicauda) were therefore assessed for oxidative stress markers, protective antioxidant enzymes and apoptosis. Activity levels of catalase and glutathione peroxidase increased with age in both species. Similarly, Cu,Zn-superoxide dismutase isoform content was elevated significantly in older animals of both species (increases of 60% in the water shrew, 25% in the short-tailed shrew). Only one oxidative stress marker (lipid peroxidation) was age-elevated; the others were stable or declined (4-hydroxynonenal adducts and dihydroethidium oxidation). Glutathione peroxidase activity was significantly higher in the short-tailed shrew, while catalase activity was 2x higher in water shrews. Oxidative stress indicators were on average higher in short-tailed shrews. Apoptosis occurred in <1% of myocytes examined, and did not increase with age. Within the constraints of the sample size we found evidence of protection against elevated oxidative stress in wild-caught shrews. PMID:20109576

Hindle, Allyson G; Lawler, John M; Campbell, Kevin L; Horning, Markus

2010-04-01

53

Nomenclatural notes and identification of small-eared shrews (Mammalia: genus Cryptotis) from Cobán, Guatemala, in The Natural History Museum, London  

USGS Publications Warehouse

A small series of shrews collected in Guatemala and registered in the British Museum between 1843 and 1907 includes parts of type series for three species: Corsira tropicalis Gray (1843), Sorex micrurus Tomes (1862), and Blarina tropicalis Merriam (1895). These three names are now considered equivalent, but my recent review of the specimens comprising the series indicates that they include three distinct species: Cryptotis merriami Choate (1970), Cryptotis oreoryctes Woodman (2011), and Cryptotis tropicalis (Merriam 1895). I review the taxonomic history of these specimens, provide current identifications tied directly to museum register numbers, describe how to distinguish the three species, and provide revised synonymies for these species.

Woodman, Neal

2011-01-01

54

The Shrew (ist's) Site  

NSDL National Science Digital Library

Created by Dr. Werner Haberl of Vienna, Austria, this site contains The Shrew Conference Hall, ShrewTalk (an e-mail newsletter/digest), a photo gallery and a skull and skeleton collection, among other features. From the ShrewTalk page, users can access a hyperlink to "The Shrew Conference Hall" which contains the photo gallery of shrews, their tracks, their enemies, and an email list of shrew researchers. The site is devoted to the biology of this often overlooked creature and its small mammal relatives.

Haberl, Werner.

1998-01-01

55

Leptospira spp. in Rodents and Shrews in Germany  

PubMed Central

Leptospirosis is an acute, febrile disease occurring in humans and animals worldwide. Leptospira spp. are usually transmitted through direct or indirect contact with the urine of infected reservoir animals. Among wildlife species, rodents act as the most important reservoir for both human and animal infection. To gain a better understanding of the occurrence and distribution of pathogenic leptospires in rodent and shrew populations in Germany, kidney specimens of 2973 animals from 11 of the 16 federal states were examined by PCR. Rodent species captured included five murine species (family Muridae), six vole species (family Cricetidae) and six shrew species (family Soricidae). The most abundantly trapped animals were representatives of the rodent species Apodemus flavicollis, Clethrionomys glareolus and Microtus agrestis. Leptospiral DNA was amplified in 10% of all animals originating from eight of the 11 federal states. The highest carrier rate was found in Microtus spp. (13%), followed by Apodemus spp. (11%) and Clethrionomys spp. (6%). The most common Leptospira genomospecies determined by duplex PCR was L. kirschneri, followed by L. interrogans and L. borgpetersenii; all identified by single locus sequence typing (SLST). Representatives of the shrew species were also carriers of Leptospira spp. In 20% of Crocidura spp. and 6% of the Sorex spp. leptospiral DNA was detected. Here, only the pathogenic genomospecies L. kirschneri was identified. PMID:25062275

Mayer-Scholl, Anne; Hammerl, Jens Andre; Schmidt, Sabrina; Ulrich, Rainer G.; Pfeffer, Martin; Woll, Dietlinde; Scholz, Holger C.; Thomas, Astrid; Nöckler, Karsten

2014-01-01

56

Characterization of Imjin Virus, a Newly Isolated Hantavirus from the Ussuri White-Toothed Shrew (Crocidura lasiura)?  

PubMed Central

Until recently, the single known exception to the rodent-hantavirus association was Thottapalayam virus (TPMV), a long-unclassified virus isolated from the Asian house shrew (Suncus murinus). Robust gene amplification techniques have now uncovered several genetically distinct hantaviruses from shrews in widely separated geographic regions. Here, we report the characterization of a newly identified hantavirus, designated Imjin virus (MJNV), isolated from the lung tissues of Ussuri white-toothed shrews of the species Crocidura lasiura (order Soricomorpha, family Soricidae, subfamily Crocidurinae) captured near the demilitarized zone in the Republic of Korea during 2004 and 2005. Seasonal trapping revealed the highest prevalence of MJNV infection during the autumn, with evidence of infected shrews' clustering in distinct foci. Also, marked male predominance among anti-MJNV immunoglobulin G antibody-positive Ussuri shrews was found, whereas the male-to-female ratio among seronegative Ussuri shrews was near 1. Plaque reduction neutralization tests showed no cross neutralization for MJNV and rodent-borne hantaviruses but one-way cross neutralization for MJNV and TPMV. The nucleotide and deduced amino acid sequences for the different MJNV genomic segments revealed nearly the same calculated distances from hantaviruses harbored by rodents in the subfamilies Murinae, Arvicolinae, Neotominae, and Sigmodontinae. Phylogenetic analyses of full-length S, M, and L segment sequences demonstrated that MJNV shared a common ancestry with TPMV and remained in a distinct out-group, suggesting early evolutionary divergence. Studies are in progress to determine if MJNV is pathogenic for humans. PMID:19357167

Song, Jin-Won; Kang, Hae Ji; Gu, Se Hun; Moon, Sung Sil; Bennett, Shannon N.; Song, Ki-Joon; Baek, Luck Ju; Kim, Heung-Chul; O'Guinn, Monica L.; Chong, Sung-Tae; Klein, Terry A.; Yanagihara, Richard

2009-01-01

57

Evidence for gene flow in parasitic nematodes between two host species of shrews.  

PubMed

We describe the genetic structure of populations of the intestinal nematode Longistriata caudabullata (Trichostrongyloidea: Heligmosomidae), a common parasite of short-tailed shrews (genus Blarina, Insectivora: Soricidae). Parasites and hosts were collected from a transect across a contact zone between two species of hosts, Blarina brevicauda and B. hylophaga, in central North America. An 800-base pairs (bp) fragment of the ND4 mitochondrial DNA (mtDNA) gene was sequenced for 28 worms and a 783-bp fragment of the mtDNA control region was analysed for 16 shrews. Phylogenetic analyses of mtDNA sequences revealed reciprocal monophyly for the shrew species, concordant with morphological diagnosis, and supported the idea that the transect cuts through a secondary contact zone between well-differentiated B. brevicauda and B. hylophaga. In contrast to this pattern, the parasitic nematode mtDNA phylogeny was not subdivided according to host affiliation. Genealogical discordance between parasite and host phylogenies suggests extensive gene flow among parasites across the host species boundary. PMID:12969487

Brant, Sara V; Ortí, Guillermo

2003-10-01

58

Chronic exposure to environmental stressors induces fluctuating asymmetry in shrews inhabiting protected Mediterranean sites.  

PubMed

Many ecotoxicological studies have addressed the effects of contaminant exposure at various levels of biological organization. However, little information exists on the effects of toxicants on wildlife populations. Here we examined exposure of populations of the greater white-toothed shrew Crocidura russula (Soricomorpha, Soricidae) occupying two protected Mediterranean sites (a polluted area, the Ebro Delta, and a control site, Garraf Massif). Bioaccumulation of selected elements (Pb, Hg, Cd, Zn, Cu, Fe, Mn, Cr, Mo, Sr, Ba, and B), a body condition index (BCI) and fluctuating asymmetry (FA) were used to assess the chronic exposure to environmental pollution. BCI was correlated neither to metal concentrations nor to FA, suggesting that this fitness measure only reflects environmental disturbances at a local level. However, shrews from the polluted area showed higher concentrations of metals and metalloids (Pb, Hg, B, and Sr) and greater shape FA than specimens from the reference area. A correlation between FA was found for both first and second principal component vectors suggesting that developmental instability increases as a result of exposure to multiple pollutants. Our results corroborate the suitability of C. russula as a bioindicator of environmental quality and show that FA is an appropriate index to examine impact of developmental stressors in populations inhabiting disturbed areas. PMID:23800592

Sánchez-Chardi, Alejandro; García-Pando, Marián; López-Fuster, María José

2013-10-01

59

A Mitochondrial Phylogeny and Biogeographical Scenario for Asiatic Water Shrews of the Genus Chimarrogale: Implications for Taxonomy and Low-Latitude Migration Routes  

PubMed Central

The six species and three subspecies in the genus Chimarrogale (Soricomorpha: Soricidae) are commonly referred to as Asiatic water shrews. The Chimarrogale are the most widely distributed group of Nectogaline shrews, extending throughout the Oriental region and Japan. Because of the limited numbers of specimens available for study, the phylogenetic relationships and biogeographical history of this genus have not been comprehensively discussed. We used mitochondrial cytochrome b gene sequences to estimate phylogenetic relationships and divergence times among four Chimarrogale species, including all three subspecies of Chimarrogale himalayica. We also conducted a species delimitation analysis and tested two alternative migration scenarios in Asia through species distribution modeling and a reconstruction of the ancestral distribution. Here, we present the first proposed hypothesis regarding the Asiatic water shrew phylogeny and reveal ten putative species within the four recognized species. Distinct phylogenetic statuses of Chimarrogale phaeura, Chimarrogale platycephala, and Chimarrogale styani were confirmed. Chimarrogale himalayica was strongly supported as paraphyletic. We suggest that three subspecies of Chimarrogale himalayica should be reconsidered as distinct species. However, these suggestions must be considered with caution because only a single locus of a mtDNA gene was used. Four additional putative species, possibly distributed in central southwestern China and Taiwan, are currently undescribed; therefore, comprehensive morphological analyses are warranted to test their taxonomic statuses. The estimated molecular divergence times indicated that rapid speciation occurred during the early Pliocene, and current distribution patterns may have been affected by global cooling during the Pliocene/Pleistocene boundary. Reconstruction of the ancestral distribution and species distribution modeling for Asiatic water shrews revealed a low-latitude migration route over which ancestral Chimarrogale migrated from Europe via Central Asia to their current distribution. Our results demonstrated that Asiatic water shrews could have evolved throughout the low-latitude migration route from Europe to East and Southeast Asia. PMID:24124605

Yuan, Shou-Li; Jiang, Xue-Long; Li, Zhen-Ji; He, Kai; Harada, Masashi; Oshida, Tatsuo; Lin, Liang-Kong

2013-01-01

60

Comparative Morphology of the Papillae Linguales and their Connective Tissue Cores in the Tongue of the Greater Japanese Shrew-mole, Urotrichus talpoides  

PubMed Central

The external morphology of the papillae linguales (papillae filiformes, papillae fungiformes and papillae vallatae) and their connective tissue cores (CTCs) of the greater Japanese shrew-mole (Urotrichus talpoides) were analysed by optical and scanning electron microscopy. Papillae filiformes were distributed over the dorsal surface of the apex linguae, and on the rostral and caudal regions of the corpus linguae but were less numerous in the mid-region. They were absent from the radix linguae. A pair of oval papillae vallatae was situated at the border between the corpus linguae and the radix linguae. Papillae foliatae were absent. The epithelial surface of each papilla filiformis consisted of a circular concavity, a ring-like wall and either a single thumb-like process or 2–3 slender pointed processes, depending on their location. The morphology of the CTCs of the papillae filiformes also varied regionally. The papillae linguales of the Japanese shrew-mole were morphologically similar to those of other Talpidae and Soricidae, including the common shrew, particularly with respect to the papillae filiformes in the mid- and caudal regions of the corpus linguae. PMID:22571539

Yoshimura, K; Shindo, J; Kageyama, I

2013-01-01

61

Origin and evolution of homologous repeated sequences in the mitochondrial DNA control region of shrews.  

PubMed

The complete mitochondrial DNA (mtDNA) control region was amplified and directly sequenced in two species of shrew, Crocidura russula and Sorex araneus (Insectivora, Mammalia). The general organization is similar to that found in other mammals: a central conserved region surrounded by two more variable domains. However, we have found in shrews the simultaneous presence of arrays of tandem repeats in potential locations where repeats tend to occur separately in other mammalian species. These locations correspond to regions which are associated with a possible interruption of the replication processes, either at the end of the three-stranded D-loop structure or toward the end of the heavy-strand replication. In the left domain the repeated sequences (R1 repeats) are 78 bp long, whereas in the right domain the repeats are 12 bp long in C. russula and 14 bp long in S. araneus (R2 repeats). Variation in the copy number of these repeated sequences results in mtDNA control region length differences. Southern blot analysis indicates that level of heteroplasmy (more than one mtDNA form within an individual) differs between species. A comparative study of the R2 repeats in 12 additional species representing three shrew subfamilies provides useful indications for the understanding of the origin and the evolution of these homologous tandemly repeated sequences. An asymmetry in the distribution of variants within the arrays, as well as the constant occurrence of shorter repeated sequences flanking only one side of the R2 arrays, could be related to asymmetry in the replication of each strand of the mtDNA molecule. The pattern of sequence and length variation within and between species, together with the capability of the arrays to form stable secondary structures, suggests that the dominant mechanism involved in the evolution of these arrays in unidirectional replication slippage. PMID:8583904

Fumagalli, L; Taberlet, P; Favre, L; Hausser, J

1996-01-01

62

Novel Hantavirus in the Flat-Skulled Shrew (Sorex roboratus)  

E-print Network

) in the dusky shrew (Sorex monticolus) (Arai et al. 2008a), and Imjin virus (MJNV) in the Ussuri whiteNovel Hantavirus in the Flat-Skulled Shrew (Sorex roboratus) Hae Ji Kang,1 Satoru Arai,2 Andrew G liver and lung tissues from 4 Siberian large-toothed shrews (Sorex daphaenodon), 5 Eurasian least shrews

63

The Taming of the Shrew  

NASA Astrophysics Data System (ADS)

Considering the extreme complexity of the turbulence problem in general and the unattainability of first-principles analytical solutions in particular, it is not surprising that controlling a turbulent flow remains a challenging task, mired in empiricism and unfulfilled promises and aspirations. Brute force suppression, or taming, of turbulence via active control strategies is always possible, but the penalty for doing so often exceeds any potential savings. The artifice is to achieve a desired effect with minimum energy expenditure. Spurred by the recent developments in chaos control, microfabrication and neural networks, efficient reactive control of turbulent flows, where the control input is optimally adjusted based on feedforward or feedback measurements, is now in the realm of the possible for future practical devices. But regardless of how the problem is approached, combating turbulence is always as arduous as the taming of the shrew. The former task will be emphasized during the oral presentation, but for this abstract we reflect on a short verse from the latter. From William Shakespeare's The Taming of the Shrew. Curtis (Petruchio's servant, in charge of his country house): Is she so hot a shrew as she's reported? Grumio (Petruchio's personal lackey): She was, good Curtis, before this frost. But thou know'st winter tames man, woman, and beast; for it hath tamed my old master, and my new mistress, and myself, fellow Curtis.

Gad-El-Hak, M.

1996-11-01

64

Shrews — Small Insectivores with Polyphasic Patterns  

Microsoft Academic Search

\\u000a Daily activity patterns of shrews are controlled by metabolic requirements commensurate with their diminutive body mass and\\u000a resultant high surfaceto-mass ratios: they must forage often to avoid exhaustion of their energy stores. To remain homeothermic,\\u000a shrews must partition a 24-h period into multiple bouts of foraging, rest, and sleep.

Joseph F. Merritt; Stephen H. Vessey

65

Short Report: Phylogenetically Distinct Hantaviruses in the Masked Shrew (Sorex cinereus) and Dusky Shrew (Sorex monticolus) in the United States  

E-print Network

Shrew (Sorex monticolus) in the United States Satoru Arai, Shannon N. Bennett, Laarni Sumibcay, Joseph A hantaviruses in the masked shrew (Sorex cinereus) from Minnesota and in the dusky shrew (Sorex monticolus) fromShort Report: Phylogenetically Distinct Hantaviruses in the Masked Shrew (Sorex cinereus) and Dusky

66

The neurobiology of Etruscan shrew active touch  

PubMed Central

The Etruscan shrew, Suncus etruscus, is not only the smallest terrestrial mammal, but also one of the fastest and most tactile hunters described to date. The shrew's skeletal muscle consists entirely of fast-twitch types and lacks slow fibres. Etruscan shrews detect, overwhelm, and kill insect prey in large numbers in darkness. The cricket prey is exquisitely mechanosensitive and fast-moving, and is as big as the shrew itself. Experiments with prey replica show that shape cues are both necessary and sufficient for evoking attacks. Shrew attacks are whisker guided by motion- and size-invariant Gestalt-like prey representations. Shrews often attack their prey prior to any signs of evasive manoeuvres. Shrews whisk at frequencies of approximately 14 Hz and can react with latencies as short as 25–30 ms to prey movement. The speed of attacks suggests that shrews identify and classify prey with a single touch. Large parts of the shrew's brain respond to vibrissal touch, which is represented in at least four cortical areas comprising collectively about a third of the cortical volume. Etruscan shrews can enter a torpid state and reduce their body temperature; we observed that cortical response latencies become two to three times longer when body temperature drops from 36°C to 24°C, suggesting that endothermy contributes to the animal's high-speed sensorimotor performance. We argue that small size, high-speed behaviour and extreme dependence on touch are not coincidental, but reflect an evolutionary strategy, in which the metabolic costs of small body size are outweighed by the advantages of being a short-range high-speed touch and kill predator. PMID:21969684

Brecht, Michael; Naumann, Robert; Anjum, Farzana; Wolfe, Jason; Munz, Martin; Mende, Carolin; Roth-Alpermann, Claudia

2011-01-01

67

Active Touch During Shrew Prey Capture  

PubMed Central

Although somatosensation in multiple whisker systems has been studied in considerable detail, relatively little information is available regarding whisker usage and movement patterns during natural behaviors. The Etruscan shrew, one of the smallest mammals, relies heavily on its whisker system to detect and kill its highly mobile insect prey. Here, we tracked whisker and body motion during prey capture. We found that shrews made periodic whisker movements (whisking) with frequencies ranging from 12 to 17?Hz. We compared shrew and rat whisking and found that shrew whisking was smaller amplitude and higher frequency than rat whisking, but that the shrew and rat whisking cycle were similar in that the velocity was higher during retraction than protraction. We were able to identify four phases during the shrew hunting behavior: (i) an immobile phase often preceding hunting, (ii) a search phase upon the initiation of hunting, (iii) a contact phase defined by whisker-to-cricket contact, and (iv) an attack phase, characterized by a rapid head movement directed toward the cricket. During the searching phase, whisking was generally rhythmic and whiskers were protracted forward. After prey contact, whisking amplitude decreased and became more variable. The final strike was associated with an abrupt head movement toward the prey with high head acceleration. Prey capture proceeded extremely fast and we obtained evidence that shrews can initiate corrective maneuvers with a minimal latency <30?ms. While the shrew's rostrum is straight and elongated during most behaviors, we show for the first time that shrews bend their rostrum during the final strike and grip their prey with a parrot beak shaped snout. PMID:21283557

Munz, Martin; Brecht, Michael; Wolfe, Jason

2010-01-01

68

Mutualism between tree shrews and pitcher plants  

PubMed Central

Three species of Nepenthes pitcher plants from Borneo engage in a mutualistic interaction with mountain tree shrews, the basis of which is the exchange of nutritional resources. The plants produce modified “toilet pitchers” that produce copious amounts of exudates, the latter serving as a food source for tree shrews. The exudates are only accessible to the tree shrews when they position their hindquarters over the pitcher orifice. Tree shrews mark valuable resources with feces and regularly defecate into the pitchers when they visit them to feed. Feces represent a valuable source of nitrogen for these Nepenthes species, but there are many facets of the mutualism that are yet to be investigated. These include, but are not limited to, seasonal variation in exudate production rates by the plants, behavioral ecology of visiting tree shrews and the mechanism by which the plants signal to tree shrews that their pitchers represent a food source. Further research into this extraordinary animal-plant interaction is required to gain a better understanding of the benefits to the participating species. PMID:20861680

Moran, Jonathan A; Chin, Lijin

2010-01-01

69

Unique regulation of thyroid hormone metabolism during fasting in the house musk shrew ( Suncus murinus, Insectivora: Soricidae)  

Microsoft Academic Search

The active hormone, 3,3?,5-triiodothyronine (T3) is derived from thyroxine (T4) by the action of iodothyronine 5?-deiodinases (5?-D). By now two types of 5?-D have been identified; Type 1 (D1) and type 2 (D2). A relative contribution of these isotypes to the circulating T3 levels in the human remains to be determined whereas a number of reports indicate that, under physiological

Yoko Takeuchi; Daisuke Suzuki; Sen-Ichi Oda; Samuel Refetoff; Koji Seki; Katsuhiko Tsunekawa; Takayuki Kasahara; Masami Murakami; Yoshiharu Murata

2006-01-01

70

Rediscovery of Enders’s small-eared shrew, Cryptotis endersi (Insectivora: Soricidae), with a redescription of the species  

E-print Network

C77C97C109C109C46 C98C105C111C108C46 C54C55 C40C50C48C48C50C41 C51C55C50C177C51C55C55 C77C97C109C109C97C108C105C97C110 C66C105C111C108C111C103C121 C227 C85C114C98C97C110 C38 C70C105C115C99C104C101C114 C86C101C114C108C97C103 C104C116C116C112C58C47C47...100C101 C83C104C111C114C116C99C111C109C109C117C110C105C99C97C116C105C111C110 C82C101C100C105C115C99C111C118C101C114C121C111C102C69C110C100C101C114C115C39C115C115C109C97C108C108C45C101C97C114C101C100C115C104C114C101C119C44 C67C114C121C112C116C111C116C...

Pine, Ronald H.; Woodman, Neal; Timm, Robert M.

2002-12-01

71

Phylogeography of the Northern short-tailed shrew, Blarina brevicauda (Insectivora: Soricidae): past fragmentation and postglacial recolonization.  

PubMed

Blarina brevicauda is distributed across the northeastern region of North America, in areas previously covered by Pleistocene glaciers. Previous molecular systematic study of the species in the genus Blarina suggested the presence of two distinct eastern and western phylogroups within B. brevicauda, in agreement with traditionally recognized semi-species. To expand the previous work, a collection of 76 individuals from 14 localities collected throughout the range of B. brevicauda was used to assess the mitochondrial (mt) cytochrome b genealogy for this species. Minimum evolution, maximum parsimony, analysis of molecular variance and nested clade analysis each supported the same conclusions of two well-differentiated and monophyletic east-west groups, separated by the Mississippi River. Denser sampling in areas immediately East of the Mississippi basin revealed further subdivision within the eastern phylogroup into an East-Central and an Appalachian clade. The western phylogroup differed from the eastern phylogroup by 2.5% mean absolute DNA sequence difference. About 65% of the genetic variance among samples was explained by the east-west subdivision alone. High haplotype diversities, low nucleotide diversities and unimodal mismatch distributions within subclades suggest recent expansion or diversification within each group. No phylogeographic structure was found within the western phylogroup, but genetic structure because of restricted gene flow and isolation by distance was inferred for the eastern group. The present distribution of B. brevicauda is best explained by past fragmentation and range expansion events during and following the Pleistocene glacial cycles. PMID:12755873

Brant, Sara V; Ortí, Guillermo

2003-06-01

72

Tripartite genetic subdivisions in the ornate shrew (Sorex ornatus)  

Microsoft Academic Search

We examined cytochrome b sequence variation in 251 ornate shrews ( Sorex ornatus ) from 20 localities distributed throughout their geographical range. Additionally, vagrant ( S. vagrans ) and montane ( S. monticolus ) shrews from four localities were used as outgroups. We found 24 haplotypes in ornate shrews from California (USA) and Baja California (Mexico) that differed by 1-31

Jesus E. Maldonado; Carles VilA; Robert K. Wayne

2001-01-01

73

Mitochondrial simple sequence repeats and 12S-rRNA gene reveal two distinct lineages of Crocidura russula (Mammalia, Soricidae).  

PubMed

A short segment (135 bp) of the control region and a partial sequence (394 bp) of the 12S-rRNA gene in the mitochondrial DNA of Crocidura russula were analyzed in order to test a previous hypothesis regarding the presence of a gene flow disruption in northern Africa. This breakpoint would have separated northeast-African C. russula populations from the European (plus the northwest-African) populations. The analysis was carried out on specimens from Tunisia (C. r. cf agilis), Sardinia (C. r. ichnusae), and Pantelleria (C. r. cossyrensis), and on C. r. russula from Spain and Belgium. Two C. russula lineages were identified; they both shared R2 tandem repeated motifs of the same length (12 bp), but not the same primary structure. These simple sequence repeats were present in 12-23 copies in the right domain of the control region. Within the northeast-African populations, a polymorphism of repeat variants, not yet found in Europe, was recorded. A neighbor-join tree, which was built by sequences of the conserved 12S-rRNA gene, separated the two sister groups; it permitted us to date a divergence time of 0.5 Myr. Our data discriminated two different mitochondrial lineages in accordance with the previous morphological and karyological data. Ecoclimatic barriers formed during the Middle Pleistocene broke the range of ancestral species in the Eastern Algeria (Kabile Mountains), leading to two genetically separate and modern lineages. The northeast-African lineage can today be located in Tunisia, Pantelleria, and Sardinia. The northwest-African lineage (Morocco and West Algeria), reaching Spain by anthropogenic introduction, spread over north Europe in modern times. The Palaearctic C. russula species is monophyletic, but a taxonomical revision (ie, to provide a full species rank for the northeast taxa and to put in synonymy some insular taxa) is required. PMID:15162115

Lo Brutto, S; Azeuleo, M; Sarà, M

2004-06-01

74

Shrews in Managed Northern Hardwood Stands in the Allegheny Mountains of West Virginia  

E-print Network

. Capture frequency of masked shrews (Sorex cinereus), smoky shrews (S. fumeus), and northern short (S. dispar) and pygmy shrews (S. hoyi), both habitat specialists that our survey did not target, were

75

Basal physiological parameters in domesticated tree shrews (Tupaia belangeri chinensis).  

PubMed

Establishing non-human primate models of human diseases is an efficient way to narrow the large gap between basic studies and translational medicine. Multifold advantages such as simplicity of breeding, low cost of feeding and facility of operating make the tree shrew an ideal non-human primate model proxy. Additional features like vulnerability to stress and spontaneous diabetic characteristics also indicate that the tree shrew could be a potential new animal model of human diseases. However, basal physiological indexes of tree shrew, especially those related to human disease, have not been systematically reported. Accordingly, we established important basal physiological indexes of domesticated tree shrews including several factors: (1) body weight, (2) core body temperature and rhythm, (3) diet metabolism, (4) locomotor rhythm, (5) electroencephalogram, (6) glycometabolism and (7) serum and urinary hormone level and urinary cortisol rhythm. We compared the physiological parameters of domesticated tree shrew with that of rats and macaques. Results showed that (a) the core body temperature of the tree shrew was 39.59±0.05 ?, which was higher than that of rats and macaques; (b) Compared with wild tree shrews, with two activity peaks, domesticated tree shrews had only one activity peak from 17:30 to 19:30; (c) Compared with rats, tree shrews had poor carbohydrate metabolism ability; and (d) Urinary cortisol rhythm indicated there were two peaks at 8:00 and 17:00 in domesticated tree shrews, which matched activity peaks in wild tree shrews. These results provided basal physiological indexes for domesticated tree shrews and laid an important foundation for diabetes and stress-related disease models established on tree shrews. PMID:23572369

Wang, Jing; Xu, Xin-Li; Ding, Ze-Yang; Mao, Rong-Rong; Zhou, Qi-Xin; Lü, Long-Bao; Wang, Li-Ping; Wang, Shuang; Zhang, Chen; Xu, Lin; Yang, Yue-Xiong

2013-04-01

76

Newfound Hantavirus in Chinese Mole Shrew, Vietnam  

PubMed Central

Sequence analysis of the full-length medium segment and the partial small and large segments of a hantavirus, detected by reverse transcription–PCR in lung tissues of the Chinese mole shrew (Anourosorex squamipes) captured in Cao Bang Province, Vietnam, in December 2006, indicated that it is genetically distinct from rodentborne hantaviruses. PMID:18217572

Song, Jin-Won; Kang, Hae Ji; Song, Ki-Joon; Truong, Thang T.; Bennett, Shannon N.; Arai, Satoru; Truong, Ninh U.

2007-01-01

77

Heart and lung adaptations to pregnancy and lactation in a crocidurine shrew.  

PubMed

Heart and lung mass, rate of oxygen consumption (VO2), respiration rate (fR), tidal volume (VT), and heart rate (fH), were measured at rest and thermoneutrality in the shrew Crocidura russula monacha [(This shrew is claimed to be Crocidura suaveolens (Catzeflis, F., T. Maddalena, S. Hellwing and P. Vogel (1985). Unexpected findings on the taxonomic status of East Mediterranean Crocidura russula auct. (Mammalia, Insectivora). Zeitschrift fur Saugetierkunde 50: 185-201)] in nullipar (N), pregnant (P) and lactating (L) females. The heart mass of N females is large (0.86% of body mass) but fH is slow (70% of that expected by mammalian allometry), while lung mass is small (87% of expected) and fR is high (47% above expected). The 31% higher than expected expired ventilation (VE) matches the 25% higher than expected VO2. In P females the fH of 560 min-1 did not change but it increased in L females to 620 min-1. VE did not change in P females but decreased in L females from 11.3 ml center dot min-1 to 10.1 ml min-1. The normal VT decreased in P and L females from 47.3 mu l to 38.4 mu l and 37.8 mu l respectively. The lower than expected resting fH of N females may provide sufficient scope for increased heart work and oxygen supply during exercise. The large heart may be more efficient. Hyperventilation in N females is indicated by the calculated relatively high fractional concentration of oxygen in expired air (FECO2), and low fractional concentration of CO2 in expired air (FECO2) (17.7% and 3.2% respectively), the high oxygen partial pressure in alveolar gas (PAO2) and low alveolar CO2 (PACO2), 119 and 34 Torr respectively, which facilitate O2 transport through the lung air-blood barrier. The elevated VO2 in P and L females is achieved by increased respiratory efficiency from the normal 15%, to 24% and 29% respectively. PMID:8904018

Mover, H; Ar, A

1995-12-01

78

Recombinogenic telomeres in diploid Sorex granarius (Soricidae, Eulipotyphla) fibroblast cells.  

PubMed

The telomere structure in the Iberian shrew Sorex granarius is characterized by unique, striking features, with short arms of acrocentric chromosomes carrying extremely long telomeres (up to 300 kb) with interspersed ribosomal DNA (rDNA) repeat blocks. In this work, we investigated the telomere physiology of S. granarius fibroblast cells and found that telomere repeats are transcribed on both strands and that there is no telomere-dependent senescence mechanism. Although telomerase activity is detectable throughout cell culture and appears to act on both short and long telomeres, we also discovered that signatures of a recombinogenic activity are omnipresent, including telomere-sister chromatid exchanges, formation of alternative lengthening of telomeres (ALT)-associated PML-like bodies, production of telomere circles, and a high frequency of telomeres carrying marks of a DNA damage response. Our results suggest that recombination participates in the maintenance of the very long telomeres in normal S. granarius fibroblasts. We discuss the possible interplay between the interspersed telomere and rDNA repeats in the stabilization of the very long telomeres in this organism. PMID:24842907

Zhdanova, N S; Draskovic, I; Minina, J M; Karamysheva, T V; Novo, C L; Liu, W-Y; Porreca, R M; Gibaud, A; Zvereva, M E; Skvortsov, D A; Rubtsov, N B; Londoño-Vallejo, A

2014-08-01

79

Recombinogenic Telomeres in Diploid Sorex granarius (Soricidae, Eulipotyphla) Fibroblast Cells  

PubMed Central

The telomere structure in the Iberian shrew Sorex granarius is characterized by unique, striking features, with short arms of acrocentric chromosomes carrying extremely long telomeres (up to 300 kb) with interspersed ribosomal DNA (rDNA) repeat blocks. In this work, we investigated the telomere physiology of S. granarius fibroblast cells and found that telomere repeats are transcribed on both strands and that there is no telomere-dependent senescence mechanism. Although telomerase activity is detectable throughout cell culture and appears to act on both short and long telomeres, we also discovered that signatures of a recombinogenic activity are omnipresent, including telomere-sister chromatid exchanges, formation of alternative lengthening of telomeres (ALT)-associated PML-like bodies, production of telomere circles, and a high frequency of telomeres carrying marks of a DNA damage response. Our results suggest that recombination participates in the maintenance of the very long telomeres in normal S. granarius fibroblasts. We discuss the possible interplay between the interspersed telomere and rDNA repeats in the stabilization of the very long telomeres in this organism. PMID:24842907

Draskovic, I.; Minina, J. M.; Karamysheva, T. V.; Novo, C. L.; Liu, W.-Y.; Porreca, R. M.; Gibaud, A.; Zvereva, M. E.; Skvortsov, D. A.; Rubtsov, N. B.

2014-01-01

80

Bioenergetics and thermal physiology of American water shrews ( Sorex palustris )  

Microsoft Academic Search

Rates of O 2 consumption and CO 2 production, telemetered body temperature ( T b) and activity level were recorded from adult and subadult water shrews ( Sorex palustris) over an air temperature ( T a) range of 3–32°C. Digesta passage rate trials were conducted before metabolic testing to estimate the minimum fasting time required for water shrews to achieve

R. W. Gusztak; R. A. MacArthur; K. L. Campbell

2005-01-01

81

Hantavirus in Northern Short-tailed Shrew, United States  

PubMed Central

Phylogenetic analyses, based on partial medium- and large-segment sequences, support an ancient evolutionary origin of a genetically distinct hantavirus detected by reverse transcription–PCR in tissues of northern short-tailed shrews (Blarina brevicauda) captured in Minnesota in August 1998. To our knowledge, this is the first evidence of hantaviruses harbored by shrews in the Americas. PMID:18252128

Arai, Satoru; Song, Jin-Won; Sumibcay, Laarni; Bennett, Shannon N.; Nerurkar, Vivek R.; Parmenter, Cheryl; Cook, Joseph A.; Yates, Terry L.

2007-01-01

82

Breeding the common shrew ( Sorex araneus ) in captivity  

Microsoft Academic Search

Summary A method for the systematic breeding of the common shrew (Sorex araneus) is described. By use of this method 20 litters of common shrew, conceived in the wild and in captivity, were reared to weaning. Success- ful fertilization was recorded for 74% of pairings and 68% of young known to have been born were reared to weaning. Breeding records

J. B. Searle

1984-01-01

83

Hantavirus in northern short-tailed shrew, United States.  

PubMed

Phylogenetic analyses, based on partial medium- and large-segment sequences, support an ancient evolutionary origin of a genetically distinct hantavirus detected by reverse transcription-PCR in tissues of northern short-tailed shrews (Blarina brevicauda) captured in Minnesota in August 1998. To our knowledge, this is the first evidence of hantaviruses harbored by shrews in the Americas. PMID:18252128

Arai, Satoru; Song, Jin-Won; Sumibcay, Laarni; Bennett, Shannon N; Nerurkar, Vivek R; Parmenter, Cheryl; Cook, Joseph A; Yates, Terry L; Yanagihara, Richard

2007-09-01

84

Tactile experience shapes prey-capture behavior in Etruscan shrews  

PubMed Central

A crucial role of tactile experience for the maturation of neural response properties in the somatosensory system is well established, but little is known about the role of tactile experience in the development of tactile behaviors. Here we study how tactile experience affects prey capture behavior in Etruscan shrews, Suncus etruscus. Prey capture in adult shrews is a high-speed behavior that relies on precise attacks guided by tactile Gestalt cues. We studied the role of tactile experience by three different approaches. First, we analyzed the hunting skills of young shrews' right after weaning. We found that prey capture in young animals in most, but not all, aspects is similar to that of adults. Second, we performed whisker trimming for 3–4 weeks after birth. Such deprivation resulted in a lasting disruption of prey capture even after whisker re-growth: attacks lacked precise targeting and had a lower success rate. Third, we presented adult shrews with an entirely novel prey species, the giant cockroach. The shape of this roach is very different from the shrew's normal (cricket) prey and the thorax—the preferred point of attack in crickets—is protected by a heavy cuticle. Initially shrews attacked giant roaches the same way they attack crickets and targeted the thoracic region. With progressive experience, however, shrews adopted a new attack strategy targeting legs and underside of the roaches while avoiding other body parts. Speed and efficiency of attacks improved. These data suggest that tactile experience shapes prey capture behavior. PMID:22701408

Anjum, Farzana; Brecht, Michael

2012-01-01

85

Tripartite genetic subdivisions in the ornate shrew (Sorex ornatus).  

PubMed

We examined cytochrome b sequence variation in 251 ornate shrews (Sorex ornatus) from 20 localities distributed throughout their geographical range. Additionally, vagrant (S. vagrans) and montane (S. monticolus) shrews from four localities were used as outgroups. We found 24 haplotypes in ornate shrews from California (USA) and Baja California (Mexico) that differed by 1-31 substitutions in 392 bp of mitochondrial DNA (mtDNA) sequence. In a subset of individuals, we sequenced 699 bp of cytochrome b to better resolve the phylogeographic relationships of populations. The ornate shrew is phylogeographically structured into three haplotype clades representing southern, central and northern localities. Analysis of allozyme variation reveals a similar pattern of variation. Several other small California vertebrates have a similar tripartite pattern of genetic subdivision. We suggest that topographic barriers and expansion and contraction of wetland habitats in the central valley during Pleistocene glacial cycles account for these patterns of genetic variation. Remarkably, the northern ornate shrew clade is phylogenetically clustered with another species of shrew suggesting that it may be a unique lowland form of the vagrant shrew that evolved in parallel to their southern California counterparts. PMID:11251793

Maldonado, J E; Vilà, C; Wayne, R K

2001-01-01

86

Molecular epidemiology of paramyxoviruses in Zambian wild rodents and shrews.  

PubMed

Rodents and shrews are known to harbour various viruses. Paramyxoviruses have been isolated from Asian and Australian rodents, but little is known about them in African rodents. Recently, previously unknown paramyxovirus sequences were found in South African rodents. To date, there have been no reports related to the presence and prevalence of paramyxoviruses in shrews. We found a high prevalence of paramyxoviruses in wild rodents and shrews from Zambia. Semi-nested reverse transcription-PCR assays were used to detect paramyxovirus RNA in 21 % (96/462) of specimens analysed. Phylogenetic analysis revealed that these viruses were novel paramyxoviruses and could be classified as morbillivirus- and henipavirus-related viruses, and previously identified rodent paramyxovirus-related viruses. Our findings suggest the circulation of previously unknown paramyxoviruses in African rodents and shrews, and provide new information regarding the geographical distribution and genetic diversity of paramyxoviruses. PMID:24189618

Sasaki, Michihito; Muleya, Walter; Ishii, Akihiro; Orba, Yasuko; Hang'ombe, Bernard M; Mweene, Aaron S; Moonga, Ladslav; Thomas, Yuka; Kimura, Takashi; Sawa, Hirofumi

2014-02-01

87

Barrelettes without Barrels in the American Water Shrew  

PubMed Central

Water shrews (Sorex palustris) depend heavily on their elaborate whiskers to navigate their environment and locate prey. They have small eyes and ears with correspondingly small optic and auditory nerves. Previous investigations have shown that water shrew neocortex is dominated by large representations of the whiskers in primary and secondary somatosensory cortex (S1 and S2). Flattened sections of juvenile cortex processed for cytochrome oxidase revealed clear borders of the whisker pad representation in S1, but no cortical barrels. We were therefore surprised to discover prominent barrelettes in brainstem of juvenile water shrews in the present investigation. These distinctive modules were found in the principal trigeminal nucleus (PrV), and in two of the three spinal trigeminal subnuclei (interpolaris – SpVi and caudalis – SpVc). Analysis of the shrew's whisker pad revealed the likely relationship between whiskers and barrelettes. Barrelettes persisted in adult water shrew PrV, but barrels were also absent from adult cortex. Thus in contrast to mice and rats, which have obvious barrels in primary somatosensory cortex and less clear barrelettes in the principal nucleus, water shrews have clear barrelettes in the brainstem and no barrels in the neocortex. These results highlight the diverse ways that similar mechanoreceptors can be represented in the central nervous systems of different species. PMID:23755296

Catania, Kenneth C.; Catania, Elizabeth H.; Sawyer, Eva K.; Leitch, Duncan B.

2013-01-01

88

Barrelettes without barrels in the American water shrew.  

PubMed

Water shrews (Sorex palustris) depend heavily on their elaborate whiskers to navigate their environment and locate prey. They have small eyes and ears with correspondingly small optic and auditory nerves. Previous investigations have shown that water shrew neocortex is dominated by large representations of the whiskers in primary and secondary somatosensory cortex (S1 and S2). Flattened sections of juvenile cortex processed for cytochrome oxidase revealed clear borders of the whisker pad representation in S1, but no cortical barrels. We were therefore surprised to discover prominent barrelettes in brainstem of juvenile water shrews in the present investigation. These distinctive modules were found in the principal trigeminal nucleus (PrV), and in two of the three spinal trigeminal subnuclei (interpolaris--SpVi and caudalis--SpVc). Analysis of the shrew's whisker pad revealed the likely relationship between whiskers and barrelettes. Barrelettes persisted in adult water shrew PrV, but barrels were also absent from adult cortex. Thus in contrast to mice and rats, which have obvious barrels in primary somatosensory cortex and less clear barrelettes in the principal nucleus, water shrews have clear barrelettes in the brainstem and no barrels in the neocortex. These results highlight the diverse ways that similar mechanoreceptors can be represented in the central nervous systems of different species. PMID:23755296

Catania, Kenneth C; Catania, Elizabeth H; Sawyer, Eva K; Leitch, Duncan B

2013-01-01

89

Water shrews detect movement, shape, and smell to find prey underwater  

Microsoft Academic Search

American water shrews (Sorex palustris) are aggressive predators that feed on a variety of terrestrial and aquatic prey. They often forage at night, diving into streams and ponds in search of food. We investigated how shrews locate submerged prey using high-speed videography, infrared lighting, and stimuli designed to mimic prey. Shrews attacked brief water movements, indicating motion is an important

Kenneth C. Catania; James F. Hare; Kevin L. Campbell

2008-01-01

90

Incidence of Testicular Lesions in a Population of Tree Shrews (Tupaia belangeri)  

Microsoft Academic Search

Background and Purpose: The sexual activity of male tree shrews is socially influenced; therefore, the testicular lesions in adult male tree shrews were of interest. Methods: The testes of 229 adult and 9 subadult male tree shrews were obtained during routine necropsy and were subjected to light microscopy. At one time, 138 animals were experimentally exposed to social conflicts. Results:

Manfred Brack; Eberhard Fuchs

91

Adoption of a nestling house mouse by a female short-tailed shrew  

USGS Publications Warehouse

A nursing female short-tailed shrew adopted a nestling house mouse. The mouse was observed in the nest with the female and her litter of shrews three days after it was introduced into the aluminum box containing the shrews, but it was found dead in the nest four days later.

Blus, L.J.; Johnson, D.A.

1969-01-01

92

DESCRIPTION AND MOLECULAR DIFFERENTIATION OF A NEW STAPHYLOCYSTOIDES (CYCLOPHYLLIDEA: HYMENOLEPIDIDAE) FROM THE DUSKY SHREW SOREX  

E-print Network

: HYMENOLEPIDIDAE) FROM THE DUSKY SHREW SOREX MONTICOLUS IN SOUTHEAST ALASKA Stephen E. Greiman, Vasyl V. Tkach gulyaevi n. sp. is described based on specimens obtained from the dusky shrew Sorex monticolus collected information on shrew helminths is completely lacking. In the summer of 2011 we collected helminths of Sorex

93

Genetic diversity and phylogeography of Seewis virus in the Eurasian common shrew in Finland and Hungary  

Microsoft Academic Search

Recent identification of a newfound hantavirus, designated Seewis virus (SWSV), in the Eurasian common shrew (Sorex araneus), captured in Switzerland, corroborates decades-old reports of hantaviral antigens in this shrew species from Russia. To ascertain the spatial or geographic variation of SWSV, archival liver tissues from 88 Eurasian common shrews, trapped in Finland in 1982 and in Hungary during 1997, 1999

Hae Ji Kang; Satoru Arai; Andrew G Hope; Jin-Won Song; Joseph A Cook; Richard Yanagihara

2009-01-01

94

Phylogenetic relationships among Nearctic shrews of the genus Sorex (Insectivora, Soricidae) inferred from combined cytochrome b and inter-SINE fingerprint data using Bayesian analysis.  

PubMed

The field of molecular systematics has relied heavily on mitochondrial DNA (mtDNA) analysis since its inception. Despite the obvious utility of mtDNA, such data inevitably only presents a limited (i.e., single genome) perspective on species evolution. A combination of mitochondrial and nuclear markers is essential for reconstructing more robust phylogenetic trees. To evaluate the utility of one category of nuclear marker (short interspersed elements or SINEs) for resolving phylogenetic relationships, we constructed an inter-SINE fingerprint for nine putative species of the genus Sorex. In addition, we analyzed 1011 nucleotides of the cytochrome b gene. Traditional neighbor-joining and maximum parsimony analyses were applied to the individual cytochrome b and inter-SINE fingerprint data sets, along with Bayesian analysis to the combined data sets. We found inter-SINE fingerprinting to be an effective species level marker; however, we were unable to reconstruct deeper branching patterns within the Sorex genus using these data. The combined data analyzed under a Bayesian analysis showed higher levels of structuring within the Otisorex subgenus, most notably recognizing a monophyletic group consisting of sister-taxa S. palustris and S. monticolus, S. cinereus and S. haydeni, and S. hoyi. An additional noteworthy result was the detection of an historic mitochondrial introgression event between S. monticolus and S. palustris. When combining disparate data sets, we emphasize researcher diligence as certain types of data and processes may overly influence the analysis. However, there is considerable phylogenetic potential stemming from inter-SINE fingerprinting. PMID:17275347

Shafer, Aaron B A; Stewart, Donald T

2007-07-01

95

Phylogenetic relationships among Nearctic shrews of the genus Sorex (Insectivora, Soricidae) inferred from combined cytochrome b and inter-SINE fingerprint data using Bayesian analysis  

Microsoft Academic Search

The field of molecular systematics has relied heavily on mitochondrial DNA (mtDNA) analysis since its inception. Despite the obvious utility of mtDNA, such data inevitably only presents a limited (i.e., single genome) perspective on species evolution. A combination of mitochondrial and nuclear markers is essential for reconstructing more robust phylogenetic trees. To evaluate the utility of one category of nuclear

Aaron B. A. Shafer; Donald T. Stewart

2007-01-01

96

Bioaccumulation of metals and effects of landfill pollution in small mammals. Part I. The greater white-toothed shrew, Crocidura russula.  

PubMed

Here we quantified the bioaccumulation of metals (lead, mercury, cadmium, iron, magnesium, zinc, copper, manganese, molybdenum, and chromium) and assessed several morphological (RI, relative weights) and genotoxic parameters as biomarkers of pollution from the landfill of Garraf (Barcelona, NE Spain). Specimens of Crocidura russula (Insectivora, Mammalia) from the landfill site showed increased Pb, Cd, Mg, Zn, Cu, and Cr concentrations in their tissues. Levels of mercury were below detection limits. Concentrations of Cd, Pb, and Cr varied significantly with age and no differences were found between males and females. While no differences were found in morphological parameters between shrews from the two sites, those from the polluted one showed more micronuclei in blood than those from reference site (1.786+/-0.272 vs. 0.088+/-0.045 per thousand; U=46.000, p<0.001). The considerable amounts of potentially toxic metals (Pb till 59.71 and Cd till 56.57microgg(-1) DW in kidneys) and the genotoxic effects indicate the harmful effect on biota. We consider necessary biomonitoring this landfill sited in a partially protected area. PMID:17367842

Sánchez-Chardi, Alejandro; Nadal, Jacint

2007-06-01

97

Boginia virus, a newfound hantavirus harbored by the Eurasian water shrew (Neomys fodiens) in Poland  

PubMed Central

Background Guided by decades-old reports of hantaviral antigens in the Eurasian common shrew (Sorex araneus) and the Eurasian water shrew (Neomys fodiens) in European Russia, we employed RT-PCR to analyze lung tissues of soricine shrews, captured in Boginia, Huta D?utowska and Kurowice in central Poland during September 2010, 2011 and 2012. Findings In addition to Seewis virus (SWSV), which had been previously found in Eurasian common shrews elsewhere in Europe, a genetically distinct hantavirus, designated Boginia virus (BOGV), was detected in Eurasian water shrews captured in each of the three villages. Phylogenetic analysis, using maximum likelihood and Bayesian methods, showed that BOGV formed a separate lineage distantly related to SWSV. Conclusions Although the pathogenic potential of BOGV and other recently identified shrew-borne hantaviruses is still unknown, clinicians should be vigilant for unusual febrile diseases and clinical syndromes occurring among individuals reporting exposures to shrews. PMID:23693084

2013-01-01

98

Circadian rhythms in the short-tailed shrew, Blarina brevicauda.  

PubMed

Circadian rhythms of wheel running and feeding were measured in the short-tailed shrew. Shrews were strongly nocturnal, and their activity rhythms entrained to both long-day (LD 16:8) and short-day (LD 6:18) photocycles. Under conditions of continuous light (LL) or darkness (DD), the activity rhythms free-ran with average periodicities of 25.1 hours and 24.1 hours, respectively. In LL the level of activity was depressed, and in some cases wheel running was completely inhibited. No significant sex differences were observed in the period or amplitude of the monitored circadian rhythms. All shrews fed throughout the day and night; however, unlike in previous reports, ultradian periods of feeding behavior were not found. The results are related to Aschoff's four observations for the effect of light on activity rhythms in nocturnal rodents. PMID:2255728

Antipas, A J; Madison, D M; Ferraro, J S

1990-08-01

99

Mass effects mediate coexistence in competing shrews.  

PubMed

Recent developments in metacommunity theory have raised awareness that processes occurring at regional scales might interfere with local dynamics and affect conditions for the local coexistence of competing species. Four main paradigms are recognized in this context (namely, neutral, patch-dynamics, species-sorting, and mass-effect), which differ according to the role assigned to ecological or life-history differences among competing species, as well as to the relative time scale of regional vs. local dynamics. We investigated the patterns of regional and local coexistence of two species of shrews (Crocidura russula and Sorex coronatus) sharing a similar diet (generalist insectivores) over four generations, in a spatially structured habitat at the altitudinal limit of their distributions. Local populations were small, and regional dynamics were strong, with high rates of extinction and recolonization. Niche analysis revealed significant habitat differentiation on a few important variables, including temperature and availability of winter resting sites. In sites suitable for both species, we found instances of local coexistence with no evidence of competitive exclusion. Patterns of temporal succession did not differ from random, with no suggestion of a colonization-competition trade-off. Altogether, our data provide support for the mass-effect paradigm, where regional coexistence is mediated by specialization on different habitat types, and local coexistence by rescue effects from source sites. The strong regional dynamics and demographic stochasticity, together with high dispersal rates, presumably contributed to mass effects by overriding local differences in specific competitive abilities. PMID:18705388

Guélat, Jérôme; Jaquiéry, Julie; Berset-Brändli, Laura; Pellegrini, Ester; Moresi, Ruben; Broquet, Thomas; Hirzel, Alexandre H; Perrin, Nicolas

2008-07-01

100

Bioenergetics and thermal physiology of American water shrews (Sorex palustris).  

PubMed

Rates of O(2) consumption and CO(2) production, telemetered body temperature (T(b)) and activity level were recorded from adult and subadult water shrews (Sorex palustris) over an air temperature (T(a)) range of 3-32 degrees C. Digesta passage rate trials were conducted before metabolic testing to estimate the minimum fasting time required for water shrews to achieve a postabsorptive state. Of the 228 metabolic trials conducted on 15 water shrews, 146 (64%) were discarded because the criteria for inactivity were not met. Abdominal T(b) of S. palustris was independent of T(a) and averaged 38.64 +/- 0.07 degrees C. The thermoneutral zone extended from 21.2 degrees C to at least 32 degrees C. Our estimate of the basal metabolic rate for resting, postabsorptive water shrews (96.88 +/- 2.93 J g(-1) h(-1) or 4.84 +/- 0.14 ml O(2) g(-1) h(-1)) was three times the mass-predicted value, while their minimum thermal conductance in air (0.282 +/- 0.013 ml O(2) g(-1) h(-1)) concurred with allometric predictions. The mean digesta throughput time of water shrews fed mealworms (Tenebrio molitor) or ground meat was 50-55 min. The digestibility coefficients for metabolizable energy (ME) of water shrews fed stickleback minnows (Culaea inconstans) and dragonfly nymphs (Anax spp. and Libellula spp.) were 85.4 +/- 1.3% and 82.8 +/- 1.1%, respectively. The average metabolic rate (AMR) calculated from the gas exchange of six water shrews at 19-22 degrees C (208.0 +/- 17.0 J g(-1) h(-1)) was nearly identical to the estimate of energy intake (202.9 +/- 12.9 J g(-1) h(-1)) measured for these same animals during digestibility trials (20 degrees C). Based on 24-h activity trials and our derived ME coefficients, the minimum daily energy requirement of an adult (14.4 g) water shrew at T(a) = 20 degrees C is 54.0 kJ, or the energetic equivalent of 14.7 stickleback minnows. PMID:15592850

Gusztak, R W; Macarthur, R A; Campbell, K L

2005-02-01

101

Molecular evolution of Holarctic martens (genus Martes, Mammalia: Carnivora: Mustelidae)  

E-print Network

Molecular evolution of Holarctic martens (genus Martes, Mammalia: Carnivora: Mustelidae) Karen D species of Martes (except for Martes gwatkinsi from India) to infer evolutionary rela- tionships Martes may be paraphyletic with respect to Gulo gulo. These data supported the fossil record's indication

102

Beitr. Palont., 26:195, Wien 2001 Gulo gulo (Mustelidae, Mammalia) im Jungpleistozn  

E-print Network

Beitr. Paläont., 26:1­95, Wien 2001 Gulo gulo (Mustelidae, Mammalia) im Jungpleistozän Mitteleuropas von Doris D�PPES*) D�PPES, D., 2001. Gulo gulo (Mustelidae, Mammalia) im Jungpleistozän Mitteleuropas. -- Beitr. Paläont., 26:1­95, Wien. Inhalt 1. Biologie des rezenten Gulo gulo (LINNAEUS, 1758

Döppes, Doris

103

[Metastrongylidae parasites of European Soricidae. Description of Paracrenosoma combesi n. sp., from Crocidura russula Hermann, 1780 (author's transl)].  

PubMed

Description of Paracrenosoma combesi n. sp. (Skrjabingylinae), a lung parasite from the common white-toothed shrew Crocidura russula Hermann, 1780 in Spain, and differentiation from the only european species of the same genus, Paracrenosoma skrajabini (Pologentsev, 1935). Description of Stefanskostrongylus soricis (Soltys, 1954) (Angiostrongylinae) from the bronches of the pygmy shrew Sorex minutus Linnaeus, 1766, in Spain and comparison with the data of the same species in Oriental Europe. PMID:931322

Mas-Coma, S

1977-01-01

104

Neuropeptide alterations in the tree shrew hypothalamus during volatile anesthesia  

E-print Network

Neuropeptide alterations in the tree shrew hypothalamus during volatile anesthesia Laetitia perception and brain cognitive state. Prolonged general anesthesia has an impact on many of these processes anesthesia administered accompanying a neurosurgical procedure. Using a predicted-peptide database and hybrid

105

Cortical organization in shrews: evidence from five species.  

PubMed

Cortical organization was examined in five shrew species. In three species, Blarina brevicauda, Cryptotis parva, and Sorex palustris, microelectrode recordings were made in cortex to determine the organization of sensory areas. Cortical recordings were then related to flattened sections of cortex processed for cytochrome oxidase or myelin to reveal architectural borders. An additional two species (Sorex cinereus and Sorex longirostris) with visible cortical subdivisions based on histology alone were analyzed without electrophysiological mapping. A single basic plan of cortical organization was found in shrews, consisting of a few clearly defined sensory areas located caudally in cortex. Two somatosensory areas contained complete representations of the contralateral body, corresponding to primary somatosensory cortex (S1) and secondary somatosensory cortex (S2). A small primary visual cortex (V1) was located closely adjacent to S1, whereas auditory cortex (A1) was located in extreme caudolateral cortex, partially encircled by S2. Areas did not overlap and had sharp, histochemically apparent and electrophysiologically defined borders. The adjacency of these areas suggests a complete absence of intervening higher level or association areas. Based on a previous study of corticospinal connections, a presumptive primary motor cortex (M1) was identified directly rostral to S1. Apparently, in shrews, the solution to having extremely little neocortex is to have only a few small cortical subdivisions. However, the small areas remain discrete, well organized, and functional. This cortical organization in shrews is likely a derived condition, because a wide range of extant mammals have a greater number of cortical subdivisions. PMID:10397395

Catania, K C; Lyon, D C; Mock, O B; Kaas, J H

1999-07-19

106

Ovarian asymmetry in the shrew, Crocidura russula monacha.  

PubMed

The total number of corpora lutea developed in the left and right overies of 170 white-toothed shrews (Crocidura russula monacha) differed significantly, showing a functional dominance of the left ovary. Blastocytes were equally distributed in both uterine horns. PMID:833781

Hellwing, S; Funkenstein, B

1977-01-01

107

The grasping behaviour, locomotion and substrate use of the tree shrews Tupaia minor and T. tana (Mammalia, Scandentia)  

E-print Network

of grasping evidence and a de®nition of hand types). Napier (1961), however, concluded that tupaiids have hands because they overgrow the ®ngertips, obstructing the grasping process. This implies that clawed.e. Tupaia, Anathana, Dendrogale, and Urogale) do not grasp (with either their hands or feet), nor do

Sargis, Eric J.

108

Immunohistochemical mapping of neuropeptide Y in the tree shrew brain.  

PubMed

Day-active tree shrews are promising animals as research models for a variety of human disorders. Neuropeptide Y (NPY) modulates many behaviors in vertebrates. Here we examined the distribution of NPY in the brain of tree shrews (Tupaia belangeri chinensis) using immunohistochemical techniques. The differential distribution of NPY-immunoreactive (-ir) cells and fibers were observed in the rhinencephalon, telencephalon, diencephalon, mesencephalon, metencephalon, and myelencephalon of tree shrews. Most NPY-ir cells were multipolar or bipolar in shape with triangular, fusiform, and/or globular perikarya. The densest cluster of NPY-ir cells were found in the mitral cell layer of the main olfactory bulb (MOB), arcuate nucleus of the hypothalamus, and pretectal nucleus of the thalamus. The MOB presented a unique pattern of NPY immunoreactivity. Laminar distribution of NPY-ir cells was observed in the MOB, neocortex, and hippocampus. Compared to rats, the tree shrews exhibited a particularly robust and widespread distribution of NPY-ir cells in the MOB, bed nucleus of the stria terminalis, and amygdala as well as the ventral lateral geniculate nucleus and pretectal nucleus of the thalamus. By contrast, a low density of neurons were scattered in the striatum, neocortex, polymorph cell layer of the dentate gyrus, superior colliculus, inferior colliculus, and dorsal tegmental nucleus. These findings provide the first detailed mapping of NPY immunoreactivity in the tree shrew brain and demonstrate species differences in the distribution of this neuropeptide, providing an anatomical basis for the participation of the NPY system in the regulation of numerous physiological and behavioral processes. PMID:25327585

Ni, Rong-Jun; Shu, Yu-Mian; Luo, Peng-Hao; Fang, Hui; Wang, Yu; Yao, Lei; Zhou, Jiang-Ning

2015-02-15

109

Short-tailed shrews as reservoirs of the agents of Lyme disease and human babesiosis.  

PubMed

To determine whether short-tailed shrews (Blarina brevicauda) serve as reservoir hosts for the Lyme disease spirochete (Borrelia burgdorferi) and the agent of human babesiosis (Babesia microti), we examined nymphal ticks that had fed as larvae on shrews collected from 3 enzootic sites in coastal Massachusetts for evidence of infection by either or both of these agents. Xenodiagnosis indicated that 11 of 14 shrews were infected by B. burgdorferi. One of 3 piroplasm-infected shrews also infected ticks with B. microti. In a site where the piroplasm is endemic, 11 of 17 shrews showed patent parasitemias by thin blood smears. Of these, 4 had parasitemias exceeding 40%. Few immature ticks infested shrews, however, suggesting that B. brevicauda, although abundant in some endemic sites and serving as a competent reservoir, would contribute minimally to the population of infected nymphs. PMID:2213411

Telford, S R; Mather, T N; Adler, G H; Spielman, A

1990-10-01

110

Muscle senescence in short-lived wild mammals, the soricine shrews Blarina brevicauda and Sorex palustris  

Microsoft Academic Search

Red-toothed (soricine) shrews are consummate predators exhibiting the highest energy turnovers and shortest life spans (ca. 18 months) of any mammal, yet virtually nothing is known regarding their physiological aging. We assessed the emerging pattern of skeletal muscle senescence (contractile\\/connective tissue components) in sympatric species, the semi-aquatic water shrew (WS), Sorex palustris, and the terrestrial short-tailed shrew (STS), Blarina brevicauda

Allyson G. Hindle; John M. Lawler; Kevin L. Campbell; Markus Horning

2009-01-01

111

Quadricuspid aortic valve and single coronary artery in a greater white-toothed shrew, Crocidura russula.  

PubMed

An adult greater white-toothed shrew (Crocidura russula) had both a quadricuspid aortic valve and a single coronary artery arising from the aorta. The shrew was caught on 10 May 1994 in the environs of Málaga, southern Spain. Both congenital anomalies may be potential causes of cardiac dysfunction, but apparently produced no significant cardiac complication in the shrew. This is the first report of a quadricuspid aortic valve in a wild-living mammal. PMID:9359065

Durán, A C

1996-10-01

112

Short-tailed shrews: Toxicity and residue relationships of DDT, dieldrin, and endrin  

USGS Publications Warehouse

Experiments involving dietary toxicity and residue relationships of DDT, dieldrin, and endrin were conducted with short-tailed shrews. Dietary concentrations of DDT dissolved in vegetable oils were usually more toxic than diets containing comparable amounts of powdered DDT. Younger shrews, particularly females, were more tolerant of powdered DDT than older animals; yet, there were no conspicuous age differences in toxicity of DDT dissolved in oils. In comparison to other mammals, short-tailed shrews are not unusually sensitive to DDT, dieldrin, or endrin on the basis of two-week feeding tests. The influence of age and sex on toxicity of DDT, endrin, and dieldrin was sometimes more important than body weight. Of those shrews of the same age and sex that were fed the same dietary dosage, heavier shrews were more tolerant than lighter individuals; and, heavier shrews tended to lose a greater percentage of body weight before death. There was a range of 15 to 105 DDT equivalents in brains of shrews dying on dietary dosages of DDT. Six shrews fed a high level of DDT seemed to have unusual metabolite capabilities and died with apparent lethal levels of DDD in their brains. Levels of dieldrin in brains of shrews that died on a dietary dosage of dieldrin ranged from 3.7 to 12.6 ppm. In the rates of gain and loss experiments where shrews were given diets containing 400 ppm DDT or 50 ppm dieldrin up to 17 days, high residues were noted in tissues of shrews after two weeks on a contaminated diet and a few died at that time. After shrews were placed on clean food, it was determined that >50% of the dieldrin residues in carcass and brain were lost in 50% of residues of DDT and metabolites in brains after 2 weeks on clean food; males lost nearly 50% of residues in carcasses after two weeks on clean food compared with a loss of only 11% in females.

Blus, L.J.

1978-01-01

113

Why do shrews twitter? Communication or simple echo-based orientation  

PubMed Central

Shrews are very vocal animals. We tested behaviourally whether the high-pitched laryngeal ‘twittering’ calls of as-yet unclear function serve for communication or echo-based orientation. We used a representative species from each of the two largest phylogenetic groups of shrews. In both species, experimental manipulation of substrate density, but not of the likelihood of conspecific presence, affected the shrews' call rate when exploring an unknown environment. This adaptation of call rate to the degree of habitat clutter parallels bat echolocation and suggests that shrews may use the echoes and reverberations of their calls for identifying routes through their habitat or for probing habitat type. To assess the acoustic feasibility of shrew echo orientation, we ensonified shrew habitats in the field with an ‘artificial shrew’ (small speaker mounted close to a sensitive microphone). The data showed that shrew-like calls can indeed yield echo scenes useful for habitat assessment at close range, but beyond the range of the shrews' vibrissae. PMID:19535367

Siemers, Björn M.; Schauermann, Grit; Turni, Hendrik; von Merten, Sophie

2009-01-01

114

No evidence of sperm selection by female common shrews.  

PubMed Central

There is currently much interest in the suggestion that females are capable of post-copulatory (or cryptic) choice for male genetic compatibility. Here, I investigate this idea using data from mixed-paternity litters of the common shrew (Sorex araneus). Females of this species are highly promiscuous and, in natural populations, regularly incur costs of inbreeding by mating with close relatives. Selection should therefore favour female ability for sperm selection on the basis of male relatedness. No evidence was found in support of this idea. Relative number of offspring sired within mixed paternity litters was not significantly correlated with genetic similarity of males to the female mated. Relative fertilization success was, however, significantly related to male epididymal sperm counts. I conclude that most variation in relative fertilization success of male common shrews can be explained in terms of sperm competition, and that females of this species may not be capable of sperm selection. PMID:9364789

Stockley, P

1997-01-01

115

Neurochemical Characterization of the Tree Shrew Dorsal Striatum  

PubMed Central

The striatum is a major component of the basal ganglia and is associated with motor and cognitive functions. Striatal pathologies have been linked to several disorders, including Huntington’s, Tourette’s syndrome, obsessive–compulsive disorders, and schizophrenia. For the study of these striatal pathologies different animal models have been used, including rodents and non-human primates. Rodents lack on morphological complexity (for example, the lack of well defined caudate and putamen nuclei), which makes it difficult to translate data to the human paradigm. Primates, and especially higher primates, are the closest model to humans, but there are ever-increasing restrictions to the use of these animals for research. In our search for a non-primate animal model with a striatum that anatomically (and perhaps functionally) can resemble that of humans, we turned our attention to the tree shrew. Evolutionary genetic studies have provided strong data supporting that the tree shrews (Scadentia) are one of the closest groups to primates, although their brain anatomy has only been studied in detail for specific brain areas. Morphologically, the tree shrew striatum resembles the primate striatum with the presence of an internal capsule separating the caudate and putamen, but little is known about its neurochemical composition. Here we analyzed the expression of calcium-binding proteins, the presence and distribution of the striosome and matrix compartments (by the use of calbindin, tyrosine hydroxylase, and acetylcholinesterase immunohistochemistry), and the GABAergic system by immunohistochemistry against glutamic acid decarboxylase and Golgi impregnation. In summary, our results show that when compared to primates, the tree shrew dorsal striatum presents striking similarities in the distribution of most of the markers studied, while presenting some marked divergences when compared to the rodent striatum. PMID:21887131

Rice, Matthew W.; Roberts, Rosalinda C.; Melendez-Ferro, Miguel; Perez-Costas, Emma

2011-01-01

116

Expression of ras gene in experimental hepatocarcinogenesis in tree shrews  

Microsoft Academic Search

Objective: In order to investigate the relationship between the expression of ras gene and the development of hepatocellular carcinoma (HCC). Materials and Methods: The experimental tree shrews were divided\\u000a into four groups: group A, infected human hepatitis B virus (HBV) and exposed to aflatoxin B1 (AFB1); group B, infected human\\u000a HBV alone; group C, only exposed to AFB1; group D,

Ke-chen Ban; Jian-jia Su; Chun Yang; Liu-liang Qin; Yuan Li; Guo-hua Huang; Xiao-ling Luo; Xiao-xian Duan; Rui-qi Yan

1999-01-01

117

Brain Mass and Cranial Nerve Size in Shrews and Moles  

PubMed Central

We investigated the relationship between body size, brain size, and fibers in selected cranial nerves in shrews and moles. Species include tiny masked shrews (S. cinereus) weighing only a few grams and much larger mole species weighing up to 90 grams. It also includes closely related species with very different sensory specializations – such as the star-nosed mole and the common, eastern mole. We found that moles and shrews have tiny optic nerves with fiber counts not correlated with body or brain size. Auditory nerves were similarly small but increased in fiber number with increasing brain and body size. Trigeminal nerve number was by far the largest and also increased with increasing brain and body size. The star-nosed mole was an outlier, with more than twice the number of trigeminal nerve fibers than any other species. Despite this hypertrophied cranial nerve, star-nosed mole brains were not larger than predicted from body size, suggesting that magnification of their somatosensory systems does not result in greater overall CNS size. PMID:25174995

Leitch, Duncan B.; Sarko, Diana K.; Catania, Kenneth C.

2014-01-01

118

The lung of shrews: morphometric estimation of diffusion capacity.  

PubMed

The lungs of 16 shrews from 8 species (Sorex minutus, Neomys fodiens, Suncus etruscus, Crocidura russula, C. juvenetae, C. poensis, C. flavescens, C. giffardi) ranging in body weight from 2.2 to 100 g were studied by morphometry in order to compare the structural diffusion capacity for oxygen. DL02, with the oxygen consumption, VO2, measured on the same animals. VO2 was determined by short term measurements using a respirometer. DLO2 was estimated morphometrically. Both parameters demonstrated good coincidence in their allometric behaviour, establishing further progress in structure-function relationship in the respiratory apparatus. Whereas VO2 as well as DLO2 of shrews with a body weight W greater than 5 g follow the same allometric function established for mammals in general, the values for shrews with W less than 5 g exhibit significantly higher values. It appears that the pulmonary gas exchange parenchyma of these smallest mammals is well suited to supply the organism with the comparatively high levels of O2 required by the high metabolic rates, exhibiting a structural adaptation of the lung to higher VO2. PMID:7394364

Gehr, P; Sehovic, S; Burri, P H; Claassen, H; Weibel, E R

1980-04-01

119

Affect intensity in voice recognized by tree shrews (Tupaia belangeri).  

PubMed

Shared acoustic cues in speech, music, and nonverbal emotional expressions were postulated to code for emotion quality and intensity favoring the hypothesis of a prehuman origin of affective prosody in human emotional communication. To explore this hypothesis, we examined in playback experiments using a habituation-dishabituation paradigm whether a solitary foraging, highly vocal mammal, the tree shrew, is able to discriminate two behaviorally defined states of affect intensity (low vs. high) from the voice of conspecifics. Playback experiments with communication calls of two different types (chatter call and scream call) given in the state of low affect intensity revealed that habituated tree shrews dishabituated to one call type (the chatter call) and showed a tendency to do so for the other one (the scream call), both given in the state of high affect intensity. Findings suggest that listeners perceive the acoustic variation linked to defined states of affect intensity as different within the same call type. Our findings in tree shrews provide first evidence that acoustically conveyed affect intensity is biologically relevant without any other sensory cue, even for solitary foragers. Thus, the perception of affect intensity in voice conveyed in stressful contexts represents a shared trait of mammals, independent of the complexity of social systems. Findings support the hypothesis that affective prosody in human emotional communication has deep-reaching phylogenetic roots, deriving from precursors already present and relevant in the vocal communication system of early mammals. PMID:22309729

Schehka, Simone; Zimmermann, Elke

2012-06-01

120

Targeting of Transmembrane Protein Shrew-1 to Adherens Junctions Is Controlled by Cytoplasmic Sorting Motifs  

PubMed Central

We recently identified transmembrane protein shrew-1 and showed that it is able to target to adherens junctions in polarized epithelial cells. This suggested shrew-1 possesses specific basolateral sorting motifs, which we analyzed by mutational analysis. Systematic mutation of amino acids in putative sorting signals in the cytoplasmic domain of shrew-1 revealed three tyrosines and a dileucine motif necessary for basolateral sorting. Substitution of these amino acids leads to apical localization of shrew-1. By applying tannic acid to either the apical or basolateral part of polarized epithelial cells, thereby blocking vesicle fusion with the plasma membrane, we obtained evidence that the apically localized mutants were primarily targeted to the basolateral membrane and were then redistributed to the apical domain. Further support for a postendocytic sorting mechanism of shrew-1 was obtained by demonstrating that ?1B, a subunit of the epithelial cell-specific adaptor complex AP-1B, interacts with shrew-1. In conclusion, our data provide evidence for a scenario where shrew-1 is primarily delivered to the basolateral membrane by a so far unknown mechanism. Once there, adaptor protein complex AP-1B is involved in retaining shrew-1 at the basolateral membrane by postendocytic sorting mechanisms. PMID:16707570

Jakob, Viktor; Schreiner, Alexander; Tikkanen, Ritva

2006-01-01

121

Muscle aging and oxidative stress in wild-caught shrews Allyson G. Hindle a,  

E-print Network

January 2010 Keywords: Senescence Antioxidant Breath-hold diving Redox Apoptosis Sorex palustris Blarina- related decline should be detrimental to fitness and survival. Muscle samples of water shrews (Sorex palustris) and sympatrically distributed short-tailed shrews (Blarina brevicauda) were therefore assessed

Campbell, Kevin L.

122

Bone-marrow mesenchymal stem cell transplantation to treat diabetic nephropathy in tree shrews.  

PubMed

Diabetic nephropathy (DN) is a common microvascular complication of diabetes. We used a new DN model in tree shrews to validate the use of bone-marrow mesenchymal stem cell (BM-MSC) transplantation to treat DN. The DN tree shrew model was established by a high-sugar and high-fat diet and four injections of streptozotocin. 4',6-Diamidino-2-phenylindole labelled BM-MSCs were injected into tree shrews. The DN tree shrew model was successfully established. Blood glucose was significantly increased ( p < 0.01) during the entire experiment. DN tree shrews showed dyslipidemia, insulin resistance and increased 24-h proteinuria. At 21 days after BM-MSC transplantation, glucose and levels of triglycerides, total cholesterol and 24-h urine volume were lower than in tree shrews with DN alone ( p < 0.01) but were still higher than control values ( p < 0.01). Levels of creatinine and urea nitrogen as well as 24-h proteinuria were lower for DN tree shrews with BM-MSCs transplantation than DN alone ( p < 0.05). High-sugar and high-fat diet combined with STZ injection can induce a tree shrew model of DN. BM-MSCs injection can home to damaged kidneys and pancreas, for reduced 24-h proteinuria and improved insulin resistance. PMID:24867093

Pan, Xing-Hua; Yang, Xiao-Yan; Yao, Xiang; Sun, Xiao-Mei; Zhu, Lu; Wang, Jin-Xiang; Pang, Rong-Qing; Cai, Xue-Min; Dai, Jie-Jie; Ruan, Guang-Ping

2014-07-01

123

Population dynamics of the northern short-tailed shrew, Blarina brevicauda: insights from a 25-year  

E-print Network

Population dynamics of the northern short-tailed shrew, Blarina brevicauda: insights from a 25-year demography of the northern short-tailed shrew, Blarina brevicauda (Say, 1823), was studied for 25 years, Blarina brevicauda (Say, 1823), a été étudiée pendant 25 ans dans des habitats de pâturin, de luzerne et d

Oli, Madan K.

124

Carving out turf in a biodiversity hotspot: multiple, previously unrecognized shrew species co-occur on  

E-print Network

Carving out turf in a biodiversity hotspot: multiple, previously unrecognized shrew species co species in a shared habitat results in niche separation. In the case of small recondite mammals in a biodiversity hotspot, by surveying shrew (genus Crocidura) diversity on the Indonesian island of Java. We

Evans, Ben J.

125

Seewis virus, a genetically distinct hantavirus in the Eurasian common shrew (Sorex araneus)  

PubMed Central

More than 20 years ago, hantaviral antigens were reported in tissues of the Eurasian common shrew (Sorex araneus), Eurasian water shrew (Neomys fodiens) and common mole (Talpa europea), suggesting that insectivores, or soricomorphs, might serve as reservoirs of unique hantaviruses. Using RT-PCR, sequences of a genetically distinct hantavirus, designated Seewis virus (SWSV), were amplified from lung tissue of a Eurasian common shrew, captured in October 2006 in Graubünden, Switzerland. Pair-wise analysis of the full-length S and partial M and L segments of SWSV indicated approximately 55%–72% similarity with hantaviruses harbored by Murinae, Arvicolinae, Neotominae and Sigmodontinae rodents. Phylogenetically, SWSV grouped with other recently identified shrew-borne hantaviruses. Intensified efforts are underway to clarify the genetic diversity of SWSV throughout the geographic range of the Eurasian common shrew, as well as to determine its relevance to human health. PMID:17967200

Song, Jin-Won; Gu, Se Hun; Bennett, Shannon N; Arai, Satoru; Puorger, Maria; Hilbe, Monika; Yanagihara, Richard

2007-01-01

126

Phylogeny and conservation priorities of afrotherian mammals (Afrotheria, Mammalia)  

E-print Network

and mammoths, dugong and manatees, hyraxes, tenrecs, golden moles, elephant shrews and aardvark. To date (hyraxes, dugongs, manatees and elephants) is supported, as is the monophyly of all afrotherian families conservation icons like Asian elephant, dugong and the three species of manatee. Conservation priority analyses

Agnarsson, Ingi

127

The humerus of Cryptotis colombiana and its bearing on the species? phylogenetic relationships (Soricomorpha: Soricidae)  

USGS Publications Warehouse

The Colombian small-eared shrew, Cryptotis colombiana Woodman and Timm, was described from the Colombian Andes in 1993. Its original allocation to the Cryptotis nigrescens-group recently was questioned based on several cranial characters the species appeared to share with some members of the Cryptotis thomasi-group. We review characteristics of the C. nigrescens- and C. thomasi-groups, and we describe the humerus of C. colombiana and the humerus and manus of Cryptotis medellinia. The morphology of the humerus joins the suite of characters that supports the hypotheses that C. colombiana is not a member of the C. thomasi-group and that all remaining South American species form a cohesive, definable set that is probably monophyletic.

Woodman, N.; Cuartas-Calle, C.A.; Delgado-V., C.A.

2003-01-01

128

Water shrews detect movement, shape, and smell to find prey underwater.  

PubMed

American water shrews (Sorex palustris) are aggressive predators that feed on a variety of terrestrial and aquatic prey. They often forage at night, diving into streams and ponds in search of food. We investigated how shrews locate submerged prey using high-speed videography, infrared lighting, and stimuli designed to mimic prey. Shrews attacked brief water movements, indicating motion is an important cue used to detect active or escaping prey. They also bit, retrieved, and attempted to eat model fish made of silicone in preference to other silicone objects showing that tactile cues are important in the absence of movement. In addition, water shrews preferentially sniffed model prey fish and crickets underwater by exhaling and reinhaling air through the nostrils, suggesting olfaction plays an important role in aquatic foraging. The possibility of echolocation, sonar, or electroreception was investigated by testing for ultrasonic and audible calls above and below water and by presenting electric fields to foraging shrews. We found no evidence for these abilities. We conclude that water shrews detect motion, shape, and smell to find prey underwater. The short latency of attacks to water movements suggests shrews may use a flush-pursuit strategy to capture some prey. PMID:18184804

Catania, Kenneth C; Hare, James F; Campbell, Kevin L

2008-01-15

129

Water shrews detect movement, shape, and smell to find prey underwater  

PubMed Central

American water shrews (Sorex palustris) are aggressive predators that feed on a variety of terrestrial and aquatic prey. They often forage at night, diving into streams and ponds in search of food. We investigated how shrews locate submerged prey using high-speed videography, infrared lighting, and stimuli designed to mimic prey. Shrews attacked brief water movements, indicating motion is an important cue used to detect active or escaping prey. They also bit, retrieved, and attempted to eat model fish made of silicone in preference to other silicone objects showing that tactile cues are important in the absence of movement. In addition, water shrews preferentially sniffed model prey fish and crickets underwater by exhaling and reinhaling air through the nostrils, suggesting olfaction plays an important role in aquatic foraging. The possibility of echolocation, sonar, or electroreception was investigated by testing for ultrasonic and audible calls above and below water and by presenting electric fields to foraging shrews. We found no evidence for these abilities. We conclude that water shrews detect motion, shape, and smell to find prey underwater. The short latency of attacks to water movements suggests shrews may use a flush-pursuit strategy to capture some prey. PMID:18184804

Catania, Kenneth C.; Hare, James F.; Campbell, Kevin L.

2008-01-01

130

Host switch during evolution of a genetically distinct hantavirus in the American shrew mole (Neurotrichus gibbsii)  

PubMed Central

A genetically distinct hantavirus, designated Oxbow virus (OXBV), was detected in tissues of an American shrew mole (Neurotrichus gibbsii), captured in Gresham, Oregon, in September 2003. Pairwise analysis of full-length S- and M- and partial L-segment nucleotide and amino acid sequences of OXBV indicated low sequence similarity with rodent-borne hantaviruses. Phylogenetic analyses using maximum-likelihood and Bayesian methods, and host-parasite evolutionary comparisons, showed that OXBV and Asama virus, a hantavirus recently identified from the Japanese shrew mole (Urotrichus talpoides), were related to soricine shrew-borne hantaviruses from North America and Eurasia, respectively, suggesting parallel evolution associated with cross-species transmission. PMID:19394994

Kang, Hae Ji; Bennett, Shannon N.; Dizney, Laurie; Sumibcay, Laarni; Arai, Satoru; Ruedas, Luis A.; Song, Jin-Won; Yanagihara, Richard

2009-01-01

131

The annular hematoma of the shrew yolk-sac placenta.  

PubMed

The annular hematoma of the shrew, Blarina brevicauda, is a specialized portion of the yolk-sac wall. In this study, we have examined the fine structure of the different cellular components of the anular hematoma. Small pieces of the gestation sacs from seven pregnant shrews were fixed in glutaraldehyde and osmium tetroxide and processed for transmission electron microscopy. In the area of the trophoblastic curtain, the maternal capillary endothelial cells were hypertrophied and syncytial trophoblast surrounded the capillaries. Cellular trophoblast covered part of the luminal surface of the curtain region, whereas masses of apparently degenerating syncytium were present on other areas of the surface. Maternal erythrocytes, released into the uterine lumen from the curtain region, were phagocytized and degraded by the columnar cells of the trophoblastic annulus. No evidence of iron or pigment accumulation was evident in the parietal endodermal cells underlying the annular trophoblast. Parietal endodermal cells were characterized by cuboidal shape, widely dilated intercellular spaces, and cytoplasm containing granular endoplasmic reticulum. Endodermal cells of the visceral yolk-sac accumulated large numbers of electron-dense granules as well as glycogen in their cytoplasm. Hemopoietic areas and vitelline capillaries were found subjacent to the visceral endoderm. The various portions of the yolk-sac wall of Blarina appear to perform complementary functions which are probably important in maternal-fetal iron transfer. PMID:677046

King, B F; Enders, A C; Wimsatt, W A

1978-05-01

132

Genetic diversity and phylogeography of Seewis virus in the Eurasian common shrew in Finland and Hungary  

PubMed Central

Recent identification of a newfound hantavirus, designated Seewis virus (SWSV), in the Eurasian common shrew (Sorex araneus), captured in Switzerland, corroborates decades-old reports of hantaviral antigens in this shrew species from Russia. To ascertain the spatial or geographic variation of SWSV, archival liver tissues from 88 Eurasian common shrews, trapped in Finland in 1982 and in Hungary during 1997, 1999 and 2000, were analyzed for hantavirus RNAs by reverse transcription-polymerase chain reaction. SWSV RNAs were detected in 12 of 22 (54.5%) and 13 of 66 (19.7%) Eurasian common shrews from Finland and Hungary, respectively. Phylogenetic analyses of S- and L-segment sequences of SWSV strains, using maximum likelihood and Bayesian methods, revealed geographic-specific genetic variation, similar to the phylogeography of rodent-borne hantaviruses, suggesting long-standing hantavirus-host co-evolutionary adaptation. PMID:19930716

2009-01-01

133

Ticks and fleas of shrews in Appalachian Georgia and North Carolina.  

PubMed

Ticks (Acari: Ixodidae) and fleas (Insecta: Siphonaptera) were recovered from 8 smoky shrews, Sorex fumeus Miller, and 9 northern short-tailed shrews, Blarina brevicauda (Say), trapped at elevations of 720-1,310 m in Macon and Jackson counties in western North Carolina and Union County in northern Georgia from April 1994 to August 1995. The ticks Ixodes angustus Neumann and Ixodes woodi Bishopp, and the flea Corrodopsylla curvata (Rothschild), were recovered from smoky shrews. The same 2 tick species, in addition to the fleas, Ctenophthalmus pseudagyrtes Baker and Doratopsylla blarinae Fox, were recovered from northern short-tailed shrews. New state records for I. angustus from Georgia and I. woodi from North Carolina are established. PMID:8691385

McCay, T S; Durden, L A

1996-08-01

134

Growth, development and maintenance of American water shrews (Sorex palustris) in captivity  

Microsoft Academic Search

This paper documents a cost-effective method for the long-term housing and main- tenance of water shrews. Wild-caught American water shrews (Sorex palustris) were success- fully maintained in this set up for up to 2 years, suggesting a maximum lifespan of 28 months for this species in captivity. In addition, we describe the postnatal growth and development of S. palustris based

Roman W. Gusztak; Kevin L. Campbell

2004-01-01

135

Prey size, prey nutrition, and food handling by shrews of different body sizes  

Microsoft Academic Search

We tested some predictions relating metabolic constraints of foraging behavior and prey selection by comparing food handling and utilization in four sympatric shrew species: Sorex minutus (mean body mass = 3.0 g), S. araneus (8.0 g), Neomys anomalus (10.0 g), and N. fodiens (14.4 g). Live fly larvae, mealworm larvae, and aquatic arthropods were offered to shrews as small prey

Leszek Rychlik

2002-01-01

136

New infectious spirochete isolated from short-tailed shrews and white-footed mice.  

PubMed

A spirochete with two periplasmic flagella was isolated from the blood or tissues of spleens and kidneys from short-tailed shrews (Blarina brevicauda) and white-footed mice (Peromyscus leucopus) in Connecticut and Minnesota. After inoculation, the shrew-mouse spirochete infected Swiss mice and Syrian hamsters. This spirochete is morphologically and serologically distinct from the species of Treponema, Borrelia, Leptospira, and Spirochaeta examined. PMID:3305565

Anderson, J F; Johnson, R C; Magnarelli, L A; Hyde, F W; Andreadis, T G

1987-08-01

137

Seewis Virus: Phylogeography of a Shrew-Borne Hantavirus in Siberia, Russia  

PubMed Central

Abstract Background Hantaviral antigens were originally reported more than 20 years ago in tissues of the Eurasian common shrew (Sorex araneus), captured in European and Siberian Russia. The recent discovery of Seewis virus (SWSV) in this soricid species in Switzerland provided an opportunity to investigate its genetic diversity and geographic distribution in Russia. Methods Lung tissues from 45 Eurasian common shrews, 4 Laxmann's shrews (Sorex caecutiens), 3 Siberian large-toothed shrews (Sorex daphaenodon), 9 pygmy shrews (Sorex minutus), 28 tundra shrews (Sorex tundrensis), and 6 Siberian shrews (Crocidura sibirica), captured in 11 localities in Western and Eastern Siberia during June 2007 to September 2008, were analyzed for hantavirus RNA by reverse transcription–polymerase chain reaction. Results Hantavirus L and S segment sequences, detected in 11 S. araneus, 2 S. tundrensis, and 2 S. daphaenodon, were closely related to SWSV, differing from the prototype mp70 strain by 16.3–20.2% at the nucleotide level and 1.4–1.7% at the amino acid level. Alignment and comparison of nucleotide and amino acid sequences showed an intrastrain difference of 0–11.0% and 0% for the L segment and 0.2–8.5% and 0% for the S segment, respectively. Phylogenetic analysis, using neighbor-joining, maximum-likelihood, and Bayesian methods, showed geographic-specific clustering of SWSV strains in Western and Eastern Siberia. Conclusions This is the first definitive report of shrew-borne hantaviruses in Siberia, and demonstrates the impressive distribution of SWSV among phylogenetically related Sorex species. Coevolution and local adaptation of SWSV genetic variants in specific chromosomal races of S. araneus may account for their geographic distribution. PMID:20426688

Abramov, Sergey A.; Gutorov, Valery V.; Dupal, Tamara A.; Krivopalov, Anton V.; Panov, Victor V.; Danchinova, Galina A.; Vinogradov, Vladislav V.; Luchnikova, Ekaterina M.; Hay, John; Kang, Hae Ji; Yanagihara, Richard

2010-01-01

138

Molecular phylogeny of a newfound hantavirus in the Japanese shrew mole (Urotrichus talpoides)  

PubMed Central

Recent molecular evidence of genetically distinct hantaviruses in shrews, captured in widely separated geographical regions, corroborates decades-old reports of hantavirus antigens in shrew tissues. Apart from challenging the conventional view that rodents are the principal reservoir hosts, the recently identified soricid-borne hantaviruses raise the possibility that other soricomorphs, notably talpids, similarly harbor hantaviruses. In analyzing RNA extracts from lung tissues of the Japanese shrew mole (Urotrichus talpoides), captured in Japan between February and April 2008, a hantavirus genome, designated Asama virus (ASAV), was detected by RT-PCR. Pairwise alignment and comparison of the S-, M-, and L-segment nucleotide and amino acid sequences indicated that ASAV was genetically more similar to hantaviruses harbored by shrews than by rodents. However, the predicted secondary structure of the ASAV nucleocapsid protein was similar to that of rodent- and shrew-borne hantaviruses, exhibiting the same coiled-coil helix at the amino terminus. Phylogenetic analyses, using the maximum-likelihood method and other algorithms, consistently placed ASAV with recently identified soricine shrew-borne hantaviruses, suggesting a possible host-switching event in the distant past. The discovery of a mole-borne hantavirus enlarges our concepts about the complex evolutionary history of hantaviruses. PMID:18854415

Arai, Satoru; Ohdachi, Satoshi D.; Asakawa, Mitsuhiko; Kang, Hae Ji; Mocz, Gabor; Arikawa, Jiro; Okabe, Nobuhiko; Yanagihara, Richard

2008-01-01

139

Chemoarchitecture of layer 4 isocortex in the American water shrew (Sorex palustris).  

PubMed

We examined the chemoarchitecture of layer 4 isocortex and the number of myelinated nerve fibers of selected cranial nerves in the American water shrew (Sorex palustris). This study took advantage of the opportunity to examine juvenile brain tissue, which often reveals the most distinctive cortical modules related to different sensory representations. Flattened cortical sections were processed for the metabolic enzyme cytochrome oxidase, revealing a number of modules and septa. Subdivisions related to sensory representations were tentatively identified by performing microelectrode recordings in a single adult shrew in this study, combined with microelectrode recordings and anatomical findings from a previous investigation. Taken together, these results suggest that characteristic chemoarchitectonic borders in the shrew neocortex can be used to delineate and quantify cortical areas. The most obvious subdivisions in the water shrew include a relatively small primary visual cortex which responded to visual stimuli, a larger representation of vibrissae in the primary somatosensory cortex, and a prominent representation of oral structures apparent in the more rostral-lateral cortex. A presumptive auditory area was located in the far caudal cortex. These findings for the cortex are consistent with counts from optic, auditory and trigeminal nerves, suggesting that somatosensory inputs dominate the shrew's senses whereas visual and auditory inputs play a small role in navigation and in finding prey. More generally, we find that shrews share unusual features of cortical organization with moles, supporting their close taxonomic relationship. PMID:21985842

Leitch, Duncan B; Gauthier, Danielle; Sarko, Diana K; Catania, Kenneth C

2011-01-01

140

Biodiversity and evolution of Imjin virus and Thottapalayam virus in Crocidurinae shrews in Zhejiang Province, China.  

PubMed

The recent discovery of numerous hantaviruses in insectivores has provided a new view of hantavirus biodiversity and evolution. To determine the presence and genetic diversity of Imjin virus (MJNV) and Thottapalayam virus (TPMV) in insectivores in Zhejiang Province, China, we captured and performed virus screening of 32 Ussuri white-toothed shrews (Crocidura lasiura) and 105 Asian house shrews (Suncus murinus) in different coastal regions. Hantavirus genome (S, M, and L segments) sequences were successfully recovered from one Ussuri white-toothed shrew and seven Asian house shrews. Phylogenetic analysis revealed that the virus carried by the Ussuri white-toothed shrew was most closely related to MJNV, but with >15% nucleotide sequence difference, suggesting that it represents a new subtype. The hantaviruses carried by Asian house shrews were closely related to the TPMV variants found in the same geographic area, but more distantly related to those sampled in India and Nepal. Additionally, the TPMV sequences obtained in this study, as well as those found previously in this area, could be divided into three lineages reflecting their geographic origins, indicative of largely allopatric evolution. Overall, our data highlights the high genetic diversity of insectivore-borne hantaviruses in China, suggesting that more may be discovered in the future. PMID:24874196

Lin, Xian-Dan; Zhou, Run-Hong; Fan, Fei-Neng; Ying, Xu-Hua; Sun, Xiao-Yu; Wang, Wen; Holmes, Edward C; Zhang, Yong-Zhen

2014-08-30

141

Paradoxical social effects on response to cold during ontogeny of the common white-toothed shrew, Crocidura russula.  

PubMed

Postnatal development of thermoregulatory responses to cold differs between shrews measured singly or in groups as a litter. Single shrews increase their metabolic response to cold within 14 days to maintain normothermia. Shrews measured in groups show little or no metabolic response to cold and do not reach normothermia before the 19th day. Lower body temperatures in groups are explained by torpor, which obviously needs the prerequisite of forming a group. Oxygen consumption of the singly measured shrews depends upon body mass. PMID:2778129

Nagel, A

1989-01-01

142

Structural and functional characterization of enamel pigmentation in shrews.  

PubMed

Pigmented tooth enamel occurs in several vertebrate clades, ranging from mammals to fish. Although an iron compound is associated with this orange to red colored pigmentation, its chemical and structural organization within the enamel is unknown. To determine the nature of the iron compound, we investigated heavily pigmented teeth of the northern short-tailed shrew Blarina brevicauda using combined characterization techniques such as scanning and transmission electron microscopy and synchrotron X-ray diffraction. We found that the pigmentation of the enamel with an iron content of around 8wt% results from a close to amorphous magnetite phase deposited around the nm-sized enamel crystals. Furthermore, the influence of the pigmentation on the enamel hardness was determined by nanoindentation measurements. Finally, the biomechanical function and biological context are discussed in light of the obtained results. PMID:24556576

Dumont, M; Tütken, T; Kostka, A; Duarte, M J; Borodin, S

2014-04-01

143

Thermoregulatory correlates of nausea in rats and musk shrews.  

PubMed

Nausea is a prominent symptom and major cause of complaint for patients receiving anticancer chemo- or radiation therapy. The arsenal of anti-nausea drugs is limited, and their efficacy is questionable. Currently, the development of new compounds with anti-nausea activity is hampered by the lack of physiological correlates of nausea. Physiological correlates are needed because common laboratory rodents lack the vomiting reflex. Furthermore, nausea does not always lead to vomiting. Here, we report the results of studies conducted in four research centers to investigate whether nausea is associated with any specific thermoregulatory symptoms. Two species were studied: the laboratory rat, which has no vomiting reflex, and the house musk shrew (Suncus murinus), which does have a vomiting reflex. In rats, motion sickness was induced by rotating them in their individual cages in the horizontal plane (0.75 Hz, 40 min) and confirmed by reduced food consumption at the onset of dark (active) phase. In 100% of rats tested at three centers, post-rotational sickness was associated with marked (~1.5°C) hypothermia, which was associated with a short-lasting tail-skin vasodilation (skin temperature increased by ~4°C). Pretreatment with ondansetron, a serotonin 5-HT3 receptor antagonist, which is used to treat nausea in patients in chemo- or radiation therapy, attenuated hypothermia by ~30%. In shrews, motion sickness was induced by a cyclical back-and-forth motion (4 cm, 1 Hz, 15 min) and confirmed by the presence of retching and vomiting. In this model, sickness was also accompanied by marked hypothermia (~2°C). Like in rats, the hypothermic response was preceded by transient tail-skin vasodilation. In conclusion, motion sickness is accompanied by hypothermia that involves both autonomic and thermoeffector mechanisms: tail-skin vasodilation and possibly reduction of the interscapular brown adipose tissue activity. These thermoregulatory symptoms may serve as physiological correlates of nausea. PMID:24728971

Ngampramuan, Sukonthar; Cerri, Matteo; Del Vecchio, Flavia; Corrigan, Joshua J; Kamphee, Amornrat; Dragic, Alexander S; Rudd, John A; Romanovsky, Andrej A; Nalivaiko, Eugene

2014-03-30

144

Physical and Cognitive Performance of the Least Shrew (Cryptotis parva) on a Calcium-Restricted Diet  

PubMed Central

Geological substrates and air pollution affect the availability of calcium to mammals in many habitats, including the Adirondack Mountain Region (Adirondacks) of the United States. Mammalian insectivores, such as shrews, may be particularly restricted in environments with low calcium. We examined the consequences of calcium restriction on the least shrew (Cryptotis parva) in the laboratory. We maintained one group of shrews (5 F, 5 M) on a mealworm diet with a calcium concentration comparable to beetle larvae collected in the Adirondacks (1.1 ± 0.3 mg/g) and another group (5 F, 3 M) on a mealworm diet with a calcium concentration almost 20 times higher (19.5 ± 5.1 mg/g). Animals were given no access to mineral sources of calcium, such as snail shell or bone. We measured running speed and performance in a complex maze over 10 weeks. Shrews on the high-calcium diet made fewer errors in the maze than shrews on the low-calcium diet (F1,14 = 12.8, p < 0.01). Females made fewer errors than males (F1,14 = 10.6, p < 0.01). Running speeds did not markedly vary between diet groups or sexes, though there was a trend toward faster running by shrews on the high calcium diet (p = 0.087). Shrews in calcium-poor habitats with low availability of mineral sources of calcium may have greater difficulty with cognitive tasks such as navigation and recovery of food hoards. PMID:25379219

Czajka, Jessica L.; McCay, Timothy S.; Garneau, Danielle E.

2012-01-01

145

Neuropeptide Y influences acute food intake and energy status affects NPY immunoreactivity in the female musk shrew (Suncus murinus) 1  

PubMed Central

Neuropeptide Y (NPY) stimulates feeding, depresses sexual behavior, and its expression in the brain is modulated by energetic status. We examined the role of NPY in female musk shrews, a species with high energetic and reproductive demands; they store little fat, and small changes in energy can rapidly diminish or enhance sexual receptivity. Intracerebroventricular infusion of NPY enhanced acute food intake in shrews, however, NPY had little affect on sexual receptivity. The distribution of NPY immunoreactivity in the female musk shrew brain was unremarkable, but energy status differentially affected NPY immunoreactivity in several regions. Similar to what has been noted in other species, NPY immunoreactivity was less dense in brains of ad libitum shrews and greater in shrews subjected to food restriction. In two midbrain regions, both of which contain high levels of gonadotropin releasing hormone II (GnRH II) which has anorexigenic actions in shrews, NPY immunoreactivity was more sensitive to changes in food intake. In these regions, acute refeeding (90–180 minutes) after food restriction reduced NPY immunoreactivity to levels noted in ad libitum shrews. We hypothesize that interactions between NPY and GnRH II maintain energy homeostasis and reproduction in the musk shrew. PMID:18191134

Bojkowska, Karolina; Hamczyk, Magdalena M.; Tsai, Houng-Wei; Riggan, Anna; Rissman, Emilie F.

2008-01-01

146

Chronic Psychosocial Stress Causes Apical Dendritic Atrophy of Hippocampal CA3 Pyramidal Neurons in Subordinate Tree Shrews  

Microsoft Academic Search

We have shown previously that repeated laboratory restraint stress or daily corticosterone administration affects the struc- ture of CA3 hippocampal neurons in rats. In the present study, we investigated the effect of repeated daily psychosocial stress on the structure of hippocampal CA3 pyramidal neurons in male tree shrews (Tupaia belangeri). Male tree shrews develop social hierarchies in which subordinates show

Ana Maria Magarinos; Bruce S. McEwen; Gabriele Flugge; Eberhard Fuchs

1996-01-01

147

Drug Target Mining and Analysis of the Chinese Tree Shrew for Pharmacological Testing  

PubMed Central

The discovery of new drugs requires the development of improved animal models for drug testing. The Chinese tree shrew is considered to be a realistic candidate model. To assess the potential of the Chinese tree shrew for pharmacological testing, we performed drug target prediction and analysis on genomic and transcriptomic scales. Using our pipeline, 3,482 proteins were predicted to be drug targets. Of these predicted targets, 446 and 1,049 proteins with the highest rank and total scores, respectively, included homologs of targets for cancer chemotherapy, depression, age-related decline and cardiovascular disease. Based on comparative analyses, more than half of drug target proteins identified from the tree shrew genome were shown to be higher similarity to human targets than in the mouse. Target validation also demonstrated that the constitutive expression of the proteinase-activated receptors of tree shrew platelets is similar to that of human platelets but differs from that of mouse platelets. We developed an effective pipeline and search strategy for drug target prediction and the evaluation of model-based target identification for drug testing. This work provides useful information for future studies of the Chinese tree shrew as a source of novel targets for drug discovery research. PMID:25105297

Liu, Jie; Lee, Wen-hui; Zhang, Yun

2014-01-01

148

Tuning of color contrast signals to visual sensitivity maxima of tree shrews by three Bornean highland Nepenthes species.  

PubMed

Three species of Nepenthes pitcher plants (Nepenthes rajah, Nepenthes lowii and Nepenthes macrophylla) specialize in harvesting nutrients from tree shrew excreta in their pitchers. In all three species, nectaries on the underside of the pitcher lid are the focus of the tree shrews' attention. Tree shrews are dichromats, with visual sensitivity in the blue and green wavebands. All three Nepenthes species were shown to produce visual signals, in which the underside of the pitcher lid (the area of highest nectar production) stood out in high contrast to the adjacent area on the pitcher (i.e., was brighter), in the blue and green wavebands visible to the tree shrews. N. rajah showed the tightest degree of "tuning," notably in the green waveband. Conversely, pitchers of Nepenthes burbidgeae, a typical insectivorous species sympatric with N. rajah, did not produce a color pattern tuned to tree shrew sensitivity maxima. PMID:22902686

Moran, Jonathan A; Clarke, Charles; Greenwood, Melinda; Chin, Lijin

2012-10-01

149

Tuning of color contrast signals to visual sensitivity maxima of tree shrews by three Bornean highland Nepenthes species  

PubMed Central

Three species of Nepenthes pitcher plants (Nepenthes rajah, Nepenthes lowii and Nepenthes macrophylla) specialize in harvesting nutrients from tree shrew excreta in their pitchers. In all three species, nectaries on the underside of the pitcher lid are the focus of the tree shrews' attention. Tree shrews are dichromats, with visual sensitivity in the blue and green wavebands. All three Nepenthes species were shown to produce visual signals, in which the underside of the pitcher lid (the area of highest nectar production) stood out in high contrast to the adjacent area on the pitcher (i.e., was brighter), in the blue and green wavebands visible to the tree shrews. N. rajah showed the tightest degree of “tuning,” notably in the green waveband. Conversely, pitchers of Nepenthes burbidgeae, a typical insectivorous species sympatric with N. rajah, did not produce a color pattern tuned to tree shrew sensitivity maxima. PMID:22902686

Moran, Jonathan A.; Clarke, Charles; Greenwood, Melinda; Chin, Lijin

2012-01-01

150

Phylogeny of the Procyonidae (Mammalia: Carnivora): Molecules, morphology and the Great American Interchange  

Microsoft Academic Search

The Procyonidae (Mammalia: Carnivora) have played a central role in resolving the controversial systematics of the giant and red pandas, but phylogenetic relationships of species within the family itself have received much less attention. Cladistic analyses of morphological characters conducted during the last two decades have resulted in topologies that group ecologically and morphologically similar taxa together. Specifically, the highly

Klaus-Peter Koepfli; Matthew E. Gompper; Eduardo Eizirik; Cheuk-Chung Ho; Leif Linden; Jesus E. Maldonado; Robert K. Wayne

2007-01-01

151

Physical and morphological aspects of the eye of the manatee trichechus inunguis natterer 1883: (Sirenia: Mammalia)  

Microsoft Academic Search

The eyes and aspects of vision of the Amazonian manatee Trichechus inunguis NATTERER 1883: (Sirenia: mammalia) have been examined in five animals, in relation to previous findings for sirenians. This paper presents a review of previous findings confirming those upon gross ocular anatomy, retinal histology and ocular refraction. The confirmation of a primarily rod retina, high receptor: ganglion cell ratio

David Piggins; W. R. A. Muntz; Robin C. Best

1983-01-01

152

NEW SKULLS OF KOLPOCHOERUS PHACOCHOEROIDES (SUIDAE, MAMMALIA) FROM THE LATE PLIOCENE OF AHL AL OUGHLAM,  

E-print Network

1 NEW SKULLS OF KOLPOCHOERUS PHACOCHOEROIDES (SUIDAE, MAMMALIA) FROM THE LATE PLIOCENE OF AHL AL dgeraads@ivry.cnrs.fr #12;2 ABSTRACT. The discovery of two male skulls of Kolpochoerus phacochoeroides specimens are two virtually complete male skulls: AaO-3655, in very good condition, and AaO-3656, which

Boyer, Edmond

153

RECUPERO DI FAUNA SELVATICA NELLA PROVINCIA DI TRIESTE NEL TRIENNIO 1994 -1996 (MAMMALIA - AVES)  

Microsoft Academic Search

Rescue of wild fauna in the Trieste Province during 1994-1996 (Mammalia - Aves). The problem regarding rescue\\/rehabilitation of wildlife tends to be more deeply felt in areas in which the anthropical impact on the environment is greatest. Records of the institutions and Associations in the Province of Trieste involved in the rescue and rehabilitation reveal that more and more animals

2003-01-01

154

The ear region of edentates and the phylogeny of the Tardigrada (Mammalia, Xenarthra)  

Microsoft Academic Search

A cladistic investigation of the phylogenetic relationships among 21 extinct and extant genera of sloths (Mammalia, Xenarthra, Tardigrada) was performed on the basis of characteristics of the bony anatomy of the auditory region. This study was undertaken in order to evaluate specific hypotheses of relationship within the group. Questions of particular interest include the relationship among the three traditional family

Timothy J. Gaudin

1995-01-01

155

Human Origins and Evolution Humans belong to the Order Primates within the Class Mammalia  

E-print Network

1 Human Origins and Evolution Humans belong to the Order Primates within the Class Mammalia Key Primates apart Monkeys are called Old World if they are found in Africa or Asia & New World if they are found in the Americas New World monkeys may have prehensile (grabbing) tails; Old World monkeys never do

Brown, Christopher A.

156

Climate history, human impacts and global body size of Carnivora (Mammalia  

E-print Network

ORIGINAL ARTICLE Climate history, human impacts and global body size of Carnivora (Mammalia. There is a moderately strong relationship between the human footprint and body size in glaciated regions, explaining 19 Anthropogenic effects, Bergmann's rule, body size, Carnivora, climate, Cope's rule, human footprint

Rodríguez, Miguel Ángel

157

Topografia do cone medular no ratão-do-banhado ( Myocastor coypus Molina, 1782 - Rodentia: Mammalia)  

Microsoft Academic Search

Topography of the medullar cone in nutria (Myocastor coypus Molina, 1782 - Rodentia: Mammalia). Aiming to investigate the topography of the medullar cone, ten adult nutria (Myocastor coypus), eight male and two female, were previously fixed in 10% aqueous formalin solution, maintained in similar solution and dissected. After the dissection the following data were noted: a) the medullar cone apex

Gilberto Valente Machado; Josy Alvarenga Cal; Arlei José Birck

158

High shrew diversity on Alaska's Seward Peninsula: Community assembly and environmental change  

USGS Publications Warehouse

In September 2010, 6 species of shrews (genus: Sorex) were collected at a single locality on the Seward Peninsula of Alaska. Such high sympatric diversity within a single mammalian genus is seldom realized. This phenomenon at high latitudes highlights complex Arctic community dynamics that reflect significant turnover through time as a consequence of environmental change. Each of these shrew species occupies a broad geographic distribution collectively spanning the entire Holarctic, although the study site lies within Eastern Beringia, near the periphery of all individual ranges. A review of published genetic evidence reflects a depauperate shrew community within ice-free Beringia through the last glaciation, and recent assembly of current diversity during the Holocene.

Hope, Andrew G.

2012-01-01

159

Muscle senescence in short-lived wild mammals, the soricine shrews Blarina brevicauda and Sorex palustris.  

PubMed

Red-toothed (soricine) shrews are consummate predators exhibiting the highest energy turnovers and shortest life spans (ca. 18 months) of any mammal, yet virtually nothing is known regarding their physiological aging. We assessed the emerging pattern of skeletal muscle senescence (contractile/connective tissue components) in sympatric species, the semi-aquatic water shrew (WS), Sorex palustris, and the terrestrial short-tailed shrew (STS), Blarina brevicauda, to determine if muscle aging occurs in wild, short-lived mammals (H(0): shrews do not survive to an age where senescence occurs), and if so, whether these alterations are species-specific. Gracilis muscles were collected from first-year (n=17) and second-year (n=17) field-caught shrews. Consistent with typical mammalian aging, collagen content (% area) increased with age in both species (S. palustris: approximately 50%; B. brevicauda: approximately 60%). Muscle was dominated by stiffer Type I collagen, and the ratio of collagen Type I:Type III more than doubled with age. The area ratio of muscle:collagen decreased with age in both species, but was considerably lower in adult STS, suggesting species-specificity of senescence. Extracellular space was age-elevated in B. brevicauda, but was preserved in S. palustris ( approximately 50 vs. 10% elevation). Though juvenile interspecific comparisons revealed no significance, adult WS myocytes had 68% larger cross-sectional area and occurred at 28% lower fibers/area than those of adult STS. We demonstrate that age-related muscle senescence does occur in wild-caught, short-lived mammals, and we therefore reject this classic aging theory tenet. Our findings moreover illustrate that differential age adjustments in contractile/connective tissue components of muscle occur in the two species of wild-caught shrews. PMID:19296507

Hindle, Allyson G; Lawler, John M; Campbell, Kevin L; Horning, Markus

2009-06-01

160

Molecular evolution of Azagny virus, a newfound hantavirus harbored by the West African pygmy shrew (Crocidura obscurior) in Côte d'Ivoire  

PubMed Central

Background Tanganya virus (TGNV), the only shrew-associated hantavirus reported to date from sub-Saharan Africa, is harbored by the Therese's shrew (Crocidura theresae), and is phylogenetically distinct from Thottapalayam virus (TPMV) in the Asian house shrew (Suncus murinus) and Imjin virus (MJNV) in the Ussuri white-toothed shrew (Crocidura lasiura). The existence of myriad soricid-borne hantaviruses in Eurasia and North America would predict the presence of additional hantaviruses in sub-Saharan Africa, where multiple shrew lineages have evolved and diversified. Methods Lung tissues, collected in RNAlater®, from 39 Buettikofer's shrews (Crocidura buettikoferi), 5 Jouvenet's shrews (Crocidura jouvenetae), 9 West African pygmy shrews (Crocidura obscurior) and 21 African giant shrews (Crocidura olivieri) captured in Côte d'Ivoire during 2009, were systematically examined for hantavirus RNA by RT-PCR. Results A genetically distinct hantavirus, designated Azagny virus (AZGV), was detected in the West African pygmy shrew. Phylogenetic analysis of the S, M and L segments, using maximum-likelihood and Bayesian methods, under the GTR+I+? model of evolution, showed that AZGV shared a common ancestry with TGNV and was more closely related to hantaviruses harbored by soricine shrews than to TPMV and MJNV. That is, AZGV in the West African pygmy shrew, like TGNV in the Therese's shrew, did not form a monophyletic group with TPMV and MJNV, which were deeply divergent and basal to other rodent- and soricomorph-borne hantaviruses. Ancestral distributions of each hantavirus lineage, reconstructed using Mesquite 2.74, suggested that the common ancestor of all hantaviruses was most likely of Eurasian, not African, origin. Conclusions Genome-wide analysis of many more hantaviruses from sub-Saharan Africa are required to better understand how the biogeographic origin and radiation of African shrews might have contributed to, or have resulted from, the evolution of hantaviruses. PMID:21798050

2011-01-01

161

Novel dynamic measures of emetic behavior in musk shrews  

PubMed Central

The emetic reflex occurs as a pattern of motor responses produced by a network of neurons in the hindbrain. Despite an understanding of the sequence of motor outputs that form an emetic episode (EE), the variability in the dynamics of multiple EEs across time remains a mystery. Nearly all clinical studies rely on once a day patient recall of total amount of vomiting, and preclinical studies frequently report only the total number of EE per unit time. The aim of the current study was to develop novel temporal measures of emetic activation in a preclinical model. Male and female musk shrews were tested with prototypical emetic stimuli: motion exposure (1 Hz), nicotine (5 mg/kg, sc), and copper sulfate (120 mg/kg, ig). New emetic measures included duration (time from first to last episode), rate, standard deviation of the inter-episode interval (SD-I), and a survival analysis of emetic latency (analyzed with Cox regression). Behavioral patterns associated with emesis were also assessed using statistical temporal pattern (T-pattern) analysis to measure nausea-like behaviors (e.g., immobility). The emetic stimuli produced different levels of total EE number, duration, rate, and SD-I. A typical antiemetic, the neurokinin 1 receptor antagonist CP-99,994, suppressed the number of EEs but was less effective for reducing the duration or prolonging the emetic latency. Overall, the current study shows the use of novel dynamic behavioral measures to more comprehensively assess emesis and the impact of therapies. PMID:23953843

Horn, Charles C.; Wang, Hong; Estival, Laureline; Meyers, Kelly; Magnusson, Magnus

2013-01-01

162

Novel dynamic measures of emetic behavior in musk shrews.  

PubMed

The emetic reflex occurs as a pattern of motor responses produced by a network of neurons in the hindbrain. Despite an understanding of the sequence of motor outputs that form an emetic episode (EE), the variability in the dynamics of multiple EEs across time remains a mystery. Many clinical investigations rely on once a day patient recall of total amount of vomiting, and preclinical studies frequently report only the total number of EE per unit time. The aim of the current study was to develop novel temporal measures of emetic activation in a preclinical model. Male and female musk shrews were tested with prototypical emetic stimuli: motion exposure (1 Hz), nicotine (5 mg/kg, sc), and copper sulfate (120 mg/kg, ig). New emetic measures included duration (time from first to last episode), rate, standard deviation of the inter-episode interval (SD-I), and a survival analysis of emetic latency (analyzed with Cox regression). Behavioral patterns associated with emesis were also assessed using statistical temporal pattern (T-pattern) analysis to measure nausea-like behaviors (e.g., immobility). The emetic stimuli produced different levels of total EE number, duration, rate, and SD-I. A typical antiemetic, the neurokinin 1 receptor antagonist CP-99,994, suppressed the number of EEs but was less effective for reducing the duration or prolonging the emetic latency. Overall, the current study shows the use of novel dynamic behavioral measures to more comprehensively assess emesis and the impact of therapies. PMID:23953843

Horn, Charles C; Wang, Hong; Estival, Laureline; Meyers, Kelly; Magnusson, Magnus S

2013-12-01

163

Ventricular myosin of the shrew Crocidura russula, correlation with contractile properties.  

PubMed

The present study demonstrates that in the shrew ventricular muscle the speed of tension development and relaxation, as well as twitch duration, are much shorter than in the guinea-pig. It also shows that ventricular myosin of the shrew has a high Ca2+-activated ATPase activity and that it is composed of alpha-type heavy chains. Namely, the native molecule is a V1 variety of myosin. These findings advance our knowledge on an as yet uncharacterized mammalian heart and further demonstrate the correlation between mechanical properties and myosin type in heart muscle. PMID:2976845

Kessler-Icekson, G; Schlesinger, H; Leger, J J; Leger, J; Braverman, Y; Binah, O

1988-11-01

164

Species interactions during diversification and community assembly in an island radiation of shrews.  

E-print Network

species are probably the result of inter-island colonization [41]. A single island was randomly selected as the first island with a shrew population. This seeding event was not counted as a colonization event. From there, colonization events occurred one... records (Camiguin Sur, Calayan, and Sibuyan; Fig. 1), plus the one PAIC (Sulu) and five oceanic islands lacking a shrew record. The oceanic islands included here are those with an area$100 km2 and records of at least three native mammal species [96, 97...

Brown, Rafe M.

2011-01-01

165

Evolution of alanine:glyoxylate aminotransferase 1 peroxisomal and mitochondrial targeting. A survey of its subcellular distribution in the livers of various representatives of the classes Mammalia, Aves and Amphibia.  

PubMed

As part of a wider study on the molecular evolution of alanine:glyoxylate aminotransferase 1 (AGT1) intracellular compartmentalization, we have determined the subcellular distribution of immunoreactive AGT1, using postembedding protein A-gold immunoelectron microscopy, in the livers of various members of the classes Mammalia, Aves, and Amphibia. As far as organellar distribution is concerned, three categories could be distinguished. In members of the first category (type I), all, or nearly all, of the immunoreactive AGT1 was concentrated within the peroxisomes. In the second category (type II), AGT1 was found more evenly distributed in both peroxisomes and mitochondria. In the third category (type III), AGT1 was localized mainly within the mitochondria with much lower, but widely variable, amounts in the peroxisomes. Type I animals include the human, two great apes (gorilla, orangutan), two Old World monkeys (anubis baboon, Japanese macaque), a New World monkey (white-faced Saki monkey), a lago, morph (European rabbit), a bat (Seba's short-tailed fruit bat), two caviomorph rodents (guinea pig, orange-rumped agouti), and two Australian marsupials (koala, Bennett's wallaby). Type II animals include two New World monkeys (common marmoset, cotton-top tamarin), three prosimians (brown lemur, fat-tailed dwarf lemur, pygmy slow loris), five rodents (a hybrid crested porcupine, Colombian ground squirrel, laboratory rat, laboratory mouse, golden hamster), an American marsupial (grey short-tailed opossum), and a bird (raven). Type III animals include the large tree shrew, three insectivores (common Eurasian mole, European hedgehog, house shrew), four carnivores (domestic cat, ocelot, domestic dog, polecat ferret), and an amphibian (common frog). In addition to these categories, some animals (e.g. guinea pig, common frog) possessed significant amounts of cytosolic AGT1. Whereas the subcellular distribution of AGT1 in some orders (e.g. Insectivora and Carnivora) did not appear to vary markedly between the different members, in other orders (e.g. Primates, Rodentia and Marsupialia) it fluctuated widely between the different species. Phylogenetic analysis indicates that the subcellular distribution of AGT1 has changed radically on numerous occasions during the evolution of mammals. The new observations presented in this paper are compatible with our previous demonstration of a relationship between AGT1 subcellular distribution and either present or putative ancestral dietary habit, and our previous suggestion that the molecular evolution of the AGT gene has been markedly influenced by dietary selection pressure. PMID:7813517

Danpure, C J; Fryer, P; Jennings, P R; Allsop, J; Griffiths, S; Cunningham, A

1994-08-01

166

The Bicolored White-Toothed Shrew Crocidura leucodon (HERMANN 1780) Is an Indigenous Host of Mammalian Borna Disease Virus  

PubMed Central

Borna disease (BD) is a sporadic neurologic disease of horses and sheep caused by mammalian Borna disease virus (BDV). Its unique epidemiological features include: limited occurrence in certain endemic regions of central Europe, yearly varying disease peaks, and a seasonal pattern with higher disease frequencies in spring and a disease nadir in autumn. It is most probably not directly transmitted between horses and sheep. All these features led to the assumption that an indigenous virus reservoir of BDV other than horses and sheep may exist. The search for such a reservoir had been unsuccessful until a few years ago five BDV-infected shrews were found in a BD-endemic area in Switzerland. So far, these data lacked further confirmation. We therefore initiated a study in shrews in endemic areas of Germany. Within five years 107 shrews of five different species were collected. BDV infections were identified in 14 individuals of the species bicolored white-toothed shrew (Crocidura leucodon, HERMANN 1780), all originating from BD-endemic territories. Immunohistological analysis showed widespread distribution of BDV antigen both in the nervous system and in epithelial and mesenchymal tissues without pathological alterations. Large amounts of virus, demonstrated by presence of viral antigen in epithelial cells of the oral cavity and in keratinocytes of the skin, may be a source of infection for natural and spill-over hosts. Genetic analyses reflected a close relationship of the BDV sequences obtained from the shrews with the regional BDV cluster. At one location a high percentage of BDV-positive shrews was identified in four consecutive years, which points towards a self-sustaining infection cycle in bicolored white-toothed shrews. Analyses of behavioral and population features of this shrew species revealed that the bicolored white-toothed shrew may indeed play an important role as an indigenous host of BDV. PMID:24699636

Dürrwald, Ralf; Kolodziejek, Jolanta; Weissenböck, Herbert; Nowotny, Norbert

2014-01-01

167

The bicolored white-toothed shrew Crocidura leucodon (HERMANN 1780) is an indigenous host of mammalian Borna disease virus.  

PubMed

Borna disease (BD) is a sporadic neurologic disease of horses and sheep caused by mammalian Borna disease virus (BDV). Its unique epidemiological features include: limited occurrence in certain endemic regions of central Europe, yearly varying disease peaks, and a seasonal pattern with higher disease frequencies in spring and a disease nadir in autumn. It is most probably not directly transmitted between horses and sheep. All these features led to the assumption that an indigenous virus reservoir of BDV other than horses and sheep may exist. The search for such a reservoir had been unsuccessful until a few years ago five BDV-infected shrews were found in a BD-endemic area in Switzerland. So far, these data lacked further confirmation. We therefore initiated a study in shrews in endemic areas of Germany. Within five years 107 shrews of five different species were collected. BDV infections were identified in 14 individuals of the species bicolored white-toothed shrew (Crocidura leucodon, HERMANN 1780), all originating from BD-endemic territories. Immunohistological analysis showed widespread distribution of BDV antigen both in the nervous system and in epithelial and mesenchymal tissues without pathological alterations. Large amounts of virus, demonstrated by presence of viral antigen in epithelial cells of the oral cavity and in keratinocytes of the skin, may be a source of infection for natural and spill-over hosts. Genetic analyses reflected a close relationship of the BDV sequences obtained from the shrews with the regional BDV cluster. At one location a high percentage of BDV-positive shrews was identified in four consecutive years, which points towards a self-sustaining infection cycle in bicolored white-toothed shrews. Analyses of behavioral and population features of this shrew species revealed that the bicolored white-toothed shrew may indeed play an important role as an indigenous host of BDV. PMID:24699636

Dürrwald, Ralf; Kolodziejek, Jolanta; Weissenböck, Herbert; Nowotny, Norbert

2014-01-01

168

Illumination of cryptic species boundaries in long-tailed shrew tenrecs (Mammalia: Tenrecidae; Microgale), with new insights into geographic variation and distributional constraints  

Microsoft Academic Search

The increasing use of mitochondrial DNA (mtDNA) to explore and test species limits among morphologically similar species is potentially compromised by phenomena poorly reflective of organismal history and speciation, including (but not limited to) stochastic lineage sorting and gene flow. In situations where molecular data are only available from a single gene or linkage partition (e.g. mtDNA), corroboration of suspected

LINK E. OLSON; STEVEN M. GOODMAN; ANNE D. YODER

169

Metabolic, respiratory and cardiac activity in the shrew Crocidura russula.  

PubMed

Oxygen consumption, respiratory rate, heart rate and body temperature of resting common white-toothed shrews (Crocidura russula, mean = 11.4 g), have been determined at ambient temperatures (Ta) between 0 and 37 degrees C. Mean basal oxygen consumption (Ta = 30 degrees C, Tb = 35.4 degrees C) was 2.3 ml.g-1.h-1 and was about 12% above the value expected on the basis of the allometric relationship applying for mammals. At 0 degree C oxygen consumption was 4.2 times that in the thermal neutral zone (TNZ) which is located at Ta of about 30 degrees C. The mean basal respiratory rate was 103 min-1 (Ta = 30 degrees C), fully 40% below the predicted value. The respiratory rate increased at 0 degree C to 3.8 times that in TNZ. The amount of oxygen consumed per breath was rather constant, increasing from a mean of 4.3 microliters (Ta = 30 degrees C) to 4.9 microliters (Ta = 0 degree C) which was only 15% above the basal value. Comparing the great changes of respiratory rate with the small alterations of oxygen consumed per breath, a dominant influence of respiratory rate in the regulation of respiration is shown. Basal heart rate was 444 min-1 (Ta = 30 degrees C), in agreement with the expected value. Heart rate increased only 1.75-fold at an ambient temperature of 0 degree C. Oxygen pulses depend very strongly on ambient temperature, increasing from 0.98 microliters (Ta = 30 degrees C) to 2.5 microliters at 0 degree C. Beat frequency and stroke volume regulation are salient features of heart function. PMID:1947455

Nagel, A

1991-08-01

170

Synaptic Organization of Connections between the Temporal Cortex and Pulvinar Nucleus of the Tree Shrew  

Microsoft Academic Search

We examined the synaptic organization of reciprocal connections between the temporal cortex and the dorsal (Pd) and central (Pc) subdivisions of the tree shrew pulvinar nucleus, regions innervated by the medial and lateral superior colliculus, respectively. Both Pd and Pc subdivisions project topographically to 2 separate regions of the temporal cortex; small injections of anterograde tracers placed in either Pd

Ranida D. Chomsung; Haiyang Wei; Jonathan D. Day-Brown; Heywood M. Petry; Martha E. Bickford

2010-01-01

171

Evolutionary biogeography of water shrews ( Neomys spp.) in the western Palaearctic Region  

Microsoft Academic Search

We studied the morphology, DNA sequence, and Recent and Pleistocene distributions of three species of the water shrew genus Neomys (N. fodiens, N. anomalus, and N. teres) represented by samples from the Balkans and Asia Minor. Adaptations to semi-aquatic life (large body size, fringes of stiff hairs bordering the hind foot, and a tail keel) were most developed in N.

B. Krystufek; A. Davison; H. I. Griffiths

2000-01-01

172

Chemoarchitecture of Layer 4 Isocortex in the American Water Shrew (Sorex palustris)  

Microsoft Academic Search

We examined the chemoarchitecture of layer 4 isocortex and the number of myelinated nerve fibers of selected cranial nerves in the American water shrew (Sorex palustris). This study took advantage of the opportunity to examine juvenile brain tissue, which often reveals the most distinctive cortical modules related to different sensory representations. Flattened cortical sections were processed for the metabolic enzyme

Duncan B. Leitch; Danielle Gauthier; Diana K. Sarko; Kenneth C. Catania

2011-01-01

173

Mitochondrial DNA variation in water shrews (Sorex palustris, Sorex bendirii) from western  

E-print Network

Mitochondrial DNA variation in water shrews (Sorex palustris, Sorex bendirii) from western North of Sorex palustris Richardson, 1828 and 6 specimens of Sorex bendirii (Merriam, 1884) from 20 locations the Coastal and the Cordilleran clades was 3.1%. Sorex palustris brooksi, a subspecies endemic to Vancouver

Baker, Robert J.

174

The neurobiology and behavior of the American water shrew (Sorex palustris).  

PubMed

American water shrews (Sorex palustris) are aggressive predators that dive into streams and ponds to find prey at night. They do not use eyesight for capturing fish or for discriminating shapes. Instead they make use of vibrissae to detect and attack water movements generated by active prey and to detect the form of stationary prey. Tactile investigations are supplemented with underwater sniffing. This remarkable behavior consists of exhalation of air bubbles that spread onto objects and are then re-inhaled. Recordings for ultrasound both above and below water provide no evidence for echolocation or sonar, and presentation of electric fields and anatomical investigations provide no evidence for electroreception. Counts of myelinated fibers show by far the largest volume of sensory information comes from the trigeminal nerve compared to optic and cochlear nerves. This is in turn reflected in the organization of the water shrew's neocortex, which contains two large somatosensory areas and much smaller visual and auditory areas. The shrew's small brain with few cortical areas may allow exceptional speed in processing sensory information and producing motor output. Water shrews can accurately attack the source of a water disturbance in only 50 ms, perhaps outpacing any other mammalian predator. PMID:23397460

Catania, Kenneth C

2013-06-01

175

The tree shrews: adjuncts and alternatives to primates as models for biomedical  

E-print Network

is extremely important. Myopia has reached epidemic proportions in Asia. The development of myopia may, hepatocellular carcinoma (HCC), myopia, and psychosocial stress. Because of the susceptibility of the tree shrews to establish myopia models. Because dramatic behavioral, physiological, and neuroendocrine changes

176

Chronic Clomipramine Treatment Reverses Core Symptom of Depression in Subordinate Tree Shrews  

PubMed Central

Chronic stress is the major cause of clinical depression. The behavioral signs of depression, including anhedonia, learning and memory deficits, and sleep disruption, result from the damaging effects of stress hormones on specific neural pathways. The Chinese tree shrew (Tupaia belangeri chinensis) is an aggressive non-human primate with a hierarchical social structure that has become a well-established model of the behavioral, endocrine, and neurobiological changes associated with stress-induced depression. The tricyclic antidepressant clomipramine treats many of the core symptoms of depression in humans. To further test the validity of the tree shrew model of depression, we examined the effects of clomipramine on depression-like behaviors and physiological stress responses induced by social defeat in subordinate tree shrews. Social defeat led to weight loss, anhedonia (as measured by sucrose preference), unstable fluctuations in locomotor activity, sustained urinary cortisol elevation, irregular cortisol rhythms, and deficient hippocampal long-term potentiation (LTP). Clomipramine ameliorated anhedonia and irregular locomotor activity, and partially rescued the irregular cortisol rhythm. In contrast, weight loss increased, cortisol levels were even higher, and in vitro LTP was still impaired in the clomipramine treatment group. These results demonstrate the unique advantage of the tree shrew social defeat model of depression. PMID:24312510

Wang, Jing; Chai, Anping; Zhou, Qixin; Lv, Longbao; Wang, Liping; Yang, Yuexiong; Xu, Lin

2013-01-01

177

Chronic clomipramine treatment reverses core symptom of depression in subordinate tree shrews.  

PubMed

Chronic stress is the major cause of clinical depression. The behavioral signs of depression, including anhedonia, learning and memory deficits, and sleep disruption, result from the damaging effects of stress hormones on specific neural pathways. The Chinese tree shrew (Tupaia belangeri chinensis) is an aggressive non-human primate with a hierarchical social structure that has become a well-established model of the behavioral, endocrine, and neurobiological changes associated with stress-induced depression. The tricyclic antidepressant clomipramine treats many of the core symptoms of depression in humans. To further test the validity of the tree shrew model of depression, we examined the effects of clomipramine on depression-like behaviors and physiological stress responses induced by social defeat in subordinate tree shrews. Social defeat led to weight loss, anhedonia (as measured by sucrose preference), unstable fluctuations in locomotor activity, sustained urinary cortisol elevation, irregular cortisol rhythms, and deficient hippocampal long-term potentiation (LTP). Clomipramine ameliorated anhedonia and irregular locomotor activity, and partially rescued the irregular cortisol rhythm. In contrast, weight loss increased, cortisol levels were even higher, and in vitro LTP was still impaired in the clomipramine treatment group. These results demonstrate the unique advantage of the tree shrew social defeat model of depression. PMID:24312510

Wang, Jing; Chai, Anping; Zhou, Qixin; Lv, Longbao; Wang, Liping; Yang, Yuexiong; Xu, Lin

2013-01-01

178

Ultrastructure of the stomach of the small short-tailed shrew, Blarina brevicauda c.  

PubMed

The normal gastric ultrastructure has been characterized for the small short-tailed shrew, Blarina brevicauda c., which is a primitive eutherian and one of the smallest living mammals with extraordinarily high metabolic rate. In general the cell types present and cytologic character of gastric mucosal, submucosal, and muscularis cells were similar to that reported for other more advanced small mammalian species. Chief cells, endocrine cells, and lamina proprial elements were morphologically identical to their counterpart in rats, ferrets and other small carnivores. Distinctive cytologic features in this species of shrew included the scanty monolayer or small number of mucous granules in the simple columnar surface epithelial cells of the mucosa, and the thin elongated shape of their microvilli. Dense bodies were absent in the parietal cell mitochondria of the shrew, though usually abundant in other mammalian parietal cells. Our data indicate few morphologic specializations in the shrew stomach which can be correlated with their high rate of food assimilation and metabolic demands, though future studies of mucosal biochemistry and lower gut morphology may reveal such adaptations. PMID:4020920

Pfeiffer, C J; Keith, J C

1985-07-01

179

Olfactory mucosa ultrastructure in the short-tailed shrews, Blarina brevicauda and Blarina carolinensis.  

PubMed

The olfactory mucosae of the northern short-tailed shrew, Blarina brevicauda, and the southern short-tailed shrew, Blarina carolinensis, were examined by light and electron microscopy. A well-developed olfactory epithelium was observed that included all of the cells necessary to provide for a sensitive olfactory system, suggesting that olfaction plays a major role in the behavior of these animals. There were no significant differences between the olfactory mucosae of these two species. The general features of the olfactory epithelium in these shrews were similar to those reported for several other macrosmatic mammals. A new type of supporting cell, called the light supporting cell, was observed in these shrews. The light supporting cell cytoplasm exhibited very little staining by light microscopy and had low electron density by transmission electron microscopy compared to that of the more common dark supporting cell. The light supporting cell had a convex apical surface with microvilli and lacked the large amounts of smooth endoplasmic reticulum (SER) typical of the apical cytoplasm of the dark supporting cell. In the lamina propria of the mucosa, the Bowman's glands consisted of two cell types, one with electron-lucent, alcian blue-positive granules, and the other with electron-dense PAS-positive granules. The cell with electron-lucent granules contained large amounts of SER and small clumps of rough ER. The cells with electron-dense granules had large amounts of RER and little SER. PMID:12221510

Byrum, L J; Carson, K A; Rose, R K

2001-12-01

180

A phylogenetic supertree of the bats (Mammalia: Chiroptera).  

PubMed

We present the first estimate of the phylogenetic relationships among all 916 extant and nine recently extinct species of bats Mammalia: Chiroptera), a group that accounts for almost one-quarter of extant mammalian diversity. This phylogeny was derived by combining 105 estimates of bat phylogenetic relationships published since 1970 using the supertree construction technique of Matrix Representation with Parsimony (MRP). Despite the explosive growth in the number of phylogenetic studies of bats since 1990, phylogenetic relationships in the order have been studied non-randomly. For example, over one-third of all bat systematic studies to date have locused on relationships within Phyllostomidae, whereas relationships within clades such as Kerivoulinae and Murinae have never been studied using cladistic methods. Resolution in the supertree similarly differs among clades: overall resolution is poor (46.4%, of a fully bifurcating solution) but reaches 100% in some groups (e.g. relationships within Mormoopidae). The supertree analysis does not support a recent proposal that Microchiroptera is paraphyletic with respect to Megachiroptera, as the majority of source topologies support microbat monophyly. Although it is not a substitute for comprehensive phylogenetic analyses of primary molecular and morphological data, the bat supertree provides a useful tool for future phylogenetic comparative and macroevolutionary studies. Additionally, it identifies clades that have been little studied, highlights groups within which relationships are controversial, and like all phylogenetic studies, provides preliminary hypotheses that can form starting points for future phylogenetic studies of bats. PMID:12056748

Jones, Kate E; Purvis, Andy; MacLarnon, Ann; Bininda-Emonds, Olaf R P; Simmons, Nancy B

2002-05-01

181

[Description of the adult stage of Staphylocystis biliarius Villot, 1877 (Cestoda: Hymenolepididae), a parasite of Crocidura russula Hermann, 1780 (Insectivora: Soricidae) (author's transl].  

PubMed

The parasitological study of the shrew Crocidura russula from Catalonia (Spain) allowed to collect several mature Hymenolepididae, the scolex framework of which corresponding perfectly to that of the larva Staphylocytis biliarius Villot, 1877. The anatomy of the adult stage of this species, which has to be denominated as Hymenolepis biliarius (Villot, 1877) n. comb., is described for the first time. PMID:613963

Mas-Coma, S; Jourdane, J

1977-01-01

182

| 46 | NATIONAL WILDLIFE DECEMBER/JANUARY 2009 | WWW.NWF.ORG | 47 | AN ADULT VAGRANT shrew in a  

E-print Network

March. During the following month, mother shrews give birth and wean young, after which the adults die- fly or moth or try to eat spiders larger than themselves. Because each bog dif- fers in the abundance

Badyaev, Alex

183

Genetic Diversity of Thottapalayam Virus, a Hantavirus Harbored by the Asian House Shrew (Suncus murinus) in Nepal  

PubMed Central

Despite the recent discovery of genetically divergent hantaviruses in shrews of multiple species in widely separated geographic regions, data are unavailable about the genetic diversity and phylogeography of Thottapalayam virus (TPMV), a hantavirus originally isolated from an Asian house shrew (Suncus murinus) captured in southern India more than four decades ago. To bridge this knowledge gap, the S, M, and L segments of hantavirus RNA were amplified by reverse transcription polymerase chain reaction from archival lung tissues of Asian house shrews captured in Nepal from January to September 1996. Pair-wise alignment and comparison revealed approximately 80% nucleotide and > 94% amino acid sequence similarity to prototype TPMV. Phylogenetic analyses, generated by maximum likelihood and Bayesian methods, showed geographic-specific clustering of TPMV, similar to that observed for rodent- and soricid-borne hantaviruses. These findings confirm that the Asian house shrew is the natural reservoir of TPMV and suggest a long-standing virus–host relationship. PMID:21896819

Kang, Hae Ji; Kosoy, Michael Y.; Shrestha, Sanjaya K.; Shrestha, Mrigendra P.; Pavlin, Julie A.; Gibbons, Robert V.; Yanagihara, Richard

2011-01-01

184

Metagenomic analysis of the shrew enteric virome reveals novel viruses related to human stool-associated viruses.  

PubMed

Shrews are small insectivorous mammals that are distributed worldwide. Similar to rodents, shrews live on the ground and are commonly found near human residences. In this study, we investigated the enteric virome of wild shrews in the genus Crocidura using a sequence-independent viral metagenomics approach. A large portion of the shrew enteric virome was composed of insect viruses, whilst novel viruses including cyclovirus, picornavirus and picorna-like virus were also identified. Several cycloviruses, including variants of human cycloviruses detected in cerebrospinal fluid and stools, were detected in wild shrews at a high prevalence rate. The identified picornavirus was distantly related to human parechovirus, inferring the presence of a new genus in this family. The identified picorna-like viruses were characterized as different species of calhevirus 1, which was discovered previously in human stools. Complete or nearly complete genome sequences of these novel viruses were determined in this study and then were subjected to further genetic characterization. Our study provides an initial view of the diversity and distinctiveness of the shrew enteric virome and highlights unique novel viruses related to human stool-associated viruses. PMID:25381053

Sasaki, Michihito; Orba, Yasuko; Ueno, Keisuke; Ishii, Akihiro; Moonga, Ladslav; Hang'ombe, Bernard M; Mweene, Aaron S; Ito, Kimihito; Sawa, Hirofumi

2015-02-01

185

The Timing of the Shrew: Continuous Melatonin Treatment Maintains Youthful Rhythmic Activity in Aging Crocidura russula  

PubMed Central

Background Laboratory conditions nullify the extrinsic factors that determine the wild expected lifespan and release the intrinsic or potential lifespan. Thus, wild animals reared in a laboratory often show an increased lifespan, and consequently an increased senescence phase. Senescence is associated with a broad suite of physiological changes, including a decreased responsiveness of the circadian system. The time-keeping hormone melatonin, an important chemical player in this system, is suspected to have an anti-aging role. The Greater White-toothed shrew Crocidura russula is an ideal study model to address questions related to aging and associated changes in biological functions: its lifespan is short and is substantially increased in captivity; daily and seasonal rhythms, while very marked the first year of life, are dramatically altered during the senescence process which starts during the second year. Here we report on an investigation of the effects of melatonin administration on locomotor activity of aging shrews. Methodology/Principal Findings 1) The diel fluctuations of melatonin levels in young, adult and aging shrews were quantified in the pineal gland and plasma. In both, a marked diel rhythm (low diurnal concentration; high nocturnal concentration) was present in young animals but then decreased in adults, and, as a result of a loss in the nocturnal production, was absent in old animals. 2) Daily locomotor activity rhythm was monitored in pre-senescent animals that had received either a subcutaneous melatonin implant, an empty implant or no implant at all. In non-implanted and sham-implanted shrews, the rhythm was well marked in adults. A marked degradation in both period and amplitude, however, started after the age of 14–16 months. This pattern was considerably delayed in melatonin-implanted shrews who maintained the daily rhythm for significantly longer. Conclusions This is the first long term study (>500 days observation of the same individuals) that investigates the effects of continuous melatonin delivery. As such, it sheds new light on the putative anti-aging role of melatonin by demonstrating that continuous melatonin administration delays the onset of senescence. In addition, the shrew appears to be a promising mammalian model for elucidating the precise relationships between melatonin and aging. PMID:19526053

Magnanou, Elodie; Attia, Joël; Fons, Roger; Boeuf, Gilles; Falcon, Jack

2009-01-01

186

Diverse Interleukin-7 mRNA Transcripts in Chinese Tree Shrew (Tupaia belangeri chinensis)  

PubMed Central

Interleukin-7 (IL7) is a pleiotropic cytokine that is actively involved in the immune system. The Chinese tree shrew (Tupaia belangeri chinensis) has been proposed as an alternative experimental animal to primates in biomedical research. However, there is a lack of biological knowledge about the immune system of the tree shrew. In this study, we cloned the IL7 gene (tIL7) in the Chinese tree shrew and quantified the expression of mRNA transcripts in eight tissues (heart, liver, spleen, lung, kidney, intestine, skeletal muscle and brain) from 20 individuals. Eleven tIL7 mRNA transcripts were identified in different tissues. The canonical form (tIL7c) had a length of 1817 bp and encoded a predicted gene product with 177 amino acids. Phylogenetic analyses based on the amino acid sequences revealed a considerably large genetic difference between tree shrew and human. Quantification of mRNA expression of transcripts tIL7c, tIL7-sv1, tIL7-sv2 and tIL7-sv3 showed that these transcripts were expressed in all tissues, albeit the expression levels varied in different tissues. Transcripts tIL7c, tIL7-sv1, and tIL7-sv2 had the lowest expression in brain, and tIL7-sv3 had a dramatically high mRNA expression in skeletal muscle and heart. The mRNA expression levels of tIL7c and tIL7-sv1 were significantly increased upon ploy(I:C) stimulation in tree shrew primary renal cells. As with human full-length IL7, tIL7c, tIL7-sv1, tIL7-sv2 and tIL7-sv3 showed similar a subcellular localization pattern. Our results identified diverse tIL7 transcripts in the Chinese tree shrew, which may play a potential role in modulating IL7-regulated biological effects. PMID:24945249

Yu, Dandan; Xu, Ling; Liu, Xiao-Hong; Fan, Yu; Lü, Long-Bao; Yao, Yong-Gang

2014-01-01

187

Haematology, genotoxicity, enzymatic activity and histopathology as biomarkers of metal pollution in the shrew Crocidura russula.  

PubMed

Haematological (WBC, RBC, Hgb and Hct) and genotoxicity (MNT) parameters, hepatic enzymatic activities (GST, GPx and GR), and a histopathological evaluation of liver, kidneys and gonads were assessed as general biomarkers of metal pollution in the shrew Crocidura russula inhabiting a pyrite mining area. Specimens exposed to metals presented a few significant alterations when compared with reference animals: GST activity decreased; micronuclei increased; and evident liver alterations related to metal exposure were observed. On the basis of all the parameters studied, age was an important factor that partly explained the observed variation, whereas sex was the least important factor. Significant correlations were also found between heavy metal concentrations and biomarkers evaluated, demonstrating the great influence of these metals in the metabolic alterations. To the best of our knowledge, these data constitute the first measurements of a battery of biomarkers in shrews from a mine site and are among the few available for insectivorous mammals. PMID:18448220

Sánchez-Chardi, A; Marques, C C; Gabriel, S I; Capela-Silva, F; Cabrita, A S; López-Fuster, M J; Nadal, J; Mathias, M L

2008-12-01

188

Development of temperature regulation in the common white-toothed shrew, Crocidura russula.  

PubMed

1. Body temperature and oxygen consumption were measured during the first month of postnatal life in two litters of Crocidura russula at four different ambient temperatures. 2. Body temperature in the nest varies from 30.5-35.0 degrees C during the first 10 days; afterwards it becomes more constant (35.5-37.0 degrees C). 3. First homoiothermic reactions occur on the 2nd day of life and become effective on the 4th day. 4. In the case of undernourished shrews, torpor is already developed on the 2nd day. 5. After the 7th day torpor is the obligatory reaction in cooling experiments. 6. This discontinuous development of temperature regulation is interpreted as typical for shrews capable of torpor. PMID:2565791

Nagel, A

1989-01-01

189

Binding sites of atrial natriuretic peptide in tree shrew adrenal gland  

SciTech Connect

Adrenal gland binding sites for atrial natriuretic peptide-(99-126) (ANP) were quantitated in tree shrew (Tupaia belangeri) by incubation of adrenal sections with (3-(/sup 125/I)-iodotyrosyl28) atrial natriuretic peptide-(99-126), followed by autoradiography with computerized microdensitometry. In the adrenal glands, there are three types of ANP binding sites. One is located in the zona glomerulosa (BMax 84 +/- 6 fmol/mg protein; Kd 122 +/- 9 pM); the second in the zona fasciculata and reticularis (BMax 29 +/- 2 fmol/mg protein; Kd 153 +/- 6 pM) and the third in the adrenal medulla (BMax 179 +/- 1 fmol/mg protein; Kd 70 +/- 2 pM). Besides the influence of ANP on the regulation of adrenocortical mineralcorticoid and glucocorticoid secretion our findings raise the possibility for a local site of action of atrial natriuretic peptide in the regulation of adrenomedullary catecholamines in the tree shrew, primates and man.

Fuchs, E.; Shigematsu, K.; Saavedra, J.M.

1986-09-01

190

Divergent ancestral lineages of newfound hantaviruses harbored by phylogenetically related crocidurine shrew species in Korea  

PubMed Central

Spurred by the recent isolation of a novel hantavirus, named Imjin virus (MJNV), from the Ussuri white-toothed shrew (Crocidura lasiura), targeted trapping was conducted for the phylogenetically related Asian lesser white-toothed shrew (Crocidura shantungensis). Pair-wise alignment and comparison of the S, M and L segments of a newfound hantavirus, designated Jeju virus (JJUV), indicated remarkably low nucleotide and amino acid sequence similarity with MJNV. Phylogenetic analyses, using maximum likelihood and Bayesian methods, showed divergent ancestral lineages for JJUV and MJNV, despite the close phylogenetic relationship of their reservoir soricid hosts. Also, no evidence of host switching was apparent in tanglegrams, generated by TreeMap 2.0?. PMID:22230701

Arai, Satoru; Gu, Se Hun; Baek, Luck Ju; Tabara, Kenji; Bennett, Shannon; Oh, Hong-Shik; Takada, Nobuhiro; Kang, Hae Ji; Tanaka-Taya, Keiko; Morikawa, Shigeru; Okabe, Nobuhiko; Yanagihara, Richard; Song, Jin-Won

2012-01-01

191

Habitat Associations of Vancouver Island Water Shrews in Restored and Natural Stream Habitats  

Microsoft Academic Search

The Vancouver Island water shrew (Sorex palustris brooksi)1 is a rare subspecies found only on Vancouver Island, British Columbia. It is a riparian specialist, specially adapted to a semi-aquatic lifestyle and strongly associated with the land\\/water interface. Human-related activities on Vancouver Island have resulted in the loss or degradation of habitat for S. p. brooksi. Mitigation efforts aimed at stream

VANESSA J. CRAIG; STEVEN F. WILSON

192

Early-life nutritional environment and spatial navigation in the water shrew, Sorex palustris (Insectivora).  

PubMed

Studies were conducted to study the effects of early-life nutritional environment on spatial navigation ability in the water shrew (Sorex palustris), as well as to provide information on life history traits and husbandry. The mean longevity of males and females in captivity was 652.3 +/- 33.8 SD and 616.2 +/- 22.5 days, respectively. Litter sizes ranged from 5 to 8 and neonatal mass ranged from 0.71 to 0.83 g. Spatial navigation was examined by use of the Morris water apparatus, where animals were required to locate the position of an escape platform in a circular tank of water. The platform was visible (proximal cue version of the task) in some tests. In other tests it was hidden beneath the surface (distal cue version) by making the water opaque using a non-toxic white dye. The tank was divided into 4 quadrants and the position of the plafform in any quadrant could be fixed for any subject or varied between subjects. Early-life under-nutrition was achieved by maintaining some shrews on a restricted diet (received half the amount of food as did controls). Under-nutrition was found to have an adverse effect on spatial navigation. Regardless of nutritional status, shrews were able to locate a hidden plafform that was placed at the center of a given quadrant more rapidly (escape latency) when it was visible (44 to 69 sec) than when it was hidden (83 to 164 sec). Results also showed that these shrews utilize both proximal and distal cues in this spatial task. Control subjects spent more time at a location where the platform had been in a previous test (69% of the trial period) than their undernourished counterparts (45 to 51%). This is the first experimental analysis of spatial navigation and the effects of early-life under-nutrition on this task, for S. palustris. PMID:15907068

Punzo, F

2004-10-01

193

Ultrastructural studies on oogenesis in the shrew (Crocidura russula): I. The preantral follicle.  

PubMed

Ultrastructural analysis of the ovarian follicle prior to antrum formation in the shrew, Crocidura russula, shows gradual differentiation of mitochondria, endoplasmic reticulum, Golgi complexes, vesicles, and multivescular bodies correlated with the growth of the oocyte from primordial to tertiary follicle and the development of the follicular wall. The growth rate of the follicle in relation to that of the oocyte was found to be biphasic. PMID:6708111

Kress, A

1984-01-01

194

Pulmonary appendix of the short-tailed shrew (Blarina): a unique immunologic organ.  

PubMed

The right bronchus of the short-tailed shrew, Blarina brevicauda, terminates in a nonrespiratory pulmonary appendix (PA) containing two bronchial extensions. The experimentally demonstrated ability of these structures to collect and peristaltically expel aspirated material was initially assumed to be a sufficient reason for their developmental persistence, but as bronchus associated lymphoid tissue (BALT) became a subject of immunologic interest in other species, a possible immunologic role for the concentrations of BALT observed in the shrew PA were investigated. As the BALT of the PA contained many well-differentiated plasma cells and numerous particle-containing macrophages, 6-mu paraffin sections were treated with an immunoperoxidase avidin-biotin preparation that chromogenically identified alpha chains of IgA in many of the PA plasma cells and their associated luminal secretions. Also, vascular injections revealed that the PA had a complex relationship with anastomotic sinusoids connecting the bronchial and pulmonary circulation systems, and scanning electron microscopy showed that the luminal epithelial surfaces of the PA were virtually identical to the scattered BALT aggregates in the bronchi of other animals. It thus appeared that these unique structures in the shrew are morphologically and topographically suited to receive aspirated antigens that induce secretory IgA production, while possibly providing other humoral and cellular immunologic products to the general circulation. PMID:11870601

Parke, Wesley Wilkin

2002-03-01

195

Cardiac ultrastructure and electrocardiogram of the short-tailed shrew, Blarina brevicauda.  

PubMed

The smaller species of shrews have been of considerable interest to scientists because of their high rate of metabolism, structure-functional and behavioral adaptations to support their energy demands. The present data are the first detailed cardiac ultrastructural findings and electrocardiographic (ECG) data of adult and immature small short-tailed shrews, Blarina brevicauda. The heart is morphologically elongated and heart rates in excess of 900 b/min were observed, but ECG components and pattern are non-distinctive for this species. Ultrastructurally, the sarcomeres, tubular and sarcotubular systems and Purkinje cells resemble closely those observed in larger, less active mammals. Several distinctive features resembling those seen in some other shrews or hummingbirds exist, including reduced quantities of myocyte glycogen, irregularly shaped and tightly packed mitochondria, increased neural and vascular elements in the myocardium, and small size and unusual dispersion of atrial specific granules. These morphologic findings suggest that the remarkable physiologic performance of the heart of Blarina brevicauda is supported by a combination of macroscopic, histologic and cellular adaptations. PMID:8269404

Pfeiffer, C J; Keith, J C

1993-10-01

196

Phylogeography of the mole-shrew ( Anourosorex yamashinai ) in Taiwan: implications of interglacial refugia in a high-elevation small mammal  

Microsoft Academic Search

To test the Pleistocene interglacial refugia hypothesis with a high-elevation mammal, we studied the phylogeography of the mole-shrew ( Anourosorex yamashinai ) using partial mitochondrial cytochrome b gene sequences (737 bases). This shrew is endemic to Taiwan. It is mainly distributed in the highlands from 1000 to 2500 m in elevation. We examined 103 specimens from 24 localities in three

SHOU-LI YUAN; LIANG-KONG LIN; TATSUO OSHIDA

197

Metal bioaccumulation in the greater white-toothed shrew, Crocidura russula, inhabiting an abandoned pyrite mine site.  

PubMed

Hepatic and renal concentrations of iron, magnesium, zinc, lead, copper, manganese, mercury, cadmium, molybdenum, chromium, and nickel were quantified in shrews (Crocidura russula) inhabiting a pyrite mine site in Portugal. Several morphological parameters (body weight, residual index, and relative weights) were also examined to clarify the physiological effects of pollution. Shrews from the mine showed increased bioavailability of Fe, Pb, Hg, Cd, Mo, and Ni in comparison with reference specimens. Adult shrews had the highest Cd levels while Cr and Ni concentrations diminished. Intersexual differences were found for Mo and Ni. As a consequence of metal pollution, the relative hepatic weight was higher in shrews from the mine site when compared with reference specimens. These data indicate that C. russula is a good bioindicator of metal pollution. We also evaluated the toxic effects of Pb, Hg, Cd, and Ni, because several shrews from the polluted site showed high concentrations of these metals. To approximate at the real biological impact of abandoned mines, after this first step it is necessary to associate the bioaccumulation levels and morphological effects with other physiological, ecological and genetical biomarkers. PMID:17107703

Sánchez-Chardi, Alejandro; Marques, Carla Cristina; Nadal, Jacint; da Luz Mathias, Maria

2007-02-01

198

Complete genome sequence and molecular phylogeny of a newfound hantavirus harbored by the Doucet's musk shrew (Crocidura douceti) in Guinea.  

PubMed

Elucidation of the molecular phylogeny of shrew-borne hantaviruses in sub-Saharan Africa has been hampered by the lack of full-length viral genomes. In this report, we present the complete genome analysis of a newfound hantavirus, designated Bowé virus, detected in ethanol-fixed intercostal muscle of a Doucet's musk shrew (Crocidura douceti), captured in southwestern Guinea in February 2012. Full-length amino acid sequence comparison of the S-, M- and L-segment gene products revealed that Bowé virus differed by 24.1-53.4%, 17.0-59.9% and 14.6-39.7%, respectively, from all other representative rodent-, shrew- and mole-borne hantaviruses. Phylogenetic analysis, using maximum-likelihood and Bayesian methods, under the GTR+I+? model of evolution, showed that Bowé virus shared a common ancestry with Tanganya virus, a hantavirus detected in the Therese's shrew (Crocidura theresae) in Guinea. Whole genome analysis of many more hantaviruses from sub-Saharan Africa are needed to better clarify how the radiation of African shrews might have contributed to the phylogeography of hantaviruses. PMID:23994121

Gu, Se Hun; Nicolas, Violaine; Lalis, Aude; Sathirapongsasuti, Nuankanya; Yanagihara, Richard

2013-12-01

199

A SKULL OF ANCYLOTHERIUM (CHALICOTHERIIDAE, MAMMALIA) FROM THE LATE MIOCENE OF THERMOPIGI (SERRES, N.GREECE), AND THE RELATIONSHIPS  

E-print Network

1 A SKULL OF ANCYLOTHERIUM (CHALICOTHERIIDAE, MAMMALIA) FROM THE LATE MIOCENE OF THERMOPIGI (SERRES has yielded a well- preserved skull of Ancylotherium pentelicum, among a rich collection of late Miocene mammals. It is the most complete Ancylotherium skull ever reported, and lack of crushing makes

Paris-Sud XI, Université de

200

Microtus guentheri (Danford & Alston) (Rodentia, Mammalia) : a bioindicator species for estimation of the influence of polymetal dust emissions  

Microsoft Academic Search

Chemical pollution of ecosystems resulting from human activity is an ecological factor in the living world, affecting individuals, populations, communities and ecosystems as a whole. This laboratory investigation studied the toxic effects of polymetal ferosilicic dust on Microtus guentheri (Rodentia, Mammalia), measuring path- ological changes in blood components (haemoglobin, erythrocyte, leucocyte and platelets number, erythrocyte sedi- mentation rate (ESR) and

Tsenka Chassovnikarova; Roumiana Metcheva; Krastio Dimitrov

201

ON SOME SPIRAL-HORNED ANTELOPES (MAMMALIA : ARTIODACTYLA : BOVIDAE) FROM THE LATE MIOCENE OF TURKEY, WITH REMARKS ON THEIR DISTRIBUTION  

E-print Network

ON SOME SPIRAL-HORNED ANTELOPES (MAMMALIA : ARTIODACTYLA : BOVIDAE) FROM THE LATE MIOCENE OF TURKEY to describe and definitely identify for the first time several species of spiral-horned antelopes-cores, spiral- horned antelopes can be identified with reasonable accuracy. Examination of some previously

Paris-Sud XI, Université de

202

Post-anesthesia vomiting: Impact of isoflurane and morphine on ferrets and musk shrews  

PubMed Central

Although partially controlled with antiemetic drugs, postoperative nausea and vomiting (PONV) continues to be a problem for many patients. Clinical research suggests that opioid analgesics and volatile anesthetics are the main triggers of PONV. The aim of this study was to develop an animal model for post-anesthesia vomiting for future studies to further determine mechanisms and preclinical drug efficacy. Ferrets (N=34) were initially used because they have served as a gold standard for emesis research. Ferrets were tested with several doses of morphine, inhaled isoflurane, and a positive control injection of cisplatin (a chemotherapy agent) to induce emesis. Musk shrews (a small animal model; N=36) were also tested for emesis with isoflurane exposure. A control injection of cisplatin produced emesis in ferrets (ip, 129.8±22.0 retches; 13.7±2.3 vomits; mean ± SEM). Morphine produced a dose-response on emesis in ferrets, with maximal responses at 0.9 mg/kg (sc, 29.6±12.6 retches; 1.8±0.9, vomits). Isoflurane exposure (2–4% for 10 min to 6 h exposure) failed to induce vomiting, was not associated with an increased frequency in emesis when combined with a low dose of morphine (0.1 mg/kg, sc), and failed to produced consistent effects on food and water intake. In contrast to ferrets, musk shrews were very sensitive to isoflurane-induced emesis (0.5 to 3%, 10 min exposure; up to 11.8±2.4 emetic episodes). Overall, these results indicate that ferrets will not be useful for delineating mechanisms responsible for isoflurane-induced emesis; however, musk shrews may prove to be a model for vomiting after inhalation of volatile agents. PMID:22504494

Horn, Charles C.; Meyers, Kelly; Pak, Diana; Nagy, Allysa; Apfel, Christian C.; Williams, Brian A.

2012-01-01

203

Is there a significant gas exchange through the skin of the shrew Crocidura russula monacha?  

PubMed

Because of its small body mass, the shrew Crocidura russula monacha has a relatively high surface area to volume ratio, thin skin, and high thermal conductance compared with larger mammals. This study was aimed at examining the possibility that such a mammal may exhibit a significant skin gas exchange. Gas composition was measured in subcutaneous gas pockets. CO2 and O2 exchange through skin were measured both in vitro and in vivo. In 7-wk-old gas pockets, the steady-state PO2 and PCO2 values were 50 Torr (where 1 Torr = 133.322 Pa) and 35 Torr, respectively, compared with PO2 and Pco2 values of 73 Torr and 33 Torr, respectively, in 1-wk-old gas pockets. These changes are attributed to an increased capillary density and a decreased skin thickness after 7 wk. There was no significant gas exchange through skin during in vitro measurements. In vivo measurements indicated that O2 uptake was 0.5% and CO2 loss was 0.9% of total body metabolism at 20 degrees C. At 35 degrees C, skin O2 uptake and CO2 loss increased to 1.3% and 2.9%, respectively. These values are only part of the expected skin metabolism; thus, the rest must come from blood. Because gas exchange through the skin of this shrew is within the range of other mammals, the relatively low PCO2 and high PO2 in the gas pockets is better explained by the relative hyperventilation state exhibited by this shrew. PMID:9678501

Mover-Lev, H; Minzberg, H; Ar, A

1998-01-01

204

Effect of PAHs on MFO induction in common shrews (Crocidura russula)  

SciTech Connect

PAHs are widespread environmental contaminants. Despite the relatively high turnover rates for enzymatic breakdown, PAHs have been detected in tissues from species at various trophic levels. As a consequence they have the potential to be passed on to the higher levels of the foodchain. As a model for the primary carnivores in the terrestrial foodchain the common shrew (Crocidura russula) is studied in the laboratories. The authors investigated the effect of exposure to benzo[a]pyrene (BaP) on cytochrome P450 isoenzymes in relation to the effect of a known strong inducer of the MFO system i.e. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The compounds were dissolved in oil and mixed with food. Shrews were exposed for a period of one week to BaP at concentrations equivalent to 10 or 100 mg/kg bodyweight per day (n = 3 for each dose group) and to TCDD at a concentration equivalent to 10 {micro}g/kg per day (n = 5). Controls received a diet with only the carier (oil) added. At termination of the experiment, hepatic CYP1A1 associated EROD activity was induced 20% in both the low and high dosed BaP group. In the TCDD exposed shrews EROD was induced up to 776% compared to the controls. Related MFO activities, including PROD, BROD, MROD and site specific testosterone hydroxylation are under investigation and the results will be presented. The relevance of MFO induction by PAHs and the use of these parameters as biomarkers for PAH exposure will be discussed.

Bosveld, A.T.C.; Bie, P. de; Weggemans, J. [Inst. for Forestry and Nature Research, Wageningen (Netherlands); Murk, A. [Agricultural Univ., Wageningen (Netherlands). Dept. of Toxicology

1995-12-31

205

Pulvinar Projections to the Striatum and Amygdala in the Tree Shrew  

PubMed Central

Visually guided movement is possible in the absence of conscious visual perception, a phenomenon referred to as “blindsight.” Similarly, fearful images can elicit emotional responses in the absence of their conscious perception. Both capabilities are thought to be mediated by pathways from the retina through the superior colliculus (SC) and pulvinar nucleus. To define potential pathways that underlie behavioral responses to unperceived visual stimuli, we examined the projections from the pulvinar nucleus to the striatum and amygdala in the tree shrew (Tupaia belangeri), a species considered to be a prototypical primate. The tree shrew brain has a large pulvinar nucleus that contains two SC-recipient subdivisions; the dorsal (Pd) and central (Pc) pulvinar both receive topographic (“specific”) projections from SC, and Pd receives an additional non-topographic (“diffuse”) projection from SC (Chomsung et al., 2008). Anterograde and retrograde tract tracing revealed that both Pd and Pc project to the caudate and putamen, and Pd, but not Pc, additionally projects to the lateral amygdala. Using immunocytochemical staining for substance P (SP) and parvalbumin (PV) to reveal the patch/matrix organization of tree shrew striatum, we found that SP-rich/PV-poor patches interlock with a PV-rich/SP-poor matrix. Confocal microscopy revealed that tracer-labeled pulvino-striatal terminals preferentially innervate the matrix. Electron microscopy revealed that the postsynaptic targets of tracer-labeled pulvino-striatal and pulvino-amygdala terminals are spines, demonstrating that the pulvinar nucleus projects to the spiny output cells of the striatum matrix and the lateral amygdala, potentially relaying: (1) topographic visual information from SC to striatum to aid in guiding precise movements, and (2) non-topographic visual information from SC to the amygdala alerting the animal to potentially dangerous visual images. PMID:21120139

Day-Brown, Jonathan D.; Wei, Haiyang; Chomsung, Ranida D.; Petry, Heywood M.; Bickford, Martha E.

2010-01-01

206

Musk shrews selectively bred for motion sickness display increased anesthesia-induced vomiting.  

PubMed

Susceptibility to motion sickness is a predictor of postoperative nausea and vomiting, and studies in humans suggest that genetic factors determine sensitivity to motion sickness. The aim of the current study was to determine if a preclinical model could be selectively bred for motion-induced emesis and to assess a potential relationship to anesthesia-induced emesis. Musk shrews were tested for motion-induced emesis using a shaker plate (10min, 1Hz, and 4cm of lateral displacement). Animals were rank ordered for motion-induced emesis and selectively bred to produce high and low response strains. Shrews were also tested with nicotine (5mg/kg, sc), copper sulfate (CuSO4; 120mg/kg, ig), and isoflurane anesthesia (10min; 3%) to measure responses to a panel of emetic stimuli. High response strain shrews demonstrated significantly more emetic episodes to motion exposure compared to low response strain animals in the F1 and F2 generations. In F2 animals, there were no significant differences in total emetic responses or emetic latency between strains after nicotine injection or CuSO4 gavage. However, isoflurane exposure stimulated more emesis in F1 and F2 high versus low strain animals, which suggests a relationship between vestibular- and inhalational anesthesia-induced emesis. Overall, these results indicate genetic determinants of motion sickness in a preclinical model and a potential common mechanism for motion sickness and inhalational anesthesia-induced emesis. Future work may include genetic mapping of potential "emetic sensitivity genes" to develop novel therapies or diagnostics for patients with high risk of nausea and vomiting. PMID:24239993

Horn, Charles C; Meyers, Kelly; Oberlies, Nicholas

2014-01-30

207

Resting-Associated Vocalization Emitted by Captive Asian House Shrews (Suncus murinus): Acoustic Structure and Variability in an Unusual Mammalian Vocalization  

PubMed Central

Shrews have rich vocal repertoires that include vocalizations within the human audible frequency range and ultrasonic vocalizations. Here, we recorded and analyzed in detail the acoustic structure of a vocalization with unclear functional significance that was spontaneously produced by 15 adult, captive Asian house shrews (Suncus murinus) while they were lying motionless and resting in their nests. This vocalization was usually emitted repeatedly in a long series with regular intervals. It showed some structural variability; however, the shrews most frequently emitted a tonal, low-frequency vocalization with minimal frequency modulation and a low, non-vocal click that was clearly noticeable at its beginning. There was no effect of sex, but the acoustic structure of the analyzed vocalizations differed significantly between individual shrews. The encoded individuality was low, but it cannot be excluded that this individuality would allow discrimination of family members, i.e., a male and female with their young, collectively resting in a common nest. The question remains whether the Asian house shrews indeed perceive the presence of their mates, parents or young resting in a common nest via the resting-associated vocalization and whether they use it to discriminate among their family members. Additional studies are needed to explain the possible functional significance of resting-associated vocalizations emitted by captive Asian house shrews. Our study highlights that the acoustic communication of shrews is a relatively understudied topic, particularly considering that they are highly vocal mammals. PMID:25390304

Schneiderová, Irena; Zouhar, Jan

2014-01-01

208

Resting-associated vocalization emitted by captive Asian house shrews (Suncus murinus): acoustic structure and variability in an unusual mammalian vocalization.  

PubMed

Shrews have rich vocal repertoires that include vocalizations within the human audible frequency range and ultrasonic vocalizations. Here, we recorded and analyzed in detail the acoustic structure of a vocalization with unclear functional significance that was spontaneously produced by 15 adult, captive Asian house shrews (Suncus murinus) while they were lying motionless and resting in their nests. This vocalization was usually emitted repeatedly in a long series with regular intervals. It showed some structural variability; however, the shrews most frequently emitted a tonal, low-frequency vocalization with minimal frequency modulation and a low, non-vocal click that was clearly noticeable at its beginning. There was no effect of sex, but the acoustic structure of the analyzed vocalizations differed significantly between individual shrews. The encoded individuality was low, but it cannot be excluded that this individuality would allow discrimination of family members, i.e., a male and female with their young, collectively resting in a common nest. The question remains whether the Asian house shrews indeed perceive the presence of their mates, parents or young resting in a common nest via the resting-associated vocalization and whether they use it to discriminate among their family members. Additional studies are needed to explain the possible functional significance of resting-associated vocalizations emitted by captive Asian house shrews. Our study highlights that the acoustic communication of shrews is a relatively understudied topic, particularly considering that they are highly vocal mammals. PMID:25390304

Schneiderová, Irena; Zouhar, Jan

2014-01-01

209

Erve virus, a probable member of Bunyaviridae family isolated from shrews (Crocidura russula) in France.  

PubMed

An apparently new agent, provisionally named Erve virus, was isolated in 1982 from tissues of three white toothed shrews, Crocidura russula, trapped near Saulges village in Western France. Results of virological and ultrastructural studies suggest that this virus belongs to the Bunyaviridae family and is a Bunyavirus-like agent. Serosurveys indicate that Erve virus had apparently a large geographical distribution in France and infects rodents, insectivores, wild boars (Sus scrofa), red deer (Cervus elaphus), sheep, herring gulls (Larus argentatus) and humans. Blood donors living in the vicinity of the Saulges area exhibit the highest incidence of antibody against Erve virus. PMID:2570514

Chastel, C; Main, A J; Richard, P; Le Lay, G; Legrand-Quillien, M C; Beaucournu, J C

1989-05-01

210

Molecular Ecology (2001) 10, 12271240 2001 Blackwell Science Ltd  

E-print Network

Phylogeography of the dusky shrew, Sorex monticolus (Insectivora, Soricidae): insight into deep and shallow 99775­6960, USA Abstract Phylogenetic relationships among the dusky shrew (Sorex monticolus) and eight related species (S. bairdi, S. bendirii, S. neomexicanus, S. ornatus, S. pacificus, S. palustris, S

211

Short-term response of shrews to prescribed fire and mechanical fuel reduction in a Southern Appalachian upland hardwood forest  

Microsoft Academic Search

As part of the multidisciplinary National Fire and Fire Surrogate study, we used drift fences with pitfall traps from May to September 2003 and 2004 to determine how three fuel reduction techniques affected shrews in the Southern Appalachian Mountains of North Carolina. Ground-dwelling macroarthropods also were collected from a subset of pitfall traps to assess relative prey availability among the

Cathryn H. Greenberg; Stanlee Miller; Thomas A. Waldrop

2007-01-01

212

Tree shrews (Tupaia belangeri) exhibit novelty preference in the novel location memory task with 24-h retention periods  

PubMed Central

Novelty preference is pervasive in mammalian species, and describes an inherent tendency to preferentially explore novelty. The novel location memory task studied here assesses the ability of animals to form accurate memories of a spatial configuration, consisting of several identical objects placed within an arena. Tree shrews were first familiarized with a particular object configuration during several sessions, and then an object was displaced during a test session. Tree shrews exhibited enhanced exploration when confronted with this novel configuration. The most reliable indicator associated with novelty preference was an enhancement in directed exploration towards the novel object, although we also observed a non-specific overall increase in exploration in one experiment. During the test session, we also observed an exploration of the location, which had previously been occupied by the displaced object, an effect termed empty quadrant. Our behavioral findings suggest multiple stages of spatial memory formation in tree shrews that are associated with various forms of behavioral responses to novelty. Reduced novelty preference has been linked to major depressive disorder in human patients. Given the established social conflict depression model in tree shrews, we anticipate that the study of the neural circuits of novelty preference and their malfunction during depression may have implications for understanding or treating depression in humans. PMID:24782805

Nair, Jayakrishnan; Topka, Marlene; Khani, Abbas; Isenschmid, Manuela; Rainer, Gregor

2014-01-01

213

Trap geometry in three giant montane pitcher plant species from Borneo is a function of tree shrew body size.  

PubMed

*Three Bornean pitcher plant species, Nepenthes lowii, N. rajah and N. macrophylla, produce modified pitchers that 'capture' tree shrew faeces for nutritional benefit. Tree shrews (Tupaia montana) feed on exudates produced by glands on the inner surfaces of the pitcher lids and defecate into the pitchers. *Here, we tested the hypothesis that pitcher geometry in these species is related to tree shrew body size by comparing the pitcher characteristics with those of five other 'typical' (arthropod-trapping) Nepenthes species. *We found that only pitchers with large orifices and lids that are concave, elongated and oriented approximately at right angles to the orifice capture faeces. The distance from the tree shrews' food source (that is, the lid nectar glands) to the front of the pitcher orifice precisely matches the head plus body length of T. montana in the faeces-trapping species, and is a function of orifice size and the angle of lid reflexion. *Substantial changes to nutrient acquisition strategies in carnivorous plants may occur through simple modifications to trap geometry. This extraordinary plant-animal interaction adds to a growing body of evidence that Nepenthes represents a candidate model for adaptive radiation with regard to nitrogen sequestration strategies. PMID:20100203

Chin, Lijin; Moran, Jonathan A; Clarke, Charles

2010-04-01

214

Inference Based on Transitive Relation in Tree Shrews ("Tupaia belangeri") and Rats ("Rattus norvegicus") on a Spatial Discrimination Task  

ERIC Educational Resources Information Center

Six tree shrews and 8 rats were tested for their ability to infer transitively in a spatial discrimination task. The apparatus was a semicircular radial-arm maze with 8 arms labeled A through H. In Experiment 1, the animals were first trained in sequence on 4 discriminations to enter 1 of the paired adjacent arms, AB, BC, CD, and DE, with right…

Takahashi, Makoto; Ushitani, Tomokazu; Fujita, Kazuo

2008-01-01

215

The evolutionary history of the two karyotypic groups of the common shrew, Sorex araneus, in Poland.  

PubMed

Genetic variability within and among two karyotypic groups and five chromosome races of the common shrew (Sorex araneus) in Poland was assayed by sequencing a 1023 bp part of the cytochrome b gene (mtDNA) from 28 individuals. Thirty-four variable positions defined 21 distinct haplotypes with a maximum sequence divergence of 0.88%. No significant differentiation in the cytochrome b gene between Western and Eastern Karyotypic groups was found. Haplotype diversity estimates within the races and groups sampled were high (h = 0.800-0.928), while nucleotide diversity estimates were low (pi = 0.0034-0.0053). The distribution of pairwise nucleotide differences fits well with expectations of a "sudden expansion" model. High haplotype diversity was accompanied by relatively high expected heterozygosity (H(E)) values in nuclear genes (calculated over 47 enzyme loci: H(E) = 0.031 - 0.049), giving no evidence for a recent bottleneck after the process of post-Pleistocene recolonization of Poland by the shrews. Thus, for S. araneus chromosome races in Poland, the data on the cytochrome b gene variability support the hypothesis assuming the Robertsonian fusions having spread into an ancestral acrocentric distribution. PMID:11920129

Ratkiewicz, M; Fedyk, S; Banaszek, A; Gielly, L; Chetnicki, W; Jadwiszczak, K; Taberlet, P

2002-04-01

216

Individual reproductive success and effective population size in the greater white-toothed shrew Crocidura russula.  

PubMed Central

In order to investigate the determinants of effective population size in the socially monogamous Crocidura russula, the reproductive output of 44 individuals was estimated through genetic assignment methods. The individual variance in breeding success turned out to be surprisingly high, mostly because the males were markedly less monogamous than expected from previous behavioural data. Males paired simultaneously with up to four females and polygynous males had significantly more offspring than monogamous ones. The variance in female reproductive success also exceeded that of a Poisson distribution (though to a lesser extent), partly because females paired with multiply mated males weaned significantly more offspring. Polyandry also occurred occasionally, but only sequentially (i.e. without multiple paternity of litters). Estimates of the effective to census size ratio were ca. 0.60, which excluded the mating system as a potential explanation for the high genetic variance found in this shrew's populations. Our data suggest that gene flow from the neighbourhood (up to one-third of the total recruitment) is the most likely cause of the high levels of genetic diversity observed in this shrew's subpopulations. PMID:10821616

Bouteiller, C; Perrin, N

2000-01-01

217

[Cellular aspects of aging in the pineal gland of the shrew, Crocidura russula].  

PubMed

The Greater White-toothed shrew Crocidura russula is short-lived species and the phase of senescence is greatly elongated in captivity. The loss of rhythmicity of biological functions that accompanies its aging is also well documented. C. russula is thus an excellent model to test the effects of aging on biological clocks. Melatonin is a key hormone in the synchronization of behaviors, metabolisms and physiological regulations with environmental factors. In the present work we want to know if the loss of rhythmicity and the reduced melatonin levels registered by the second year of life in this species could be associated to modified ultrastructural features of the pineal parenchyma, site of melatonin synthesis. Transmission electron microscopy (TEM) analysis of young (1-4 months) and old (25-28 months) shrew's pineals show that in older individuals, the parenchyma undergoes alterations affecting mainly nucleus, mitochondria and endoplasmic reticulum cisternae, with increased numbers of dense bodies and the formation of many concretions as well as a depletion of secretory products. These changes suggest a process of slowing pinealocytes metabolism which could explain the gradual reduction of melatonin levels registered during aging in C. russula. PMID:22226159

Dekar-Madoui, Aicha; Besseau, Laurence; Magnanou, Elodie; Fons, Roger; Ouali, Saliha; Bendjelloul, Mounira; Falcon, Jack

2012-01-01

218

Energy expenditure in Crocidurinae shrews (Insectivora): is metabolism a key component of the insular syndrome?  

PubMed

A cascade of morphological, ecological, demographical and behavioural changes operates within island communities compared to mainland. We tested whether metabolic rates change on islands. Using a closed circuit respirometer, we investigated resting metabolic rate (RMR) of three species of Crocidurinae shrews: Suncus etruscus, Crocidura russula, and C. suaveolens. For the latter, we compared energy expenditure of mainland and island populations. Our measurements agree with those previously reported for others Crocidurinae: the interspecific comparison (ANCOVA) demonstrated an allometric relation between energy requirements and body mass. Energy expenditure also scaled with temperature. Island populations (Corsica and Porquerolles) of C. suaveolens differed in size from mainland (gigantism). A GLM showed a significant relationship between energy expenditure, temperature, body mass and locality. Mass specific RMR allometrically scales body mass, but total RMR does not significantly differ between mainland and island, although island shrews are giant. Our results are consistent with other studies: that demonstrated that the evolution of mammalian metabolism on islands is partially independent of body mass. In relation to the insular syndrome, we discuss how island selective forces (changes in resource availability, decrease in competition and predation pressures) can operate in size and physiological adjustments. PMID:16154371

Magnanou, Elodie; Fons, Roger; Blondel, Jacques; Morand, Serge

2005-11-01

219

The role of rodents and shrews in the transmission of Toxoplasma gondii to pigs.  

PubMed

Inadequate rodent control is considered to play a role in Toxoplasma gondii infection of pigs. This issue was addressed in the current study by combining a 4-month rodent control campaign and a 7-month longitudinal analysis of T. gondii seroprevalence in slaughter pigs. Three organic pig farms with known rodent infestation were included in the study. On these farms, presence of T. gondii in trapped rodents was evaluated by real-time PCR. All rodent species and shrews investigated had T. gondii DNA in brain or heart tissue. Prevalence was 10.3% in Rattus norvegicus, 6.5% in Mus musculus, 14.3% in Apodemus sylvaticus and 13.6% in Crocidura russula. Initial T. gondii seroprevalence in the slaughter pigs ranged between 8% and 17% and dropped on the three farms during the rodent control campaign to 0-10%, respectively. After 4 months of rodent control, T. gondii infection was absent from pigs from two of the three farms investigated and appeared again in one of those two farms after the rodent control campaign had stopped. This study emphasizes the role of rodents and shrews in the transmission of T. gondii to pigs and the importance of rodent control towards production of T. gondii-free pig meat. PMID:18606498

Kijlstra, Aize; Meerburg, Bastiaan; Cornelissen, Jan; De Craeye, Stéphane; Vereijken, Pieter; Jongert, Erik

2008-10-01

220

Individual reproductive success and effective population size in the greater white-toothed shrew Crocidura russula.  

PubMed

In order to investigate the determinants of effective population size in the socially monogamous Crocidura russula, the reproductive output of 44 individuals was estimated through genetic assignment methods. The individual variance in breeding success turned out to be surprisingly high, mostly because the males were markedly less monogamous than expected from previous behavioural data. Males paired simultaneously with up to four females and polygynous males had significantly more offspring than monogamous ones. The variance in female reproductive success also exceeded that of a Poisson distribution (though to a lesser extent), partly because females paired with multiply mated males weaned significantly more offspring. Polyandry also occurred occasionally, but only sequentially (i.e. without multiple paternity of litters). Estimates of the effective to census size ratio were ca. 0.60, which excluded the mating system as a potential explanation for the high genetic variance found in this shrew's populations. Our data suggest that gene flow from the neighbourhood (up to one-third of the total recruitment) is the most likely cause of the high levels of genetic diversity observed in this shrew's subpopulations. PMID:10821616

Bouteiller, C; Perrin, N

2000-04-01

221

Size evolution in Goodwin?s small-eared shrew, Cryptotis goodwini  

USGS Publications Warehouse

Fossils of Cryptotis goodwini from Honduras indicate that body sizes of modern individuals average at least 18% larger than among members of the late Pleistocene population of this species. Palynological and other paleoenvironmental studies provide evidence that the Neotropical montane environments that these shrews inhabit were cooler and drier in the late Pleistocene than at present and supported communities of plants without modern analog. Therefore, the most likely cause of this change in size ultimately was related to climatic change at the end of the Pleistocene?but to what specific factors did the species respond? I examined the possibilities that this species changed in size: to accommodate a change in temperature regime; to escape from predators; as a response to a change in intensity of interspecific competition; to take advantage of a newly abundant food resource. Based on evidence from studies of modern communities of shrews and niche partitioning, I hypothesized that size evolution in C. goodwini was directly related to changes in the community of soil and soil-surface invertebrates upon which the species depends, specifically an increase in the availability of earthworms (Annelida).

Woodman, N.

2005-01-01

222

Cortical projections to the superior colliculus in tree shrews (Tupaia belangeri)  

PubMed Central

The visuomotor functions of the superior colliculus depend not only on direct inputs from the retina, but also on inputs from neocortex. As mammals vary in the areal organization of neocortex, and in the organization of the number of visual and visuomotor areas, patterns of corticotectal projections vary. Primates in particular have a large number of visual areas projecting to the superior colliculus. As tree shrews are close relatives of primates, and they are also highly visual, we studied the distribution of cortical neurons projecting to the superior colliculus by injecting anatomical tracers into the colliculus. Since projections from visuotopically organized visual areas are expected to match the visuotopy of the superior colliculus, injections at different retinotopic locations in the superior colliculus provide information about the locations and organization of topographic areas in extrastriate cortex. Small injections in the superior colliculus labeled neurons in locations within areas 17 (V1) and 18 (V2) that are consistent with the known topography of these areas and the superior colliculus. In addition, the separate locations of clusters of labeled cells in temporal visual cortex provide evidence for five or more topographically organized areas. Injections that included deeper layers of the superior colliculus also labeled neurons in medial frontal cortex, likely in premotor cortex. Only occasional labeled neurons were observed in somatosensory or auditory cortex. Regardless of tracer injection location, we found that unlike primates, a substantial projection to the superior colliculus from posterior parietal cortex is not a characteristic of tree shrews. PMID:23124770

Baldwin, Mary K L; Wei, Haiyang; Reed, Jamie L; Bickford, Martha E; Petry, Heywood M; Kaas, Jon H

2012-01-01

223

Anaplasma phagocytophilum strains from voles and shrews exhibit specific ankA gene sequences  

PubMed Central

Background Anaplasma phagocytophilum is a Gram-negative bacterium that replicates obligate intracellularly in neutrophils. It is transmitted by Ixodes spp. ticks and causes acute febrile disease in humans, dogs, horses, cats, and livestock. Because A. phagocytophilum is not transmitted transovarially in Ixodes spp., it is thought to depend on reservoir hosts to complete its life cycle. In Europe, A. phagocytophilum was detected in roe deer, red deer, wild boars, and small mammals. In contrast to roe deer, red deer and wild boars have been considered as reservoir hosts for granulocytic anaplasmosis in humans, dogs, and horses according to groESL- and ankA-based genotyping. A. phagocytophilum variants infecting small mammals in Europe have not been characterized extensively to date. Results We amplified the total ankA open reading frames of 27 strains from voles and shrews. The analysis revealed that they harboured A. phagocytophilum strains that belonged to a distinct newly described ankA gene cluster. Further, we provide evidence that the heterogeneity of ankA gene sequences might have arisen via recombination. Conclusions Based on ankA-based genotyping voles and shrews are unlikely reservoir hosts for granulocytic anaplasmosis in humans, dogs, horses, and livestock in Europe. PMID:24283328

2013-01-01

224

Demography of short-tailed shrew populations living on polychlorinated biphenyl-contaminated sites.  

PubMed

In ecological risk assessment, a key necessity is to understand how contaminants known to have negative impact on laboratory mammals affect the population demography of mammals living in their natural environment. We examined the demography of six local populations of the short-tailed shrew (Blarina brevicauda) living in eastern deciduous forest palustrine habitat along the Housatonic River (MA, USA) on soils contaminated with a range of polychlorinated biphenyl (PCB) concentrations (1.5-38.3 ppm). The objective of the study was to assess whether PCBs adversely affect the population demography of these small mammals living in their natural environment. Blarina were selected for study because they would be expected to readily bioaccumulate PCBs from the soil. Populations were intensively live trapped on 1-ha grids from spring to autumn 2001. There was no relationship between any demographic parameter and PCB soil concentrations. Densities were high (usually exceeding 20/ha, and on two grids exceeded 60/ha in summer); survival was good (typically 60-75% per 30 d); and sex ratio, reproduction rates, growth rates, and body mass were within the ranges reported in the literature. Thus, these shrew populations showed no detectable impact on their population demography from living on PCB-contaminated sites. PMID:12785599

Boonstra, Rudy; Bowman, Lanna

2003-06-01

225

Prevalence of zoonotic Bartonella species among rodents and shrews in Thailand.  

PubMed

We investigated the prevalence of Bartonella species in 10 rodent and one shrew species in Thailand. From February 2008 to May 2010, a total of 375 small animals were captured in 9 provinces in Thailand. Bartonella strains were isolated from 57 rodents (54 from Rattus species and 3 from Bandicota indica) and one shrew (Suncus murinus) in 7 of the 9 provinces, and identified to the species level. Sequence analysis of the citrate synthase and RNA polymerase ? subunit genes identified the 58 isolates from each Bartonella-positive animal as B. tribocorum in 27 (46.6%) animals, B. rattimassiliensis in 17 (29.3%) animals, B. elizabethae in 10 (17.2%) animals and B. queenslandensis in 4 (6.9%) animals. R. norvegicus, R. rattus, and Suncus murinus carried B. elizabethae, which causes endocarditis in humans. The prevalence of Bartonella bacteremic animals by province was 42.9% of the animals collected in Phang Nga, 26.8% in Chiang Rai, 20.4% in Sa Kaeo, 16.7% in Nakhon Si Thammarat, 12.0% in Surat Thani, 9.1% in Mae Hong Son and Loei Provinces. These results indicate that Bartonella organisms are widely distributed in small mammals in Thailand and some animal species may serve as important reservoirs of zoonotic Bartonella species in the country. PMID:24393304

Pangjai, Decha; Maruyama, Soichi; Boonmar, Sumalee; Kabeya, Hidenori; Sato, Shingo; Nimsuphan, Burin; Petkanchanapong, Wimol; Wootta, Wattanapong; Wangroongsarb, Piyada; Boonyareth, Maskiet; Preedakoon, Poom; Saisongkorh, Watcharee; Sawanpanyalert, Pathom

2014-03-01

226

Distinct Innate Immune Responses in Human Macrophages and Endothelial Cells Infected with Shrew-borne Hantaviruses  

PubMed Central

Although hantaviruses have been previously considered as rodent-borne pathogens, recent studies demonstrate genetically distinct hantaviruses in evolutionarily distant non-rodent reservoirs, including shrews, moles and bats. The immunological responses to these newfound hantaviruses in humans are unknown. We compared the innate immune responses to Imjin virus (MJNV) and Thottapalayam virus (TPMV), two shrew-borne hantaviruses, with that toward two rodent-borne hantaviruses, pathogenic Hantann virus (HTNV) and nonpathogenic Prospect Hill virus (PHV). Infection of human macrophages and endothelial cells with either HTNV or MJNV triggered productive viral replication and up-regulation of anti-viral responsive gene expression from day 1 to day 3 postinfection, compared with PHV and TPMV. Furthermore, HTNV, MJNV and TPMV infection led to prolonged increased production of pro-inflammatory cytokines from days 3 to 7 postinfection. By contrast, PHV infection failed to induce pro-inflammatory responses. Distinct patterns of innate immune activation caused by MJNV suggest that it might be pathogenic to humans. PMID:22944108

Shin, Ok Sarah; Yanagihara, Richard; Song, Jin-Won

2013-01-01

227

Metals distribution and interactions in tissues of shrews (Sorex spp.) from copper- and zinc-contaminated areas in Poland.  

PubMed

To assess the risk from heavy metal accumulation to insectivorous species exposed to different pollutants, shrews [Sorex araneus (Linnaeus 1758) and Sorex minutus (Linnaeus 1766)] were collected in the Olkuski Ore Region (OOR; a Zn and Cd smelter area), Legnicko-G?ogowski Copper Mine Region (LGCR; a copper ore-mining area), and Bia?owieza Forest (BF; a control area). A few sites were chosen in each region and a total of 57 animals were collected from them. The liver and kidneys were dissected from the animals, dried, and digested in a 4:1 mixture of HNO3 (nitric acid) and HClO4 (perchloric acid). Cadmium, lead, zinc, copper, and iron were determined in the samples by flame or flameless atomic absorption spectrometry. The interactions between toxic and essential metals were calculated for each tissue. The data showed that accumulation of metals by insectivores is high; shrews accumulated much higher amounts of cadmium and lead than bank voles, studied by other researchers, from the same areas. The expected high tissue accumulation of copper at LGCR and zinc at OOR was not seen, but the levels of both elements were higher in the tissues of shrews from OOR than from LGCR. The lowest copper concentrations were in the tissues of shrews from BF. The highest cadmium and lead concentrations were found in the tissues of shrews from OOR. Some significant correlations were found between the tissue concentrations of xenobiotic and essential metals (e.g., between cadmium and zinc and between lead and iron). PMID:16091604

Swiergosz-Kowalewska, R; Gramatyka, M; Reczy?ski, W

2005-01-01

228

Modelling and monitoring organochlorine and heavy metal accumulation in soils, earthworms, and shrews in Rhine-delta floodplains.  

PubMed

In the Rhine-delta, accumulation of microcontaminants in floodplain foodwebs has received little attention in comparison with aquatic communities. To investigate organochlorine and metal concentrations in a terrestrial foodchain, samples of soil, earthworms (Lumbricus rubellus), and shrew (Crocidura russula, Sorex araneus) livers and kidneys were taken from two moderately to heavily polluted floodplains. Chlorobiphenyl residues in earthworm fat were 0.10 to 3.5 times the concentrations in soil organic matter, whereas ratios for other organochlorines varied between 0.87 and 8.8. These ratios are one order of magnitude lower than expected from laboratory experiments with earthworms, and laboratory and field studies on aquatic invertebrates. Bioconcentration ratios for heavy metals are in accordance with literature values for other locations, confirming the high potential for cadmium accumulation in Lumbricidae. Concentrations of organochlorines in shrew liver lipids were 1.0 to 13 times the residues in earthworm fat. These values are higher than lipid-corrected biomagnification ratios for laboratory rodents, but equal to those measured for benthivorous birds in the Rhine-delta. On a dry weight basis, kidney-earthworm ratios for cadmium were about one order of magnitude lower than previously reported values for insectivores. Soil concentrations of many compounds in both floodplains did not meet Dutch quality standards. Yet, hexachlorobenzene, chlorobiphenyl 153 (PCB153), gamma-hexachlorocyclohexane, sigma DDT, and dieldrin residues in earthworms and shrews did not exceed diet levels expected to be safe for endothermic species. An exception was noted for cadmium in worms and shrew kidneys. Heavy metal pollution in soil was close to levels that are critical to earthworms in laboratory studies. Cadmium concentrations in shrew kidneys were below levels suggested to be safe for Sorex araneus, but above those that were critical to the rat. PMID:7794009

Hendriks, A J; Ma, W C; Brouns, J J; de Ruiter-Dijkman, E M; Gast, R

1995-07-01

229

Genetic diversity of Imjin virus in the Ussuri white-toothed shrew (Crocidura lasiura) in the Republic of Korea, 2004-2010  

Microsoft Academic Search

Recently, Imjin virus (MJNV), a genetically distinct hantavirus, was isolated from lung tissues of the Ussuri white-toothed shrew (Crocidura lasiura) captured near the demilitarized zone in the Republic of Korea. To clarify the genetic diversity of MJNV, partial M- and L-segment sequences were amplified from lung tissues of 12 of 37 (32.4%) anti-MJNV IgG antibody-positive Ussuri white-toothed shrews captured between

Se Hun Gu; Hae Ji Kang; Luck Ju Baek; Ji Yun Noh; Heung-Chul Kim; Terry A Klein; Richard Yanagihara; Jin-Won Song

2011-01-01

230

Dental and Mandibular Morphologies of Arboroharamiya (Haramiyida, Mammalia): A Comparison with Other Haramiyidans and Megaconus and Implications for Mammalian Evolution  

PubMed Central

Background Two recent studies published in the same issue of Nature reached conflicting conclusions regarding the phylogeny of early mammals: One places the clade containing haramiyidans and multituberculates within the Mammalia and the other separates haramiyidans from multituberculates and places the former outside of the Mammalia. These two contrasting results require that the minimally oldest divergence time of the Mammalia was within the Late Triassic or the Middle Jurassic, respectively. Morphological descriptions of the species named in the two papers were brief, and no comparisons between the newly named species were possible. Principal Findings Here we present a detailed description of the dentary bone, teeth, occlusal and wear patterns of the haramiyidan Arboroharamiya and compare it with other haramiyidans and Megaconus. Using this new information, we suggest that tooth identifications and orientations of several previously described haramiyidan species are incorrect, and that previous interpretations of haramiyidan occlusal pattern are problematic. We propose that the published upper tooth orientation of Megaconus was problematic and question the number of upper molars, the length of dentition and mandible, and presence of the mandibular middle ear in Megaconus. Conclusions The additional morphological descriptions and comparisons presented here further support the view that Arboroharamiya, as a derived haramiyidan, shows similarity to multituberculates in tooth and mandible morphologies. Our comparison also suggests that Megaconus lacks many diagnostic features for the family Eleutherodontidae and that its close affinity with multituberculates cannot be ruled out. The detailed morphological data demonstrate that haramiyidans are more similar to multituberculates than to any other mammaliaforms. PMID:25494181

Meng, Jin; Bi, Shundong; Wang, Yuanqing; Zheng, Xiaoting; Wang, Xiaoli

2014-01-01

231

Dietary competition between the alien Asian Musk Shrew (Suncus murinus) and a re-introduced population of Telfair's Skink (Leiolopisma telfairii).  

PubMed

Re-introduction of rare species to parts of their historical range is becoming increasingly important as a conservation strategy. Telfair's Skinks (Leiolopisma telfairii), once widespread on Mauritius, were until recently found only on Round Island. There it is vulnerable to stochastic events, including the introduction of alien predators that may either prey upon it or compete for food resources. Consequently, skinks have been introduced to Ile aux Aigrettes, another small Mauritian island that has been cleared of rats. However, the island has been invaded by Asian Musk Shrews (Suncus murinus), a commensal species spread by man well beyond its natural Asian range. Our aim was to use next-generation sequencing to analyse the diets of the shrews and skinks to look for niche competition. DNA was extracted from skink faeces and from the stomach contents of shrews. Application of shrew- and skink-specific primers revealed no mutual predation. The DNA was then amplified using general invertebrate primers with tags to identify individual predators, and then sequenced by 454 pyrosequencing. 119 prey MOTUs (molecular taxonomic units) were isolated, although none could be identified to species. Seeding of cladograms with known sequences allowed higher taxonomic assignments in some cases. Although most MOTUs were not shared by shrews and skinks, Pianka's niche overlap test showed significant prey overlap, suggesting potentially strong competition where food resources are limited. These results suggest that removal of the shrews from the island should remain a priority. PMID:24033506

Brown, D S; Burger, R; Cole, N; Vencatasamy, D; Clare, E L; Montazam, A; Symondson, W O C

2014-08-01

232

Effect of land cover, habitat fragmentation and ant colonies on the distribution and abundance of shrews in southern California  

USGS Publications Warehouse

1. Because effects of habitat fragmentation and anthropogenic disturbance on native animals have been relatively little studied in arid areas and in insectivores, we investigated the roles of different land covers, habitat fragmentation and ant colonies on the distribution and abundance of shrews, Notiosorex crawfordi and Sorex ornatus, in southern California. 2. Notiosorex crawfordi was the numerically dominant species (trap-success rate 0.52) occurring in 21 of the 22 study sites in 85% of the 286 pitfall arrays used in this study. Sorex ornatus was captured in 14 of the sites, in 52% of the arrays with a total trap-success rate of 0.2. Neither of the species was found in one of the sites. 3. The population dynamics of the two shrew species were relatively synchronous during the 4-5-year study; the peak densities usually occurred during the spring. Precipitation had a significant positive effect, and maximum temperature a significant negative effect on the trap-success rate of S. ornatus. 4. Occurrence and abundance of shrews varied significantly between sites and years but the size of the landscape or the study site had no effect on the abundance of shrews. The amount of urban edge had no significant effect on the captures of shrews but increased edge allows invasion of the Argentine ants, which had a highly significant negative impact on the abundance of N. crawfordi. 5. At the trap array level, the percentage of coastal sage scrub flora had a significant positive, and the percentage of other flora had a significant negative effect on the abundance of N. crawfordi. The mean canopy height and the abundance of N. crawfordi had a significant positive effect on the occurrence of S. ornatus. 6. Our study suggests that the loss of native coastal sage scrub flora and increasing presence of Argentine ant colonies may significantly effect the distribution and abundance of N. crawfordi. The very low overall population densities of both shrew species in most study sites make both species susceptible to extinction in isolated habitat fragments due to environmental stochasticity, and anthropogenic disturbance.

Laakkonen, J.; Fisher, R.N.; Case, T.J.

2001-01-01

233

A new oxyurid species (Nematoda) collected from a Japanese serow, Capricornis crispus (Mammalia: Bovidae), in Japan.  

PubMed

Skrjabinema kamosika sp. n. (Nematoda: Oxyuridae) is described based on both sexes collected from endemic Japanese serows, Capricornis crispus (Mammalia: Bovidae), of Wakayama Prefecture, western Honshu Island, and Kochi Prefecture, Shikoku Island, Japan. It is readily distinguished from the congeners by having tricuspid sub-interlabial projections in males, large triangular lateral lobes of the lips that do not reach the mouth rim, and a large length ratio of alate/nonalate portions of the tail in females. Close identity in the nucleotide arrangement of ITS2 region between the present material and that from C. crispus of Iwate Prefecture, northern Honshu Island, suggests wide distribution of S. kamosika in Japan. In partial 18S rDNA nucleotide sequence, 0.77% differed from that of Skrjabinema sp. from Capra hircus in the United States. PMID:22662765

Hasegawa, Hideo; Sato, Hiroshi; Suzuki, Kazuo; Kaneshiro, Yoshinori

2012-12-01

234

Sexual receptivity and oestrus in the white-toothed shrew, Crocidura russula monacha.  

PubMed

In common white-toothed shrews, the vaginal smear was an inadequate indicator of receptivity. Nucleated epithelial cells usually predominated and most matings took place when the smear was of this type. Cornified cells in the smear in infrequent. Mating tests showed that virgin females 2 to 4 months old, were unreceptive for extended periods. Willingness to mate increased gradually with the age of the female. Females were receptive throughout pregnancy, suggesting a continuous secretion of oestrogen during gestation. There was a post-partum oestrus whether or not the young of the litter were being suckled, and an oestrus at the end of lactation. During mid-lactation, females were in a state of low receptivity, whether or not they were suckling. PMID:1206646

Hellwing, S

1975-12-01

235

A beta-defensin 1-like antimicrobial peptide from the tree shrew, Tupaia belangeri.  

PubMed

A novel beta-defensin 1-like antimicrobial peptide (?-defensin 1TB) containing 36 amino acid residues was purified and characterized from the serum of the tree shrew, Tupaia belangeri. Its amino acid sequence was determined as DHYLCVKNEGICLYSSCPSYTKIEGTCYGGKAKCCK, by Edman degradation, mass spectrometry analysis, and cDNA cloning. Evolution analysis indicated that ?-defensin 1TB showed maximal similarity to the ?-defensin 1 identified from cotton-top tamarin, Saguinus oedipus. ?-defensin 1TB exerted potential antimicrobial activities against wide spectrum of microorganisms including Gram-negative and -positive bacteria and fungi. It showed little hemolitic activity to human or rabbit red cells. To the best of our knowledge, this is the first report of antimicrobial peptide from Tupaiidae. PMID:22939868

Yang, Xiaomei; Dong, Li; Lv, Longbao; Yan, Xiuwen; Lai, Ren; Liu, Rui

2012-11-10

236

A new Ixodes species (Acari: Ixodidae), parasite of shrew tenrecs (Afrosoricida: Tenrecidae) in Madagascar.  

PubMed

Abstract :? A new tick species belonging to the African subgenus Afrixodes Morel, 1966 of the genus Ixodes Latreille, 1795, namely, Ixodes (Afrixodes) microgalei n. sp., is described. Females of this species are most similar to those of Ixodes colasbelcouri Arthur, 1957 and Ixodes nesomys Uilenberg & Hoogstraal, 1969. The female of the new species can easily be differentiated from I. colasbelcouri by a short spur on coxae IV, and from I. nesomys by longer spurs on coxae I and large punctations on its scutum. Ixodes microgalei is known only from the eastern humid forest of Madagascar, specifically in the Province of Antananarivo, where its females have been collected from several species of shrew tenrecs (Afrosoricida, Tenrecidae), namely, Microgale dobsoni Thomas, Microgale parvula Grandidier, and Microgale soricoides Jenkins. PMID:23901784

Apanaskevich, Dmitry A; Soarimalala, Voahangy; Goodman, Steven M

2013-12-01

237

Solar Radiation during Rewarming from Torpor in Elephant Shrews: Supplementation or Substitution of Endogenous Heat Production?  

PubMed Central

Many small mammals bask in the sun during rewarming from heterothermy, but the implications of this behaviour for their energy balance remain little understood. Specifically, it remains unclear whether solar radiation supplements endogenous metabolic thermogenesis (i.e., rewarming occurs through the additive effects of internally-produced and external heat), or whether solar radiation reduces the energy required to rewarm by substituting (i.e, replacing) metabolic heat production. To address this question, we examined patterns of torpor and rewarming rates in eastern rock elephant shrews (Elephantulus myurus) housed in outdoor cages with access to either natural levels of solar radiation or levels that were experimentally reduced by means of shade cloth. We also tested whether acclimation to solar radiation availability was manifested via phenotypic flexibility in basal metabolic rate (BMR), non-shivering thermogenesis (NST) capacity and/or summit metabolism (Msum). Rewarming rates varied significantly among treatments, with elephant shrews experiencing natural solar radiation levels rewarming faster than conspecifics experiencing solar radiation levels equivalent to approximately 20% or 40% of natural levels. BMR differed significantly between individuals experiencing natural levels of solar radiation and conspecifics experiencing approximately 20% of natural levels, but no between-treatment difference was evident for NST capacity or Msum. The positive relationship between solar radiation availability and rewarming rate, together with the absence of acclimation in maximum non-shivering and total heat production capacities, suggests that under the conditions of this study solar radiation supplemented rather than substituted metabolic thermogenesis as a source of heat during rewarming from heterothermy. PMID:25853244

Thompson, Michelle L.; Mzilikazi, Nomakwezi; Bennett, Nigel C.; McKechnie, Andrew E.

2015-01-01

238

Broad geographical distribution and high genetic diversity of shrew-borne Seewis hantavirus in Central Europe.  

PubMed

For a long time hantaviruses were believed to be exclusively rodent-borne pathogens. Recent findings of numerous shrew- and mole-borne hantaviruses raise important questions on their phylogenetic origin. The objective of our study was to prove the presence and distribution of shrew-associated Seewis virus (SWSV) in different Sorex species in Central Europe. Therefore, a total of 353 Sorex araneus, 59 S. minutus, 27 S. coronatus, and one S. alpinus were collected in Germany, the Czech Republic, and Slovakia. Screening by hantavirus-specific L-segment RT-PCR revealed specific amplification products in tissues of 49 out of 353 S. araneus and four out of 59 S. minutus. S-segment sequences were obtained for 45 of the L-segment positive S. araneus and all four L-segment positive S. minutus. Phylogenetic investigation of these sequences from Germany, the Czech Republic, and Slovakia demonstrated their similarity to SWSV sequences from Hungary, Finland, Austria, and other sites in Germany. The low intra-cluster sequence variability and the high inter-cluster divergence suggest a long-term SWSV evolution in isolated Sorex populations. In 28 of the 49 SWSV S-segment sequences, an additional putative open reading frame (ORF) on the opposite strand to the nucleocapsid protein-encoding ORF was identified. This is the first comprehensive sequence analysis of SWSV strains from Germany, the Czech Republic, and Slovakia, indicating its broad geographical distribution and high genetic divergence. Future studies have to prove whether both S. araneus and S. minutus represent SWSV reservoir hosts or spillover infections are responsible for the parallel molecular detection of SWSV in both species. PMID:22467179

Schlegel, Mathias; Radosa, Lukáš; Rosenfeld, Ulrike M; Schmidt, Sabrina; Triebenbacher, Cornelia; Löhr, Paul-Walter; Fuchs, Dieter; Heroldová, Marta; Jánová, Eva; Stanko, Michal; Mošanský, Ladislav; Fri?ová, Jana; Pej?och, Milan; Suchomel, Josef; Purchart, Luboš; Groschup, Martin H; Krüger, Detlev H; Klempa, Boris; Ulrich, Rainer G

2012-08-01

239

Gene expression signatures in tree shrew choroid in response to three myopiagenic conditions.  

PubMed

We examined gene expression in tree shrew choroid in response to three different myopiagenic conditions: minus lens (ML) wear, form deprivation (FD), and continuous darkness (DK). Four groups of tree shrews (n=7 per group) were used. Starting 24 days after normal eye opening (days of visual experience [DVE]), the ML group wore a monocular -5D lens for 2 days. The FD group wore a monocular translucent diffuser for 2 days. The DK group experienced continuous darkness binocularly for 11 days, starting at 17 DVE. An age-matched normal group was examined at 26 DVE. Quantitative PCR was used to measure the relative (treated eye vs. control eye) differences in mRNA levels in the choroid for 77 candidate genes. Small myopic changes were observed in the treated eyes (relative to the control eyes) of the ML group (-1.0±0.2D; mean±SEM) and FD group (-1.9±0.2D). A larger myopia developed in the DK group (-4.4±1.0D) relative to Normal eyes (both groups, mean of right and left eyes). In the ML group, 28 genes showed significant differential mRNA expression; eighteen were down-regulated. A very similar pattern occurred in the FD group; twenty-seven of the same genes were similarly regulated, along with five additional genes. Fewer expression differences in the DK group were significant compared to normal or the control eyes of the ML and FD groups, but the pattern was similar to that of the ML and FD differential expression patterns. These data suggest that, at the level of the choroid, the gene expression signatures produced by "GO" emmetropization signals are highly similar despite the different visual conditions. PMID:25072854

He, Li; Frost, Michael R; Siegwart, John T; Norton, Thomas T

2014-09-01

240

A novel set of microsatellite marker loci linkage-mapped in the house musk shrew, Suncus murinus.  

PubMed

Ten microsatellite DNA loci developed for the white-toothed shrew (Crocidura russula) were tested for PCR amplification and for utility in linkage studies in the house musk shrew, Suncus murinus. Four primer pairs successfully yielded PCR amplicons and showed polymorphism between two mutant strains, BAN-kc,oeb and WZ. Cloning and sequencing of the PCR amplicons of all the four loci confirmed the presence of microsatellite sequences. Alleles segregating in an F2 resource population constructed from the two strains ranged between two and five. Linkage analysis of the four loci together with 18 other polymorphic markers and three mutant loci resulted in five linkage groups containing three newly mapped microsatellite loci. This study reports the first microsatellite markers being registered in this species. PMID:17283891

Adjei, Samuel; Ishikawa, Akira

2007-01-01

241

Discovery of natural infection by Metagonimus hakubaensis Shimazu, 1999 (Trematoda: Heterophyidae) in Japanese water shrews (Chimarrogale platycephala) in Japan.  

PubMed

A total of 611 preserved adult Metagonimus spp. specimens recovered from 32 of 53 Japanese water shrews (Chimarrogale platycephala) that had previously been collected in Aomori Prefecture between June 1994 and August 1996, were examined in this study. Morphological examination revealed that 603 of these flukes were identical to M. hakubaensis Shimazu, 1999, and that the others were M. takahashii Suzuki, 1930 (n=4), M. otsurui Saito et Shimizu, 1968 (n=2), and M. miyatai Saito et al., 1997 (n=2). Each of the 32 Japanese water shrews infected with M. hakubaensis contained between 1 and 83 flukes. This is the first record of the natural final host for M. hakubaensis, since this fluke species was described. PMID:25131808

Kudo, Noboru; Shigeta, Kai; Matsumoto, Koji; Oyamada, Takashi

2014-11-01

242

Discovery of Natural Infection by Metagonimus hakubaensis Shimazu, 1999 (Trematoda: Heterophyidae) in Japanese Water Shrews (Chimarrogale platycephala) in Japan  

PubMed Central

ABSTRACT ABSTRACT. A total of 611 preserved adult Metagonimus spp. specimens recovered from 32 of 53 Japanese water shrews (Chimarrogale platycephala) that had previously been collected in Aomori Prefecture between June 1994 and August 1996, were examined in this study. Morphological examination revealed that 603 of these flukes were identical to M. hakubaensis Shimazu, 1999, and that the others were M. takahashii Suzuki, 1930 (n=4), M. otsurui Saito et Shimizu, 1968 (n=2), and M. miyatai Saito et al., 1997 (n=2). Each of the 32 Japanese water shrews infected with M. hakubaensis contained between 1 and 83 flukes. This is the first record of the natural final host for M. hakubaensis, since this fluke species was described. PMID:25131808

KUDO, Noboru; SHIGETA, Kai; MATSUMOTO, Koji; OYAMADA, Takashi

2014-01-01

243

Delineation of vagal emetic pathways: intragastric copper sulfate-induced emesis and viral tract tracing in musk shrews  

PubMed Central

Signals from the vestibular system, area postrema, and forebrain elicit nausea and vomiting, but gastrointestinal (GI) vagal afferent input arguably plays the most prominent role in defense against food poisoning. It is difficult to determine the contribution of GI vagal afferent input on emesis because various agents (e.g., chemotherapy) often act on multiple sensory pathways. Intragastric copper sulfate (CuSO4) potentially provides a specific vagal emetic stimulus, but its actions are not well defined in musk shrews (Suncus murinus), a primary small animal model used to study emesis. The aims of the current study were 1) to investigate the effects of subdiaphragmatic vagotomy on CuSO4-induced emesis and 2) to conduct preliminary transneuronal tracing of the GI-brain pathways in musk shrews. Vagotomy failed to inhibit the number of emetic episodes produced by optimal emetic doses of CuSO4 (60 and 120 mg/kg ig), but the effects of lower doses were dependent on an intact vagus (20 and 40 mg/kg). Vagotomy also failed to affect emesis produced by motion (1 Hz, 10 min) or nicotine administration (5 mg/kg sc). Anterograde transport of the H129 strain of herpes simplex virus-1 from the ventral stomach wall identified the following brain regions as receiving inputs from vagal afferents: the nucleus of the solitary tract, area postrema, and lateral parabrachial nucleus. These data indicate that the contribution of vagal pathways to intragastric CuSO4-induced emesis is dose dependent in musk shrews. Furthermore, the current neural tracing data suggest brain stem anatomical circuits that are activated by GI signaling in the musk shrew. PMID:24430885

Meyers, Kelly; Lim, Audrey; Dye, Matthew; Pak, Diana; Rinaman, Linda; Yates, Bill J.

2014-01-01

244

Shrew species diversity and abundance in Ziama Biosphere Reserve, Guinea: comparison among primary forest, degraded forest and restoration plots  

Microsoft Academic Search

The aim of our study was to compare the shrew community diversity and structure in gradients of tropical forest degradation\\u000a and restoration. Four plots within each of six habitats of the Ziama Biosphere Reserve were surveyed, including primary forest,\\u000a secondary forest, cultivated fields, recently (less than 3 years) abandoned fields, young (10–12 years) forest restoration\\u000a plots, and old (34 years) restoration plots. From

Violaine Nicolas; Patrick Barrière; Audrey Tapiero; Marc Colyn

2009-01-01

245

Delineation of vagal emetic pathways: intragastric copper sulfate-induced emesis and viral tract tracing in musk shrews.  

PubMed

Signals from the vestibular system, area postrema, and forebrain elicit nausea and vomiting, but gastrointestinal (GI) vagal afferent input arguably plays the most prominent role in defense against food poisoning. It is difficult to determine the contribution of GI vagal afferent input on emesis because various agents (e.g., chemotherapy) often act on multiple sensory pathways. Intragastric copper sulfate (CuSO4) potentially provides a specific vagal emetic stimulus, but its actions are not well defined in musk shrews (Suncus murinus), a primary small animal model used to study emesis. The aims of the current study were 1) to investigate the effects of subdiaphragmatic vagotomy on CuSO4-induced emesis and 2) to conduct preliminary transneuronal tracing of the GI-brain pathways in musk shrews. Vagotomy failed to inhibit the number of emetic episodes produced by optimal emetic doses of CuSO4 (60 and 120 mg/kg ig), but the effects of lower doses were dependent on an intact vagus (20 and 40 mg/kg). Vagotomy also failed to affect emesis produced by motion (1 Hz, 10 min) or nicotine administration (5 mg/kg sc). Anterograde transport of the H129 strain of herpes simplex virus-1 from the ventral stomach wall identified the following brain regions as receiving inputs from vagal afferents: the nucleus of the solitary tract, area postrema, and lateral parabrachial nucleus. These data indicate that the contribution of vagal pathways to intragastric CuSO4-induced emesis is dose dependent in musk shrews. Furthermore, the current neural tracing data suggest brain stem anatomical circuits that are activated by GI signaling in the musk shrew. PMID:24430885

Horn, Charles C; Meyers, Kelly; Lim, Audrey; Dye, Matthew; Pak, Diana; Rinaman, Linda; Yates, Bill J

2014-03-01

246

Novel sperm crypts and behavior of gametes in the fallopian tube of the white-toothed shrew, Crocidura russula monacha.  

PubMed

The gametes of an insectivore, the white-toothed shrew, Crocidura russula monacha, present certain idiosyncratic features not seen in most other eutherian mammals. The spermatozoa display an acrosome of giant proportions, and are produced in relatively small numbers. In trans-illuminated oviducts examined with DIC optics, spermatozoa were first sequestered in languid clutches within the isthmus in deep narrow crypts, with some eventually ingested by the crypt epithelium. Then, at ovulation (ca. 15 hr after hCG), many ascended to occupy "bubble-like" ciliated crypts distributed randomly within the ampulla, as active groups of acrosome-intact spermatozoa. However, eggs (3.95; range 2-6) were first retained for several hours and were fertilized in an upper crypt-free infundibulum before moving down to the ampulla. At fertilization, individual spermatozoa penetrate an unusually compact matrix-free cumulus oophorus which is stabilized by intercellular junctions, is insensitive to hyaluronidase, and persists for approximately 13 hr around fertilized and for approximately 24 hr around unfertilized eggs. In contrast to the free ampullary spermatozoa, active spermatozoa accumulating within the cumulus all had shed the acrosome, an observation consistent with evidence from other shrews suggesting that the cumulus may necessarily induce the acrosome reaction in this ancient line. Hypertrophy of the acrosome, isthmic sperm storage crypts, and stable cumulus oophorus that develops a peri-zona space, all may prove to be typically crocidurine characteristics of use where the classification of a shrew is in doubt. PMID:9063000

Bedford, J M; Phillips, D M; Mover-Lev, H

1997-02-15

247

A skull of Machairodus giganteus (Felidae, Mammalia) from the Late Miocene of Turkey Denis GERAADS -UPR 2147 CNRS, 44 rue de l'Amiral Mouchez, 75014 PARIS, France  

E-print Network

A skull of Machairodus giganteus (Felidae, Mammalia) from the Late Miocene of Turkey Denis GERAADS, Late Miocene, Turkey, phylogeny, cladistics. Abstract: A skull and associated mandible from the upper) is a fragment of skull with incomplete mandible, that BONIS referred to Machairodus aphanistus, but the genus

Boyer, Edmond

248

Vol. 32, no. 1, pp. 1-14 December 15, 2008 NEW PRIMATES (MAMMALIA) FROM THE EARLY AND MIDDLE EOCENE OF  

E-print Network

Vol. 32, no. 1, pp. 1-14 December 15, 2008 NEW PRIMATES (MAMMALIA) FROM THE EARLY AND MIDDLE EOCENE Eocene primates, including three new adapiforms and one new omomyiform, are described from the Ghazij and Kuldana formations of northwestern Pakistan. These are among the oldest primates known from the Indo

Licciardi, Joseph M.

249

Phylogeny of the Procyonidae (Mammalia: Carnivora): molecules, morphology and the Great American Interchange.  

PubMed

The Procyonidae (Mammalia: Carnivora) have played a central role in resolving the controversial systematics of the giant and red pandas, but phylogenetic relationships of species within the family itself have received much less attention. Cladistic analyses of morphological characters conducted during the last two decades have resulted in topologies that group ecologically and morphologically similar taxa together. Specifically, the highly arboreal and frugivorous kinkajou (Potos flavus) and olingos (Bassaricyon) define one clade, whereas the more terrestrial and omnivorous coatis (Nasua), raccoons (Procyon), and ringtails (Bassariscus) define another clade, with the similar-sized Nasua and Procyon joined as sister taxa in this latter group. These relationships, however, have not been tested with molecular sequence data. We examined procyonid phylogenetics based on combined data from nine nuclear and two mitochondrial gene segments totaling 6534bp. We were able to fully resolve relationships within the family with strongly supported and congruent results from maximum parsimony, maximum likelihood, minimum evolution, and Bayesian analyses. We identified three distinct lineages within the family: a (Nasua, Bassaricyon) clade, a (Bassariscus, Procyon) clade, and a Potos lineage, the last of which is sister to the other two clades. These findings, which are in strong disagreement with prior fossil and morphology-based assessments of procyonid relationships, reemphasize the morphological and ecological flexibility of these taxa. In particular, morphological similarities between unrelated genera possibly reflect convergence associated with similar lifestyles and diets rather than ancestry. Furthermore, incongruence between the molecular supermatrix and a morphological character matrix comprised mostly of dental characters [Baskin, J.A., 2004. Bassariscus and Probassariscus (Mammalia, Carnivora, Procyonidae) from the early Barstovian (Middle Miocene). J. Vert. Paleo. 24, 709-720] may be due to non-independence among atomized dental characters that does not take into account the high developmental genetic correlation of these characters. Finally, molecular divergence dating analyses using a relaxed molecular clock approach suggest that intergeneric and intrageneric splits in the Procyonidae mostly occurred in the Miocene. The inferred divergence times for intrageneric splits for several genera whose ranges are bisected by the Panamanian Isthmus is significant because they suggest diversification well precedes the Great American Interchange, which has long been considered a primary underlying mechanism for procyonid evolution. PMID:17174109

Koepfli, Klaus-Peter; Gompper, Matthew E; Eizirik, Eduardo; Ho, Cheuk-Chung; Linden, Leif; Maldonado, Jesus E; Wayne, Robert K

2007-06-01

250

Species of coccidia (Apicomplexa: Eimeriidae) in shrews from Alaska, U.S.A., and northeastern Siberia, Russia, with description of two new species.  

PubMed

Fecal samples (n = 636) from 10 species of shrews collected in Alaska (n = 540) and northeastern Siberia (n = 96) were examined for the presence of coccidia (Apicomplexa: Eimeriidae). Five distinct oocyst morphotypes were observed. Three types were consistent with oocysts of previously recognized coccidia species from other shrew hosts. These were Eimeria inyoni, E. vagrantis, and Isospora brevicauda, originally described from the inyo shrew (Sorex tenellus), dusky shrew (S. monticolus), and northern short-tailed shrew (Blarina brevicauda), respectively. We found 5 new host records for E. inyoni, 3 for E. vagrantis, and 3 for I. brevicauda. The 2 additional oocyst morphotypes, both from the tundra shrew (Sorex tundrensis), are putative new species. Sporulated oocysts of Eimeria beringiacea n. sp. are subspheroidal, 17.7 x 15.6 microm (14-24 x 13-20 microm) with a length (L)/width (W) ratio of 1.1 (1.0-1.4); these lack a micropyle (M), an oocyst residuum (OR), and a polar granule (PG). Sporocysts are ellipsoidal, 10.3 x 6.1 microm (7-14 x 4-8 microm), with a L/W ratio of 1.7 (1.3-2.3) and have a Stieda body (SB), Substieda body (SSB), and sporocyst residuum (SR). Oocysts of Eimeria tundraensis n. sp. are spheroidal to subspheroidal, 24.8 x 23.5 microm (23-26 x 22-25 microm), with a L/W ratio of 1.1 (1.0-1.2); these lack a M and OR, but a single PG is present. Sporocysts are elongate ellipsoidal, 15.4 x 8.3 microm (13-17 x 7-9 microm), with a L/W ratio of 1.9 (1.4-2.1) and have a SB, SSB, and SR. PMID:18576829

Lynch, A J; Duszynski, D W

2008-08-01

251

Affinities of `hyopsodontids' to elephant shrews and a Holarctic origin of Afrotheria  

NASA Astrophysics Data System (ADS)

Macroscelideans (elephant shrews or sengis) are small-bodied (25-540g), cursorial (running) and saltatorial (jumping), insectivorous and omnivorous placental mammals represented by at least 15 extant African species classified in four genera. Macroscelidea is one of several morphologically diverse but predominantly African placental orders classified in the superorder Afrotheria by molecular phylogeneticists. The distribution of modern afrotheres, in combination with a basal position for Afrotheria within Placentalia and molecular divergence-time estimates, has been used to link placental diversification with the mid-Cretaceous separation of South America and Africa. Morphological phylogenetic analyses do not support Afrotheria and the fossil record favours a northern origin of Placentalia. Here we describe fossil postcrania that provide evidence for a close relationship between North American Palaeocene-Eocene apheliscine `hyopsodontid' `condylarths' (early ungulates or hoofed mammals) and extant Macroscelidea. Apheliscine postcranial morphology is consistent with a relationship to other ungulate-like afrotheres (Hyracoidea, Proboscidea) but does not provide support for a monophyletic Afrotheria. As the oldest record of an afrothere clade, identification of macroscelidean relatives in the North American Palaeocene argues against an African origin for Afrotheria, weakening support for linking placental diversification to the break-up of Gondwana.

Zack, Shawn P.; Penkrot, Tonya A.; Bloch, Jonathan I.; Rose, Kenneth D.

2005-03-01

252

Convergent evolution of novel protein function in shrew and lizard venom.  

PubMed

How do proteins evolve novel functions? To address this question, we are studying the evolution of a mammalian toxin, the serine protease BLTX [1], from the salivary glands of the North American shrew Blarina brevicauda. Here, we examine the molecular changes responsible for promoting BLTX toxicity. First, we show that regulatory loops surrounding the BLTX active site have evolved adaptively via acquisition of small insertions and subsequent accelerated sequence evolution. Second, these mutations introduce a novel chemical environment into the catalytic cleft of BLTX. Third, molecular-dynamic simulations show that the observed changes create a novel chemical and physical topology consistent with increased enzyme catalysis. Finally, we show that a toxic serine protease from the Mexican beaded lizard (GTX) [2] has evolved convergently through almost identical functional changes. Together, these results suggest that the evolution of toxicity might be predictable-arising via adaptive structural modification of analogous labile regulatory loops of an ancestral serine protease-and thus might aid in the identification of other toxic proteins. PMID:19879144

Aminetzach, Yael T; Srouji, John R; Kong, Chung Yin; Hoekstra, Hopi E

2009-12-01

253

RADIATION ECOLOGY ISSUES ASSOCIATED WITH MURINE RODENTS AND SHREWS IN THE CHERNOBYL EXCLUSION ZONE  

SciTech Connect

This article describes major studies performed by the Chernobyl Center's International Radioecology Laboratory (Slavutich, Ukraine) on radioecology of murine rodents and shrews inhabiting the Chernobyl Exclusion Zone. The article addresses the long-term (1986-2005) and seasonal dynamics of radioactive contamination of animals, and reviews interspecies differences in radionuclide accumulations and factors affecting the radionuclide accumulations. It is shown that bioavailability of radionuclides in the 'soil-to-plant' chain and a trophic specialization of animals play key roles in determining their actual contamination levels. The total absorbed dose rates in small mammals significantly reduced during the years following the Chernobyl Nuclear Power Plant accident. In 1986, the absorbed dose rate reached 1.3-6.0 Gy hr{sup -1} in the central areas of the Chernobyl Exclusion Zone (the 'Red Forest'). In 1988 and 1990, the total absorbed dose rates were 1.3 and 0.42 Gy hr{sup -1}, respectively. In 1995, 2000, and 2005, according to the present study, the total absorbed dose rates rarely exceeded 0.00023, 0.00018, and 0.00015 Gy hr{sup -1}, respectively. Contributions of individual radiation sources into the total absorbed dose are described.

Farfan, E.; Jannik, T.

2011-10-01

254

Habitat-quality effects on metapopulation dynamics in greater white-toothed shrews, Crocidura russula.  

PubMed

The effects of patch size and isolation on metapopulation dynamics have received wide empirical support and theoretical formalization. By contrast, the effects of patch quality seem largely underinvestigated, partly due to technical difficulties in properly assessing quality. Here we combine habitat-quality modeling with four years of demographic monitoring in a metapopulation of greater white-toothed shrews (Crocidura russula) to investigate the role of patch quality on metapopulation processes. Together, local patch quality and connectivity significantly enhanced local population sizes and occupancy rates (R2 = 14% and 19%, respectively). Accounting for the quality of patches connected to the focal one and acting as potential sources improved slightly the model explanatory power for local population sizes, pointing to significant source-sink dynamics. Local habitat quality, in interaction with connectivity, also increased colonization rate (R2 = 28%), suggesting the ability of immigrants to target high-quality patches. Overall, patterns were best explained when assuming a mean dispersal distance of 800 m, a realistic value for the species under study. Our results thus provide evidence that patch quality, in interaction with connectivity, may affect major demographic processes. PMID:18959315

Jaquiéry, J; Guélat, J; Broquet, T; Berset-Brändli, L; Pellegrini, E; Moresi, R; Hirzel, A H; Perrin, N

2008-10-01

255

Disentangling Reasons for Low Y Chromosome Variation in the Greater White-Toothed Shrew (Crocidura russula)  

PubMed Central

Y chromosome variation is determined by several confounding factors including mutation rate, effective population size, demography, and selection. Disentangling these factors is essential to better understand the evolutionary properties of the Y chromosome. We analyzed genetic variation on the Y chromosome, X chromosome, and mtDNA of the greater white-toothed shrew, a species with low variance in male reproductive success and limited sex-biased dispersal, which enables us to control to some extent for life-history effects. We also compared ancestral (Moroccan) to derived (European) populations to investigate the role of demographic history in determining Y variation. Recent colonization of Europe by a small number of founders (combined with low mutation rates) is largely responsible for low diversity observed on the European Y and X chromosomes compared to mtDNA. After accounting for mutation rate, copy number, and demography, the Y chromosome still displays a deficit in variation relative to the X in both populations. This is possibly influenced by directional selection, but the slightly higher variance in male reproductive success is also likely to play a role, even though the difference is small compared to that in highly polygynous species. This study illustrates that demography and life-history effects should be scrutinized before inferring strong selective pressure as a reason for low diversity on the Y chromosome. PMID:16582448

Lawson Handley, Lori J.; Berset-Brändli, Laura; Perrin, Nicolas

2006-01-01

256

Disentangling reasons for low Y chromosome variation in the greater white-toothed shrew (Crocidura russula).  

PubMed

Y chromosome variation is determined by several confounding factors including mutation rate, effective population size, demography, and selection. Disentangling these factors is essential to better understand the evolutionary properties of the Y chromosome. We analyzed genetic variation on the Y chromosome, X chromosome, and mtDNA of the greater white-toothed shrew, a species with low variance in male reproductive success and limited sex-biased dispersal, which enables us to control to some extent for life-history effects. We also compared ancestral (Moroccan) to derived (European) populations to investigate the role of demographic history in determining Y variation. Recent colonization of Europe by a small number of founders (combined with low mutation rates) is largely responsible for low diversity observed on the European Y and X chromosomes compared to mtDNA. After accounting for mutation rate, copy number, and demography, the Y chromosome still displays a deficit in variation relative to the X in both populations. This is possibly influenced by directional selection, but the slightly higher variance in male reproductive success is also likely to play a role, even though the difference is small compared to that in highly polygynous species. This study illustrates that demography and life-history effects should be scrutinized before inferring strong selective pressure as a reason for low diversity on the Y chromosome. PMID:16582448

Handley, Lori J Lawson; Berset-Brändli, Laura; Perrin, Nicolas

2006-06-01

257

Regulation of longitudinal esophageal motility in the house musk shrew (Suncus murinus).  

PubMed

Suncus murinus (house musk shrew; suncus) is a species of insectivore that has an ability to vomit. Although longitudinal movement of the esophagus would be related to the emetic response, regulatory mechanisms for the suncus esophageal motility are unclear. Therefore, the aim of the present study was to clarify components that regulate esophageal motility in the suncus. An isolated segment of the suncus esophagus was placed in an organ bath, and longitudinal mechanical responses were recorded using a force transducer. Electrical stimulation of the vagus trunk evoked a biphasic contractile response. The first phase of the contractile response was blocked by ?-bungarotoxin, a blocker of nicotinic acetylcholine receptors on striated muscle cells, whereas the second one was blocked by atropine, a blocker of muscarinic acetylcholine receptors on smooth muscle cells. Next, we investigated whether mast cells are involved in motor functions of the suncus esophagus. Application of a mast cell stimulator, compound 48/80, elicited contractile responses, which was resistant to tetrodotoxin. Exogenous application of serotonin and histamine induced contractile responses. The mast cell activation-mediated contraction was abolished by double desensitization by serotonin and histamine and pre-treatment with indomethacin, a cyclooxygenase inhibitor. The findings show that cholinergic and non-cholinergic transmitters induce longitudinal contraction in the suncus esophagus, which might contribute to esophageal shortening during emesis. Cholinergic transmitters are derived from vagal efferents, and non-cholinergic transmitters, which are thought to be serotonin, histamine and prostaglandins, are released from mast cells. PMID:25694232

Shiina, Takahiko; Naitou, Kiyotada; Nakamori, Hiroyuki; Sakai, Hiroki; Shimizu, Yasutake

2015-05-01

258

Restricted gene flow at specific parts of the shrew genome in chromosomal hybrid zones.  

PubMed

The species and races of the shrews of the Sorex araneus group exhibit a broad range of chromosomal polymorphisms. European taxa of this group are parapatric and form contact or hybrid zones that span an extraordinary variety of situations, ranging from absolute genetic isolation to almost free gene flow. This variety seems to depend for a large part on the chromosome composition of populations, which are primarily differentiated by various Robertsonian fusions of a subset of acrocentric chromosomes. Previous studies suggested that chromosomal rearrangements play a causative role in the speciation process. In such models, gene flow should be more restricted for markers on chromosomes involved in rearrangements than on chromosomes common in both parent species. In the present study, we address the possibility of such differential gene flow in the context of two genetically very similar but karyotypically different hybrid zones between species of the S. araneus group using microsatellite loci mapped to the chromosome arm level. Interspecific genetic structure across rearranged chromosomes was in general larger than across common chromosomes. However, the difference between the two classes of chromosomes was only significant in the hybrid zone where the complexity of hybrids is expected to be larger. These differences did not distinguish populations within species. Therefore, the rearranged chromosomes appear to affect the reproductive barrier between karyotypic species, although the strength of this effect depends on the complexity of the hybrids produced. PMID:17017071

Basset, Patrick; Yannic, Glenn; Brünner, Harald; Hausser, Jacques

2006-08-01

259

A climate for speciation: rapid spatial diversification within the Sorex cinereus complex of shrews  

USGS Publications Warehouse

The cyclic climate regime of the late Quaternary caused dramatic environmental change at high latitudes. Although these events may have been brief in periodicity from an evolutionary standpoint, multiple episodes of allopatry and divergence have been implicated in rapid radiations of a number of organisms. Shrews of the Sorex cinereus complex have long challenged taxonomists due to similar morphology and parapatric geographic ranges. Here, multi-locus phylogenetic and demographic assessments using a coalescent framework were combined to investigate spatiotemporal evolution of 13 nominal species with a widespread distribution throughout North America and across Beringia into Siberia. For these species, we first test a hypothesis of recent differentiation in response to Pleistocene climate versus more ancient divergence that would coincide with pre-Pleistocene perturbations. We then investigate the processes driving diversification over multiple continents. Our genetic analyses highlight novel diversity within these morphologically conserved mammals and clarify relationships between geographic distribution and evolutionary history. Demography within and among species indicates both regional stability and rapid expansion. Ancestral ecological differentiation coincident with early cladogenesis within the complex enabled alternating and repeated episodes of allopatry and expansion where successive glacial and interglacial phases each promoted divergence. The Sorex cinereus complex constitutes a valuable model for future comparative assessments of evolution in response to cyclic environmental change.

Hope, Andrew G.; Speer, Kelly A.; Demboski, John R.; Talbot, Sandra L.; Cook, Joseph A.

2012-01-01

260

Radiation ecology issues associated with murine rodents and shrews in the Chernobyl exclusion zone.  

PubMed

This article describes major studies performed by the Chernobyl Center's International Radioecology Laboratory (Slavutich, Ukraine) on radioecology of murine rodents and shrews inhabiting the Chernobyl Exclusion Zone. The article addresses the long-term (1986-2005) and seasonal dynamics of radioactive contamination of animals and reviews interspecies differences in radionuclide accumulations and factors affecting the radionuclide accumulations. It is shown that bioavailability of radionuclides in the "soil-to-plant" chain and a trophic specialization of animals play key roles in determining their actual contamination levels. The total absorbed dose rates in small mammals significantly reduced during the years following the Chernobyl Nuclear Power Plant accident. In 1986, the absorbed dose rate reached 1.3-6.0 Gy h(-1) in the central areas of the Chernobyl Exclusion Zone (the "Red Forest"). In 1988 and 1990, the total absorbed dose rates were 1.3 and 0.42 Gy h(-1), respectively. In 1995, 2000, and 2005, according to the present study, the total absorbed dose rates rarely exceeded 0.00023, 0.00018, and 0.00015 Gy h(-1), respectively. Contributions of individual radiation sources into the total absorbed dose are described. PMID:21878767

Gaschak, Sergey P; Maklyuk, Yulia A; Maksimenko, Andrey M; Bondarkov, Mikhail D; Jannik, G Timothy; Farfán, Eduardo B

2011-10-01

261

Invading and Expanding: Range Dynamics and Ecological Consequences of the Greater White-Toothed Shrew (Crocidura russula) Invasion in Ireland  

PubMed Central

Establishing how invasive species impact upon pre-existing species is a fundamental question in ecology and conservation biology. The greater white-toothed shrew (Crocidura russula) is an invasive species in Ireland that was first recorded in 2007 and which, according to initial data, may be limiting the abundance/distribution of the pygmy shrew (Sorex minutus), previously Ireland's only shrew species. Because of these concerns, we undertook an intensive live-trapping survey (and used other data from live-trapping, sightings and bird of prey pellets/nest inspections collected between 2006 and 2013) to model the distribution and expansion of C. russula in Ireland and its impacts on Ireland's small mammal community. The main distribution range of C. russula was found to be approximately 7,600 km2 in 2013, with established outlier populations suggesting that the species is dispersing with human assistance within the island. The species is expanding rapidly for a small mammal, with a radial expansion rate of 5.5 km/yr overall (2008–2013), and independent estimates from live-trapping in 2012–2013 showing rates of 2.4–14.1 km/yr, 0.5–7.1 km/yr and 0–5.6 km/yr depending on the landscape features present. S. minutus is negatively associated with C. russula. S. minutus is completely absent at sites where C. russula is established and is only present at sites at the edge of and beyond the invasion range of C. russula. The speed of this invasion and the homogenous nature of the Irish landscape may mean that S. minutus has not had sufficient time to adapt to the sudden appearance of C. russula. This may mean the continued decline/disappearance of S. minutus as C. russula spreads throughout the island. PMID:24955824

McDevitt, Allan D.; Montgomery, W. Ian; Tosh, David G.; Lusby, John; Reid, Neil; White, Thomas A.; McDevitt, C. Damien; O'Halloran, John; Searle, Jeremy B.; Yearsley, Jon M.

2014-01-01

262

Invading and expanding: range dynamics and ecological consequences of the greater white-toothed shrew (Crocidura russula) invasion in Ireland.  

PubMed

Establishing how invasive species impact upon pre-existing species is a fundamental question in ecology and conservation biology. The greater white-toothed shrew (Crocidura russula) is an invasive species in Ireland that was first recorded in 2007 and which, according to initial data, may be limiting the abundance/distribution of the pygmy shrew (Sorex minutus), previously Ireland's only shrew species. Because of these concerns, we undertook an intensive live-trapping survey (and used other data from live-trapping, sightings and bird of prey pellets/nest inspections collected between 2006 and 2013) to model the distribution and expansion of C. russula in Ireland and its impacts on Ireland's small mammal community. The main distribution range of C. russula was found to be approximately 7,600 km2 in 2013, with established outlier populations suggesting that the species is dispersing with human assistance within the island. The species is expanding rapidly for a small mammal, with a radial expansion rate of 5.5 km/yr overall (2008-2013), and independent estimates from live-trapping in 2012-2013 showing rates of 2.4-14.1 km/yr, 0.5-7.1 km/yr and 0-5.6 km/yr depending on the landscape features present. S. minutus is negatively associated with C. russula. S. minutus is completely absent at sites where C. russula is established and is only present at sites at the edge of and beyond the invasion range of C. russula. The speed of this invasion and the homogenous nature of the Irish landscape may mean that S. minutus has not had sufficient time to adapt to the sudden appearance of C. russula. This may mean the continued decline/disappearance of S. minutus as C. russula spreads throughout the island. PMID:24955824

McDevitt, Allan D; Montgomery, W Ian; Tosh, David G; Lusby, John; Reid, Neil; White, Thomas A; McDevitt, C Damien; O'Halloran, John; Searle, Jeremy B; Yearsley, Jon M

2014-01-01

263

Gene expression signatures in tree shrew choroid during lens-induced myopia and recovery.  

PubMed

Gene expression in tree shrew choroid was examined during the development of minus-lens induced myopia (LIM, a GO condition), after completion of minus-lens compensation (a STAY condition), and early in recovery (REC) from induced myopia (a STOP condition). Five groups of tree shrews (n = 7 per group) were used. Starting 24 days after normal eye-opening (days of visual experience [DVE]), one minus-lens group wore a monocular -5 D lens for 2 days (LIM-2), another minus-lens group achieved stable lens compensation while wearing a monocular -5 D lens for 11 days (LIM-11); a recovery group also wore a -5 D lens for 11 days and then received 2 days of recovery starting at 35 DVE (REC-2). Two age-matched normal groups were examined at 26 DVE and 37 DVE. Quantitative PCR was used to measure the relative differences in mRNA levels in the choroid for 77 candidate genes that were selected based on previous studies or because a whole-transcriptome analysis suggested their expression would change during myopia development or recovery. Small myopic changes were observed in the treated eyes of the LIM-2 group (-1.0 ± 0.2 D; mean ± SEM) indicating eyes were early in the process of developing LIM. The LIM-11 group exhibited complete refractive compensation (-5.1 ± 0.2 D) that was stable for five days. The REC-2 group recovered by 1.3 ± 0.3 D from full refractive compensation. Sixty genes showed significant mRNA expression differences during normal development, LIM, or REC conditions. In LIM-2 choroid (GO), 18 genes were significantly down-regulated in the treated eyes relative to the fellow control eyes and 10 genes were significantly up-regulated. In LIM-11 choroid (STAY), 10 genes were significantly down-regulated and 12 genes were significantly up-regulated. Expression patterns in GO and STAY were similar, but not identical. All genes that showed differential expression in GO and STAY were regulated in the same direction in both conditions. In REC-2 choroid (STOP), 4 genes were significantly down-regulated and 18 genes were significantly up-regulated. Thirteen genes showed bi-directional regulation in GO vs. STOP. The pattern of differential gene expression in STOP was very different from that in GO or in STAY. Significant regulation was observed in genes involved in signaling as well as extracellular matrix turnover. These data support an active role for the choroid in the signaling cascade from retina to sclera. Distinctly different treated eye vs. control eye mRNA signatures are present in the choroid in the GO, STAY, and STOP conditions. The STAY signature, present after full compensation has occurred and the GO visual stimulus is no longer present, may participate in maintaining an elongated globe. The 13 genes with bi-directional expression differences in GO and STOP responded in a sign of defocus-dependent manner. Taken together, these data further suggest that a network of choroidal gene expression changes generate the signal that alters scleral fibroblast gene expression and axial elongation rate. PMID:24742494

He, Li; Frost, Michael R; Siegwart, John T; Norton, Thomas T

2014-06-01

264

Comparative morphology and morphometry of the nasal fossae of four species of North American shrews (Soricinae).  

PubMed

The present study compares the morphology of the nasal conchae and the relative development (i.e., surface area and neurosensory cell number) of the olfactory epithelium between four species of shrews occupying different ecotopes (Blarina brevicauda, Sorex cinereus, S. fumeus, S. palustris). The number of olfactory cells was corrected for split cell error. Data were analyzed by using size indices based on the allometric method. The convoluted shape of the maxilloturbinal in Blarina, with large respiratory epithelial surface area, could not be related with certainty to the subterranean ecotope. From the comparison between Soricinae and Crocidurinae, one major difference concerned the shape and attachment of ectoturbinal 3. Differences in the relative development of the olfactory organ are discussed with regard to differences in the use of chemical signals. The semi-fossorial B. brevicauda, with the more developed olfactory organ, is reported to possess more scent-glands and to manifest active scent-marking behaviors and fecal deposits associated with territoriality. The two terrestrial species, S. cinereus and S. fumeus, have olfactory epithelia showing an intermediate development. Published accounts of fewer scent-glands and a lack of active scent-marking behavior indicate a lesser use of olfactory communication in these two species where mutual avoidance seems the rule. Indication of an even more reduced use of olfactory signals in social interactions by the semiaquatic S. palustris is suggested by its least-developed olfactory epithelium. The comparison between Soricinae and Crocidurinae supports a relationship between the development of the olfactory organ and the relative use of olfactory communication known to occur in social interactions. PMID:2618929

Larochelle, R; Baron, G

1989-11-01

265

Phenotypic Variation across Chromosomal Hybrid Zones of the Common Shrew (Sorex araneus) Indicates Reduced Gene Flow  

PubMed Central

Sorex araneus, the Common shrew, is a species with more than 70 karyotypic races, many of which form parapatric hybrid zones, making it a model for studying chromosomal speciation. Hybrids between races have reduced fitness, but microsatellite markers have demonstrated considerable gene flow between them, calling into question whether the chromosomal barriers actually do contribute to genetic divergence. We studied phenotypic clines across two hybrid zones with especially complex heterozygotes. Hybrids between the Novosibirsk and Tomsk races produce chains of nine and three chromosomes at meiosis, and hybrids between the Moscow and Seliger races produce chains of eleven. Our goal was to determine whether phenotypes show evidence of reduced gene flow at hybrid zones. We used maximum likelihood to fit tanh cline models to geometric shape data and found that phenotypic clines in skulls and mandibles across these zones had similar centers and widths as chromosomal clines. The amount of phenotypic differentiation across the zones is greater than expected if it were dissipating due to unrestricted gene flow given the amount of time since contact, but it is less than expected to have accumulated from drift during allopatric separation in glacial refugia. Only if heritability is very low, Ne very high, and the time spent in allopatry very short, will the differences we observe be large enough to match the expectation of drift. Our results therefore suggest that phenotypic differentiation has been lost through gene flow since post-glacial secondary contact, but not as quickly as would be expected if there was free gene flow across the hybrid zones. The chromosomal tension zones are confirmed to be partial barriers that prevent differentiated races from becoming phenotypically homogenous. PMID:23874420

Polly, P. David; Polyakov, Andrei V.; Ilyashenko, Vadim B.; Onischenko, Sergei S.; White, Thomas A.; Shchipanov, Nikolay A.; Bulatova, Nina S.; Pavlova, Svetlana V.; Borodin, Pavel M.; Searle, Jeremy B.

2013-01-01

266

Diffuse and specific tectopulvinar terminals in the tree shrew: synapses, synapsins, and synaptic potentials.  

PubMed

The pulvinar nucleus of the tree shrew receives both topographic (specific) and nontopographic (diffuse) projections from superior colliculus (SC), which form distinct synaptic arrangements. We characterized the physiological properties of these synapses and describe two distinct types of excitatory postsynaptic potentials (EPSPs) that correlate with structural properties of the specific and diffuse terminals. Synapses formed by specific terminals were found to be significantly longer than those formed by diffuse terminals. Stimulation of these two terminal types elicited two types of EPSPs that differed in their latency and threshold amplitudes. In addition, in response to repetitive stimulation (0.5-20 Hz) one type of EPSP displayed frequency-dependent depression whereas the amplitudes of the second type of EPSP were not changed by repetitive stimulation of up to 20 Hz. To relate these features to vesicle release, we compared the synapsin content of terminals in the pulvinar nucleus and the dorsal lateral geniculate (dLGN) by combining immunohistochemical staining for synapsin I or II with staining for the type 1 or type 2 vesicular glutamate transporters (markers for corticothalamic and tectothalamic/retinogeniculate terminals, respectively). We found that retinogeniculate terminals do not contain either synapsin I or synapsin II, corticothalamic terminals in the dLGN and pulvinar contain synapsin I, but not synapsin II, whereas tectopulvinar terminals contain both synapsin I and synapsin II. Finally, both types of EPSPs showed a graded increase in amplitude with increasing stimulation intensity, suggesting convergence; this was confirmed using a combination of anterograde tract tracing and immunocytochemistry. We suggest that the convergent synaptic arrangements, as well as the unique synapsin content of tectopulvinar terminals, allow them to relay a dynamic range of visual signals from the SC. PMID:21858222

Wei, Haiyang; Masterson, Sean P; Petry, Heywood M; Bickford, Martha E

2011-01-01

267

Behavioral Patterns Associated with Chemotherapy-Induced Emesis: A Potential Signature for Nausea in Musk Shrews  

PubMed Central

Nausea and vomiting are common symptoms in patients with many diseases, including cancer and its treatments. Although the neurological basis of vomiting is reasonably well known, an understanding of the physiology of nausea is lacking. The primary barrier to mechanistic research on the nausea system is the lack of an animal model. Indeed investigating the effects of anti-nausea drugs in pre-clinical models is difficult because the primary readout is often emesis. It is known that animals show a behavioral profile of sickness, associated with reduced feeding and movement, and possibly these general measures are signs of nausea. Studies attempting to relate the occurrence of additional behaviors to emesis have produced mixed results. Here we applied a statistical method, temporal pattern (t-pattern) analysis, to determine patterns of behavior associated with emesis. Musk shrews were injected with the chemotherapy agent cisplatin (a gold standard in emesis research) to induce acute (<24?h) and delayed (>24?h) emesis. Emesis and other behaviors were coded and tracked from video files. T-pattern analysis revealed hundreds of non-random patterns of behavior associated with emesis, including sniffing, changes in body contraction, and locomotion. There was little evidence that locomotion was inhibited by the occurrence of emesis. Eating, drinking, and other larger body movements including rearing, grooming, and body rotation, were significantly less common in emesis-related behavioral patterns in real versus randomized data. These results lend preliminary evidence for the expression of emesis-related behavioral patterns, including reduced ingestive behavior, grooming, and exploratory behaviors. In summary, this statistical approach to behavioral analysis in a pre-clinical emesis research model could be used to assess the more global effects and limitations of drugs used to control nausea and its potential correlates, including reduced feeding and activity levels. PMID:21808604

Horn, Charles C.; Henry, Séverine; Meyers, Kelly; Magnusson, Magnus S.

2011-01-01

268

Overview of the Cestode fauna of European shrews of the genus Sorex with an exploration of historical processes in post-glacial Europe  

Technology Transfer Automated Retrieval System (TEKTRAN)

The cestode fauna in shrews of the genus Sorex from the European region consists of seventeen species. Twelve cestode species have broad Palearctic distributions, three belong to the Western-Asian–European faunistic complex, and only two are endemic to the European zone. Postglacial expansion into ...

269

The position of tree shrews in the mammalian tree: Comparing multi-gene analyses with phylogenomic results leaves monophyly of Euarchonta doubtful.  

PubMed

The well-accepted Euarchonta grandorder is a pruned version of Archonta nested within the Euarchontoglires (or Supraprimates) clade. At present, it includes tree shrews (Scandentia), flying lemurs (Dermoptera) and primates (Primates). Here, a phylogenomic dataset containing 1912 exons from 22 representative mammals was compiled to investigate the phylogenetic relationships within this group. Phylogenetic analyses and hypothesis testing suggested that tree shrews can be classified as a sister group to Primates or to Glires or even as a basal clade within Euarchontoglires. Further analyses of both modified and original previously published datasets found that the phylogenetic position of tree shrews is unstable. We also found that two of three exonic indels reported as synapomorphies of Euarchonta in a previous study do not unambiguously support the monophyly of such a clade. Therefore, the monophyly of both Euarchonta and Sundatheria (Dermoptera + Scandentia) are suspect. Molecular dating and divergence rate analyses suggested that the ancestor of Euarchontoglires experienced a rapid divergence, which may cause the unresolved position of tree shrews even using the whole genomic data. PMID:25311886

Zhou, Xuming; Sun, Fengming; Xu, Shixia; Yang, Guang; Li, Ming

2015-03-01

270

How does the greater white-toothed shrew, Crocidura russula, responds to long-term heavy metal contamination? -- A case study.  

PubMed

Heavy metals accumulation in parallel with the evaluation of physiological and biochemical effects resulting from continued metal exposure were considered here using for the first time the great white-toothed shrew Crocidura russula as an in vivo model. Shrews were originated from an abandoned lead/zinc mining area and from a reference area, both in Alentejo, southern Portugal. Hepatic contents of nickel, copper, zinc, cadmium, mercury and lead were quantified by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). Haematological parameters (white blood cells, red blood cells, haemoglobin and haematocrit) were obtained in a Coulter Counter Analyser and biochemical markers of the redox balance (glutathione S-transferase, glutathione peroxidase, and glutathione reductase) activities were measured spectrophotometrically using a Duo-50 spectrophotometer. Compared with control animals, significantly higher concentration of hepatic cadmium (9.29 vs. 1.18 micorg/g dry weight) and nickel (1.56 vs. 0.343 microg/g dry weight) were detected in the shrews collected in the mining area. However, no significant changes were observed on haematological or enzymatic parameters in animals exposed to metal pollution. The obtained results show that shrews are good bioaccumulators of toxic heavy metals, but very tolerant to their effects, revealing an interesting long-term adaptation to polluted environments. In addition, this study provides reference values for haematological parameters and antioxidant enzymes levels in C. russula, which may be relevant for comparative purposes in further studies. PMID:17321569

Marques, Carla Cristina; Sánchez-Chardi, Alejandro; Gabriel, Sofia Isabel; Nadal, Jacint; Viegas-Crespo, Ana Maria; da Luz Mathias, Maria

2007-04-15

271

Description and molecular differentiation of a new Staphylocystoides (Cyclophyllidea: Hymenolepididae) from the dusky shrew Sorex monticolus in Southeast Alaska.  

PubMed

Staphylocystoides gulyaevi n. sp. is described based on specimens obtained from the dusky shrew Sorex monticolus collected on Sukkwan Island, southeast Alaska. Staphylocystoides gulyaevi n. sp. is compared with other North American members of the genus having 10 rostellar hooks. The new species is morphologically similar to Staphylocystoides parvissima and Staphylocystoides asketus. The uterus in S. gulyaevi n. sp. develops much more rapidly, and a well-developed uterus appears abruptly after it is barely visible in a previous proglottid. In S. parvissima the uterus grows gradually, and its early development is seen in several proglottids. At the level of pre-gravid proglottids the uterus of S. gulyaevi n. sp. occupies only the middle field of the proglottid, while in S. parvissima it fills the whole proglottid including lateral fields. The rostellar hooks in the new species are significantly smaller in size than in S. asketus. Additionally, the new species has fewer proglottids than S. asketus, while having a similar strobila length. Molecular comparison, using 3 genes (28s rDNA, cox1, and nad1), between S. gulyaevi n. sp. and S. parvissima, further corroborates the status of S. gulyaevi n. sp. as a new species. The new species is the seventh species of Staphylocystoides found in North America and the first cestode or any helminth reported from shrews in southeast Alaska. PMID:23919726

Greiman, Stephen E; Tkach, Vasyl V; Cook, Joseph A

2013-12-01

272

Feeding mechanics and dietary implications in the fossil sloth Neocnus (Mammalia: Xenarthra: Megalonychidae) from Haiti.  

PubMed

Haitian species of the extinct ground sloth genus Neocnus (Mammalia: Pilosa: Megalonychidae) have previously been hypothesized to have a much reduced jugal bone and a correspondingly reduced masseter musculature but a paucity of specimens has prevented further investigation of this hypothesis. Recent discovery of jugal bones belonging to Haitian specimens of Neocnus within the University of Florida Museum collections enables the element to be more accurately described. The discovery also makes it possible to explore mastication in these sloths. Osteological characters related to feeding were examined, along with comparative estimations of bite force with the extant tree sloths, Bradypus and Choloepus, and their known dietary habits as a means to infer aspects of the paleodiet of Neocnus. There is a significant difference in moment arm calculations for m. masseter between predicted and actual jugals, but the overall significance for bite force is lost and hampered by small sample size. Neocnus demonstrates a variety of characters that are similar to those of Bradypus and not to Choloepus, which is a close phylogenetic relative. The masticatory musculature of Neocnus enabled a chewing cycle emphasizing a grinding combination of mesiodistal and linguobuccal movements of the molariform dentition. The orientations of m. masseter and m. temporalis are estimated to produce relatively high bite force ratios that imply a masticatory system with stronger versus faster components. Because of the similarity of bite forces and jaw mechanics to those of Bradypus, in addition to a number of osteological adaptations indicative of herbivorous grazers (elevated mandibular condyle, large and complex masseter, and robust angular process), the Haitian forms of Neocnus are considered to have been selective feeders with a folivorous diet. PMID:21638306

McAfee, Robert K

2011-10-01

273

Cyclophosphamide causes activation of protein kinase A (PKA) in the brainstem of vomiting least shrews (Cryptotis parva).  

PubMed

Complete control of emesis caused by cyclophosphamide (CPA) is of immense interest to both patients and physicians. Serotonin 5-HT3- and tachykinin NK1-receptor antagonists are widely used antiemetics in clinic, but they fail to completely control CPA-induced emesis. New antiemetic targets for the full control of CPA-induced vomiting are lacking. We therefore examined the effects of CPA on emetic targets downstream of 5-HT3- and NK1- receptors in an attempt to better understand the molecular bases of CPA-induced emesis. Acute CPA (200 mg/kg, i.p.) administration in the least shrew caused a biphasic pattern of emesis over a 40 h observation period, with maximal peak vomit frequency during the 1st hour of treatment (acute phase), followed by a delayed-phase which peaks at 27th hour. The NK1 receptor mRNA levels increased significantly at 8 h post-CPA treatment in the brainstem, and at 28 h in the whole intestine. Substance P mRNA levels tended to increase both in the brainstem and intestine at most time-points post-CPA injection, however due to large variability, they failed to attain significance. Likewise, protein expression profiles of both NK1- and 5-HT3 -receptors in the brainstem were unchanged at any time-point. However, phosphorylation levels of protein kinase A (PKA), but not of extracellular signal-regulated protein kinase 1/2 (ERK1/2), were increased at 2, 8, 22, 28, and 33 h time-points after the treatment with CPA. Moreover, brainstem but not frontal cortex cAMP tissue levels tended to be elevated at most time-points, but significant increases occurred only at 1 and 2 h post-CPA treatment. The phosphodiesterase inhibitor, rolipram, caused significant increases in shrew brainstem cAMP levels which were associated with its capacity to produce vomiting, while pretreatment with SQ22536, an inhibitor of adenylyl cyclase, prevented rolipram-induced emesis. The results demonstrate that accumulation of cAMP and subsequent activation of PKA in the brainstem may help to initiate and sustain emesis induced by CPA in the least shrew. Our findings suggest that suppression of the cAMP/PKA cascade may have antiemetic potential in the management of CPA-induced emesis. PMID:24513510

Alkam, Tursun; Chebolu, Seetha; Darmani, Nissar A

2014-01-01

274

Une nouvelle espèce d'hyracoïde du genre Bunohyrax (Mammalia) de l'Éocène de Bir El Ater (Algérie).  

NASA Astrophysics Data System (ADS)

A new species of Bunohyrax, B. matsumotoi n. sp. (Hyracoidea, Mammalia) from the Bir El Ater locality (Algeria) is described and compared with the two known species from the Oligocene of the Fayum (Egypt). This new hyracoid is documented by fragmentary remains, but the characters are significant enough to establish a new species, particularly because of its extremely small size. B. matsumotoi appears to be more primitive than the Egyptian Bunohyrax. The Algerian species, together with geological and palaeontological data, argues for a late Middle to Late Eocene age for the Bir El Ater site, rather than an Oligocene age, equivalent to the upper sequence of the Fayum, as suggested by Rasmussen et al. [17].

Tabuce, Rodolphe; Coiffait, Brigitte; Coiffait, Philippe-Emmanuel; Mahboubi, Mohamed; Jaeger, Jean-Jacques

2000-07-01

275

Short interspersed elements (SINEs) from insectivores. Two classes of mammalian SINEs distinguished by Arich tail structure  

Microsoft Academic Search

.   Four tRNA-related SINE families were isolated from the genome of the shrew Sorex araneus (SOR element), mole Mogera robusta (TAL element), and hedgehog Mesechinus dauuricus (ERI-1 and ERI-2 elements). Each of these SINEs families is specific for a single Insectivora family: SOR, for Soricidae\\u000a (shrews); TAL, for Talpidae (moles and desmans); ERI-1 and ERI-2, for Erinaceidae (hedgehogs). There is

Olga R. Borodulina; Dmitri A. Kramerov

2001-01-01

276

Computerized detection and analysis of cancer chemotherapy-induced emesis in a small animal model, musk shrew  

PubMed Central

Vomiting is a common side effect of cancer chemotherapy and many drug treatments and diseases. In animal studies, the measurement of vomiting usually requires direct observation, which is time consuming and often lacks temporal precision. Musk shrews have been used to study the neurobiology of emesis and have a rapid emetic episode (~1 s for a sequence of retching and expulsion). The aims of the current study were to develop a method to automatically detect and characterize emetic episodes induced by the cancer chemotherapy agent cisplatin. The body contour in each video frame was tracked and normalized to a parameterized shape basis. The tracked shape was projected to a feature space that maximizes the shape variations in the consecutive frames during retching. The resulting one dimensional projection was sufficient to detect most emetic episodes in the acute (peak at 2 h) and delayed (peak at 54 h) phases after cisplatin treatment. Emetic episodes were relatively invariant in the number of retches (~6.2), duration (~1.2 s), inter-retch interval (~198 ms), and amplitude during the 72 h after cisplatin treatment. This approach should open a new vista into emesis research to permit tracking and analysis of emesis in small animal models and facilitate the development of new antiemetic therapies. These results also yield a better understanding of the brain’s central pattern generator for emesis and indicate that the retching response in the musk shrew (at ~5.4 Hz) is the fastest ever recorded in a free-moving animal. PMID:21392533

Huang, Dong; Meyers, Kelly; Henry, Séverine; De la Torre, Fernando; Horn, Charles C.

2011-01-01

277

Nonshivering thermogenesis capacity associated to mitochondrial DNA haplotypes and gender in the greater white-toothed shrew, Crocidura russula.  

PubMed

A selection gradient was recently suggested as one possible cause for a clinal distribution of mitochondrial DNA (mtDNA) haplotypes along an altitudinal transect in the greater white-toothed shrew, Crocidura russula (Ehinger et al. 2002). One mtDNA haplotype (H1) rare in lowland, became widespread when approaching the altitudinal margin of the distribution. As H1 differs from the main lowland haplotype by several nonsynonymous mutations (including on ATP6), and as mitochondria play a crucial role in metabolism and thermogenesis, distribution patterns might stem from differences in the thermogenic capacity of different mtDNA haplotypes. In order to test this hypothesis, we measured the nonshivering thermogenesis (NST) associated with different mtDNA haplotypes. Sixty-two shrews, half of which had the H1 haplotype, were acclimated in November at semioutdoor conditions and measured for NST throughout winter. Our results showed the crucial role of NST for winter survival in C. russula. The individuals that survived winter displayed a higher significant increase in NST during acclimation, associated with a significant gain in body mass, presumably from brown fat accumulation. The NST capacity (ratio of NST to basal metabolic rate) was exceptionally high for such a small species. NST was significantly affected by a gender x haplotype interaction after winter-acclimation: females bearing the H1 haplotype displayed a better thermogenesis at the onset of the breeding season, while the reverse was true for males. Altogether, our results suggest a sexually antagonistic cyto-nuclear selection on thermogenesis. PMID:15660955

Fontanillas, Pierre; Dépraz, Aline; Giorgi, Maud S; Perrin, Nicolas

2005-02-01

278

Anandamide transport inhibition by ARN272 attenuates nausea-induced behaviour in rats, and vomiting in shrews (Suncus murinus)  

PubMed Central

Background and Purpose To understand how anandamide transport inhibition impacts the regulation of nausea and vomiting and the receptor level mechanism of action involved. In light of recent characterization of an anandamide transporter, fatty acid amide hydrolase-1-like anandamide transporter, to provide behavioural support for anandamide cellular reuptake as a facilitated transport process. Experimental Approach The systemic administration of the anandamide transport inhibitor ARN272 ([(4-(5-(4-hydroxy-phenyl)-3,4-diaza-bicyclo[4.4.0]deca-1(6),2,4,7,9-pentaen-2-ylamino)-phenyl)-phenylamino-methanone]) was used to evaluate the prevention of LiCl-induced nausea-induced behaviour (conditioned gaping) in rats, and LiCl-induced emesis in shrews (Suncus murinus). The mechanism of how prolonging anandamide availability acts to regulate nausea in rats was explored by the antagonism of cannabinoid 1 (CB1) receptors with the systemic co-administration of SR141716. Key Results The systemic administration of ARN272 produced a dose-dependent suppression of nausea-induced conditioned gaping in rats, and produced a dose-dependent reduction of vomiting in shrews. The systemic co-administration of SR141716 with ARN272 (at 3.0?mg·kg?1) in rats produced a complete reversal of ARN272-suppressed gaping at 1.0?mg·kg?1. SR141716 alone did not differ from the vehicle solution. Conclusions and Implications These results suggest that anandamide transport inhibition by the compound ARN272 tonically activates CB1 receptors and as such produces a type of indirect agonism to regulate toxin-induced nausea and vomiting. The results also provide behavioural evidence in support of a facilitated transport mechanism used in the cellular reuptake of anandamide. PMID:23991698

O'Brien, L D; Limebeer, C L; Rock, E M; Bottegoni, G; Piomelli, D; Parker, L A

2013-01-01

279

A new hantavirus from the stripe-backed shrew (Sorex cylindricauda) in the People's Republic of China.  

PubMed

Inspired by the recent discovery of genetically distinct hantaviruses from insectivore species worldwide, we performed a small-scale search for insectivore-borne hantaviruses. In this paper, we report the discovery of a new hantavirus, which was designated the Qian Hu Shan virus (QHSV). This virus was detected in the lung tissues of three stripe-backed shrews (Sorex cylindricauda), which were captured in the Yunnan Province, China. The full-length S genomic segment of the representative QHSV strain YN05-284 was 1661 nucleotides and is predicted to encode a nucleocapsid protein of 429 amino acids that starts at nucleotide position 48. It exhibited the highest similarity with other Sorex-related hantaviruses, with 68.1%-72.8% nucleotide and 71.9%-84.4% amino acid sequence identities. An analysis of a 1430-nucleotide region of the partial M segment exhibited approximately 54.4%-79.5% nucleotide and 43.2%-90.8% amino acid sequence identities to other hantaviruses. A comparison of a 432-nucleotide region of the L segment also showed similar degrees of identity, with 68.9%-78.4% nucleotide and 71.1%-93.8% amino acid sequence identities to other hantaviruses. Phylogenetic analyses using Bayesian methods indicated that QHSV shared the most recent common ancestor with other Sorex-related hantaviruses. The host was identified using a morphological assessment and verified using mitochondrial cytochrome b (mt-Cyt b) gene sequencing. A pair-wise comparison of the 1140-nucleotide mt-Cyt b gene sequence from the host demonstrated that the host was close to S. cylindricauda from Nepal with 94.3% identity. The virus-host association tanglegram, which was constructed using the Dendroscope software, indicated that the QHSV phylogeny and the host phylogeny were approximately matched, which suggests no evidence of host switching for QHSV. Our results contribute to a wider viewpoint regarding the heterogeneity of viruses that infect shrews. PMID:24553099

Zuo, Shu-Qing; Gong, Zheng-Da; Fang, Li-Qun; Jiang, Jia-Fu; Zhang, Jiu-Song; Zhao, Qiu-Min; Cao, Wu-Chun

2014-05-12

280

Soricid response to forest stand age in southern Appalachian cove hardwood communities  

Microsoft Academic Search

Monthly from May 1994 until April 1995, we examined four age classes (15, 25, 50, and > 85 years old) of southern Appalachian cove hardwood stands in the Chattahoochee National Forest of Georgia to determine the effects of even-aged forest management (clearcutting) on the relative abundance of shrews (Insectivora: Soricidae). Stands were sampled using drift-fence\\/pitfall trap methodologies. During 60 060

William M. Ford; Joshua Laerm; Katherine G. Barker

1997-01-01

281

Molecular evidence for multiple origins of Insectivora and for a new order of endemic African insectivore mammals  

Microsoft Academic Search

The traditional views regarding the mamma- lian order Insectivora are that the group descended from a single common ancestor and that it is comprised of the following families: Soricidae (shrews), Tenrecidae (tenrecs), Solenodonti- dae (solenodons), Talpidae (moles), Erinaceidae (hedgehogs and gymnures), and Chrysochloridae (golden moles). Here we present a molecular analysis that includes representatives of all six families of insectivores,

MICHAEL J. STANHOPE; V ICTOR G. WADDELL; O LE MADSEN; W ILFRIED DE JONG; S. B LAIR; GREGORY C. CLEVENi; MARK S. SPRINGER

1998-01-01

282

Effect of ethanol on esophageal cell proliferation and the development of N -methyl- N? -nitro- N -nitrosoguanidine induced-esophageal carcinoma in shrews  

Microsoft Academic Search

The effect of ethanol (EtOH) on esophageal cell proliferation and the development of esophageal cancers induced byN-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in shrews were investigated. Sequential histological examination was done, and cell proliferation was assessed by BrdU labeling. At 5 weeks of age, animals were given tap water, 2% EtOH, 50 ppm MNNG, or 50 ppm MNNG plus 2%, 5% or 10% EtOH

Nobuaki Shikata; Yogendra Singh; Hideto Senzaki; Katsumasa Shirai; Tomoyuki Watanabe; Airo Tsubura

1996-01-01

283

The X-autosome translocation in the common shrew ( Sorex araneus L.): late replication in female somatic cells and pairing in male meiosis  

Microsoft Academic Search

Common shrews have an XX\\/XY1Y2 sex chromosome system, with the “X” chromosome being a translocation (tandem fusion) between the “original” X and an autosome; in males this autosome is represented by the Y2 chromosome. From G-banded chromosomes, the Y2 is homologous to the long arm and centromeric part of the short arm of the X. The region of the X

Svetlana D. Pack; Pavel M. Borodin; Oleg L. Serov; Jeremy B. Searle

1993-01-01

284

Dasypodidae Borner, 1919 (Insecta, Hymenoptera): Proposed emendation of spelling to Dasypodaidae, so removing the homonymy with Dasypodidae Gray, 1821 (Mammalia, Xenarthra)  

USGS Publications Warehouse

The family-group name DASYPODIDAE Borner, 1919 (Insecta, Hymenoptera) is a junior homonym Of DASYPODIDAE Gray, 1821 (Mammalia, Xenarthra). It is proposed that the homonymy between the two names, which relate to short-tongued bees and armadillos respectively, should be removed by emending the stem of the generic name Dasypoda Latreille, 1802, on which the insect familygroup name is based, to give DASYPODAIDAE, while leaving the mammalian name (based on Dasypus Linnaeus, 1758) unchanged. Dasypus novemcinctus Linnaeus, 1758, the type species of Dasypus, has a wide distribution in the southern United States, Central and South America. The genus Dasypoda ranges throughout most of the Palearctic region.

Alexander, B.A.; Michener, C.D.; Gardner, A.L.

1998-01-01

285

Broad-spectrum antiemetic efficacy of the L-type calcium channel blocker amlodipine in the least shrew (Cryptotis parva).  

PubMed

The dihydropyridine l-type calcium (Ca(2+)) channel blockers nifedipine and amlodipine reduce extracellular Ca(2+) entry into cells. They are widely used for the treatment of hypertensive disorders. We have recently demonstrated that extracellular Ca(2+) entry via l-type Ca(2+) channels is involved in emesis and that nifedipine has broad-spectrum antiemetic activity. The aim of this study was to evaluate the antiemetic efficacy of the longer-acting l-type Ca(2+) channel blocker, amlodipine. Fully effective emetic doses of diverse emetogens such as the l-type Ca(2+) channel agonist (FPL 64176) as well as selective and/or nonselective agonists of serotonergic 5-HT3 (e.g. 5-HT or 2-Me-5-HT)-, dopamine D2 (e.g. apomorphine or quinpirole)-, cholinergic M1 (e.g. pilocarpine or McN-A343)- and tachykininergic NK1 (e.g. GR73632)-receptors, were administered intraperitoneally (i.p.) in the least shrew to induce vomiting. The broad-spectrum antiemetic potential of amlodipine was evaluated against these emetogens. Subcutaneous (s.c.) administration of amlodipine (0.5-10mg/kg) attenuated in a dose-dependent and potent manner both the frequency and percentage of shrews vomiting in response to intraperitoneal (i.p.) administration of FPL 64176 (10mg/kg), 5-HT (5mg/kg), 2-Me-5-HT (5mg/kg), apomorphine (2mg/kg), quinpirole (2mg/kg), pilocarpine (2mg/kg), McN-A343 (2mg/kg), or GR73632 (5mg/kg). A combination of non-effective doses of amlodipine (0.5mg/kg, s.c.) and the 5-HT3 receptor antagonist palonosetron (0.05 mg/kg, s.c.) was more effective against FPL 64176-induced vomiting than their corresponding doses tested alone. Amlodipine by itself suppressed the frequency of acute cisplatin (10mg/kg, i.p)-induced vomiting in a dose-dependent manner. Moreover, a combination of a non-effective dose of amlodipine (1mg/kg) potentiated the antiemetic efficacy of a semi-effective dose of palonosetron (0.5mg/kg, s.c.) against acute vomiting caused by cisplatin. We confirm that influx of extracellular Ca(2±) ion underlies vomiting due to diverse causes and demonstrate that l-type Ca(2+) channel blockers are a new class of broad-spectrum antiemetics. PMID:24631485

Zhong, Weixia; Chebolu, Seetha; Darmani, Nissar A

2014-05-01

286

Tissue, age, and sex distribution of thallium in shrews from Doñana, a protected area in SW Spain.  

PubMed

In 1998, the protected area of Doñana, an important natural region in SW Europe, was affected with great amount of acidic waters and sludge from a pyrite mine loaded with toxic metals such as thallium (Tl). Since this ecological catastrophe, several studies have addressed the effects of this pollution on the flora and fauna in this protected area. However, in contrast to other non-essential metals, scarce information on Tl was available after this disaster, especially in terrestrial environments. This study reported a 3- and 10-fold increase in Tl in liver and kidneys, respectively, of the greater white-toothed shrew, Crocidura russula, in the polluted site in comparison with reference animals. Kidneys showed the highest concentrations of this metal in the polluted site, whereas both organs analysed have similar concentrations in the reference site. Although no significant age-dependent variation was found, adults had higher concentrations than juveniles. Moreover, females showed higher concentrations than males. These results demonstrate the high entrance and transfer of Tl in terrestrial food-chains. To the best of my knowledge, these data constitute the first measurements of Tl in mammals from the protected area of Doñana and are among the few available for insectivorous mammals. PMID:17570462

Sánchez-Chardi, Alejandro

2007-09-20

287

Sex-specific selective pressures on body mass in the greater white-toothed shrew, Crocidura russula.  

PubMed

The direction, intensity and shape of viability-, sexual- and fecundity selection on body mass were investigated in a natural population of the greater white-toothed shrew (Crocidura russula), combining parentage assignment through molecular techniques and mark-recapture data over several generations. A highly significant stabilizing viability selection was found in both sexes, presumably stemming from the constraints imposed by their insectivorous habits and high metabolic costs. Sexual selection, directional in both sexes, was twice as large in males than in females. Our results suggest that body mass matters in this context by facilitating the acquisition and defense of a breeding territory. No fecundity selection could be detected. The direction of sexual size dimorphism (SSD) was in agreement with the observed pattern of selective pressures: males were heavier than females, because of stronger sexual selection. SSD intensity, however, was low compared with other mammals, because of the low level of polygyny, the active role of females in territory defense and the intensity of stabilizing viability selection. PMID:15715835

Bouteiller-Reuter, C; Perrin, N

2005-03-01

288

The shrew tamed by Wolff's law: Do functional constraints shape the skull through muscle and bone covariation?  

PubMed

Bone is a highly plastic tissue that reflects the many potential sources of variation in shape. Here, we focus on the functional aspects of bone remodeling. We choose the skull for our analyses because it is a highly integrated system that plays a fundamental role in feeding and is thus, likely under strong natural selection. Its principal mechanical components are the bones and muscles that jointly produce bite force and jaw motion. Understanding the covariations among these three components is of interest to understand the processes driving the evolution of the feeding apparatus. In this study, we quantitatively and qualitatively compare interactions between these three components in shrews from populations known to differ in shape and bite force. Bite force was measured in the field using a force transducer and skull shape was quantified using surface geometric morphometric approaches based on µCT-scans of the skulls of same individuals. The masseter, temporalis, pterygoideus, and digastricus muscles of these individuals were dissected and their cross sectional areas determined. Our results show strong correlations between bite force and muscle cross sectional areas as well as between bite force and skull shape. Moreover, bite force explains an important amount of skull shape variation. We conclude that interactions between bone shape and muscle characteristics can produce different morpho-functional patterns that may differ between populations and may provide a suitable target for selection to act upon. J. Morphol. 276:301-309, 2015. © 2014 Wiley Periodicals, Inc. PMID:25385121

Cornette, Raphaël; Tresset, Anne; Herrel, Anthony

2015-03-01

289

Blarina toxin, a mammalian lethal venom from the short-tailed shrew Blarina brevicauda: Isolation and characterization.  

PubMed

Venomous mammals are rare, and their venoms have not been characterized. We have purified and characterized the blarina toxin (BLTX), a lethal mammalian venom with a tissue kallikrein-like activity from the submaxillary and sublingual glands of the short-tailed shrew Blarina brevicauda. Mice administered BLTX i.p. developed irregular respiration, paralysis, and convulsions before dying. Based on the amino acid sequence of purified protein, we cloned the BLTX cDNA. It consists of a prosequence and an active form of 253 aa with a typical catalytic triad of serine proteases, with a high identity with tissue kallikreins. BLTX is an N-linked microheterogeneous glycoprotein with a unique insertion of 10 residues, L(106)TFFYKTFLG(115). BLTX converted kininogens to kinins, which may be one of the toxic pathogens, and had dilatory effects on the blood vessel walls. The acute toxicity and proteolytic activity of BLTX were strongly inhibited by aprotinin, a kallikrein inhibitor, suggesting that its toxicity is due to a kallikrein-like activity of the venom. PMID:15136743

Kita, Masaki; Nakamura, Yasuo; Okumura, Yuushi; Ohdachi, Satoshi D; Oba, Yuichi; Yoshikuni, Michiyasu; Kido, Hiroshi; Uemura, Daisuke

2004-05-18

290

A mongoose remain (Mammalia: Carnivora) from the Upper Irrawaddy sediments, Myanmar and its significance in evolutionary history of Asian herpestids  

NASA Astrophysics Data System (ADS)

A tooth of a mongoose (Mammalia: Carnivora: Herpestidae) was discovered from the Upper Irrawaddy sediments in central Myanmar. The age of the fauna is not older than the mid-Pliocene. It is identified as a right first upper molar of a small species of Urva (formally included in the genus Herpestes) based on its size and shape. The present specimen is the first carnivoran from the Upper Irrawaddy sediments and is the first record of mongooses in the Pliocene and early Pleistocene of Asia. It confirms that mongooses had already dispersed into Southeast Asia by the late Pliocene, being consistent with the previous molecular phylogenetic analyses. The fossil may belong to one of the extant species, but an assignment to a specific species is difficult due to the fragmentary nature of the specimen and the small interspecific differences in dental shape among the Asian mongooses. The size of the tooth suggests that the Irrawaddy specimen is within or close to the clade of Urva auropunctata + javanica + edwardsii, and this taxonomic assignment agrees with the geographical distribution.

Egi, Naoko; Thaung-Htike; Zin-Maung-Maung-Thein; Maung-Maung; Nishioka, Yuichiro; Tsubamoto, Takehisa; Ogino, Shintaro; Takai, Masanaru

2011-11-01

291

Fiber type distribution in the shoulder muscles of the tree shrew, the cotton-top tamarin, and the squirrel monkey related to shoulder movements and forelimb loading.  

PubMed

Muscle fiber type composition of intrinsic shoulder muscles was examined in tree shrews, cotton-top tamarins, and squirrel monkeys with respect to their shoulder kinematics and forelimb loading during locomotion. Enzyme- and immunohistochemical techniques were applied to differentiate muscle fiber types on serial cross-sections of the shoulder. In the majority of the shoulder muscles, the proportions of fatigue resistant slow-twitch fibers (SO) and fatigable fast-twitch fibers (FG) were inversely related to each other, whereas the percentage of intermediate FOG-fibers varied independently. A segregation of fatigue resistant SO-fibers into deep muscle regions is indicative of differential activation of histochemically distinct muscle regions in which deep regions stabilize the joint against gravitational loading. In all three species, this antigravity function was demonstrated for both the supraspinatus and the cranial subscapularis muscle, which prevent passive joint flexion during the support phase of the limb. The infraspinatus muscle showed a high content of SO-fibers in the primate species but not in the tree shrew, which demonstrates the "new" role of the infraspinatus muscle in joint stabilization related to the higher degree of humeral protraction in primates. In the tree shrew and the cotton-top tamarin, a greater proportion of the body weight is carried on the forelimb, but the squirrel monkey exhibits a weight shift to the hind limbs. The lower amount of forelimb loading is reflected by an overall lower proportion of fatigue resistant muscle fibers in the shoulder muscles of the squirrel monkey. Several muscles such as the deltoid no longer function as joint stabilizers and allow the humerus to move beyond the scapular plane. These differences among species demonstrate the high plasticity of the internal muscle architecture and physiology which is suggested to be the underlying reason for different muscle activity patterns in homologous muscles. Implications for the evolution of new locomotor modes in primates are discussed. PMID:17289114

Schmidt, Manuela; Schilling, Nadja

2007-04-01

292

Delta 9-tetrahydrocannabinol suppresses vomiting behavior and Fos expression in both acute and delayed phases of cisplatin-induced emesis in the least shrew.  

PubMed

Cisplatin chemotherapy frequently causes severe vomiting in two temporally separated clusters of bouts dubbed the acute and delayed phases. Cannabinoids can inhibit the acute phase, albeit through a poorly understood mechanism. We examined the substrates of cannabinoid-mediated inhibition of both the emetic phases via immunolabeling for serotonin, Substance P, cannabinoid receptors 1 and 2 (CB(1), CB(2)), and the neuronal activation marker Fos in the least shrew (Cryptotis parva). Shrews were injected with cisplatin (10mg/kg i.p.), and one of vehicle, Delta(9)-THC, or both Delta(9)-THC and the CB(1) receptor antagonist SR141716A (2mg/kg i.p.), and monitored for vomiting. Delta(9)-THC-pretreatment caused concurrent decreases in the number of shrews expressing vomiting and Fos-immunoreactivity (Fos-IR), effects which were blocked by SR141716A-pretreatment. Acute phase vomiting induced Fos-IR in the solitary tract nucleus (NTS), dorsal motor nucleus of the vagus (DMNX), and area postrema (AP), whereas in the delayed phase Fos-IR was not induced in the AP at all, and was induced at lower levels in the other nuclei when compared to the acute phase. CB(1) receptor-IR in the NTS was dense, punctate labeling indicative of presynaptic elements, which surrounded Fos-expressing NTS neurons. CB(2) receptor-IR was not found in neuronal elements, but in vascular-appearing structures. All areas correlated with serotonin- and Substance P-IR. These results support published acute phase data in other species, and are the first describing Fos-IR following delayed phase emesis. The data suggest overlapping but separate mechanisms are invoked for each phase, which are sensitive to antiemetic effects of Delta(9)-THC mediated by CB(1) receptors. PMID:18721829

Ray, Andrew P; Griggs, Lisa; Darmani, Nissar A

2009-01-01

293

Projections from the parabigeminal nucleus to the dorsal lateral geniculate nucleus in the tree shrew Tupaia glis.  

PubMed

The parabigeminal nucleus receives its major input from the superficial layers of the superior colliculus via the tectoparabigeminal projection. An extensive reciprocal parabigeminotectal pathway has also been observed. This close connectional association between the superficial gray and the parabigeminal nucleus is reflected in the collicularlike response characteristics of parabigeminal neurons (see Sherk: Brain Res. 145:375-379, '78, J. Neurophysiol. 42:1640-1655, 1656-1668, '79a,b, for review). Further documentation of the connectional relationship between the superior colliculus and the parabigeminal nucleus comes from the present data. Thus, our retrograde and anterograde transport findings reveal an extensive projection from the parabigeminal nucleus to layers 3 and 6 and several interlaminar zones of the contralateral dorsal lateral geniculate nucleus. These same layers and interlaminar zones receive tectogeniculate axons and have been shown to contain small cells that project to layers 1 and 3 of area 17. In addition to the distribution of parabigeminal axons to tectally innervated, small-celled zones, considerable parabigeminal input also reaches layers 1 and 5 of the tree shrew lateral geniculate nucleus. Each of these layers is the ipsilaterally (i.e., retinal) innervated component of a matched pair (layers 1 and 2 are considered magnocellular, while 4 and 5 are parvicellular), and it has been shown that layer 1 projects to lamina IVa of area 17, while layer 5 projects to lamina IVB. When the total distribution of parabigeminogeniculate axons is considered, it is apparent that the cells of origin of each of the major (small-celled, parvi- and magnocellular) geniculocortical channels receives parabigeminal input. Such an extensive distribution of parabigeminal axons within the lateral geniculate nucleus suggests that the information they convey might play an important role in geniculocortical function(s). PMID:2422229

Hashikawa, T; Van Lieshout, D; Harting, J K

1986-04-15

294

Identification of ghrelin in the house musk shrew (Suncus murinus): cDNA cloning, peptide purification and tissue distribution.  

PubMed

Ghrelin is the endogenous ligand for the growth hormone (GH) secretagogue receptor, and the sequence of ghrelin has been determined in many species from fish to mammals. In the present study, to reveal the production of ghrelin in the house musk shrew (Suncus murinus, order: Insectivora, suncus is used as a laboratory name), we determined the cDNA sequence and structure of suncus ghrelin and also demonstrated the ghrelin-producing cells in the gastrointestinal tract. Results of cDNA cloning and mass spectrometry analysis revealed that suncus ghrelin is composed of 18 or 26 amino acid residues and that the 3rd Ser was acylated mainly by n-octanoic acid. The 10 amino acids of the N-terminal region of suncus mature ghrelin were consistent with those of other mammals. Quantitative RT-PCR revealed that suncus ghrelin mRNA is highly expressed in the gastric corpus and pyloric antrum, and low expression levels were found in various tissues, including the intestinal tract. Ghrelin cells were found only in the corpus and antrum by immunohistochemistry and in situ hybridization, and most of the ghrelin cells were closed-type cells with relatively rich cytoplasm and scattered in the glandular body and base of the gastric mucosa. The density of ghrelin cells in the corpus was significantly greater than that in the antrum. The results of this study together with our recent results regarding motilin production in the suncus indicate that the suncus will be a useful model animal for study of physiological function of the motilin/ghrelin family. PMID:19428777

Ishida, Yuko; Sakahara, Satoshi; Tsutsui, Chihiro; Kaiya, Hiroyuki; Sakata, Ichiro; Oda, Sen-Ichi; Sakai, Takafumi

2009-05-01

295

Physiological characteristics of gastric contractions and circadian gastric motility in the free-moving conscious house musk shrew (Suncus murinus).  

PubMed

Although many studies have demonstrated the physiological action of motilin on the migrating motor complex, the precise mechanisms remain obscure. To obtain new insights into the mechanisms, we focused on the house musk shrew (Suncus murinus, suncus used as a laboratory name) as a small model animal for in vivo motilin study, and we studied the physiological characteristics of suncus gastrointestinal motility. Strain gauge transducers were implanted on the serosa of the gastric body and duodenum, and we recorded gastrointestinal contractions in the free-moving conscious suncus and also examined the effects of intravenous infusion of various agents on gastrointestinal motility. During the fasted state, the suncus stomach and duodenum showed clear migrating phase III contractions (intervals of 80-150 min) as found in humans and dogs. Motilin (bolus injection, 100-300 ng/kg; continuous infusion, 10-100 ng·kg(-1)·min(-1)) and erythromycin (80 ?g·kg(-1)·min(-1)) induced gastric phase III contractions, and motilin injection also increased the gastric motility index in a dose-dependent manner (P < 0.05, vs. saline). Pretreatment with atropine completely abolished the motilin-induced gastric phase III contractions. On the other hand, in the free-feeding condition, the suncus showed a relatively long fasting period in the light phase followed by spontaneous gastric phase III contractions. The results suggest that the suncus has almost the same gastrointestinal motility and motilin response as those found in humans and dogs, and we propose the suncus as a new small model animal for studying gastrointestinal motility and motilin in vivo. PMID:20686171

Sakahara, Satoshi; Xie, Zuoyun; Koike, Kanako; Hoshino, Satoya; Sakata, Ichiro; Oda, Sen-ichi; Takahashi, Toku; Sakai, Takafumi

2010-10-01

296

Transformation of Receptive Field Properties from Lateral Geniculate Nucleus to Superficial V1 in the Tree Shrew  

PubMed Central

Tree shrew primary visual cortex (V1) exhibits a pronounced laminar segregation of inputs from different classes of relay neurons in the lateral geniculate nucleus (LGN). We examined how several receptive field (RF) properties were transformed from LGN to V1 layer 4 to V1 layer 2/3. The progression of RF properties across these stages differed markedly from that found in the cat. V1 layer 4 cells are largely similar to the the LGN cells that provide their input, being dominated by a single sign (ON or OFF) and being strongly modulated by sinusoidal gratings. Some layer 4 neurons, notably those near the edges of layer 4, exhibited increased orientation selectivity, and most layer 4 neurons exhibited a preference for lower temporal frequencies. Neurons in cortical layer 2/3 differ significantly from those in the LGN; most exhibited strong orientation tuning and both ON and OFF responses. The strength of orientation selectivity exhibited a notable sublaminar organization, with the strongest orientation tuned neurons in the most superficial parts of layer 2/3. Modulation indexes provide evidence for simple and complex cells in both layer 4 and layer 2/3. However, neurons with high modulation indexes were heterogenous in the spatial organization of ON and OFF responses, with many of them exhibiting unbalanced ON and OFF responses rather than well-segregated ON and OFF subunits. When compared to the laminar organization of V1 in other mammals, these data show that the process of natural selection can result in significantly altered structure/function relationships in homologous cortical circuits. PMID:23843520

Roy, Arani; Rhodes, Heather J.; Culp, Julie H.; Fitzpatrick, David

2013-01-01

297

Bioaccumulation of lead, mercury, and cadmium in the greater white-toothed shrew, Crocidura russula, from the Ebro Delta (NE Spain): sex- and age-dependent variation.  

PubMed

We quantified bioaccumulation of lead, mercury, and cadmium in bones from 105 greater white-toothed shrews (Crocidura russula) collected at the Ebro Delta, a polluted area, and the Medas Islands, a control site. Lead and mercury levels varied with site, age, and sex, although statistical significances depended on each factor. Globally, shrews from the polluted area exhibited significantly higher concentrations of Pb and Hg. Increment of Pb with age was particularly remarkable in wetland animals and was interpreted in relation to human activities, namely hunting. Unlike males, females from the Ebro Delta maintained low Hg levels, which were associated with gestation and lactation. Cadmium levels did not differ between sites, sexes, or ages. This study provides the first data on heavy metals in mammals from this wetland and suggests that C. russula is a good bioindicator of metal pollution. We concluded that sex and age may represent an important source of variation in the bioaccumulation of these metals in wild populations. PMID:16777291

Sánchez-Chardi, Alejandro; López-Fuster, María José; Nadal, Jacint

2007-01-01

298

Metals in liver and kidneys and the effects of chronic exposure to pyrite mine pollution in the shrew Crocidura russula inhabiting the protected wetland of Doñana.  

PubMed

Historically impacted by anthropogenic activities, the nature reserve of Doñana (SW Spain) was affected by an unprecedented spillage of mud and acidic water from the Aznalcóllar pyrite mine in April 1998. Although several studies have addressed the influence of this spill on soils, water, and biota, there is little information on mammals, especially carnivorous species. We measured the concentrations of Fe, Mg, Pb, Hg, Cd, Zn, Cu, Mn, Mo, Co, and Cr in specimens of the greater white-toothed shrew, Crocidura russula, inhabiting the protected area affected by the mine spillage. We also examined other parameters to approach at the physiological effects of pollution. We found an increase in non-essential metals (Pb, Cd, and Hg), and morphometric, histological and genotoxic alterations. Age and gender were two significant factors explaining metal bioaccumulation: adults had higher Hg and Cd levels than juveniles, whereas males bioaccumulated more Pb and Co and less Mo than females. The micronucleus frequencies in blood erythrocytes were significantly higher in specimens from the polluted site than animals from the control site. Shrews from the impacted area also had hepatic alterations, namely increased liver-body ratio, focal necrosis, and signs of apoptosis in hepatocytes. Due to the relevance of small mammals in the diet of endangered species such as carnivorous birds and mammals, the findings of our study are of practical use for the management of the Doñana wildlife reserve and other protected Mediterranean wetlands. PMID:19394996

Sánchez-Chardi, Alejandro; Ribeiro, Ciro Alberto Oliveira; Nadal, Jacint

2009-07-01

299

Evolutionary history of the greater white-toothed shrew (Crocidura russula) inferred from analysis of mtDNA, Y, and X chromosome markers.  

PubMed

We investigate the evolutionary history of the greater white-toothed shrew across its distribution in northern Africa and mainland Europe using sex-specific (mtDNA and Y chromosome) and biparental (X chromosome) markers. All three loci confirm a large divergence between eastern (Tunisia and Sardinia) and western (Morocco and mainland Europe) lineages, and application of a molecular clock to mtDNA divergence estimates indicates a more ancient separation (2.25 M yr ago) than described by some previous studies, supporting claims for taxonomic revision. Moroccan ancestry for the mainland European population is inconclusive from phylogenetic trees, but is supported by greater nucleotide diversity and a more ancient population expansion in Morocco than in Europe. Signatures of rapid population expansion in mtDNA, combined with low X and Y chromosome diversity, suggest a single colonization of mainland Europe by a small number of Moroccan shrews >38 K yr ago. This study illustrates that multilocus genetic analyses can facilitate the interpretation of species' evolutionary history but that phylogeographic inference using X and Y chromosomes is restricted by low levels of observed polymorphism. PMID:16098767

Brändli, Laura; Handley, Lori-Jayne Lawson; Vogel, Peter; Perrin, Nicolas

2005-12-01

300

The Sahara as a vicariant agent, and the role of Miocene climatic events, in the diversification of the mammalian order Macroscelidea (elephant shrews)  

PubMed Central

Although the Sahara is a major geographical feature of the African continent, its role in the diversification of animal species is not well understood. We present here a molecular phylogeny for members of the endemic African mammalian order Macroscelidea (elephant shrews) with molecular-clock calculations; this molecular phylogeny provides convincing evidence that the genus Elephantulus is diphyletic. Elephantulus rozeti, the only elephant shrew species that resides north of the Sahara, is the sister group of a species from a different genus (Petrodromus tetradactylus), which resides just south of the Sahara. The split between these taxa coincided with major Miocene climatic events, which triggered the cooling and aridification of midlatitude continental regions, and a shift in the Sahara from a tropical to an arid environment. Thus, the North African distribution of E. rozeti is not the result of dispersion from an eastern species of the genus, but instead the result of a vicariant event involving the formation of the Sahara. The splitting events involved with most Elephantulus species in our analysis appear to coincide with these climatic events. This coincidence suggests that the environmental consequences associated with this period played an important role in the radiation of this order of mammals. The strongly supported phylogeny provides compelling evidence for a complex history of mosaic evolution, including pronounced bradytelic morphological evolution in some lineages, accelerated morphological evolution in others, and a remarkably slow rate of evolution of the male reproductive structure. PMID:12821774

Douady , Christophe J.; Catzeflis, François; Raman, Jaishree; Springer , Mark S.; Stanhope , Michael J.

2003-01-01

301

Purification and characterisation of blarinasin, a new tissue kallikrein-like protease from the short-tailed shrew Blarina brevicauda: comparative studies with blarina toxin.  

PubMed

A new tissue kallikrein-like protease, blarinasin, has been purified from the salivary glands of the short-tailed shrew Blarina brevicauda. Blarinasin is a 32-kDa N-glycosylated protease with isoelectric values ranging between 5.3 and 5.7, and an optimum pH of 8.5 for enzyme activity. The cloned blarinasin cDNA coded for a pre-pro-sequence and a mature peptide of 252 amino acids with a catalytic triad typical for serine proteases and 43.7-54.0% identity to other mammalian tissue kallikreins. Blarinasin preferentially hydrolysed Pro-Phe-Arg-4-methylcoumaryl-7-amide (MCA) and N-tert-butyloxycarbonyl-Val-Leu-Lys-MCA, and preferentially converted human high-molecular-weight kininogen (HK) to bradykinin. The activity of blarinasin was prominently inhibited by aprotinin (K(i) =3.4 nM). A similar kallikrein-like protease, the lethal venom blarina toxin, has previously been purified from the salivary glands of the shrew Blarina and shows 67.9% identity to blarinasin. However, blarinasin was not toxic in mice. Blarinasin is a very abundant kallikrein-like protease and represents 70-75% of kallikrein-like enzymes in the salivary gland of B. brevicauda. PMID:15843162

Kita, Masaki; Okumura, Yuushi; Ohdachi, Satoshi D; Oba, Yuichi; Yoshikuni, Michiyasu; Nakamura, Yasuo; Kido, Hiroshi; Uemura, Daisuke

2005-02-01

302

Extreme environmental change and evolution: stress-induced morphological variation is strongly concordant with patterns of evolutionary divergence in shrew mandibles.  

PubMed Central

Morphological structures often consist of simpler traits which can be viewed as either integrated (e.g. correlated due to functional interdependency) or non-integrated (e.g. functionally independent) traits. The combination of a long-term stabilizing selection on the entire structure with a short-term directional selection on an adaptively important subset of traits should result in long historical persistence of integrated functional complexes, with environmentally induced variation and macroevolutionary change confined mostly to non-integrated traits. We experimentally subjected populations of three closely related species of Sorex shrews to environmental stress. As predicted, we found that most of the variation in shrew mandibular shape was localized between rather than within the functional complexes; the patterns of integration did not change between the species. The stress-induced variation was confined to nonintegrated traits and was highly concordant with the patterns of evolutionary change--species differed in the same set of non-integrated traits which were most sensitive to stress within each species. We suggest that low environmental and genetic canalization of non-integrated traits may have caused these traits to be most sensitive not only to the environmental but also to genetic perturbations associated with stress. The congruence of stress-induced and between-species patterns of variation in non-integrated traits suggests that stress-induced variation in these traits may play an important role in species divergence. PMID:10722219

Badyaev, A V; Foresman, K R

2000-01-01

303

Genetic diversity of Imjin virus in the Ussuri white-toothed shrew (Crocidura lasiura) in the Republic of Korea, 2004-2010  

PubMed Central

Recently, Imjin virus (MJNV), a genetically distinct hantavirus, was isolated from lung tissues of the Ussuri white-toothed shrew (Crocidura lasiura) captured near the demilitarized zone in the Republic of Korea. To clarify the genetic diversity of MJNV, partial M- and L-segment sequences were amplified from lung tissues of 12 of 37 (32.4%) anti-MJNV IgG antibody-positive Ussuri white-toothed shrews captured between 2004 and 2010. A 531-nucleotide region of the M segment (coordinates 2,255 to 2,785) revealed that the 12 MJNV strains differed by 0-12.2% and 0-2.3% at the nucleotide and amino acid levels, respectively. A similar degree of nucleotide (0.2-11.9%) and amino acid (0-3.8%) difference was found in a 632-nucleotide length of the L segment (coordinates 962 to 1,593) of nine MJNV strains. Phylogenetic analyses, based on the partial M and L segments of MJNV strains generated by the neighbor-joining and maximum likelihood methods, showed geographic-specific clustering, akin to the phylogeography of rodent-borne hantaviruses. PMID:21303516

2011-01-01

304

Diet is a major factor governing the fecal butyrate-producing community structure across Mammalia, Aves and Reptilia.  

PubMed

Butyrate-producing bacteria have an important role in maintaining host health. They are well studied in human and medically associated animal models; however, much less is known for other Vertebrata. We investigated the butyrate-producing community in hindgut-fermenting Mammalia (n=38), Aves (n=8) and Reptilia (n=8) using a gene-targeted pyrosequencing approach of the terminal genes of the main butyrate-synthesis pathways, namely butyryl-CoA:acetate CoA-transferase (but) and butyrate kinase (buk). Most animals exhibit high gene abundances, and clear diet-specific signatures were detected with but genes significantly enriched in omnivores and herbivores compared with carnivores. But dominated the butyrate-producing community in these two groups, whereas buk was more abundant in many carnivorous animals. Clustering of protein sequences (5% cutoff) of the combined communities (but and buk) placed carnivores apart from other diet groups, except for noncarnivorous Carnivora, which clustered together with carnivores. The majority of clusters (but: 5141 and buk: 2924) did not show close relation to any reference sequences from public databases (identity <90%) demonstrating a large 'unknown diversity'. Each diet group had abundant signature taxa, where buk genes linked to Clostridium perfringens dominated in carnivores and but genes associated with Ruminococcaceae bacterium D16 were specific for herbivores and omnivores. Whereas 16S rRNA gene analysis showed similar overall patterns, it was unable to reveal communities at the same depth and resolution as the functional gene-targeted approach. This study demonstrates that butyrate producers are abundant across vertebrates exhibiting great functional redundancy and that diet is the primary determinant governing the composition of the butyrate-producing guild. PMID:25343515

Vital, Marius; Gao, Jiarong; Rizzo, Mike; Harrison, Tara; Tiedje, James M

2015-01-01

305

A new amphicyonid (Mammalia, Carnivora, Amphicyonidae) from the late middle Miocene of northern Thailand and a review of the amphicyonine record in Asia  

NASA Astrophysics Data System (ADS)

Recent field research conducted in the middle Miocene basin of Mae Moh, northern Thailand, allow discovering dental remains of a new amphicyonid (Mammalia, Carnivora, Amphicyonidae). A thorough comparison with all known Asian and non-Asian Miocene genera of Amphicyonidae supports the assignment of these specimens to a new amphicyonine, Maemohcyon potisati gen. et sp. nov. We propose the first review of the fossil record of the Amphicyoninae and we discuss the possible geographic origin and phylogenetic relationships of this new taxon. It appears that Maemohcyon does not have close relationships with contemporary ( Amphicyon, Pseudocyon, Ischyrocyon, Pliocyon) or earlier ( Ictiocyon, Pseudarctos, Cynelos, Ysengrinia) genera. We suggest that the Maemohcyon lineage probably arrived much earlier than 13 Ma (age of Mae Moh fauna) and evolved in this insulated region until the late middle Miocene.

Peigné, Stéphane; Chaimanee, Yaowalak; Yamee, Chotima; Tian, Pannipa; Jaeger, Jean-Jacques

2006-04-01

306

Brain Volume of the Newly-Discovered Species Rhynchocyon udzungwensis (Mammalia: Afrotheria: Macroscelidea): Implications for Encephalization in Sengis  

PubMed Central

The Gray-faced Sengi (Rhynchocyon udzungwensis) is a newly-discovered species of sengi (elephant-shrew) and is the largest known extant representative of the order Macroscelidea. The discovery of R. udzungwensis provides an opportunity to investigate the scaling relationship between brain size and body size within Macroscelidea, and to compare this allometry among insectivorous species of Afrotheria and other eutherian insectivores. We performed a spin-echo magnetic resonance imaging (MRI) scan on a preserved adult specimen of R. udzungwensis using a 7-Tesla high-field MR imaging system. The brain was manually segmented and its volume was compiled into a dataset containing previously-published allometric data on 56 other species of insectivore-grade mammals including representatives of Afrotheria, Soricomorpha and Erinaceomorpha. Results of log-linear regression indicate that R. udzungwensis exhibits a brain size that is consistent with the allometric trend described by other members of its order. Inter-specific comparisons indicate that macroscelideans as a group have relatively large brains when compared with similarly-sized terrestrial mammals that also share a similar diet. This high degree of encephalization within sengis remains robust whether sengis are compared with closely-related insectivorous afrotheres, or with more-distantly-related insectivorous laurasiatheres. PMID:23516530

Kaufman, Jason A.; Turner, Gregory H.; Holroyd, Patricia A.; Rovero, Francesco; Grossman, Ari

2013-01-01

307

Binocular Lens Treatment in Tree Shrews: Effect of Age and Comparison of Plus Lens Wear with Recovery from Minus Lens-induced Myopia  

PubMed Central

We examined normal emmetropization and the refractive responses to binocular plus or minus lenses in young (late infantile) and juvenile tree shrews. In addition, recovery from lens-induced myopia was compared with the response to a similar amount of myopia produced with plus lenses in age-matched juvenile animals. Normal emmetropization was examined with daily noncycloplegic autorefractor measures from 11 days after natural eye-opening (days of visual experience [VE]) when the eyes were in the infantile, rapid growth phase and their refractions were substantially hyperopic, to 35 days of VE when the eyes had entered the juvenile, slower growth phase and the refractions were near emmetropia. Starting at 11 days of VE, two groups of young tree shrews wore binocular +4 D lenses (n = 6) or ?5 D lenses (n = 5). Starting at 24 days of VE, four groups of juvenile tree shrews (n = 5 each) wore binocular +3 D, +5 D, ?3 D, or ?5 D lenses. Non-cycloplegic measures of refractive state were made frequently while the animals wore the assigned lenses. The refractive response of the juvenile plus-lens wearing animals was compared with the refractive recovery of an age-matched group of animals (n=5) that were myopic after wearing a ?5 D lens from 11 to 24 days of VE. In normal tree shrews, refractions (corrected for the small eye artifact) declined rapidly from (mean ± SEM) 6.6 ± 0.6 D of hyperopia at 11 VE to 1.4 ± 0.2 D at 24 VE and 0.8 ± 0.4 D at 35 VE. Plus 4 D lens treatment applied at 11 days of VE initially corrected or over-corrected the young animals’ hyperopia and produced a compensatory response in most animals; the eyes became nearly emmetropic while wearing the +4 D lenses. In contrast, plus-lens treatment starting at 24 days of VE initially made the juvenile eyes myopic (over-correction) and, on average, was less effective. The response ranged from no change in refractive state (eye continued to experience myopia) to full compensation (emmetropic with the lens in place). Minus-lens wear in both the young and juvenile groups, which initially made eyes more hyperopic, consistently produced compensation to the minus lens so that eyes reached age-appropriate refractions while wearing the lenses. When the minus lenses were removed, the eyes recovered quickly to age-matched normal values. The consistent recovery response from myopia in juvenile eyes after minus-lens compensation, compared with the highly variable response to plus lens wear in age-matched juvenile animals suggests that eyes retain the ability to detect the myopic refractive state, but there is an age-related decrease in the ability of normal eyes to use myopia to slow their elongation rate below normal. If juvenile human eyes, compared with infants, have a similar difficulty in using myopia to slow axial elongation, this may contribute to myopia development, especially in eyes with a genetic pre-disposition to elongate. PMID:20713041

Siegwart, John T.; Norton, Thomas T.

2010-01-01

308

These studies were conducted to assess the effects of lead toxicity on exploratory behavior and running. Effects of lead on exploratory behavior and running speed in the shrew, Blarina brevicauda (Insectivora).  

PubMed

These studies were conducted to assess the effects of lead toxicity on exploratory behavior and running speed in the short-tailed shrew, Blarina brevicauda. Shrews from the experimental group received 25 mg/kg/day of lead acetate in their drinking water for a period of 90 days. Control subjects received sodium acetate. Exploratory behavior was determined using a computerized activity chamber where movements of test subjects broke infrared beams projected onto the floor of the apparatus. Time spent (sec) in exploration was recorded over eight 6-min intervals. Running speed (km/hr) was measured in a microprocessor-controlled rectangular racetrack fitted with photocell timers. With respect to time spent in exploration, there were significant differences between lead-exposed (20.5-23.9 sec per 6-min testing session) and control subjects (6.8-8.1 sec) after the sixth testing interval in the activity chamber. With respect to maximal running speed, control subjects ran significantly faster (mean: 14.8 km/hr) than their lead-exposed counterparts (5.83 km/hr). Lead-exposed animals exhibited hyperactivity and increased random locomotor movements. They would frequently bump into the walls and their movements were more random. Controls typically ran along the racetrack in a straight line. These results represent the first data for the effects of lead exposure on exploratory behavior and running speed for shrews. PMID:15248655

Punzo, F; Farmer, C

2003-10-01

309

Patterns of mRNA and protein expression during minus-lens compensation and recovery in tree shrew sclera  

PubMed Central

Purpose To increase our understanding of the mechanisms that remodel the sclera during the development of lens-induced myopia, when the sclera responds to putative “go” signals of retinal origin, and during recovery from lens-induced myopia, when the sclera responds to retinally-derived “stop” signals. Methods Seven groups of tree shrews were used to examine mRNA levels during minus lens compensation and recovery. Starting 24 days after eye opening (days of visual experience [VE]) lens compensation animals wore a monocular –5D lens for 1, 4, or 11 days. Recovery animals wore the –5D lens for 11 days, which was then removed for 1 or 4 days. Normal animals were examined at 24 and 38 days of VE. All groups contained 8 animals. Scleral mRNA levels were examined in the treated and contralateral control eyes with quantitative real-time polymerase chain reaction (qPCR) for 27 genes divided into four categories: 1) signaling molecules, 2) matricellular proteins, 3) metalloproteinases (MPs) and tissue inhibitors of metalloproteinases (TIMPs), and 4) cell adhesion and other proteins. Four groups (n=5 per group) were used to examine protein levels. One group wore a –5D lens for 4 days. A second group recovered for 4 days after 11 days of ?5D lens treatment. Two groups were used to examine age-matched normal protein levels at 28 and 39 days of VE. The levels of six scleral proteins that showed differential mRNA expression were examined with quantitative western blots. Results Nineteen of the genes showed differential (treated eye versus control eye) expression of mRNA levels in at least one group of animals. Which genes showed differential expression differed after 1 and 4 days of compensation and after 1 or 4 days of recovery. The mRNA level for one gene, a disintegrin and metalloproteinase with thrombospondin motifs 1 (ADAMTS1), was upregulated in the treated eyes after 1 day of compensation. After 4 days, transforming growth factor beta receptor 3 (TGFBR3), transforming growth factor-beta-induced protein ig-h3 (TGFBI), and matrix metalloproteinase 14 (MMP14) mRNA levels were upregulated. Downregulated were mRNA levels for transforming growth factor beta-1 (TGFB1), transforming growth factor beta-2 (TGFB2), thrombospondin 1 (THBS1), tenascin (TNC), osteonectin (SPARC), osteopontin (SPP1), tissue inhibitor of metalloproteinases 3 (TIMP3), and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5). After 11 days of lens wear, there was no differential expression. During recovery, after 1 day, treated-eye mRNA downregulation was found for TGFB2, TGFBR1, TGFBR2, TGFBR3, SPARC, ADAMTS1, ADAMTS5, syndecan 4 (SDC4), and collagen type VI, alpha 1 (COL6A1). After 4 days, TGFB1, TGFB2, TGFB3, THBS2, and TIMP3 mRNA levels were upregulated in the recovering eye. Significant downregulation, relative to normal eyes, was found in both the control and treated eyes for most genes after 1 day of compensation; a similar decrease was found, compared to lens-compensated eyes, after one day of recovery. Protein levels for THBS1 showed positive correlation with the differential mRNA levels and TGFBR3 showed a negative correlation. No differential protein expression was found for TGFB2, TGFBI, MMP14, and TIMP3. Conclusions The different patterns of differential mRNA expression during minus lens compensation (hyperopia) and recovery (myopia) show that scleral fibroblasts distinguish between “go” and “stop” conditions. There is evidence of binocular global downregulation of genes at the start of both lens wear and recovery. As additional information accumulates about changes in gene expression that occur during compensation and recovery the “signature” of differential changes may help us to understand in more detail how the sclera responds in “go” and “stop” conditions. PMID:21541268

Gao, Hong; Frost, Michael R.; Norton, Thomas T.

2011-01-01

310

Histochemical localization of cytochrome oxidase activity in the visual system of the tree shrew:normal patterns and the effect of retinal impulse blockage.  

PubMed

The tree shrew Tupaia belangeri has three functional pathways (ON-center, OFF-center, and W-like cells) that arise in the retina and proceed through separate LGN laminae to separate cortical targets. To determine whether these pathways have consistent differences in activity, cytochrome oxidase (C.O.) patterns were examined in the retina, LGN, and striate cortex. In six normal tree shrews the outer and inner plexiform layers of the retina were highly reactive for C.O. A pale, vascularized cleft zone separated the a (OFF) and b (ON) inner plexiform sublaminae, which seemed about equally reactive for C.O. In the LGN, laminae 1 and 2 (ON-center cells) and laminae 4 and 5 (mostly OFF-center cells) were highly reactive for C.O. LGN lamina 3 and 6 are part of an W-like afferent pathway. Lamina 3 was distinctly paler than laminae 1, 2, 4, and 5 while lamina 6 was intermediate. In the striate cortex, layer IV was the most reactive layer. Sublayer IVb (predominantly an OFF region) was consistently more reactive than sublayer IVa (predominantly ON). The middle portion, layer IVm, was paler than either IVa or IVb. This paler region includes, but extends above and below, the cell-sparse "cleft" region. Thus, considering all three levels of the retinogeniculostriate pathway, the ON and OFF systems were equally active until they reached the striate cortex, where the OFF system appeared to be more active than the ON. The W-cell laminae in the LGN exhibited the lowest level of activity. The contribution of ganglion cell activity to these patterns was assessed by intravitreal administration of tetrodotoxin (TTX) blockade either monocularly (three animals) or binocularly (two animals). In the TTX-treated retinae, the inner plexiform a and b sublaminae were paler for C.O., although visible, and were still separated by the pale cleft. The ganglion cell layer was very pale in comparison to the normal. In the LGN, monocular TTX blockade reduced the C.O. reactivity in the ON and OFF laminae that received input from the treated eye but had little effect on the W-like cell laminae. The ipsilaterally innervated ON and OFF laminae were more affected than were the contralaterally innervated laminae. Binocular TTX treatment resulted in a decrease of C.O. activity in the binocular segment of the ON and OFF LGN laminae. In the striate cortex, the most marked changes following TTX treatment occurred in layer IV.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2843584

Wong-Riley, M T; Norton, T T

1988-06-22

311

Biomic Specialization and Speciation Rates in Ruminants (Cetartiodactyla, Mammalia): A Test of the Resource-Use Hypothesis at the Global Scale  

PubMed Central

The resource-use hypothesis proposed by E.S. Vrba predicts that specialist species have higher speciation and extinction rates than generalists because they are more susceptible to environmental changes and vicariance. In this work, we test some of the predictions derived from this hypothesis on the 197 extant and recently extinct species of Ruminantia (Cetartiodactyla, Mammalia) using the biomic specialization index (BSI) of each species, which is based on its distribution within different biomes. We ran 10000 Monte Carlo simulations of our data in order to get a null distribution of BSI values against which to contrast the observed data. Additionally, we drew on a supertree of the ruminants and a phylogenetic likelihood-based method (QuaSSE) for testing whether the degree of biomic specialization affects speciation rates in ruminant lineages. Our results are consistent with the predictions of the resource-use hypothesis, which foretells a higher speciation rate of lineages restricted to a single biome (BSI?=?1) and higher frequency of specialist species in biomes that underwent high degree of contraction and fragmentation during climatic cycles. Bovids and deer present differential specialization across biomes; cervids show higher specialization in biomes with a marked hydric seasonality (tropical deciduous woodlands and schlerophyllous woodlands), while bovids present higher specialization in a greater variety of biomes. This might be the result of divergent physiological constraints as well as a different biogeographic and evolutionary history. PMID:22174888

Cantalapiedra, Juan L.; Hernández Fernández, Manuel; Morales, Jorge

2011-01-01

312

Taxonomic uncertainty and the loss of biodiversity on Christmas Island, Indian Ocean.  

PubMed

The taxonomic uniqueness of island populations is often uncertain which hinders effective prioritization for conservation. The Christmas Island shrew (Crocidura attenuata trichura) is the only member of the highly speciose eutherian family Soricidae recorded from Australia. It is currently classified as a subspecies of the Asian gray or long-tailed shrew (C. attenuata), although it was originally described as a subspecies of the southeast Asian white-toothed shrew (C. fuliginosa). The Christmas Island shrew is currently listed as endangered and has not been recorded in the wild since 1984-1985, when 2 specimens were collected after an 80-year absence. We aimed to obtain DNA sequence data for cytochrome b (cytb) from Christmas Island shrew museum specimens to determine their taxonomic affinities and to confirm the identity of the 1980s specimens. The Cytb sequences from 5, 1898 specimens and a 1985 specimen were identical. In addition, the Christmas Island shrew cytb sequence was divergent at the species level from all available Crocidura cytb sequences. Rather than a population of a widespread species, current evidence suggests the Christmas Island shrew is a critically endangered endemic species, C. trichura, and a high priority for conservation. As the decisions typically required to save declining species can be delayed or deferred if the taxonomic status of the population in question is uncertain, it is hoped that the history of the Christmas Island shrew will encourage the clarification of taxonomy to be seen as an important first step in initiating informed and effective conservation action. PMID:24283832

Eldridge, Mark D B; Meek, Paul D; Johnson, Rebecca N

2014-04-01

313

[Contribution to the study of Microphallidae travassos, 1920 (Trematoda). XLV. Description of Maritrema feliui n. sp., parasite of shrews (Mammals) in Spain].  

PubMed

The authors describe and illustrate the morphology of the adult stage of Maritrema feliui n. sp. (Trematoda Microphallidae) obtained from the intestine of the shrew Crocidura russula (Hermann, 1780), definitive host of the fluke present in the estuary of the river Llobregat (Catalonia, Spain). The larval stages are found in two hosts obtained from the area: 1) Mercuria confusa (Frauenfeld) [= Pseudamnicola similis (Draparnaud)] (Mollusca: Hydrobiidae), and 2) Gammarus aequicauda (Martynov) (Crustacea: Amphipoda). The adult stage is anatomically related to the Maritrema with a mean size of the body, two equal suckers, a short oesophagus and long caeca, and a short and transversal cirrus pouch with a smooth and filiform cirrus. According to morphological and geographical affinities, the authors propose the synonymies of 1) Maritrema "opisthometra" sensu Bridgman et al., 1972 with M. chiriacae Deblock, 1975; 2) Maritrema longiforme Kifune et al., 1972, with Maritrema laricola Ching, 1963. Besides Maritreminoides congjiangensis Chiu et Gu, 1981 is transferred into the genus Quasimaritrema Deblock, 1973 according to Maritreminoides Rankin is invalidated. PMID:8215113

Gracenea, M; Montoliu, I; Deblock, S

1993-01-01

314

The testis of greater white-toothed shrew Crocidura russula in Southern European populations: a case of adaptive lack of seasonal involution?  

PubMed

Males of all seasonal breeding mammals undergo circannual periods of testis involution resulting in almost complete ablation of the germinative epithelium. We performed a morphometric, histological, hormonal, and gene-expression study of the testes from winter and summer males of the greater white-toothed shrew, Crocidura russula, in populations of the southeastern Iberian Peninsula. Unexpectedly, we found no significant differences between the two study groups. Surprisingly, female data confirmed a non-breeding period in the summer, evidencing that males retain full testis function even when most females are not receptive. This situation, which has not been described before, does not occur in northern populations of the same species where, in addition, the reproductive cycle is inverted with respect to those in the south, as the non-breeding period occurs in winter instead in summer. Considering that the non-reproductive period shortens at lower latitude locations, we hypothesize that in southern populations the non-breeding period is short enough to make testis regression inefficient in terms of energy savings, because: (1) testes of C. russula are very small, a condition derived from their monogamy that implies low investment in spermatogenesis; and (2) the spermatogenic cycle of this species is slow and long. The inverted seasonal breeding cycle and the lack of seasonal testis regression described here are new adaptive processes that deserve further research, and provide evidence that the genetic and hormonal mechanisms controlling reproduction timing in mammals are more plastic and versatile than initially suspected. PMID:24895181

Massoud, Diaa; Barrionuevo, Francisco J; Ortega, Esperanza; Burgos, Miguel; Jiménez, Rafael

2014-07-01

315

Redescription and systematic position of Soricinia tripartita Zarnowski, 1955 (Cestoda: Cyclophyllidea), a cestode species parasitic in shrews of the genus Sorex, including erection of Gulyaevilepis gen. n.  

PubMed

Soricinia tripartita Zarnowski, 1955 is redescribed on the basis of specimens from the type host Sorex araneus Linnaeus from Lithuania, Latvia and Russia (Republic of Karelia and Republic of Komi - a new geographical record) as well as from Sorex satunini Ognev and Sorex volnuchini Ognev from Russia (Nalchik Area in the Caucasus Mountains). The strobilar morphology of S. tripartita is compared with that of other hymenolepidid cestodes of shrews with an unarmed scolex and serial development of proglottides in the strobila, i.e. species of Mathevolepis Spassky, 1948, Ditestolepis Soltys, 1952, Spasskylepis Schaldybin, 1964, Ecrinolepis Spassky et Karpenko, 1983 and Diorchilepis Lykova, Gulyaev, Melnikova et Karpenko, 2006. It was noted that S. tripartita does not correspond to any of the known genera. The following unique characters are found for S. tripartita: heteronomous serial strobilation with one or two sterile proglottides at the end of each series in the strobila and the whole copulatory part of the vagina covered with numerous, fine spines. Therefore, the new genus Gulyaevilepis is erected, with Gulyaevilepis tripartita (Zarnowski, 1955) comb. n. as its type and only species. Since the type material of Soricinia tripartita is not known to exist, a neotype from the same host species and from a locality close to the type locality is designated. PMID:24822320

Kornienko, Svetlana A; Binkiene, Rasa

2014-04-01

316

Additive antiemetic efficacy of low-doses of the cannabinoid CB(1/2) receptor agonist ?(9)-THC with ultralow-doses of the vanilloid TRPV1 receptor agonist resiniferatoxin in the least shrew (Cryptotis parva).  

PubMed

Previous studies have shown that cannabinoid CB1/2 and vanilloid TRPV1 agonists (delta-9-tetrahydrocannabinol (?(9)-THC) and resiniferatoxin (RTX), respectively) can attenuate the emetic effects of chemotherapeutic agents such as cisplatin. In this study we used the least shrew to demonstrate whether combinations of varying doses of ?(9)-THC with resiniferatoxin can produce additive antiemetic efficacy against cisplatin-induced vomiting. RTX by itself caused vomiting in a bell-shaped dose-dependent manner with maximal vomiting at 18 ?g/kg when administered subcutaneously (s.c.) but not intraperitoneally (i.p.). ?(9)-THC up to 10 mg/kg provides only 80% protection of least shrews from cisplatin-induced emesis with an ID50 of 0.3-1.8 mg/kg. Combinations of 1 or 5 ?g/kg RTX with varying doses of ?(9)-THC completely suppressed both the frequency and the percentage of shrews vomiting with ID50 dose values 5-50 times lower than ?(9)-THC doses tested alone against cisplatin. A less potent TRPV1 agonist, capsaicin, by itself did not cause emesis (i.p. or s.c.), but it did significantly reduce vomiting induced by cisplatin given after 30 min but not at 2 h. The TRPV1-receptor antagonist, ruthenium red, attenuated cisplatin-induced emesis at 5mg/kg; however, another TRPV1-receptor antagonist, capsazepine, did not. In summary, we present evidence that combination of CB1/2 and TRPV1 agonists have the capacity to completely abolish cisplatin-induced emesis at doses that are ineffective when used individually. PMID:24157976

Darmani, Nissar A; Chebolu, Seetha; Zhong, Weixia; Trinh, Chung; McClanahan, Bryan; Brar, Rajivinder S

2014-01-01

317

L-type calcium channels contribute to 5-HT3-receptor-evoked CaMKII? and ERK activation and induction of emesis in the least shrew (Cryptotis parva).  

PubMed

Activation of serotonergic 5-HT3 receptors by its selective agonist 2-methyl serotonin (2-Me-5-HT) induces vomiting, which is sensitive to selective antagonists of both 5-HT3 receptors (palonosetron) and L-type calcium channels (LTCC) (amlodipine or nifedipine). Previously we demonstrated that 5-HT3 receptor activation also causes increases in a palonosetron-sensitive manner in: i) intracellular Ca(2+) concentration, ii) attachment of calmodulin (CaM) to 5-HT3 receptor, and iii) phosphorylation of Ca(2+)/calmodulin-dependent protein kinase II? (CaMKII?) and extracellular-signal-regulated kinase 1/2 (ERK1/2). Here, we investigate the role of the short-acting LTCC blocker nifedipine on 2-Me-5-HT-evoked intracellular Ca(2+) increase and on downstream intracellular emetic signaling, which have been shown to be coupled with 2-Me-5-HT?s emetic effects in the least shrew. Using the cell-permeant Ca(2+) indicator fluo-4 AM, here we present evidence for the contribution of Ca(2+) influx through LTCCs (sensitive to nifedipine) in 2-Me-5-HT (1µM) -evoked rise in cytosolic Ca(2+) levels in least shrew brainstem slices. Nifedipine pretreatment (10mg/kg, s.c.) also suppressed 2-Me-5-HT-evoked interaction of 5-HT3 receptors with CaM as well as phosphorylation of CaMKII? and ERK1/2 in the least shrew brainstem, and 5-HT3 receptors -CaM colocalization in jejunum of the small intestine. In vitro exposure of isolated enterochromaffin cells of the small intestine to 2-Me-5-HT (1µM) caused CaMKII? phosphorylation, which was also abrogated by nifedipine pretreatment (0.1µM). In addition, pretreatment with the CaMKII inhibitor KN62 (10mg/kg, i.p.) suppressed emesis and also the activation of CaMKII?, and ERK in brainstem caused by 2-Me-5-HT (5mg/kg, i.p.). This study provides further mechanistic explanation for our published findings that nifedipine can dose-dependently protect shrews from 2-Me-5-HT-induced vomiting. PMID:25748600

Hutchinson, Tarun E; Zhong, Weixia; Chebolu, Seetha; Wilson, Sean M; Darmani, Nissar A

2015-05-15

318

High levels of antimicrobial resistance among escherichia coli isolates from livestock farms and synanthropic rats and shrews in the Mekong Delta of Vietnam.  

PubMed

In Mekong Delta farms (Vietnam), antimicrobials are extensively used, but limited data are available on levels of antimicrobial resistance (AMR) among Escherichia coli isolates. We performed a structured survey of AMR in E. coli isolates (n = 434) from 90 pig, chicken, and duck farms. The results were compared with AMR among E. coli isolates (n = 234) from 66 small wild animals (rats and shrews) trapped on farms and in forests and rice fields. The isolates were susceptibility tested against eight antimicrobials. E. coli isolates from farmed animals were resistant to a median of 4 (interquartile range [IQR], 3 to 6) antimicrobials versus 1 (IQR, 1 to 2) among wild mammal isolates (P < 0.001). The prevalences of AMR among farmed species isolates (versus wild animals) were as follows: tetracycline, 84.7% (versus 25.6%); ampicillin, 78.9% (versus 85.9%); trimethoprim-sulfamethoxazole, 52.1% (versus 18.8%); chloramphenicol, 39.9% (versus 22.5%); amoxicillin-clavulanic acid, 36.6% (versus 34.5%); and ciprofloxacin, 24.9% (versus 7.3%). The prevalence of multidrug resistance (MDR) (resistance against three or more antimicrobial classes) among pig isolates was 86.7% compared to 66.9 to 72.7% among poultry isolates. After adjusting for host species, MDR was ?8 times greater among isolates from wild mammals trapped on farms than among those trapped in forests/rice fields (P < 0.001). Isolates were assigned to unique profiles representing their combinations of susceptibility results. Multivariable analysis of variance indicated that AMR profiles from wild mammals trapped on farms and those from domestic animals were more alike (R(2) range, 0.14 to 0.30) than E. coli isolates from domestic animals and mammals trapped in the wild (R(2) range, 0.25 to 0.45). The results strongly suggest that AMR on farms is a key driver of environmental AMR in the Mekong Delta. PMID:25398864

Nhung, N T; Cuong, N V; Campbell, J; Hoa, N T; Bryant, J E; Truc, V N T; Kiet, B T; Jombart, T; Trung, N V; Hien, V B; Thwaites, G; Baker, S; Carrique-Mas, J

2015-02-01

319

High Levels of Antimicrobial Resistance among Escherichia coli Isolates from Livestock Farms and Synanthropic Rats and Shrews in the Mekong Delta of Vietnam  

PubMed Central

In Mekong Delta farms (Vietnam), antimicrobials are extensively used, but limited data are available on levels of antimicrobial resistance (AMR) among Escherichia coli isolates. We performed a structured survey of AMR in E. coli isolates (n = 434) from 90 pig, chicken, and duck farms. The results were compared with AMR among E. coli isolates (n = 234) from 66 small wild animals (rats and shrews) trapped on farms and in forests and rice fields. The isolates were susceptibility tested against eight antimicrobials. E. coli isolates from farmed animals were resistant to a median of 4 (interquartile range [IQR], 3 to 6) antimicrobials versus 1 (IQR, 1 to 2) among wild mammal isolates (P < 0.001). The prevalences of AMR among farmed species isolates (versus wild animals) were as follows: tetracycline, 84.7% (versus 25.6%); ampicillin, 78.9% (versus 85.9%); trimethoprim-sulfamethoxazole, 52.1% (versus 18.8%); chloramphenicol, 39.9% (versus 22.5%); amoxicillin-clavulanic acid, 36.6% (versus 34.5%); and ciprofloxacin, 24.9% (versus 7.3%). The prevalence of multidrug resistance (MDR) (resistance against three or more antimicrobial classes) among pig isolates was 86.7% compared to 66.9 to 72.7% among poultry isolates. After adjusting for host species, MDR was ?8 times greater among isolates from wild mammals trapped on farms than among those trapped in forests/rice fields (P < 0.001). Isolates were assigned to unique profiles representing their combinations of susceptibility results. Multivariable analysis of variance indicated that AMR profiles from wild mammals trapped on farms and those from domestic animals were more alike (R2 range, 0.14 to 0.30) than E. coli isolates from domestic animals and mammals trapped in the wild (R2 range, 0.25 to 0.45). The results strongly suggest that AMR on farms is a key driver of environmental AMR in the Mekong Delta. PMID:25398864

Nhung, N. T.; Cuong, N. V.; Campbell, J.; Hoa, N. T.; Bryant, J. E.; Truc, V. N. T.; Kiet, B. T.; Jombart, T.; Trung, N. V.; Hien, V. B.; Thwaites, G.; Baker, S.

2014-01-01

320

Synaptonemal complex analysis of interracial hybrids between the Moscow and Neroosa chromosomal races of the common shrew Sorex araneus showing regular formation of a complex meiotic configuration (ring-of-four)  

PubMed Central

Abstract Immunocytochemical and electron microscopic analysis of synaptonemal complexes (SCs) was carried out for the first time in homozygotes and complex Robertsonian heterozygotes (hybrids) of the common shrew, Sorex araneus Linnaeus, 1758, from a newly discovered hybrid zone between the Moscow and the Neroosa chromosomal races. These races differ in four monobrachial homologous metacentrics, and closed SC tetravalent is expected to be formed in meiosis of a hybrid. Indeed, such a multivalent was found at meiotic prophase I in hybrids. Interactions between multivalent and both autosomes and/or the sex chromosomes were observed. For the first time we have used immunocytochemical techniques to analyse asynapsis in Sorex araneus and show that the multivalent pairs in an orderly fashion with complete synapsis. Despite some signs of spermatocytes arrested in the meiotic prophase I, hybrids had large number of active sperm. Thus, Moscow – Neroosa hybrid males that form a ring-of-four meiotic configuration are most likely not sterile. Our results support previous demonstrations that monobrachial homology of metacentrics of the common shrew does not lead to complete reproductive isolation between parapatric chromosomal races of the species. PMID:24260670

Matveevsky, Sergey N.; Pavlova, Svetlana V.; Maret M. Acaeva;  Oxana L. Kolomiets

2012-01-01

321

The electrocardiogram of European shrews.  

PubMed

A recording method of electrocardiograms in resting animals is described. The electrocardiograms of Crocidura russula, Crocidura leucodon, Crocidura suaveolens, Neomys fodiens and Sorex araneus are similar to those of other small mammals. T-wave directly follows the QRS-complex. The duration of electrocardiograms depends on heart mass and body temperature. Heart rate shows no influence on the duration of electrocardiograms. PMID:2870871

Nagel, A

1986-01-01

322

Serotonin 5-HT3 Receptor-Mediated Vomiting Occurs via the Activation of Ca2+/CaMKII-Dependent ERK1/2 Signaling in the Least Shrew (Cryptotis parva)  

PubMed Central

Stimulation of 5-HT3 receptors (5-HT3Rs) by 2-methylserotonin (2-Me-5-HT), a selective 5-HT3 receptor agonist, can induce vomiting. However, downstream signaling pathways for the induced emesis remain unknown. The 5-HT3R channel has high permeability to extracellular calcium (Ca2+) and upon stimulation allows increased Ca2+ influx. We examined the contribution of Ca2+/calmodulin-dependent protein kinase II? (Ca2+/CaMKII?), interaction of 5-HT3R with calmodulin, and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling to 2-Me-5-HT-induced emesis in the least shrew. Using fluo-4 AM dye, we found that 2-Me-5-HT augments intracellular Ca2+ levels in brainstem slices and that the selective 5-HT3R antagonist palonosetron, can abolish the induced Ca2+ signaling. Pre-treatment of shrews with either: i) amlodipine, an antagonist of L-type Ca2+ channels present on the cell membrane; ii) dantrolene, an inhibitor of ryanodine receptors (RyRs) Ca2+-release channels located on the endoplasmic reticulum (ER); iii) a combination of their less-effective doses; or iv) inhibitors of CaMKII (KN93) and ERK1/2 (PD98059); dose-dependently suppressed emesis caused by 2-Me-5-HT. Administration of 2-Me-5-HT also significantly: i) enhanced the interaction of 5-HT3R with calmodulin in the brainstem as revealed by immunoprecipitation, as well as their colocalization in the area postrema (brainstem) and small intestine by immunohistochemistry; and ii) activated CaMKII? in brainstem and in isolated enterochromaffin cells of the small intestine as shown by Western blot and immunocytochemistry. These effects were suppressed by palonosetron. 2-Me-5-HT also activated ERK1/2 in brainstem, which was abrogated by palonosetron, KN93, PD98059, amlodipine, dantrolene, or a combination of amlodipine plus dantrolene. However, blockade of ER inositol-1, 4, 5-triphosphate receptors by 2-APB, had no significant effect on the discussed behavioral and biochemical parameters. This study demonstrates that Ca2+ mobilization via extracellular Ca2+ influx through 5-HT3Rs/L-type Ca2+ channels, and intracellular Ca2+ release via RyRs on ER, initiate Ca2+-dependent sequential activation of CaMKII? and ERK1/2, which contribute to the 5-HT3R-mediated, 2-Me-5-HT-evoked emesis. PMID:25121483

Zhong, Weixia; Hutchinson, Tarun E.; Chebolu, Seetha; Darmani, Nissar A.

2014-01-01

323

Lipotyphla limb myology comparison.  

PubMed

Fore- and hindlimb muscles were dissected in four species of Lipotyphla: the western European hedgehog Erinaceus europaeus (Erinaceidae, Erinaceinae); the moonrat Echinosorex gymnura (Erinaceidae, Hylomyinae or Galericinae); the tailless tenrec Tenrec ecaudatus (Tenrecidae, Tenrecinae); and the common European white-toothed shrew Crocidura russula (Soricidae, Soricinae). This work completely reviews the limb musculature of these walking mammals. Twelve myological characters were evaluated in order to disclose phylogenetic relationships. The cladogram obtained supported previous ones based on cranial and dental characters. This study shows that myological characters are valuable in phylogenetic analyses. PMID:11921044

Neveu, Pauline; Gasc, Jean-Pierre

2002-05-01

324

The historical biogeography of Mammalia  

PubMed Central

Palaeobiogeographic reconstructions are underpinned by phylogenies, divergence times and ancestral area reconstructions, which together yield ancestral area chronograms that provide a basis for proposing and testing hypotheses of dispersal and vicariance. Methods for area coding include multi-state coding with a single character, binary coding with multiple characters and string coding. Ancestral reconstruction methods are divided into parsimony versus Bayesian/likelihood approaches. We compared nine methods for reconstructing ancestral areas for placental mammals. Ambiguous reconstructions were a problem for all methods. Important differences resulted from coding areas based on the geographical ranges of extant species versus the geographical provenance of the oldest fossil for each lineage. Africa and South America were reconstructed as the ancestral areas for Afrotheria and Xenarthra, respectively. Most methods reconstructed Eurasia as the ancestral area for Boreoeutheria, Euarchontoglires and Laurasiatheria. The coincidence of molecular dates for the separation of Afrotheria and Xenarthra at approximately 100 Ma with the plate tectonic sundering of Africa and South America hints at the importance of vicariance in the early history of Placentalia. Dispersal has also been important including the origins of Madagascar's endemic mammal fauna. Further studies will benefit from increased taxon sampling and the application of new ancestral area reconstruction methods. PMID:21807730

Springer, Mark S.; Meredith, Robert W.; Janecka, Jan E.; Murphy, William J.

2011-01-01

325

Broad-spectrum antiemetic potential of the L-type calcium channel antagonist nifedipine and evidence for its additive antiemetic interaction with the 5-HT(3) receptor antagonist palonosetron in the least shrew (Cryptotis parva).  

PubMed

Cisplatin-like chemotherapeutics cause vomiting via release of multiple neurotransmitters (dopamine, serotonin (5-HT), or substance P (SP)) from the gastrointestinal enterochromaffin cells and/or the brainstem via a calcium dependent process. Diverse channels in the plasma membrane allow extracellular Ca(2+) entry into cells for the transmitter release process. Agonists of 5-HT3 receptors increase calcium influx through both 5-HT3 receptors and L-type Ca(2+) channels. We envisaged that L-type calcium agonists such as FPL 64176 should cause vomiting and corresponding antagonists such as nifedipine would behave as broad-spectrum antiemetics. Administration of FPL 64176 did cause vomiting in the least shrew in a dose-dependent fashion. Nifedipine and the 5-HT3 receptor antagonist palonosetron, potently suppressed FPL 64176-induced vomiting, while a combination of ineffective doses of these antagonists was more efficacious. Subsequently, we investigated the broad-spectrum antiemetic potential of nifedipine against diverse emetogens including agonists of serotonergic 5-HT3- (e.g. 5-HT or 2-Me-5-HT), SP tachykinin NK1- (GR73632), dopamine D2- (apomorphine or quinpirole), and cholinergic M1- (McN-A-343) receptors, as well as the non-specific emetogen, cisplatin. Nifedipine by itself suppressed vomiting in a potent and dose-dependent manner caused by the above emetogens except cisplatin. Moreover, low doses of nifedipine potentiated the antiemetic efficacy of non-effective or semi-effective doses of palonosetron against vomiting caused by either 2-Me-5-HT or cisplatin. Thus, our findings demonstrate that activation of L-type calcium channels causes vomiting, whereas blockade of these ion channels by nifedipine-like antagonists not only provides broad-spectrum antiemetic activity but can also potentiate the antiemetic efficacy of well-established antiemetics such as palonosetron. L-type calcium channel antagonists should also provide antiemetic activity against drug-induced vomiting as well as other emetogens including bacterial and viral proteins. PMID:24513517

Darmani, Nissar A; Zhong, Weixia; Chebolu, Seetha; Vaezi, Mariam; Alkam, Tursun

2014-01-01

326

Evolutionary Insights from a Genetically Divergent Hantavirus Harbored by the European Common Mole (Talpa europaea)  

PubMed Central

Background The discovery of genetically distinct hantaviruses in shrews (Order Soricomorpha, Family Soricidae) from widely separated geographic regions challenges the hypothesis that rodents (Order Rodentia, Family Muridae and Cricetidae) are the primordial reservoir hosts of hantaviruses and also predicts that other soricomorphs harbor hantaviruses. Recently, novel hantavirus genomes have been detected in moles of the Family Talpidae, including the Japanese shrew mole (Urotrichus talpoides) and American shrew mole (Neurotrichus gibbsii). We present new insights into the evolutionary history of hantaviruses gained from a highly divergent hantavirus, designated Nova virus (NVAV), identified in the European common mole (Talpa europaea) captured in Hungary. Methodology/Principal Findings Pair-wise alignment and comparison of the full-length S- and L-genomic segments indicated moderately low sequence similarity of 54–65% and 46–63% at the nucleotide and amino acid levels, respectively, between NVAV and representative rodent- and soricid-borne hantaviruses. Despite the high degree of sequence divergence, the predicted secondary structure of the NVAV nucleocapsid protein exhibited the characteristic coiled-coil domains at the amino-terminal end, and the L-segment motifs, typically found in hantaviruses, were well conserved. Phylogenetic analyses, using maximum-likelihood and Bayesian methods, showed that NVAV formed a distinct clade that was evolutionarily distant from all other hantaviruses. Conclusions Newly identified hantaviruses harbored by shrews and moles support long-standing virus-host relationships and suggest that ancestral soricomorphs, rather than rodents, may have been the early or original mammalian hosts. PMID:19582155

Kang, Hae Ji; Bennett, Shannon N.; Sumibcay, Laarni; Arai, Satoru; Hope, Andrew G.; Mocz, Gabor; Song, Jin-Won; Cook, Joseph A.; Yanagihara, Richard

2009-01-01

327

Photoreceptor types and distributions in the retinae of insectivores.  

PubMed

The retinae of insectivores have been rarely studied, and their photoreceptor arrangements and expression patterns of visual pigments are largely unknown. We have determined the presence and distribution of cones in three species of shrews (common shrew Sorex araneus, greater white-toothed shrew Crocidura russula, dark forest shrew Crocidura poensis; Soricidae) and in the lesser hedgehog tenrec Echinops telfairi (Tenrecidae). Special cone types were identified and quantified in flattened whole retinae by antisera/antibodies recognizing the middle-to-long-wavelength-sensitive (M/L-)cone opsin and the short-wavelength-sensitive (S-)cone opsin, respectively. A combination of immunocytochemistry with conventional histology was used to assess rod densities and cone/rod ratios. In all four species the rods dominate at densities of about 230,000-260,000/mm2. M/L- and S-cones are present, comprising between 2% of the photoreceptors in the nocturnal Echinops telfairi and 13% in Sorex araneus that has equal diurnal and nocturnal activity phases. This suggests dichromatic color vision like in many other mammals. A striking feature in all four species are dramatically higher S-cone proportions in ventral than in dorsal retina (0.5% vs. 2.5-12% in Sorex, 5-15% vs. 30-45% in Crocidura poensis, 3-12% vs. 20-50% in Crocidura russula, 10-30% vs. 40-70% in Echinops). The functional and comparative aspects of these structural findings are discussed. PMID:11193110

Peichl, L; Künzle, H; Vogel, P

2000-01-01

328

OF AFRICAVOLUME IV HEDGEHOGS, SHREWS AND BATS  

E-print Network

is available from the British Library. Library of Congress Cataloging-in-Publication Data has been applied for Leone, Liberia, Guinea, Cote d'Ivoire, Ghana, Togo, Cameroon, perhaps Central African Republic

Richner, Heinz

329

Reproduction in the arctic shrew, Sorex arcticus  

E-print Network

outwash sand. Trapping was conducted from 1973 to 1977, in a wet, grass-sedge meadow. The vegetation was dominated by reed canary grass (Phalaris arundinacea). Patches of reed grass (Calamagrostis canadensis) and sedges (Carex spp.) grew...

Baird, Donna Day; Timm, Robert M.; Nordquist, Gerda E.

1983-05-01

330

EVOLUTIONARY RELATIONSHIPS IN MACROTUS (MAMMALIA: CHIROPTERA) : BIOCHEMICAL  

E-print Network

of the New World populations of Myotis velifer (a vesper- leaf-nosed bats of the genus Macrotus by tilionid- vespertilionid bats, Pipistrellus hsperus edge of changing patterns of genotype and Myotis californicus were

Baker, Robert J.

331

Arthritis in a glyptodont (Mammalia, Xenarthra, Cingulata).  

PubMed

Arthritic lesions have been frequently diagnosed in the fossil record, with spondyloarthropathy (a type of erosive and pan-mammalian arthritis) being one of the most common types described to date for mammals, though not restricted to this group. Here, we identify spondyloarthropathy in fossil bones from the late Pleistocene in Brazil assignable to a large glyptodont individual. Bone erosions in the peripheral joints (viz., the ulna, radius, left femur and tibiae-fibulae) associated with osteosclerosis allow the diagnosis of spondyloarthropathy. The presence of osteophytes in seven bones of the forelimbs (viz., the ulna and radius) and hind limbs (viz., the tibiae-fibulae, left femur and patellae) and a subchondral cyst in one element (viz., the left femur) indicate secondary osteoarthritis. A calcified deposition on the articular surface of the left patella indicates the presence of calcium pyrophosphate deposition disease, which, like the observed osteoarthritic alterations, likely represents a complication of spondyloarthropathy. This is the first report of spondyloarthropathy for xenarthrans. PMID:24551126

Barbosa, Fernando Henrique de Souza; Porpino, Kleberson de Oliveira; Fragoso, Ana Bernadete Lima; Oliveira, Edison Vicente

2014-01-01

332

Molecular evidence for multiple origins of Insectivora and for a new order of endemic African insectivore mammals  

PubMed Central

The traditional views regarding the mammalian order Insectivora are that the group descended from a single common ancestor and that it is comprised of the following families: Soricidae (shrews), Tenrecidae (tenrecs), Solenodontidae (solenodons), Talpidae (moles), Erinaceidae (hedgehogs and gymnures), and Chrysochloridae (golden moles). Here we present a molecular analysis that includes representatives of all six families of insectivores, as well as 37 other taxa representing marsupials, monotremes, and all but two orders of placental mammals. These data come from complete sequences of the mitochondrial 12S rRNA, tRNA-Valine, and 16S rRNA genes (2.6 kb). A wide range of different methods of phylogenetic analysis groups the tenrecs and golden moles (both endemic to Africa) in an all-African superordinal clade comprised of elephants, sirenians, hyracoids, aardvark, and elephant shrews, to the exclusion of the other four remaining families of insectivores. Statistical analyses reject the idea of a monophyletic Insectivora as well as traditional concepts of the insectivore suborder Soricomorpha. These findings are supported by sequence analyses of several nuclear genes presented here: vWF, A2AB, and ?-? hemoglobin. These results require that the order Insectivora be partitioned and that the two African families (golden moles and tenrecs) be placed in a new order. The African superordinal clade now includes six orders of placental mammals. PMID:9707584

Stanhope, Michael J.; Waddell, Victor G.; Madsen, Ole; de Jong, Wilfried; Hedges, S. Blair; Cleven, Gregory C.; Kao, Diana; Springer, Mark S.

1998-01-01

333

Diversification processes in an island radiation of shrews  

E-print Network

Southeast Asian mammals are known for their remarkable levels of diversity and endemism. However, few explicit tests of the mechanisms that may promote or inhibit speciation have been conducted on regional clades. I use ...

Esselstyn, Jacob Aaron

2010-04-22

334

Inbreeding in the greater white-toothed shrew, Crocidura russula.  

PubMed

We combined mark-and-recapture studies with genetic techniques of parentage assignment to evaluate the interactions between mating, dispersal, and inbreeding, in a free-ranging population of Crocidura russula. We found a pattern of limited and female-biased dispersal, followed by random mating within individual neighborhoods. This results in significant inbreeding at the population level: mating among relatives occurs more often than random, and F(IT) analyses reveal significant deficits in heterozygotes. However, related mating partners were not less fecund, and inbred offspring had no lower lifetime reproductive output. Power analyses show these negative results to be quite robust. Absence of phenotypic evidence of inbreeding depression might result from a history of purging: local populations are small and undergo disequilibrium gene dynamics. Dispersal is likely caused by local saturation and (re)colonization of empty breeding sites, rather than inbreeding avoidance. PMID:12703953

Duarte, L C; Bouteiller, C; Fontanillas, I P; Petit, E; Perrin, N

2003-03-01

335

A Reexamination of the Carnivora Malleus (Mammalia, Placentalia)  

PubMed Central

Authoritative anatomical references depict domestic dogs and cats as having a malleus with a short rostral (anterior) process that is connected via a ligament to the ectotympanic of the auditory bulla. Similar mallei have been reported for representatives of each of the 15 extant families of Carnivora, the placental order containing dogs and cats. This morphology is in contrast to a malleus with a long rostral process anchored to the ectotympanic that is considered to be primitive for mammals. Our reexamination of extant carnivorans found representatives from 12 families that possess an elongate rostral process anchored to the ectotympanic. Consequently, the malleus also is a component of the bulla. In a subset of our carnivoran sample, we confirmed that the elongate rostral process on the ectotympanic is continuous with the rest of the malleus through a thin osseous lamina. This morphology is reconstructed as primitive for Carnivora. Prior inaccurate descriptions of the taxa in our sample having mallei continuous with the bulla were based on damaged mallei. In addition to coupling to the ectotympanic, the rostral process of the malleus was found to have a hook-like process that fits in a facet on the skull base in representatives from seven families (felids, nandiniids, viverrids, canids, ursids, procyonids, and mustelids); its occurrence in the remaining families could not be ascertained. This feature is named herein the mallear hook and is likewise reconstructed to be primitive for Carnivora. We also investigated mallei in one additional placental order reported to have mallei not connected to the ectotympanic, Pholidota (pangolins), the extant sister group of Carnivora. We found pholidotans to also have anchored mallei with long rostral processes, but lacking mallear hooks. In light of our results, other mammals previously reported to have short rostral processes should be reexamined. PMID:23209753

Wible, John R.; Spaulding, Michelle

2012-01-01

336

Generic names of northern and southern fur seals (Mammalia: Otariidae)  

USGS Publications Warehouse

We have resolved a nomenclatural problem discovered during research on the northern fur seal that concerns the correct generic name for this taxon and for fur seals of the Southern Hemisphere. The unfortunate practice by some 19th century authors to use names in their Latinized form, but to date them from their first appearance as French common names led to the use of Arctocephalus for southern fur seals when the name correctly applies to the northern fur seal, known today as Callorhinus ursinus. However, Arctocephalus and Callorhinus are antedated by Otoes G. Fischer, 1817, which is the earliest available generic for the fur seal of the northern Pacific. The earliest available generic name for southern fur seals is Halarctus Gill, 1866. To avoid the confusion that would result from replacing the currently used generic names with those required by strict adherence to the Principle of Priority, we have petitioned the International Commission on Zoological nomenclature to preserve Arctocephalus and Callorhinus for the southern and northern fur seals, respectively.

Gardner, A.L.; Robbins, C.B.

1998-01-01

337

The deciduous premolars of Mammut americanum (Mammalia, Proboscidea)  

Microsoft Academic Search

Deciduous premolars of Mammut americanum have received relatively little study, and previous work was based on small sample sizes. We present morphologic descriptions and quantitative data for a sample of over 135 deciduous premolars of M. americanum from Florida. Most second and third deciduous premolars are bilophodont, although a few anomalous teeth deviate from this pattern to a varying degree.

Jeremy L. Green; Richard C. Hulbert Jr

2005-01-01

338

Evolution of chromosomal variation in cottontails, genus Sylvilagus (Mammalia: Lagomorpha)  

Microsoft Academic Search

Chromosomes from cultured fibroblasts of four cottontail species (Sylvilagus audubonii, 2n = 42; S. idahoensis, 2n = 44; S. nuttallii, 2n = 42; and S. palustris, 2n = 38) were analyzed using G- and C-banding techniques. The evolutionary restructuring of the genomes of these species was traced by comparing their banded chromosomes to those of Lepus saxatilis, a species of

T. J. Robinson; F. F. B. Elder; J. A. Chapman

1984-01-01

339

Breaking constraint: axial patterning in Trichechus (Mammalia: Sirenia).  

PubMed

Meristic variation is often limited in serially homologous systems with high internal differentiation and high developmental modularity. The mammalian neck, an extreme example, has a fixed (at seven) count of diversely specialized segments. Imposition of the mammalian cervical constraint has been tentatively linked to the origin of the diaphragm, which is muscularized by cells that migrate from cervical somites during development. With six cervical vertebrae, the genus Trichechus (manatee) has apparently broken this constraint, although the mechanism of constraint escape is unknown. Hypotheses for the developmental origin of Trichechus cervical morphology include cervical rib 7 repatterning, a primaxial/abaxial patterning shift, and local homeosis at the cervical/thoracic boundary. We tested predictions of these hypotheses by documenting vertebral morphology, axial ossification patterns, regionalization of the postcranial skeleton, and the relationship of thoracic ribs to sternal subunits in a large data set of fetal and adult Trichechus and Dugong specimens. These observations forced rejection of all three hypotheses. We propose alternatively that a global slowing of the rate of somitogenesis reduced somite count and disrupted alignment of Hox-generated anatomical markers relative to somite (and vertebral) boundaries throughout the Trichechus column. This hypothesis is consistent with observations of the full range of traditional cervical morphologies in the six cervical vertebrae, conserved postcranial proportions, and column-wide reduction in count relative to its sister taxon, Dugong. It also suggests that the origin of the mammalian cervical constraint lies in patterning, not in count, and that Trichechus and the tree sloths have broken the constraint using different developmental mechanisms. PMID:25339599

Buchholtz, Emily A; Wayrynen, Kaisa L; Lin, Iris W

2014-01-01

340

Ecological correlates to cranial morphology in Leporids (Mammalia, Lagomorpha)  

PubMed Central

The mammalian order Lagomorpha has been the subject of many morphometric studies aimed at understanding the relationship between form and function as it relates to locomotion, primarily in postcranial morphology. The leporid cranial skeleton, however, may also reveal information about their ecology, particularly locomotion and vision. Here we investigate the relationship between cranial shape and the degree of facial tilt with locomotion (cursoriality, saltation, and burrowing) within crown leporids. Our results suggest that facial tilt is more pronounced in cursors and saltators compared to generalists, and that increasing facial tilt may be driven by a need for expanded visual fields. Our phylogenetically informed analyses indicate that burrowing behavior, facial tilt, and locomotor behavior do not predict cranial shape. However, we find that variables such as bullae size, size of the splenius capitus fossa, and overall rostral dimensions are important components for understanding the cranial variation in leporids. PMID:25802812

Sherratt, Emma; Bumacod, Nicholas; Wedel, Mathew J.

2015-01-01

341

A phylogenetic estimate for golden moles (Mammalia, Afrotheria, Chrysochloridae)  

E-print Network

_pres, 40 occiput / 0_90angle 1_mushroom, 41 sinus_canal_AH47 / 0_pres 1_abs, 42 sinus_canal_foramen_AH48 / 0_confl_sphenorb_fissure '1_betw_sphenorb-ethmoid' 2_confl_ethmoid, 43 frontal_proportions_AH61 / 0_elongate 1_similar_parietal 2_shorter...

Asher, Robert J; Maree, Sarita; Bronner, Gary; Bennett, Nigel C; Bloomer, Paulette; Czechowski, Paul; Meyer, Matthias; Hofreiter, Michael

2010-03-09

342

Karyological study of four Japanese Myotis bats (Chiroptera, Mammalia)  

Microsoft Academic Search

Karyological investigations of four Japanese Myotis species were made based on Gand C-banding pattern analysis. It was revealed that the four species, M. nattereri, M. hosonoi, M. frater kaguyae and M. macrodactylus have all 2n=44 and their karyotypes are, excepting one chromosome pair, identical each other. The only difference in their karyotypes was found on the morphology of the chromosome

M. Harada; T. H. Yosida

1978-01-01

343

Postcanine Dental Form in the Mustelidae and Viverridae (Carnivora: Mammalia)  

E-print Network

morphology of mustelid and viverrid postcanine dentitions corresponds with differences in diet. For each. Principal components analysis distinguishes species according to morphological differences in the dentition are more likely to be corre- spondingly specialized in the dentition and species with varied food sources

Meyers, Ron

344

On the development of the shoulder girdle in Crocidura russula (Soricidae) and other placental mammals: evolutionary and functional aspects.  

PubMed

The development of the shoulder girdle was studied in embryonic stages and a neonate of Crocidura russula using histological sections and 3-D reconstructions. Neonatal stages of Suncus etruscus and Mesocricetus auratus, both altricial placentals, were also studied. The earliest stage of C russula, in which the scapula is still partially blastematous, has already a supraspinous fossa. The dorsal portion of the scapular spine does not develop from the anterior margin of the scapula. Its mode of development varies among the placentals studied to date. In some it is completely appositional bone, in others it consists of bone formed mostly by endochondral ossification of a dorsal cartilaginous process stemming from the acromium. During development the supraspinatus muscle increases in size in proportion to the infraspinatus muscle and the humeral head increases in size in relation to the glenoid fossa. Placentals have secondary cartilage in the sternal and acromial ends of the clavicle, a derived feature absent in Marsupialia. Even the most altricial placentals have a more developed shoulder girdle at birth than any newborn marsupial studied to date. PMID:12448772

Grossmann, Martin; Sánchez-Villagra, Marcelo R; Maier, Wolfgang

2002-11-01

345

On the development of the shoulder girdle in Crocidura russula (Soricidae) and other placental mammals: evolutionary and functional aspects  

PubMed Central

The development of the shoulder girdle was studied in embryonic stages and a neonate of Crocidura russula using histological sections and 3-D reconstructions. Neonatal stages of Suncus etruscus and Mesocricetus auratus, both altricial placentals, were also studied. The earliest stage of C. russula, in which the scapula is still partially blastematous, has already a supraspinous fossa. The dorsal portion of the scapular spine does not develop from the anterior margin of the scapula. Its mode of development varies among the placentals studied to date. In some it is completely appositional bone, in others it consists of bone formed mostly by endochondral ossification of a dorsal cartilaginous process stemming from the acromium. During development the supraspinatus muscle increases in size in proportion to the infraspinatus muscle and the humeral head increases in size in relation to the glenoid fossa. Placentals have secondary cartilage in the sternal and acromial ends of the clavicle, a derived feature absent in Marsupialia. Even the most altricial placentals have a more developed shoulder girdle at birth than any newborn marsupial studied to date. PMID:12448772

Großmann, Martin; Sánchez-Villagra, Marcelo R; Maier, Wolfgang

2002-01-01

346

Blarina hylophaga (Soricomorpha: Soricidae) CODY W. THOMPSON, JERRY R. CHOATE*, HUGH H. GENOWAYS, AND ELMER J. FINCK  

E-print Network

Blarina brevicauda hulophaga Elliot, 1899:287. Type locality ``Dougherty, Indian Territory.'' (5 Dougherty, Murray Co., Oklahoma, USA). Blarina [(Blarina)] brevicauda hylophaga Elliot, 1905:461. Justified emendation of Blarina brevicauda hulophaga Elliot, 1899:287. Blarina brevicauda carolinensis: Blair, 1939

Hayssen, Virginia

347

Shared Ancestry between a Newfound Mole-Borne Hantavirus and Hantaviruses Harbored by Cricetid Rodents ?†  

PubMed Central

Discovery of genetically distinct hantaviruses in multiple species of shrews (order Soricomorpha, family Soricidae) and moles (family Talpidae) contests the conventional view that rodents (order Rodentia, families Muridae and Cricetidae) are the principal reservoir hosts and suggests that the evolutionary history of hantaviruses is far more complex than previously hypothesized. We now report on Rockport virus (RKPV), a hantavirus identified in archival tissues of the eastern mole (Scalopus aquaticus) collected in Rockport, TX, in 1986. Pairwise comparison of the full-length S, M, and L genomic segments indicated moderately low sequence similarity between RKPV and other soricomorph-borne hantaviruses. Phylogenetic analyses, using maximum-likelihood and Bayesian methods, showed that RKPV shared a most recent common ancestor with cricetid-rodent-borne hantaviruses. Distributed widely across the eastern United States, the fossorial eastern mole is sympatric and syntopic with cricetid rodents known to harbor hantaviruses, raising the possibility of host-switching events in the distant past. Our findings warrant more-detailed investigations on the dynamics of spillover and cross-species transmission of present-day hantaviruses within communities of rodents and moles. PMID:21632770

Kang, Hae Ji; Bennett, Shannon N.; Hope, Andrew G.; Cook, Joseph A.; Yanagihara, Richard

2011-01-01

348

Long-term effects of precommercial thinning on small mammals in northern Maine  

USGS Publications Warehouse

Precommercial thinning (PCT) is being practiced increasingly throughout the Acadian forest of eastern North America to meet silvicultural objectives; however, effects of this practice on wildlife, both immediately and several years post-treatment are not well understood. Forest dependent small mammals have ecological roles as prey for numerous avian and mammalian predators, dispersers of seeds, fruit, and spores, and contribute to nutrient cycling. Researchers in the northwestern USA have suggested that thinning of young, regenerating clearcuts may increase the abundance and diversity of some forest-dependent small mammals by increasing rates of forest development and enhancing the ecological representation of mid-successional stands across managed landscapes. We examined the effects of PCT within conifer-dominated forest stands 1-, 6-, 11-, and 16-years post-treatment, on abundances of mice, voles, and shrews, and on within-stand structure in the commercially managed, Acadian forests of northern Maine. We live-trapped small mammals on 24 herbicide-treated clearcuts treated with PCT and on 13 similar, unthinned stands during summers of 2000 and 2001. Thinning of mid-successional conifer stands resulted in increased abundances, (red-backed voles, Clethrionomys gapperi, P = 0.008; masked shrews, Sorex cinereus, P < 0.001) or had no detectable effect on (deer mice, Peromyscus maniculatus, P = 0.544; short-tailed shrews, Blarina brevicauda, P = 0.517) the 4 most common species of Muridae and Soricidae in northern Maine. In general, abundance of deer mice responded more positively to increasing development class and to the number of years since thinning than other species of small mammals. Several within-stand habitat characteristics associated with stand maturity, such as larger stem diameters and a partially open canopy, occurred in thinned stands. Thus, PCT may accelerate the development of habitat attributes typical of mid-successional conifer stands in intensively managed stands within the Acadian Forest. PCT may increase abundances of small mammal species associated with mid-seral forest conditions at the scale of the forest stand. ?? 2004 Elsevier B.V. All rights reserved.

Homyack, J.A.; Harrison, D.J.; Krohn, W.B.

2005-01-01

349

Nonintralaminar thalamostriatal projections in the gray squirrel (Sciurus carolinensis) and tree shrew (Tupaia glis).  

PubMed

In mammals, the corpus striatum receives prominent projections from the neocortex and from the intralaminar nuclei of the dorsal thalamus. The present study provides evidence based on anterograde degeneration and axonal transport that the corpus striatum also receives input from two nonintralaminar thalamic nuclei, the pulvinar and the medial geniculate body. Each of these nuclei projects to a separate region of the corpus striatum. Moreover, the same regions of the corpus striatum that receive projections from the pulvinar and medial geniculate body also receive projections from the cortical targets of these nuclei. PMID:6096412

Lin, C S; May, P J; Hall, W C

1984-11-20

350

Species Interactions during Diversification and Community Assembly in an Island Radiation of Shrews  

Microsoft Academic Search

BackgroundClosely related, ecologically similar species often have adjacent distributions, suggesting competitive exclusion may contribute to the structure of some natural communities. In systems such as island archipelagos, where speciation is often tightly associated with dispersal over oceanic barriers, competitive exclusion may prevent population establishment following inter-island dispersal and subsequent cladogenesis.Methodology\\/Principal FindingsUsing a combination of tools, we test the hypothesis that

Jacob A. Esselstyn; Sean P. Maher; Rafe M. Brown

2011-01-01

351

Anita. Behav., 1987,35, 1215-1224 Search paths of foraging common shrews Sorex araneus  

E-print Network

to food patches, which prey to eat and how to locate prey (Pyke et al. 1977). Of these, the question of how foragers locate prey has received relativelylittle attention (see reviews by Krebs et al. 1983 on conditions (Andersson 1981; Janetos 1982). Second, there is the question of how fast to travel while

Pierce, Graham

352

Comparative aspects of lipid metabolism in two shrews (Suncus etruscus and Crocidura russula).  

PubMed

1. The amounts of tissue lipids were higher in S. etruscus than in C. russula. 2. The level of liver phospholipids was specially low in C. russula, 2650 mg/100 g as opposed to 3725 g in S. etruscus. 3. This is in good agreement with a reduced rate of the labelled acetate incorporation into the lipids of C. russula. 4. The proportion of unsaturated fatty acids was greater in the liver of S. etruscus; however, the percentage of arachidonic acid was higher in C. russula--15% as opposed to 8%. PMID:318366

Sicart, R; Sable-Amplis, R; Fons, R

1978-01-01

353

Blood oxygen transport and organ weights of two shrew species (S. etruscus and C. russula).  

PubMed

Blood parameters concerning oxygen transport and relative organ weights of 11 Suncus etruscus and 13 Crocidura russula under light halothane anesthesia were investigated. Mean body weight of S. etruscus was 2.5 g and for C. russula was 9 g, hemoglobin concentration was 17.4 and 15.6 g/100 ml blood, hematocrit was 50 and 44%, red blood cells were 18 and 11 X 10(6)/microliter, respectively. Mean corpuscular volume was calculated to be 26 and 41 micron3, mean diameter 5.5 and 7 micron, and mean thickness 1.2 and 1.1 micron, respectively. Mean corpuscular hemoglobin concentration was in the normal range of mammalian red blood cells. A blood oxygen half-saturation pressure of 35 and 34 Torr at pH 7.4, 37 degrees C and a Bohr factor deltalog P50/deltapH of -0.61 and -0.66 was measured. Experiments with stripped hemoglobin showed that 2,3-diphosphoglycerate is the main oxygen affinity reducing allosteric factor. Relative weights of heart, kidney, and liver are remarkably high in S. etruscus. The maximal oxygen transport of 400 ml . kg-1 . min-1 of S. etruscus is feasible by an enormous heart rate, a large relative stroke volume, a high hemoglobin concentration combined with a low oxygen affinity, and a large Bohr effect. PMID:426099

Bartels, H; Bartels, R; Baumann, R; Fons, R; Jürgens, K D; Wright, P

1979-03-01

354

Mitochondrial DNA variation along an altitudinal gradient in the greater white-toothed shrew, Crocidura russula.  

PubMed

The distribution of mitochondrial control region-sequence polymorphism was investigated in 15 populations of Crocidura russula along an altitudinal gradient in western Switzerland. High-altitude populations are smaller, sparser and appear to undergo frequent bottlenecks. Accordingly, they showed a loss of rare haplotypes, but unexpectedly, were less differentiated than lowland populations. Furthermore, the major haplotypes segregated significantly with altitude. The results were inconsistent with a simple model of drift and dispersal. They suggested instead a role for historical patterns of colonization, or, alternatively, present-day selective forces acting on one of the mitochondrial genes involved in metabolic pathways. PMID:11975709

Ehinger, M; Fontanillas, P; Petit, E; Perrin, N

2002-05-01

355

Food of Vagrant Shrews (Sorex vagrans) Irom Grant County, Oregon, as Relaled to Livestock Grazing Pressures  

Microsoft Academic Search

Maior foods of the vagrant shrcat (Sorcx ltagrdnt) in a relatively non-gtazed potior of a mountain meadow itr Grant County wete earthworms, spiders, crickets, caterpillars, moths, slugs and snails. and Juoe beetles and their larvae. ln two similat areas subjected to greater recent grazing, flightless lorms (except caterpillars) were much less used; tbey were replaced primarily by caterpillars and flying

John O. Whitake; Stephen P. Cross; Chris Maserl

1983-01-01

356

Flying lemurs - the "flying tree shrews"? Molecular cytogenetic evidence for a Scandentia-Dermoptera sister clade  

E-print Network

, Alongkoad Tanomtong3, Vitaly Volobouev4, Malcolm A Ferguson-Smith2 and Fengtang Yang*5 Address: 1State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, People's Republic... @mail.kiz.ac.cn; Beiyuan Fu - bf204@cam.ac.uk; Patricia CM O'Brien - pco20@mole.bio.cam.ac.uk; Jinhuan Wang - goldjing2007@yahoo.cn; Weiting Su - su3.1010@hotmail.com; Alongkoad Tanomtong - tanomtong@hotmail.com; Vitaly Volobouev - vitaly@mnhn.fr; Malcolm A Ferguson-Smith...

Nie, Wenhui; Fu, Beiyuan; O'Brien, Patricia C M; Wang, Jinhuan; Su, Weiting; Tanomtong, Alongklod; Volobouev, Vitaly; Ferguson-Smith, Malcolm A; Yang, Fengtang

2008-05-01

357

House musk shrew ( Suncus murinus, order: Insectivora) as a new model animal for motilin study  

Microsoft Academic Search

Although many studies have demonstrated the action of motilin on migrating motor complex by using human subjects and relatively large animals, the precise physiological mechanisms of motilin remain obscure. One reason for the lack of progress in this research field is that large animals are generally not suitable for molecular-level study. To overcome this problem, in this study, we focused

Chihiro Tsutsui; Kie Kajihara; Takatsugu Yanaka; Ichiro Sakata; Zen Itoh; Sen-ichi Oda; Takafumi Sakai

2009-01-01

358

Scleral gene expression during recovery from myopia compared with expression during myopia development in tree shrew  

PubMed Central

Purpose During postnatal refractive development, the sclera receives retinally generated signals that regulate its biochemical properties. Hyperopic refractive error causes the retina to produce “GO” signals that, through the direct emmetropization pathway, cause scleral remodeling that increases the axial elongation rate of the eye, reducing the hyperopia. Myopia causes the retina to generate “STOP” signals that produce scleral remodeling, slowing the axial elongation rate and reducing the myopia. Our aim was to compare the pattern of gene expression produced in the sclera by the STOP signals with the GO gene expression signature we described previously. Methods The GO gene expression signature was produced by monocular –5 diopter (D) lens wear for 2 days (ML-2) or 4 days (ML-4); an additional “STAY” condition was examined after eyes had fully compensated for a –5 D lens after 11 days of lens wear (ML-11). After 11 days of ?5 D lens wear had produced full refractive compensation, gene expression in the STOP condition was examined during recovery (without the lens) for 2 days (REC-2) or 4 days (REC-4). The untreated contralateral eyes served as a control in all groups. Two age-matched normal groups provided a comparison with the treated groups. Quantitative real-time PCR was used to measure mRNA levels for 55 candidate genes. Results The STAY group compensated fully for the lens (treated eye versus control eye, –5.1±0.2 D). Wearing the lens, the hyperopic signal for elongation had dissipated (–0.3±0.3 D). In the STOP groups, the refraction in the recovering eyes became less myopic relative to the control eyes (REC-2, +1.3±0.3 D; REC-4, +2.6±0.4 D). In the STAY group, three genes showed significant downregulation. However, many genes that were significantly altered in GO showed smaller, nonsignificant, expression differences in the same direction in STAY, suggesting the gene expression signature in STAY is a greatly weakened form of the GO signature. In the STOP groups, a different gene expression pattern was observed, characterized by mostly upregulation with larger fold differences after 4 days than after 2 days of recovery. Eleven of the 55 genes examined showed significant bidirectional GO/STOP regulation in the ML-2 and REC-2 groups, and 13 genes showed bidirectional regulation in the ML-4 and REC-4 groups. Eight of these genes (NPR3, CAPNS1, NGEF, TGFB1, CTGF, NOV, TIMP1, and HS6ST1) were bidirectionally regulated at both time points in the GO and STOP conditions. An additional 15 genes showed significant regulation in either GO or STOP conditions but not in both. Conclusions Many genes are involved in scleral remodeling and the control of axial length. The STOP (recovery) gene expression signature in the sclera involves some of the same genes, bidirectionally regulated, as the GO signature. However, other genes, regulated in GO, are not differentially regulated in STOP, and others show differential regulation only in STOP. PMID:25540576

Guo, Lin; Frost, Michael R.; Siegwart, John T.

2014-01-01

359

Noradrenalin induces thermogenesis in a phylogenetically ancient eutherian mammal, the rock elephant shrew, Elephantulus myurus  

Microsoft Academic Search

The evolution of endothermy is thought to have been facilitated by the advent of endothermic energy sources such as brown\\u000a adipose tissue (BAT), the principal site of non-shivering thermogenesis (NST). In marsupials, heat is primarily produced through\\u000a shivering and NST in skeletal muscle because BAT is either absent or appears to be non-functional. The most basal group of\\u000a the eutherian

Nomakwezi Mzilikazi; Barry G. Lovegrove

2006-01-01

360

Response to Interrupted Hyperopia after Restraint of Axial Elongation in Tree Shrews  

PubMed Central

Purpose To determine if early restraint of axial elongation in response to plus lenses increases the subsequent response to interrupted hyperopia. Methods The normal, interrupted hyperopia group (n=5) had normal visual exposure until 24 days of visual experience (VE). Then, from 24 to 45 days of VE, the animals wore binocular ?4 D lenses which shifted the refractive state of the eyes in the direction of hyperopia. Interrupted hyperopia was produced by removing the lenses for 2 hours per day. The early restraint, interrupted hyperopia group (n=5) wore binocular +4 D lenses continuously from 11 to 24 days of VE, becoming emmetropic with the lenses in place and hyperopic when they were removed. Then, from 24 to 45 days of VE, the lenses were removed 22 hours per day and replaced for 2 hours per day. This created the same initial regimen of interrupted hyperopia as in the normal, interrupted hyperopia group. A plus-lens control group wore binocular +4 D lenses (n=5) continuously from 11 to 45 Days of VE to assess the stability of the refractive compensation. Results In the normal, interrupted hyperopia animals, 2 hours of relief from the imposed hyperopia was sufficient to prevent myopia development. In the early restraint, interrupted hyperopia animals, 2 hours of relief from the hyperopia did not prevent myopia development; the eyes became myopic while wearing the lens. The control animals compensated for the +4 D lenses and maintained a stable with-the-lens emmetropia through 45 days of VE, demonstrating that the myopic shift in the early-restraint group was due to the interrupted hyperopia. Conclusions Compensation for plus lenses, involving slowed axial elongation, increases the response to subsequent interrupted hyperopia. Similar to previous reports of an eye-size factor in elongated eyes, these data provide evidence for an eye-size mechanism operating, in this case, in eyes that have restrained their axial length. PMID:23314128

Siegwart, John T.; Norton, Thomas T.

2012-01-01

361

Late Pleistocene potential distribution of the North African sengi or elephant-shrew  

E-print Network

, Golden Gate Park, San Francisco, CA 94118, U.S.A. Received 6 August 2009. Accepted 2 June 2010 The Sahara the possibility of more recent connections of popula- tions of this species across the Sahara Desert that would-Pleistocene vicariance across an increasingly arid Sahara. We emphasize the importance of multiple sets of evidence

362

Organization of Territorial Marking Behavior by Testosterone During Puberty in Male Tree Shrews  

Microsoft Academic Search

According to current hypotheses, in mammals male-specific behavior is organized perinatally, and activated in adulthood by male gonadal hormones. However, this strict differentiation between early organizational and late activational hormone effects has been criticized recently. Around puberty the testosterone levels of male mammals rise far above adult levels. In this study we examined the relevance of this pubertal testosterone peak

Florian Eichmann; Dietrich V Holst

1998-01-01

363

TOXICITY EVALUATION OF 1,3,5-TRINITROBENZENE (TNB) IN SHREWS (CRYPTOTIS PARVA)  

EPA Science Inventory

TNB has been detected as an environmental contaminant of soil and water at certain Army installations and production waste disposal sites. At present there are no toxicity data on TNB in small wild mammals that might be used for ecological risk assessment. Therefore, a 14-day to...

364

Geographic and host range of the nematode Soboliphyme baturini across Beringia.  

PubMed

The nematode Soboliphyme baturini Petrov, 1930, was found to represent a single species with a relatively broad geographic range across Beringia and northwestern North America on the basis of the assessment of molecular sequence data for adult and juvenile parasites. Refuted are hypotheses suggesting that several cryptic species could be partitioned either among an array of mustelid definitive hosts or across the vast region that links North America and Eurasia. Host specificity for this species is examined on the basis of a comprehensive list for definitive hosts, derived from new field surveys and existing literature for S. baturini. Only 5 mustelids (Gulo gulo, Martes americana, M. caurina, M. zibellina, and Neovison vison) appear to have significant roles in the life history, persistence, and transmission of this nematode. Soboliphyme baturini readily switches among M. americana, M. caurina, Mustela erminea, or N. vison at any particular locality throughout its geographic range in North America, although Martes spp. could represent the source for nematodes in a broader array of mustelids. Molecular analyses (243 base pairs of mitochondrial gene nicotinamide dehydrogenase [ND4]) suggest that hypotheses for host specificity across an array of mustelid definitive hosts are not supported. The life cycle of S. baturini is explored through a review of diet literature for 2 marten species, M. americana and M. caurina, and other mustelids across the Holarctic. Shrews (Soricomorpha: Soricidae) comprise >8% of prey for these species of Martes, suggesting their putative role as paratenic hosts. Juvenile nematodes found in the diaphragms of soricids are genetically identical to adult S. baturini found in the stomachs of mustelids at the same locations in both Asia and North America, corroborating a role in transmission for species of Sorex. PMID:18163341

Koehler, Anson V A; Hoberg, Eric P; Dokuchaev, Nikolai E; Cook, Joseph A

2007-10-01

365

DOI 10.1515/mammalia-2011-0138Mammalia 2013; 77(1): 2130 Arielle Waldstein Parsons*, Theodore R. Simons, Allan F. O'Connell Jr. and  

E-print Network

of an isolated, unmanaged raccoon Procyon lotor (Procyonidae, Carnivora) population on the Outer Banks of North Carolina Abstract: Raccoons (Procyon lotor) are highly adapt- able meso-carnivores that inhabit many-carnivore; Procyon lotor; raccoon. *Corresponding author: Arielle Waldstein Parsons, US Geological Survey, North

Simons, Theodore R.

366

The Insect Eaters.  

ERIC Educational Resources Information Center

Presents information about insectivores, including definitions and characteristics of shrews, moles, hedgehogs, and tenrecs. Contains descriptions of the teaching activities "Little Starnose" and "You and a Shrew." A reproducible worksheet is provided for use in "You and a Shrew." (TW)

Naturescope, 1986

1986-01-01

367

A structural intermediate between triisodontids and mesonychians (Mammalia, Acreodi) from the earliest Eocene of Portugal  

NASA Astrophysics Data System (ADS)

A new mammal, Mondegodon eutrigonus gen. et sp. nov., is described from the earliest Eocene locality of Silveirinha, Portugal. This species shows dental adaptations indicative of a carnivorous diet. M. eutrigonus is referred to the order Acreodi and considered, along with the early Paleocene North American species Oxyclaenus cuspidatus, as a morphological intermediate between two groups of ungulate-like mammals, namely, the triisodontids and mesonychians. Considering that triisodontids are early to early-late Paleocene North American taxa, Mondegodon probably belongs to a group that migrated from North America towards Europe during the first part of the Paleocene. Mondegodon could represent thus a relict genus, belonging to the ante-Eocene European mammalian fauna. The occurrence of such a taxon in Southern Europe may reflect a period of isolation of this continental area during the Paleocene/Eocene transition. In this context, the non-occurrence of closely allied forms of Mondegodon in the Eocene North European mammalian faunas is significant. This strengthens the hypothesis that the mammalian fauna from Southern Europe is characterized by a certain degree of endemism during the earliest Eocene. Mondegodon also presents some striking similarities with an unnamed genus from the early Eocene of India which could represent the first Asian known transitional form between the triisodontids and mesonychians.

Tabuce, Rodolphe; Clavel, Julien; Antunes, Miguel Telles

2011-02-01

368

Philodryas chamissonis (Reptilia: Squamata: Colubridae) preys on the arboreal marsupial Dromiciops gliroides (Mammalia: Microbiotheria: Microbiotheriidae).  

PubMed

Philodryas chamissonis, the Chilean long-tailed snake, is a diurnal predator mainly of Liolaemus lizards, but also of amphibians, birds, rodents and juvenile rabbits. Dromiciops gliroides (Colocolo opossum) is an arboreal marsupial endemic of temperate rainforest of southern South America. Little information is available about this marsupial's biology and ecology. Here we report the predation of one Colocolo opossum by an adult female P. chamissonis in a mixed Nothofagus forest, composed mainly by N. dombeyi, N. glauca and N. alpina trees, in the "Huemules de Niblinto" National Reserve, Nevados de Chillán, Chile. Since these two species have different activity and habitat use patterns, we discuss how this encounter may have occurred. Although it could just have been an opportunistic event, this finding provides insights into the different components of food chains in forest ecosystems of Chile. PMID:23644784

Muñoz-Leal, S; Ardiles, K; Figueroa, R A; González-Acuña, D

2013-02-01

369

Cranial functional morphology of fossil dogs and adaptation for durophagy in Borophagus and Epicyon (Carnivora, Mammalia).  

PubMed

Morphological specialization is a complex interplay of adaptation and constraint, as similarly specialized features often evolve convergently in unrelated species, indicating that there are universally adaptive aspects to these morphologies. The evolutionary history of carnivores offers outstanding examples of convergent specialization. Among larger predators, borophagine canids were highly abundant during the tertiary of North America and are regarded as the ecological vicars of Afro-Eurasian hyenas. Borophaginae is an extinct group of 60+ species, the largest forms evolving robust skulls with prominently domed foreheads, short snouts, and hypertrophied fourth premolars. These specializations have been speculated to enhance bone cracking. To test the extent that the skulls of derived borophagines were adapted for producing large bite forces and withstanding the mechanical stresses associated with bone cracking relative to their nonrobust sister clades, we manipulated muscle forces in models of six canid skulls and analyzed their mechanical response using 3D finite element analysis. Performance measures of bite force production efficiency and deformation minimization showed that skulls of derived borophagines Borophagus secundus and Epicyon haydeni are particularly strong in the frontal region; maximum stresses are lower and more evenly distributed over the skull than in other canids. Frontal strength is potentially coupled with a temporalis-driven bite to minimize cranial stress during biting in the two derived genera, as tensile stress incurred by contracting temporalis muscles is dissipated rostro-ventrally across the forehead and face. Comparison of estimated masticatory muscle cross section areas suggests that the temporalis-masseter ratio is not strongly associated with morphological adaptations for bone cracking in Borophagus and Epicyon; larger body size may explain relatively larger temporalis muscles in the latter. When compared with previous studies, the overall cranial mechanics of the derived borophagines is more similar to bone-cracking hyaenids and percrocutids than to their canid relatives, indicating convergence in both morphological form and functional capability. PMID:20799339

Tseng, Zhijie Jack; Wang, Xiaoming

2010-11-01

370

Paroodectes feisti , der erste Miacide (Carnivora, Mammalia) aus dem Mittel-Eozän von Messel  

Microsoft Academic Search

\\u000a Abstract  From the Middle Eocene (Lower Lutetian) Oil Shale of Messel near Darmstadt (South-Hesse) the first completely preserved Miacid\\u000a is described. The systematic position of the Miacidae is discussed before. A short review of the paleogeographic (North-America,\\u000a Eurasia) and stratigraphic (L. Paleocene — U. Eocene, ? U. Oligocene) distribution is given; the fossil record of European\\u000a species is more detailed. The

Rainer Springhorn

1980-01-01

371

Deux nouvelles espèces de Suini (Mammalia, Suidae) du continent Africain (Éthiopie; Tchad)  

Microsoft Academic Search

Two new small Suines, Kolpochoerus deheinzelini sp. nov. and Kolpochoerus cookei sp. nov., are described. The first one represents the earliest appearance of the genus and the earliest African Suine. K. deheinzelini n. sp. is the ancestor of K. afarensis, previously considered as an Eurasiatic migrant in the Middle Pliocene of Africa (Pickford, 1994). The second one is the smallest species of the

Michel Brunet; Tim D White

2001-01-01

372

Phylogeographic Patterns and Evolution of the Mitochondrial DNA Control Region in Two Neotropical Cats (Mammalia, Felidae)  

Microsoft Academic Search

.   The ocelot (Leopardus pardalis) and margay (L. wiedii) are sister-species of Neotropical cats which evolved from a lineage that migrated into South America during the formation\\u000a of the Panamanian land bridge 3–5 million years ago. Patterns of population genetic divergence of each species were studied\\u000a by phylogenetic analyses of mitochondrial DNA (mtDNA) control region sequences in individuals sampled across

Eduardo Eizirik; Sandro L. Bonatto; Warren E. Johnson; Peter G. Crawshaw Jr.; Jean Cristophe Vié; Dulce M. Brousset; Stephen J. O'Brien; Francisco M. Salzano

1998-01-01

373

Phenotypic Convergence in Genetically Distinct Lineages of a Rhinolophus Species Complex (Mammalia, Chiroptera)  

PubMed Central

Phenotypes of distantly related species may converge through adaptation to similar habitats and/or because they share biological constraints that limit the phenotypic variants produced. A common theme in bats is the sympatric occurrence of cryptic species that are convergent in morphology but divergent in echolocation frequency, suggesting that echolocation may facilitate niche partitioning, reducing competition. If so, allopatric populations freed from competition, could converge in both morphology and echolocation provided they occupy similar niches or share biological constraints. We investigated the evolutionary history of a widely distributed African horseshoe bat, Rhinolophus darlingi, in the context of phenotypic convergence. We used phylogenetic inference to identify and date lineage divergence together with phenotypic comparisons and ecological niche modelling to identify morphological and geographical correlates of those lineages. Our results indicate that R. darlingi is paraphyletic, the eastern and western parts of its distribution forming two distinct non-sister lineages that diverged ~9.7 Mya. We retain R. darlingi for the eastern lineage and argue that the western lineage, currently the sub-species R. d. damarensis, should be elevated to full species status. R. damarensis comprises two lineages that diverged ~5 Mya. Our findings concur with patterns of divergence of other co-distributed taxa which are associated with increased regional aridification between 7-5 Mya suggesting possible vicariant evolution. The morphology and echolocation calls of R. darlingi and R. damarensis are convergent despite occupying different biomes. This suggests that adaptation to similar habitats is not responsible for the convergence. Furthermore, R. darlingi forms part of a clade comprising species that are bigger and echolocate at lower frequencies than R. darlingi, suggesting that biological constraints are unlikely to have influenced the convergence. Instead, the striking similarity in morphology and sensory biology are probably the result of neutral evolutionary processes, resulting in the independent evolution of similar phenotypes. PMID:24312666

Jacobs, David S.; Babiker, Hassan; Bastian, Anna; Kearney, Teresa; van Eeden, Rowen; Bishop, Jacqueline M.

2013-01-01

374

DNA Profiling of B Chromosomes from the Yellow-necked Mouse Apodemus flavicollis (Rodentia, Mammalia)  

PubMed Central

Using AP-PCR-based DNA profiling we examined some structural features of B chromosomes from yellow-necked mice Apodemus flavicollis. Mice harboring one, two, or three or lacking B chromosomes were examined. Chromosomal structure was scanned for variant bands by using a series of arbitrary primers and from these, informative bands were selected. The selection criteria used were the ability to differentiate between individuals of the species, to detect markers common for both A and B chromosomes, and, importantly, to differentiate between A- and B-chromosome sets. In addition to primers, profiling conditions were found to be critical for meeting the selection criteria. Primers and analysis conditions that demonstrated structural characteristics unique to the B-chromosome set are described. These characteristics included variant bands as qualitative parameters and altered electrophoretic band intensities as quantitative distinctions estimated by integration of densitometric profiles of electrophoretograms. B chromosome-specific molecular markers are easy to detect by AP-PCR-based DNA profiling in the presence of a full set of A chromosomes. Models for the origin of yellow-necked mouse B chromosomes are discussed in the context of presented data. PMID:10645950

Tani?, Nikola; Dedovi?, Nasta; Vujos?evi?, Mladen; Dimitrijevi?, Bogomir

2000-01-01

375

The proboscis of tapirs (Mammalia: Perissodactyla): a case study in novel narial anatomy  

Microsoft Academic Search

The trunk-like proboscis of tapirs provides a prime case study in the evolution of anatomical novelty. Morphological study of this unique structure was undertaken employing several specimens and a combination of analytical techniques: gross anatomical dissection, radiographic imaging and histological sectioning. Evolution of the proboscis of tapirs entailed wholesale transformation of the narial apparatus and facial architecture relative to perissodactyl

Lawrence M. Witmer; Scott D. Sampson; Nikos Solounias

1999-01-01

376

New genus of tapir (Mammalia: Tapiridae) from the Arikareean (earliest Miocene) of the Texas Coastal Plain  

Microsoft Academic Search

The nearly complete dentition of the rare tapirid Miotapirus marslandensis was recovered from the recently discovered late Arikareean Toledo Bend Local Fauna, Newton County, Texas. The species was previously known from only two associated upper molars found near Marsland, Nebraska, in 1917. The Nebraska molars, together with the Toledo Bend material and additional specimens from the Monroe Creek Formation, South

L. Barry Albright

1998-01-01

377

Discovery of the extinct red panda Parailurus (Mammalia, Carnivora) in Japan  

Microsoft Academic Search

An isolated upper fourth premolar (P4) of the extinct red panda Parailurus was recovered from the Pliocene (3–4 Ma) Ushigakubi Formation near Tochio, Niigata Prefecture, Japan. This is the first report of Parailurus from Asia, a genus previously known from Europe and northwestern North America. The Tochio P4 is about 50 percent larger than that of the extant Ailurus fulgens,

Ichiro Sasagawa; Keiichi Takahashi; Tatsuya Sakumoto; Hideaki Nagamori; Hideo Yabe; Iwao Kobayashi

2003-01-01

378

Phylogeny of the Carnivora (Mammalia): Congruence vs Incompatibility among Multiple Data Sets  

Microsoft Academic Search

The purpose of this study was to determine the higher-level phylogenetic relationships among Carnivora, using a conditional data combination (CDC) approach to analyzing multiple data sets. New nucleotide sequences (851 base pairs from intron I of the transthyretin gene) among 22 representatives of the 11 families of Carnivora were generated and analyzed in concert with, and comparison to, other mitochondrial

John J. Flynn; Michael A. Nedbal

1998-01-01

379

Building large trees by combining phylogenetic information: a complete phylogeny of the extant Carnivora (Mammalia)  

Microsoft Academic Search

One way to build larger, more comprehensive phylogenies is to combine the vast amount of phylogenetic information already available. We review the two main strategies for accomplishing this (combining raw data versus combining trees), but employ a relatively new variant of the latter: supertree construction. The utility of one supertree technique, matrix representation using parsimony analysis (MRP), is demonstrated by

OLAF R. P. BININDA-EMONDS; JOHN L. GITTLEMAN; ANDY PURVIS

1999-01-01

380

Red pandas (Mammalia, Carnivora: Parailurus ) in the biomes of North Eurasia and North America  

Microsoft Academic Search

The discovery of the Pliocene red panda (Parailurus) in the West Transbaikal area, as well as Asian raccoons in North Eurasia and North America, indicates that forested areas\\u000a with bamboo bushes were wide-spread in the Holarctic during the Neogene. During the Late Pliocene, due to a gradual cooling\\u000a of the climate, altiplanation, and other factors, their habitat started disintegrating, and

G. G. Matishov; N. P. Kalmykov

2011-01-01

381

Late Cenozoic History of the Genus Micromys (Mammalia, Rodentia) in Central Europe  

PubMed Central

Molecular phylogeography suggests that Micromys minutus, the sole extant species of the genus, colonized its extensive range quite recently, during the Late Pleistocene-Holocene period. Rich Pliocene and Pleistocene fossil records both from Europe and China suggest rather continuous and gradual in situ phenotype rearrangements from the Pliocene to the Recent periods. To elucidate the discrepancy we reexamined a considerable part of the European fossil record of the genus (14 sites from MN15 to Q3, 0.4–4.2 Ma, including the type series of M. preaminutus from MN15 Csarnóta 2), analyzed them with the aid of detailed morphometric comparisons, and concluded that: (a) The European Pliocene form, M. praeminutus, differs significantly from the extant species; (b) it exhibits a broad phenotypic variation covering the presumptive diagnostic characters of MN16 M. caesaris; (c) despite having smaller dimensions, the Early and Middle Pleistocene forms (MN17-Q3, 2.6–0.4 Ma) seem to be closer to M. praeminutus than to the extant species; (d) the extinction of M. praeminutus during Q3 and the re-occupation of its niche by the recent expansion of M. minutus from E-European – C Asiatic sources (suggested by phylogeographic hypotheses) cannot be excluded. Discussing interpretations of the phylogenetic past of the genus we emphasize the distinct history of the West Palearctic clade (Late Miocene-Early Pleistocene) terminating with M. praeminutus and the East Asiatic clade (chalceus, tedfordi, minutus), and the possible identity of the Western clade with the Late Miocene genus Parapodemus. PMID:23671605

Horá?ek, Ivan; Knitlová, Markéta; Wagner, Jan; Kordos, László; Nadachowski, Adam

2013-01-01

382

Reproductive anatomy of the female Amazonian manatee Trichechus inunguis Natterer, 1883 (Mammalia: Sirenia).  

PubMed

The Amazonian manatee (Trichechus inunguis) is uniparous and has a slow reproduction cycle due to a long gestation period and long interval between births. Even though protected by law, hunting remains one of the main causes hindering the natural population growth of this species in the wild. The histology and reproductive anatomy provide information on the history and reproductive status of the female and offer a tool for the conservation of the species. The present study describes the anatomy of the female reproductive tract in T. inunguis. It is based on materials from three reproductive tracts fixed in 10% buffered formalin. The ovaries, uterine tubes, uterus, vagina, and external genitalia are described. The hymen presents two tiny openings separated by a segment that, upon rupturing during the first copulation, should make up a single vaginal opening. A still intact hymen and the absence of placental scars in the uterus were found in one specimen. Additionally, the presence of a hemorrhagic body and Graafian follicles on the right ovary were observed, as well as whitish scars and among them, possible corpora albicantia. These findings suggest that T. inunguis undergoes infertile estrus cycles before its first gestation. Macroscopically, counting of the whitish scars is hindered by the small diameter of these structures. It is not possible to differentiate between the scars resulting from ruptured (corpora albicantia) and nonruptured follicles (regressed corpora atretica). The presence of whitish scars on both ovaries of the same specimen suggests their bilateral function in T. inunguis. PMID:18383272

Rodrigues, Fernanda Rosa; Da Silva, Vera Maria Ferreira; Barcellos, José Fernando Marques; Lazzarini, Stella Maris

2008-05-01

383

Signature information and individual recognition in the isolation calls of Amazonian manatees, Trichechus inunguis (Mammalia: Sirenia)  

Microsoft Academic Search

Acoustic signals are assumed to form the basis of manatee communication. Empirical evidence of individual vocal recognition has been reported. If manatees can recognize one another by acoustical means, it should be possible to identify individual vocal patterns. We recorded vocalizations of 14 individually housed Amazonian manatees and then digitized selected vocalizations, allowing seven variables to be measured and subjected

Renata S. Sousa-Lima; Adriano P. Paglia; Gustavo A. B. Da Fonseca

2002-01-01

384

A new middle eocene whale (Mammalia: Cetacea: Archaeoceti) and associated biota from Georgia  

USGS Publications Warehouse

A shallow-marine fossil biota was recovered from the Blue Bluff unit (formerly part of the McBean Formation) in the Upper Coastal Plain of eastern Georgia. Biochronologically significant mollusks (e.g., Turritella nasuta, Cubitostrea sellaeformis, Pteropsella lapidosa) and calcareous nannoplankton (e.g., Chiasmolithus solitus, Reticulofenestra umbilica, Cribocentrum reticulatum) indicate a latest Lutetian-earliest Bartonian age, or about 40 to 41 Ma. Georgiacetus vogtlensis new genus and species is described from a well-preserved, partial skeleton. Georgiacetus is the oldest known whale with a true pterygoid sinus fossa in its basicranium and a pelvis that did not articulate directly with the sacral vertebrae, two features whose acquisitions were important steps toward adaptation to a fully marine existence. The posterior four cheek teeth of G. vogtlensis form a series of carnassial-like shearing blades. These teeth also bear small, blunt accessory cusps, which are regarded as being homologous with the larger, sharper accessory cusps of basilosaurid cheek teeth.

Hulbert, R.C., Jr.; Petkewich, R.M.; Bishop, G.A.; Bukry, D.; Aleshire, D.P.

1998-01-01

385

Griphotherion peiranoi, gen. et sp. nov., a new Eocene Notoungulata (Mammalia, Meridiungulata) from northwestern Argentina  

Microsoft Academic Search

Griphotherion peiranoi, a new genus and species of notoungulate from northwestern Argentina, is presented here. The material studied consists of a nearly complete skull and part of the postcranial skeleton, recovered in the Lumbrera Formation (Eocene) at the locality of El Simbolar (Salta Province, northwestern Argentina). The specimen was evaluated in terms of a matrix of 28 craniodental characters and

Daniel A. García López; Jaime E. Powell

2011-01-01

386

Chromosomes of some squirrels (mammalia — sciuridae) from the genera Sciurus and Glaucomys  

Microsoft Academic Search

Zusammenfassung Die Analyse der mitotischen Chromosomen beiSciurus carolinensis, S. niger undS. aberti ergibt die diploide Zahl 40 und gleichartige Karyotypen.S. griseus, 2n 40, hat einzigeY Chromosomen und sekundäre Konstriktionen in 4 Autosomen.Glaucomys sabrinus undG. volans, 2n 48, zeigten kleinere Unterschiede der Karyotypen. Taxonomische Bezeichnungen vonSciurus, Glaucomys undTamiasciurus werden erörtert.

C. F. Nadler; D. A. Sutton

1967-01-01

387

The hipparions (Mammalia, Perissodactyla) from the Turolian locality “Nikiti-2” (NIK), Macedonia, N. Greece  

Microsoft Academic Search

The hipparions from the late Miocene locality Nikiti-2 (NIK), Macedonia, Greece are described and compared with those from the other Greek and Eurasian localities. Two species have been determined, the medium-sized Hipparion dietrichi and the small-sized Hipparion macedonicum, while a third large-sized Hipparion is also recognized. The scanty material of the latter species indicates similarities with Hipparion proboscideum, as well

Theodora Vlachou; George D Koufos

2002-01-01

388

New material of Carnivora (Mammalia) from the Late Miocene of Axios Valley, Macedonia, Greece  

Microsoft Academic Search

A new collection of carnivores from the late Miocene deposits of Axios Valley, Macedonia, Greece was collected in 2004–2009 at the localities named Xirochori 1 (XIR) and Ravin de la Pluie (RPl), dated to the late Vallesian (MN 10), as well as in Ravin des Zouaves 5 (RZO), dated to the early Turolian (MN 11). The studied material is described

George D. Koufos

389

New material of Vallesian Late Miocene hipparions (Mammalia, Perissodactyla) from the lower Axios valley, Macedonia, Greece  

Microsoft Academic Search

The hipparions from Vallesian Late Miocene localities of the Axios valley (Macedonia, Greece) are described and compared with\\u000a those from Eurasia. In addition to the previously recognized species,H. primigenium andH. macedonicum, a third species has been determined mainly in the material from the locality of “Pentalophos 1”, PNT. It has primitive features\\u000a and it is similar toH. depereti but with

George D. Koufos

2000-01-01

390

A new species of Murina (Mammalia: Chiroptera: Vespertilionidae) from peninsular Thailand.  

PubMed

A new species of Murina belonging to 'suilla-group' is described based on two specimens collected with harp traps in lowland evergreen forest in the southernmost part of peninsular Thailand. Morphology and molecular (mitochondrial COI) data suggest that the new species is most closely related to M. eleryi, which is currently known from Indochina. The new species, however, can be distinguished by the size and shape of the upper canine, the shape of the upper and lower premolars, and the colour of the ventral pelage. Additional data on bacular morphology, echolocation, ecology, and distribution are included. PMID:25113497

Soisook, Pipat; Karapan, Sunate; Satasook, Chutamas; Bates, Paul J J

2013-01-01

391

NEW CRANIAL AND POSTCRANIAL REMAINS OF LATE PALEOCENE PLESIADAPIDAE ("PLESIADAPIFORMES," MAMMALIA) FROM NORTH  

E-print Network

Professor of Paleontology, Professor of Geology, Biology, and Anthropology, Director of Museum of Paleontology, University of Michigan, Ann Arbor This dissertation is accepted by the Graduate School Lawrence anatomy more accurately and comprehensively than previously possible. I use quantitative comparative

Boyer, Doug M.

392

Microstructure of dental hard tissues in fossil and recent xenarthrans (Mammalia: Folivora and Cingulata).  

PubMed

A striking difference between xenarthrans and other mammals is the complete loss of tooth enamel in all members but the earliest armadillos. However, sloth and armadillo teeth show structured wear facets, which in all other mammals are formed by tooth enamel. How is that possible? Here, I report about an analysis of fossil and recent xenarthran dental hard tissue microstructure. It shows that osteodentine is not exclusive to fossil Cingulata, but also occurs in some recent taxa. Furthermore, I found profound modifications of orthodentine architecture in comparison to other mammals. Remarkable features are (a) a larger proportion of the highly mineralized, collagen-free peritubular dentine, and (b) a modified architecture of the odontoblastic process with frequent interconnections between the extensions and unusually intensive branching of the extensions forming a complex meshwork, penetrating the intertubular dentine matrix. The orthodentine microstructural build-up is unique in Folivora and Cingulata. PMID:21456028

Kalthoff, Daniela C

2011-06-01

393

A tubulidentate suiform lineage (Tayassuidae, Mammalia) from the Early Miocene of Spain  

NASA Astrophysics Data System (ADS)

Small suiform artiodactyls from Moheda, Loranca and Corcolés, Spain, possess tubulidentate microstructure in their cheek tooth roots. The oldest specimens from Moheda (MN 2a) have a few scattered tubules near the apices of the molar roots, those from Loranca (MN 2b) have numerous tubules of various diameters in contact with each other, but oriented at various angles, while specimens from Corcolés (MN 4) are completely tubulidentate with well developed, sub-parallel tubules of sub-equal diameter running the entire length of the roots. The same series of fossils shows that with the passage of geological time the roots of this tayassuid lineage became more hypsorhizic and fusion of the roots increased, while the crowns of the teeth became simpler and thinner enamelled. Selection in this lineage was therefore focused upon increasing the longevity and wear resistance of the roots, while the role of the crowns of the teeth in mastication was de-emphasised. It is hypothesised that, as in Tubulidentata and Edentata, this suiform lineage was ingesting food items which contained significant quantities of adhérant earth. Whether the diet also contained ants and termites is not known.

Pickford, Martin; Morales, Jorge

1998-08-01

394

Identification of Bacterial Specialists in Hosts belonging to Aves, Mammalia, and Pisces  

EPA Science Inventory

Only a portion of bacteria found in animal guts are able to establish specific associations within animal hosts. Taxa that have formed these specialized relationships may have played a prominent role in host evolution and may also contribute significantly to current host physiolo...

395

Phylogeny and divergence of the pinnipeds (Carnivora: Mammalia) assessed using a multigene dataset  

PubMed Central

Background Phylogenetic comparative methods are often improved by complete phylogenies with meaningful branch lengths (e.g., divergence dates). This study presents a dated molecular supertree for all 34 world pinniped species derived from a weighted matrix representation with parsimony (MRP) supertree analysis of 50 gene trees, each determined under a maximum likelihood (ML) framework. Divergence times were determined by mapping the same sequence data (plus two additional genes) on to the supertree topology and calibrating the ML branch lengths against a range of fossil calibrations. We assessed the sensitivity of our supertree topology in two ways: 1) a second supertree with all mtDNA genes combined into a single source tree, and 2) likelihood-based supermatrix analyses. Divergence dates were also calculated using a Bayesian relaxed molecular clock with rate autocorrelation to test the sensitivity of our supertree results further. Results The resulting phylogenies all agreed broadly with recent molecular studies, in particular supporting the monophyly of Phocidae, Otariidae, and the two phocid subfamilies, as well as an Odobenidae + Otariidae sister relationship; areas of disagreement were limited to four more poorly supported regions. Neither the supertree nor supermatrix analyses supported the monophyly of the two traditional otariid subfamilies, supporting suggestions for the need for taxonomic revision in this group. Phocid relationships were similar to other recent studies and deeper branches were generally well-resolved. Halichoerus grypus was nested within a paraphyletic Pusa, although relationships within Phocina tend to be poorly supported. Divergence date estimates for the supertree were in good agreement with other studies and the available fossil record; however, the Bayesian relaxed molecular clock divergence date estimates were significantly older. Conclusion Our results join other recent studies and highlight the need for a re-evaluation of pinniped taxonomy, especially as regards the subfamilial classification of otariids and the generic nomenclature of Phocina. Even with the recent publication of new sequence data, the available genetic sequence information for several species, particularly those in Arctocephalus, remains very limited, especially for nuclear markers. However, resolution of parts of the tree will probably remain difficult, even with additional data, due to apparent rapid radiations. Our study addresses the lack of a recent pinniped phylogeny that includes all species and robust divergence dates for all nodes, and will therefore prove indispensable to comparative and macroevolutionary studies of this group of carnivores. PMID:17996107

Higdon, Jeff W; Bininda-Emonds, Olaf RP; Beck, Robin MD; Ferguson, Steven H

2007-01-01

396

Urinary parameters of Trichechus inunguis (Mammalia, Sirenia): reference values for the Amazonian Manatee.  

PubMed

The Amazonian manatee, Trichechus inunguis (Natterer 1883) is endemic to the Amazon Basin and is currently considered a vulnerable species. In order to establish normality ranges of urinary parameters to help monitor the health of this species in captivity, chemical urinalyses were performed on twelve males and nine females of various age groups. Urine was collected once a month for twelve months in the tanks just after being drained, by placing stainless steel containers under the genital slit of females and applying abdominal massages to males in order to stimulate urination. Quantitative data of glucose, urea, creatinine, uric acid and amylase levels were obtained using colorimetric spectrophotometry. Dip strips were also useful for routine analyses, despite only providing qualitative results. Normal range to glucose levels, regardless of sex or age class, was 3.0 to 3.6 mgxdL-1, coinciding with qualitative values of glucose measured by dip strips. Statistical differences observed in some parameter levels suggest that some urine parameters analysed must take into consideration the sex and the age class of the animal studied, being these differences less remarkable in creatinine and amylase levels. To this last one, statistical difference was detected only in the calve's urine (7.0 to 11.5 mgxdL-1) compared to other age classes samples (4.1 to 5.3 mgxdL-1). The results presented here may be used as comparative data in future research on urinalysis in related species. PMID:20730348

Pantoja, T M A; Da Rosas, F C W; Dos Silva, V M F; Santos, A M F

2010-08-01

397

The mammary glands of the Amazonian manatee, Trichechus inunguis (Mammalia: Sirenia): morphological characteristics and microscopic anatomy.  

PubMed

The mammaries from carcasses of two female Amazonian manatees were examined. Trichechus inunguis possesses two axillary mammaries beneath the pectoral fins, one on each side of the body. Each papilla mammae has a small hole on its apex--the ostium papillare. The mammaries are covered by a stratified squamous keratinized epithelium. The epithelium of the mammary ducts became thinner more deeply in the tissue and varied from stratified to simple cuboidal. There was no evidence of glandular activity or secretion into the ducts of the mammary glands. PMID:24920139

Rodrigues, Fernanda Rosa; da Silva, Vera Maria Ferreira; Barcellos, José Fernando Marques

2014-08-01

398

Histological patterns of the intestinal attachment of Corynosoma australe (Acanthocephala: Polymorphidae) in Arctocephalus australis (Mammalia: Pinnipedia).  

PubMed

The mucosal attachment pattern of Corynosoma australe in the intestines of Arctocephalus australis is described. Normal and abnormal tissue were sampled from 32 hosts to be submitted to histological routine protocol to embedding in paraffin and permanent mounting in balsam. Corynosoma australe shows three different degrees of body depth intestinal attachment (BDINA-1-3). BDINA-1: it is exclusive of the small intestine and the parasite attaches on the villi; BDINA-2: parasite affects the Lieberkühn crypts in several depth levels and, BDINA-3: the parasite reaches the submucosa. These attachment patterns alter the mucosa by degeneration and dysfunction due to necrosis of mucosal structure, great quantities of cellular debris and significant reduction of the mucosal thickness. Other aspects are crater-like concave holes (CLCHs) as sites where C. australe could be attached-detached several times according to adult migratory processes within luminal intestine space. The submucosa shows edema probably due to the local mucosal alterations resulting in homeostatic break. There is no severe inflammatory response by host but BDINA-1 to BDINA-3 and CLCH could represent foci to secondary opportunistic infections and significant areas of malabsorption in severally infected hosts contributing to increase clinical signs of preexistent pathologies. PMID:25320494

Silva, Renato Z; Pereira, Joaber; Cousin, João Carlos B

2014-12-01

399

Pelvic peritoneum in male armadillo and anteater (Xenarthra, Mammalia): a comparative survey.  

PubMed

The literature supports the hypothesis that the pelvic excavation is the bottom of the abdominal cavity, which is covered by the peritoneal serous membrane in order to promote visceral dynamics. We studied the peritoneum in eight specimens of Xenarthra (Euphractus sexcinctus, Myrmecophaga tridactyla and Tamandua tetradactyla). The animals were fixed in formaldehyde (10%). For description and analyzes of the pelvic peritoneum, dissection and photo documentation were performed. We saw that the parietal serous membrane reflected, involving the pelvic viscera. The urorectal septum is the floor of the higher pelvis as a serosa reflection between the bladder and the rectum. The bladder and gonads are completely peritonized in adult armadillo. In anteaters and young armadillos, the testicles are in a position analogous to the uterus, joined by the conjunctive septum at the midline and along with the bladder, they partially project to the higher and lower pelvis. In Myrmecophagidae, vesicogenital, rectogenital and sacrorectal recesses were observed. In Dasypodidae, the recesses are similar to those of other recent vertebrates. PMID:23317367

Rezende, Lorenna Cardoso; Ferreira, Jussara Rocha

2013-01-01

400

Morphometric study of phylogenetic and ecologic signals in procyonid (mammalia: carnivora) endocasts.  

PubMed

Endocasts provide a proxy for brain morphology but are rarely incorporated in phylogenetic analyses despite the potential for new suites of characters. The phylogeny of Procyonidae, a carnivoran family with relatively limited taxonomic diversity, is not well resolved because morphological and molecular data yield conflicting topologies. The presence of phylogenetic and ecologic signals in the endocasts of procyonids will be determined using three-dimensional geometric morphometrics. Endocasts of seven ingroup species and four outgroup species were digitally rendered and 21 landmarks were collected from the endocast surface. Two phylogenetic hypotheses of Procyonidae will be examined using methods testing for phylogenetic signal in morphometric data. In analyses of all taxa, there is significant phylogenetic signal in brain shape for both the morphological and molecular topologies. However, the analyses of ingroup taxa recover a significant phylogenetic signal for the morphological topology only. These results indicate support for the molecular outgroup topology, but not the ingroup topology given the brain shape data. Further examination of brain shape using principal components analysis and wireframe comparisons suggests procyonids possess more developed areas of the brain associated with motor control, spatial perception, and balance relative to the basal musteloid condition. Within Procyonidae, similar patterns of variation are present, and may be associated with increased arboreality in certain taxa. Thus, brain shape derived from endocasts may be used to test for phylogenetic signal and preliminary analyses suggest an association with behavior and ecology. PMID:25066912

Ahrens, Heather E

2014-12-01

401

Late Pleistocene carnivores (Carnivora: Mammalia) from a cave sedimentary deposit in northern Brazil.  

PubMed

The Brazilian Quaternary terrestrial Carnivora are represented by the following families: Canidae, Felidae, Ursidae, Procyonidae Mephitidae and Mustelidae. Their recent evolutionary history in South America is associated with the uplift of the Panamanian Isthmus, and which enabled the Great American Biotic Interchange (GABI). Here we present new fossil records of Carnivora found in a cave in Aurora do Tocantins, Tocantins, northern Brazil. A stratigraphical controlled collection in the sedimentary deposit of the studied cave revealed a fossiliferous level where the following Carnivora taxa were present: Panthera onca, Leopardus sp., Galictis cuja, Procyon cancrivorus, Nasua nasua and Arctotherium wingei. Dating by Electron Spinning Resonance indicates that this assemblage was deposited during the Last Glacial Maximum (LGM), at least, 22.000 YBP. The weasel, G. cuja, is currently reported much further south than the record presented here. This may suggest that the environment around the cave was relatively drier during the LGM, with more open vegetation, and more moderate temperatures than the current Brazilian Cerrado. PMID:25424041

Rodrigues, Shirlley; Avilla, Leonardo S; Soibelzon, Leopoldo H; Bernardes, Camila

2014-11-28

402

Molecular evidence for a recent demographic expansion in the puma (Puma concolor) (Mammalia, Felidae)  

PubMed Central

The puma is an iconic predator that ranges throughout the Americas, occupying diverse habitats. Previous phylogeographic analyses have revealed that it exhibits moderate levels of genetic structure across its range, with few of the classically recognized subspecies being supported as distinct demographic units. Moreover, most of the species’ molecular diversity was found to be in South America. To further investigate the phylogeographic structure and demographic history of pumas we analyzed mtDNA sequences from 186 individuals sampled throughout their range, with emphasis on South America. Our objectives were to refine the phylogeographic assessment within South America and to investigate the demographic history of pumas using a coalescent approach. Our results extend previous phylogeographic findings, reassessing the delimitation of historical population units in South America and demonstrating that this species experienced a considerable demographic expansion in the Holocene, ca. 8,000 years ago. Our analyses indicate that this expansion occurred in South America, prior to the hypothesized re-colonization of North America, which was therefore inferred to be even more recent. The estimated demographic history supports the interpretation that pumas suffered a severe demographic decline in the Late Pleistocene throughout their distribution, followed by population expansion and re-colonization of the range, initiating from South America. PMID:24385863

Matte, Eunice M.; Castilho, Camila S.; Miotto, Renata A.; Sana, Denis A.; Johnson, Warren E.; O’Brien, Stephen J.; de Freitas, Thales R. O.; Eizirik, Eduardo

2013-01-01

403

Late Pleistocene carnivores (Carnivora: Mammalia) from a cave sedimentary deposit in northern Brazil.  

PubMed

The Brazilian Quaternary terrestrial Carnivora are represented by the following families: Canidae, Felidae, Ursidae, Procyonidae Mephitidae and Mustelidae. Their recent evolutionary history in South America is associated with the uplift of the Panamanian Isthmus, and which enabled the Great American Biotic Interchange (GABI). Here we present new fossil records of Carnivora found in a cave in Aurora do Tocantins, Tocantins, northern Brazil. A stratigraphical controlled collection in the sedimentary deposit of the studied cave revealed a fossiliferous level where the following Carnivora taxa were present: Panthera onca, Leopardus sp., Galictis cuja, Procyon cancrivorus, Nasua nasua and Arctotherium wingei. Dating by Electron Spinning Resonance indicates that this assemblage was deposited during the Last Glacial Maximum (LGM), at least, 22.000 YBP. The weasel, G. cuja, is currently reported much further south than the record presented here. This may suggest that the environment around the cave was relatively drier during the LGM, with more open vegetation, and more moderate temperatures than the current Brazilian Cerrado. PMID:25590705

Rodrigues, Shirlley; Avilla, Leonardo S; Soibelzon, Leopoldo H; Bernardes, Camila

2014-12-01

404

A record from Surinam of the bat Chiroderma trinitatum Goodwin, 1958 (Mammalia, Chiroptera)  

Microsoft Academic Search

Re-examination of a collection of bats from Surinam in the Zoölogisch Museum, Amsterdam, uncovered a specimen representing the Phyllostomatid bat Chiroderma trinitatum Goodwin, 1958. This species does not appear in the monograph of the Chiroptera of Surinam by Husson (1962), nor in his more recent works on the mammals of that country (1973; 1978). The present specimen therefore seems to

W. Bergmans

1979-01-01

405

Digital dissection of the masticatory muscles of the naked mole-rat, Heterocephalus glaber (Mammalia, Rodentia)  

PubMed Central

The naked mole-rat, Heterocephalus glaber, of the family Bathyergidae is a subterranean rodent that feeds on underground roots and tubers and digs extensive tunnel systems with its incisors. It is a highly unusual mammal with regard to its social structure, longevity, pain insensitivity and cancer resistance, all of which have made it the subject of a great deal of research in recent years. Yet, much of the basic anatomy of this species remains undocumented. In this paper, we describe the morphology of the jaw-closing musculature of the naked mole-rat, as revealed by contrast-enhanced micro-computed tomography. This technique uses an iodine stain to enable the imaging of soft tissues with microCT. The iodine-enhanced scans were used to create 3D reconstructions of the naked mole-rat masticatory muscles from which muscle masses were calculated. The jaw-closing musculature of Heterocephalus glaber is relatively very large compared to other rodents and is dominated by the superficial masseter, the deep masseter and the temporalis. The temporalis in particular is large for a rodent, covering the entirety of the braincase and much of the rear part of the orbit. The morphology of the masseter complex described here differs from two other published descriptions of bathyergid masticatory muscles, but is more similar to the arrangement seen in other rodent families. The zygomaticomandibularis (ZM) muscle does not protrude through the infraorbital foramen on to the rostrum and thus the naked mole-rat should be considered protrogomorphous rather than hystricomorphous, and the morphology is consistent with secondarily lost hystricomorphy as has been previously suggested for Bathyergidae. Overall, the morphology of the masticatory musculature indicates a species with a high bite force and a wide gape–both important adaptations for a life dominated by digging with the incisors. PMID:25024917

Faulkes, Chris G.

2014-01-01

406

Comparative Morphology of Premolar Foramen in Lagomorphs (Mammalia: Glires) and Its Functional and Phylogenetic Implications  

PubMed Central

Lagomorphs (a group that consists of pikas, hares, rabbits and allies) are notable for their conservative morphology retained for most of their over 50 million years evolutionary history. On the other hand, their remarkable morphological uniformity partly stems from a considerable number of homoplasies in cranial and dental structures that hamper phylogenetic analyses. The premolar foramen, an opening in the palate of lagomorphs, has been characterized as an important synapomorphy of one clade, Ochotonidae (pikas). Within Lagomorpha, however, its phylogenetic distribution is much wider, the foramen being present not only in all ochotonids but also in leporids and stem taxa; its morphology and incidence also varies considerably across the order, even intraspecifically. In this study, we provide a broad survey of the taxonomic distribution of the premolar foramen in extant and fossil Lagomorpha and describe in detail the morphological variation of this character within the group. Micro-computed tomography was used to examine the hard palate and infraorbital groove morphology in Poelagus (Leporidae) and Ochotona. Scans revealed the course and contacts of the canal behind the premolar foramen and structural differences between the two crown clades. We propose that the premolar foramen has evolved independently in several lineages of Lagomorpha, and we discuss development and function of this foramen in the lagomorph skull. This study shows the importance of comprehensive studies on phylogenetically informative non-dental characters in Lagomorpha. PMID:24278178

Fostowicz-Frelik, ?ucja; Meng, Jin

2013-01-01

407

Phenotypic convergence in genetically distinct lineages of a Rhinolophus species complex (Mammalia, Chiroptera).  

PubMed

Phenotypes of distantly related species may converge through adaptation to similar habitats and/or because they share biological constraints that limit the phenotypic variants produced. A common theme in bats is the sympatric occurrence of cryptic species that are convergent in morphology but divergent in echolocation frequency, suggesting that echolocation may facilitate niche partitioning, reducing competition. If so, allopatric populations freed from competition, could converge in both morphology and echolocation provided they occupy similar niches or share biological constraints. We investigated the evolutionary history of a widely distributed African horseshoe bat, Rhinolophus darlingi, in the context of phenotypic convergence. We used phylogenetic inference to identify and date lineage divergence together with phenotypic comparisons and ecological niche modelling to identify morphological and geographical correlates of those lineages. Our results indicate that R. darlingi is paraphyletic, the eastern and western parts of its distribution forming two distinct non-sister lineages that diverged ~9.7 Mya. We retain R. darlingi for the eastern lineage and argue that the western lineage, currently the sub-species R. d. damarensis, should be elevated to full species status. R. damarensis comprises two lineages that diverged ~5 Mya. Our findings concur with patterns of divergence of other co-distributed taxa which are associated with increased regional aridification between 7-5 Mya suggesting possible vicariant evolution. The morphology and echolocation calls of R. darlingi and R. damarensis are convergent despite occupying different biomes. This suggests that adaptation to similar habitats is not responsible for the convergence. Furthermore, R. darlingi forms part of a clade comprising species that are bigger and echolocate at lower frequencies than R. darlingi, suggesting that biological constraints are unlikely to have influenced the convergence. Instead, the striking similarity in morphology and sensory biology are probably the result of neutral evolutionary processes, resulting in the independent evolution of similar phenotypes. PMID:24312666

Jacobs, David S; Babiker, Hassan; Bastian, Anna; Kearney, Teresa; van Eeden, Rowen; Bishop, Jacqueline M

2013-01-01

408

A time-calibrated species-level phylogeny of bats (Chiroptera, Mammalia)  

PubMed Central

Despite their obvious utility, detailed species-level phylogenies are lacking for many groups, including several major mammalian lineages such as bats. Here we provide a cytochrome b genealogy of over 50% of bat species (648 terminal taxa). Based on prior analyzes of related mammal groups, cytb emerges as a particularly reliable phylogenetic marker, and given that our results are broadly congruent with prior knowledge, the phylogeny should be a useful tool for comparative analyzes. Nevertheless, we stress that a single-gene analysis of such a large and old group cannot be interpreted as more than a crude estimate of the bat species tree. Analysis of the full dataset supports the traditional division of bats into macro- and microchiroptera, but not the recently proposed division into Yinpterochiroptera and Yangochiroptera. However, our results only weakly reject the former and strongly support the latter group, and furthermore, a time calibrated analysis of a pruned dataset where most included taxa have the entire 1140bp cytb sequence finds monophyletic Yinpterochiroptera. Most bat families and many higher level groups are supported, however, relationships among families are in general weakly supported, as are many of the deeper nodes of the tree. The exceptions are in most cases apparently due to the misplacement of species with little available data, while in a few cases the results suggest putative problems with current classification, such as the non-monophyly of Mormoopidae. We provide this phylogenetic hypothesis, and an analysis of divergence times, as tools for evolutionary and ecological studies that will be useful until more inclusive studies using multiple loci become available. PMID:21327164

Agnarsson, Ingi; Zambrana-Torrelio, Carlos M.; Flores-Saldana, Nadia Paola; May-Collado, Laura J.

2011-01-01

409

Evolution of nectarivory in phyllostomid bats (Phyllostomidae Gray, 1825, Chiroptera: Mammalia)  

PubMed Central

Background Bats of the family Phyllostomidae show a unique diversity in feeding specializations. This taxon includes species that are highly specialized on insects, blood, small vertebrates, fruits or nectar, and pollen. Feeding specialization is accompanied by morphological, physiological and behavioural adaptations. Several attempts were made to resolve the phylogenetic relationships within this family in order to reconstruct the evolutionary transitions accompanied by nutritional specialization. Nevertheless, the evolution of nectarivory remained equivocal. Results Phylogenetic reconstructions, based on a concatenated nuclear-and mitochondrial data set, revealed a paraphyletic relationship of nectarivorous phyllostomid bats. Our phylogenetic reconstructions indicate that the nectarivorous genera Lonchophylla and Lionycteris are closer related to mainly frugivorous phyllostomids of the subfamilies Rhinophyllinae, Stenodermatinae, Carolliinae, and the insectivorous Glyphonycterinae rather than to nectarivorous bats of the Glossophaginae. This suggests an independent origin of morphological adaptations to a nectarivorous lifestyle within Lonchophyllinae and Glossophaginae. Molecular clock analysis revealed a relatively short time frame of about ten million years for the divergence of subfamilies. Conclusions Our study provides strong support for diphyly of nectarivorous phyllostomids. This is remarkable, since their morphological adaptations to nutrition, like elongated rostrums and tongues, reduced teeth and the ability to use hovering flight while ingestion, closely resemble each other. However, more precise examinations of their tongues (e.g. type and structure of papillae and muscular innervation) revealed levels of difference in line with an independent evolution of nectarivory in these bats. PMID:20525339

2010-01-01

410

Late Cenozoic History of the Genus Micromys (Mammalia, Rodentia) in Central Europe  

E-print Network

, Charles University, Praha, Czech Republic, 2 Institute of Geology AS CR, v.v.i., Praha, Czech Republic, 3, Australia Received December 4, 2012; Accepted March 22, 2013; Published May 6, 2013 Copyright: Ã? 2013 Hora AVOZ30130516 and RVO67985831 of the Institute of Geology AS CR, v.v.i. (JW). The funders had no role

Horacek, Ivan

411

Nucleolus organizer regions and B-chromosomes of wood mice (mammalia, rodentia, Apodemus)  

SciTech Connect

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 = 53). 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. 29 refs., 4 figs., 1 tab.

Boeskorov, G.G. [Yakutia Institute of Biology, Yakutsk (Russian Federation); Kartavtseva, I.V. [Biological Soil Institute, Vladivostok (Russian Federation); Zagorodnyuk, I.V. [Shmal`gausen Institute of Zoology, Kiev (Ukraine); Belyanin, A.N. [Saratov State Univ. (Russian Federation); Lyapunova, E.A. [Kol`tsov Institute of Developmental Biology, Moscow (Russian Federation)

1995-02-01

412

Revision of the Wind River faunas, early Eocene of central Wyoming. X - Bunophorus (Mammalia, Artiodactyla)  

NASA Technical Reports Server (NTRS)

Research on the holotypes and large collections of the species of Wasatchia and Bunophorus is reviewed. It is concluded that Bunophorus is a senior synonym of Wasatchia and includes six valid species, namely, B. etsagicus, B. grangeri, B. pattersoni, B. macropternus, B. sinclairi, and B. robustus. B. sinclairi includes two penecontemporaneous geographic variants: B.s. sinclairi from the Wind River, Piceance and Green River basins, and B.s. robinsoni, n. ssp., from the Huerfano Basin.

Stucky, Richard K.; Krishtalka, Leonard

1990-01-01

413

Insectivora (Mammalia) from the Lower Miocene of the Aktau Mountains, South-Eastern Kazakhstan  

Microsoft Academic Search

Recently a new association of isolated teeth of small mammals including rodents (cricetids, ctenodactylids, sciurids, zapodids),\\u000a insectivores and lagomorphs was collected from the middle member of the Chul’adyr Formation but about 5 m above the main fossiliferous\\u000a horizon that has yielded large mammals (Kordikova & Mavrin 1996b). Among the small mammal teeth at least 85 isolated teeth belong to insectivores

Elena G. Kordikova

2000-01-01

414

Foraging behaviour, food selection and diet digestion of Babyrousa babyrussa (Suidae, Mammalia  

E-print Network

A population of 79 babirusa distributed over 19 zoos in Europe and the United States were the subject of a study of the foraging behaviour, food selection, and digestion of the babirusa (Babyrousa babyrussa). Stomachs ...

Leus, Kristin

415

The Endemic Insular and Peninsular Species Chaetodipus spinatus (Mammalia, Heteromyidae) Breaks Patterns for Baja California  

PubMed Central

The Baja California peninsula is the second longest, most geographically isolated peninsula on Earth. Its physiography and the presence of many surrounding islands has facilitated studies of the underlying patterns and drivers of genetic structuring for a wide spectrum of organisms. Chaetodipus spinatus is endemic to the region and occurs on 12 associated islands, including 10 in the Gulf of California and two in the Pacific Ocean. This distribution makes it a model species for evaluating natural historical barriers. We test hypotheses associated with the relationship between the range of the species, patterns in other species, and its relationship to Pleistocene-Holocene climatic changes. We analyzed sequence data from mtDNA genes encoding cytochrome b (Cytb) and cytochrome c oxidase subunits I (COI) and III (COIII) in 26 populations including all 12 islands. The matrilineal genealogy, statistical parsimony network and Bayesian skyline plot indicated an origin of C. spinatus in the southern part of the peninsula. Our analyses detected several differences from the common pattern of peninsular animals: no mid-peninsula break exists, Isla Carmen hosts the most divergent population, the population on an ancient southern Midriff island does not differ from peninsular populations, and a mtDNA peninsular discordance occurs near Loreto. PMID:25542029

Álvarez-Castañeda, Sergio Ticul; Murphy, Robert W.

2014-01-01

416

[Bats (Chiroptera: Mammalia) from Yurubí National Park, Venezuela: taxonomic list and community study].  

PubMed

Bats represent a key component in the dynamics of many terrestrial ecosystems, and one of the groups of mammals with the highest levels of diversification in the Neotropics. Here we describe the results of a study of the bat fauna from Yurubí National Park (mountain area in Northern Venezuela), that includes a taxonomic list and the characterization of some community attributes in forested areas. Data was collected from zoological collections and diversified sampling methods from February to July of 2009 in an altitudinal gradient (100-1 500m), with three principal ecological units: semideciduous, evergreen and cloud forests. We recorded 64 species grouped in five families (63% of the bats known from La Cordillera de la Costa), of which Phyllostomidae was the dominant taxa (42 species; 66% of total), followed by Vespertilionidae, Molossidae, Emballonuridae and Mormoopidae. The community with the highest taxonomic diversification was found in the lowest elevation range, while the lowest number of species was found at the highest range. Eleven trophic guilds were identified; the insectivorous guild was the richest, whereas the frugivorous was the most abundant. Our results allow us to indicate these forest ecosystems have an appropriate conservation status, taking into account the presence of a relatively high proportion of species from the subfamily Phyllostominae, as well as the presence of other species with conservation priorities. All these aspects, and the fact that this represents a reservoir of the biological diversity of the forest ecosystems of La Cordillera de la Costa, make this protected area of an essential conservation value, in a highly endangered bioregion by neighboring socio-economic growth. PMID:22208091

Delgado-Jaramillo, Mariana; Machado, Marjorie; García, Franger J; Ochoa, José

2011-12-01

417

Immunocytochemical study of gastrintestinal endocrine cells in insectivorous bats (Mammalia: Chiroptera).  

PubMed

The regional distribution and relative frequency of endocrine cells in the stomach and intestine of Phyllostomidae: Lonchorhina aurita and Molossidae: Molossus molossus bats were studied immunohistochemically. Three types of immunoreactive (IR) endocrine cells--to serotonin (5-HT), gastrin (GAS) and enteroglucagon (GLUC)--were found in the gastric mucosa and four types of IR cells were identified in the intestinal mucosa. This study showed an interespecfic difference in the regional distribution and relative frequency of endocrine cells in the Chiropteran alimentary tract. PMID:18833490

Santos, C M; Nascimento, A A; Peracchi, A L; Sales, A; Mikalauskas, J S; Gouveia, S F

2008-08-01

418

Patterns of postnatal development in skulls of lynxes, genus Lynx (Mammalia: Carnivora).  

PubMed

Studies on ossification patterns and other ontogenetic events associated with postnatal cranial growth of wild felids are scarce. An analysis of developmental processes undergone by several cranial structures (presphenoidal and sphenooccipital synchondroses, temporal and sagittal crests, and deciduous and permanent teeth) during postnatal growth has been conducted on a sample of 336 specimens belonging to the four Recent species of lynxes (Lynx pardinus, Lynx lynx, Lynx rufus, and Lynx canadensis). Age has been estimated based on tooth replacement, skull size, and by counting the annual lines of cementum growth. Comparison of the results obtained for each of the four species reveal (1) a single pattern for both tooth replacement and ossification of the sphenooccipital synchondrosis, (2) two ossification patterns for the presphenoidal synchondrosis, (3) a common pattern for development of temporal ridges and sagittal crest showing different degrees of morphological expression, and (4) evidence suggesting the involvement of a heterochronic process, neoteny, in the morphological differentiation of several populations and species of the genus Lynx. These data also support the hypothesis that processes involved in the replacement of carnassials are based on functional requirements. PMID:8765807

Garcia-Perea, R

1996-09-01

419

Molecular evidence for a recent demographic expansion in the puma (Puma concolor) (Mammalia, Felidae).  

PubMed

The puma is an iconic predator that ranges throughout the Americas, occupying diverse habitats. Previous phylogeographic analyses have revealed that it exhibits moderate levels of genetic structure across its range, with few of the classically recognized subspecies being supported as distinct demographic units. Moreover, most of the species' molecular diversity was found to be in South America. To further investigate the phylogeographic structure and demographic history of pumas we analyzed mtDNA sequences from 186 individuals sampled throughout their range, with emphasis on South America. Our objectives were to refine the phylogeographic assessment within South America and to investigate the demographic history of pumas using a coalescent approach. Our results extend previous phylogeographic findings, reassessing the delimitation of historical population units in South America and demonstrating that this species experienced a considerable demographic expansion in the Holocene, ca. 8,000 years ago. Our analyses indicate that this expansion occurred in South America, prior to the hypothesized re-colonization of North America, which was therefore inferred to be even more recent. The estimated demographic history supports the interpretation that pumas suffered a severe demographic decline in the Late Pleistocene throughout their distribution, followed by population expansion and re-colonization of the range, initiating from South America. PMID:24385863

Matte, Eunice M; Castilho, Camila S; Miotto, Renata A; Sana, Denis A; Johnson, Warren E; O'Brien, Stephen J; de Freitas, Thales R O; Eizirik, Eduardo

2013-12-01

420

The Asian Colobinae (Mammalia: Cercopithecidae) as indicators of Quaternary climatic change  

Microsoft Academic Search

A reappraisal of the zoogeography and systematics of Asian colobines demonstrates marked discontinuities in their distribution. The Borean proboscis monkey is separated by Sumatra from its sole congener on the Mentawai Islands.Pygathrixspecies have a discontinuous distribution at the range limit of the Asian Colobinae. The existence in the Himalayas of some disjunct relatives of the south Indian fauna, has obscured

DOUGLAS BRANDON-JONES

1996-01-01