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1

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. J. Morphol. 275:745-759, 2014. © 2014 Wiley Periodicals, Inc. PMID:24470078

Woodman, Neal; Gaffney, Sarah A

2014-07-01

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

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

4

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

5

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

6

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

7

Inheritance of male hybrid sterility in the house musk shrew (Suncus murinus, Insectivora, Soricidae).  

PubMed

Two geographic races of the house musk shrew (Suncus murinus) were crossed and intercrossed in the laboratory. Many cases of male sterility were detected among the hybrids. Segregation analysis of the pedigree data showed that the inheritance of male sterility in interracial hybrids of S. murinus can be described within the framework of monogene polyallele model with sterility of a single allele combination. This model is similar if not identical to that proposed by Dobzhansky and Muller. PMID:9924792

Axenovich, T I; Rogatcheva, M B; Oda, S; Borodin, P M

1998-12-01

8

Inheritance of litter size at birth in the house musk shrew (Suncus murinus, Insectivora, Soricidae).  

PubMed

In this research we estimated the contribution of a major-gene effect to the control of litter size in hybrids between two local populations of the house musk shrew (Suncus murinus). Segregation analysis was performed on the basis of a mixed polygene and major-gene model. The model presumes that two parental populations may differ from each other in gene frequencies and in the values of polygenic effects but not in the major-gene contribution of the trait. Moreover, the peculiarity of the trait--litter size--is taken into account. This trait is not an individual attribute. It characterizes the parental couple and may depend on the genotypes of both parents. Results of segregation analysis of a large hybrid pedigree of Suncus murinus indicate that the parental populations differ in the allele frequency of the major gene (one population is homozygous, while the other contains the two alleles in approximately equal proportions) and in the values of average polygenic effects. Both major-gene and polygenic components are necessary for the correct description of litter size inheritance in interracial hybrids of S murinus, inasmuch as the exclusion of either of them leads to a significant drop in likelihood. The Elston-Stewart criterion also confirms the Mendelian inheritance of the major gene. PMID:9674383

Aulchenko YuS; Oda, S I; Rogatcheva, M B; Borodin, P M; Axenovich, T I

1998-02-01

9

Chromosome pairing in inter-racial hybrids of the house musk shrew (Suncus murinus, Insectivora, Soricidae).  

PubMed

Two chromosome races of the house shrew Suncus murinus that differ from each other for five Robertsonian translocations (8.17, 9.13, 10.12, 11.16, and 14.15), heterochromatic insertions in chromosomes 7 and X, and multiple rearrangements in the Y chromosome were crossed and then intercrossed in captivity to produce a hybrid stock. Electron-microscopic analysis of synaptonemal complexes in fertile and sterile hybrid males was carried out. Meiosis in sterile males did not progress beyond pachytene and was severely disrupted. Meiotic arrest was not determined by structural heterozygosity: heterozygotes for all variant chromosomes distinguishing two parental races were found in both sterile and fertile male hybrids. Fertile hybrids demonstrated an orderly pairing of all chromosomes. In heterozygotes for Robertsonian fusions, completely paired trivalents were formed between the Robertsonian metacentrics and homologous acrocentrics. In heterozygotes for chromosome 7, bivalents with a small buckle were observed in a small fraction of pachytene cells. No differences were found in the morphology and pairing pattern of sex bivalents, composed of the X and Y chromosomes derived from the same or different parental races. Univalents, multivalents, and associations between X and Y chromosomes and autosomal trivalents, as well as associations of autosomal trivalents with each other, were observed in a small fraction of the pachytene cells of fertile males. Our results indicate that the system controlling male sterility in interracial hybrids of S. murinus is of genic rather than of chromosomal type. PMID:9549061

Borodin, P M; Rogatcheva, M B; Zhelezova, A I; Oda, S

1998-02-01

10

Natural hybridization between extremely divergent chromosomal races of the common shrew (Sorex araneus, Soricidae, Soricomorpha): hybrid zone in European Russia.  

PubMed

The Moscow and Seliger chromosomal races of the common shrew differ by Robertsonian fusions and possibly whole-arm reciprocal translocations (WARTs) such that their F? hybrids produce a chain-of-eleven configuration at meiosis I and are expected to suffer substantial infertility. Of numerous hybrid zones that have been described in the common shrew, those between the Moscow and Seliger races involve the greatest chromosomal difference. We collected 211 individuals from this zone to generate a total dataset of 298 individuals from 187 unique global positioning system (GPS) locations within the vicinity of interracial contact. We used a geographic information system (GIS) to map the location of the hybrid zone, which follows a direct route between two lakes, as would be anticipated from tension zone theory. Even within the central area of the hybrid zone, there is a much higher frequency of pure race individuals than hybrid, making this a clear example of a bimodal zone in the sense of Jiggins & Mallet (2000). The zone runs through good habitat for common shrews, but nevertheless it is very narrow (standard cline widths: 3-4 km), as would be anticipated from low hybrid fitness. There is clear potential for an interruption to gene flow and build-up of reproductive isolation. As found in some other hybrid zones, there is a high frequency of novel genetic variants, in this case, new chromosomal rearrangements. Here, we report a de novo Robertsonian fission and a de novo reciprocal translocation, both for the first time in the common shrew. There is an extraordinarily high frequency of de novo mutations recorded in F? hybrids in the zone and we discuss how chromosomal instability may be associated with such hybrids. The occurrence of a de novo Robertsonian fission is of considerable significance because it provides missing evidence that fissions are the basis of the novel acrocentric forms found and apparently selected for in certain common shrew hybrid zones. PMID:21159004

Bulatova, N; Jones, R M; White, T A; Shchipanov, N A; Pavlova, S V; Searle, J B

2011-03-01

11

First evidence of poisonous shrews with an envenomation apparatus  

NASA Astrophysics Data System (ADS)

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 from two Early Pleistocene cave deposits of the Sierra de Atapuerca in Burgos, Spain. The two soricine taxa from Atapuerca have evolved specialized teeth as EAs, which differ from those of recently reported mammals of the Paleocene age, being more similar to the ones described in the modern Solenodon. This discovery reveals the first instance of shrews possessing what appears to be an EA, an evolutionary adaptation that, in these species, was probably related to an increase in body mass and hunting of a larger-sized prey. The Atapuerca specimens would have a highly specialized EA, one of the very few reported for an extinct or living mammal of any time. In addition to the presence of a gutter-like groove along the medial side of the crown of the lower incisors, these two species also present stout jaws and a modified mandibular symphysis with a conspicuous cavity, which in life would likely contain large amounts of connective tissue. The strong mandible architecture of these large shrews would be, in this way, reinforced by a more immovable symphysis, increasing the bite force exerted over a potential prey. This adaptation, together with the grooved incisors, would ensure a rapid and efficient transmission of the poisonous saliva to paralyze relatively large-sized prey.

Cuenca-Bescós, Gloria; Rofes, Juan

2007-02-01

12

Metal and metalloid accumulation in shrews (Soricomorpha, Mammalia) from two protected Mediterranean coastal sites.  

PubMed

Although ecotoxicological data on heavy metals are abundant, information on other potentially toxic elements with attributed deficiency and/or toxic disturbances is scarce. Here we quantify zinc, copper, iron, manganese, chromium, molybdenum, strontium, barium, and boron in bones of greater white-toothed shrews, Crocidura russula, inhabiting two protected Mediterranean coastal sites: the Ebro Delta, a wetland impacted by human activities, and the Medas Islands, a reference site. Natural and anthropogenic inputs significantly increase Fe, Mn, Mo, Sr, Ba, and B in specimens from the Ebro Delta, whereas Cu and Cr were higher in Medas' shrews. Principal component analysis allowed complete separation between sites along the first two axes in particular due to B, Sr, and Cu. This study provides metal reference values in bones of insectivores, explores their variability and bioaccumulation patterns in depth, and assesses the potential environmental risk and toxicity for biota exposed to the above elements. PMID:19144455

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

2009-04-01

13

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

PubMed

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

14

Phylogeny and Taxonomy of the Round-Eared Sengis or Elephant-Shrews, Genus Macroscelides (Mammalia, Afrotheria, Macroscelidea)  

PubMed Central

The round-eared sengis or elephant-shrews (genus Macroscelides) exhibit striking pelage variation throughout their ranges. Over ten taxonomic names have been proposed to describe this variation, but currently only two taxa are recognized (M. proboscideus proboscideus and M. p. flavicaudatus). Here, we review the taxonomic history of Macroscelides, and we use data on the geographic distribution, morphology, and mitochondrial DNA sequence to evaluate the current taxonomy. Our data support only two taxa that correspond to the currently recognized subspecies M. p. proboscideus and M. p. flavicaudatus. Mitochondrial haplotypes of these two taxa are reciprocally monophyletic with over 13% uncorrected sequence divergence between them. PCA analysis of 14 morphological characters (mostly cranial) grouped the two taxa into non-overlapping clusters, and body mass alone is a relatively reliable distinguishing character throughout much of Macroscelides range. Although fieldworkers were unable to find sympatric populations, the two taxa were found within 50 km of each other, and genetic analysis showed no evidence of gene flow. Based upon corroborating genetic data, morphological data, near sympatry with no evidence of gene flow, and differences in habitat use, we elevate these two forms to full species.

Dumbacher, John P.; Rathbun, Galen B.; Smit, Hanneline A.; Eiseb, Seth J.

2012-01-01

15

Ultrastructure of the Eimer's organs of the Japanese shrew mole, Urotrichus talpoides (Insectivora, Mammalia) and their changes following infraorbital axotomy.  

PubMed

The Eimer's organ and adjacent structures and their changes after infraorbital axotomy was examined with LM, TEM and SEM in the Japanese shrew mole, Urotrichus talpoides. Approximately 3,000 of Eimer's organ covers the hairless snout tip of this animal. It protrudes to the corium from epidermis, and consists of column-shaped core and the cylindrical peripheral structures. About a dozen of naked fibers ascend vertically in the core; one or a few of them runs amidst the core and the others along its circumferential part. Each fiber has shelf-like endings one in each of 5 to 7 succeeding cells in the upper part of the core. At the uppermost part of the core structure is an opaque degenerating cell. Neurites were considered to grow up with the epidermal cells to which their endings are attached. This pattern of nerve ending was clearly observed for the first time in this study. Usually 3 Merkel cells lie at the base of an Eimer's organ contacting with a soup-plate-shape nerve terminal. In the dermis, an encapsulated corpuscle enveloping a nerve endings is found underneath each Eimer's organ. After axotomy, ipsilateral nerve fibers and their endings totally disappeared from Eimer's organ in a week. Perforation in the domes, flattening of the dome surface, and degeneration of the encapsulated corpuscles appeared on the transected side. In addition to this, several features of degeneration also appeared on the contralateral side. It might be considered as an effect of disuse from the disorders of the other side. PMID:3400878

Shibanai, S

1988-01-01

16

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

17

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.

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

2010-01-01

18

Distribution and coexistence of shrews in patchy landscapes: A field test of multiple hypotheses  

NASA Astrophysics Data System (ADS)

Despite the important role of shrews (Soricomorpha: Soricidae) in the functioning of ecosystems, as predators and prey, the effects of habitat loss and fragmentation on this guild of mammals are still unclear. We studied the distribution of 5 species (the greater white toothed shrew Crocidura leucodon; the lesser white toothed shrew Crocidura suaveolens; the pigmy shrew Sorex minutus; the Appennine shrew Sorex samniticus and the Etruscan shrew Suncus etruscus) in a fragmented landscape in central Italy. Shrews were trapped with pitfall traps made from plastic water bottles, the number of traps increased with patch size. A total of 170 individuals, of 5 species of shrews were captured. Shrews were widely distributed in our study area, however patch occupancy was determined mainly by vegetation and geometrical characteristics of the patches. Our data supports the hypotheses that patterns of habitat selection and the dynamics of seasonal abundance (habitat and temporal partitioning between similarly sized species) reduce competitive pressure, thus allowing coexistence of shrews in relatively species-rich assemblages, for such small amounts of habitat. The most important outcome of our results is the crucial role played by vegetation structure in determining distribution patterns. These results strongly suggest that measurements of the vegetation structure of habitat patches should always be included as explanatory variables when studying the distribution of shrews in fragmented landscapes.

Mortelliti, Alessio; Boitani, Luigi

2009-11-01

19

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

20

Leptospira spp. in Rodents and Shrews in Germany.  

PubMed

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

21

Designation of the type species of Musaraneus Pomel, 1848 (Mammalia: Soricomorpha: Soricidae)  

USGS Publications Warehouse

The genus name Musaraneus often is attributed to Brisson (1762), however, most of Brisson's names are unavailable. Pomel (1848) subsequently made the name Musaraneus available, but did not designate a type species. The 18 species that Pomel listed under Musaraneus currently are distributed among five modern genera, two of which (Cryptotis Pomel, 1848 and Diplomesodon Brandt, 1852) are predated by Musaraneus. Because Cryptotis and Diplomesodon potentially could be considered junior synonyms of Musaraneus, I propose Sorex leucodon Hermann, 1780 (= Crocidura leucodon) as the type species for Musaraneus, thereby establishing Musaraneus as a junior synonym of Crocidura Wagler, 1832.

Woodman, N.

2004-01-01

22

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.

Yoshimura, K; Shindo, J; Kageyama, I

2013-01-01

23

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

24

CONTIGUOUS ALLOPATRY OF THE MASKED SHREW AND SOUTHEASTERN SHREW IN THE SOUTHERN APPALACHIANS: SEGREGATION ALONG AN ELEVATIONAL AND HABITAT GRADIENT  

Microsoft Academic Search

Southeastern shrew (Sorex longirostris) and masked shrew (Sorex ci- nereus) distributions converge in the southern Appalachians. A 306,454-pitfal l- trapnight survey in Alabama, Georgia, North Carolina, and South Carolina doc- umented the presence of southeastern shrews in the Cumberland Plateau, Ridge and Valley, Upper Piedmont, and Blue Ridge physiographic provinces. South- eastern shrews occur at low elevations (x = 524.9

W. MARK FORD; MICHAEL A. MENZEL; TIMOTHY S. MCCAY

25

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.

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

2011-01-01

26

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

27

Osteology of the musk shrew (Suncus murinus).  

PubMed

In the present study using 29 adult musk shrew of both sexes, most findings were identified to be similar to those by Sharma (1958) on the osteology , and there was no remarkable difference between skeletal structure of wild musk shrew in India and that of breeding species in Japan except the number of the vertebra lumbalis and existance of the dens caninus . However, it was elucidated that the os articulare coccygis like H-letter in shape is characteristic for this animal, and shows 17 components as many between interspace ventral to the adjacent os coccygis , and that there exists the proc. spinosus appendicularis nominated newly over the vertebra thoracica II, which plays significant role to head and neck as origin or insertion for strong m. serratus dorsalis, m. splenius, and m. semispinalis . PMID:6721174

Isomura, G; Yoshizawa, M; Oda, S

1984-01-01

28

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.

Anjum, Farzana; Brecht, Michael

2012-01-01

29

Tactile guidance of prey capture in Etruscan shrews  

PubMed Central

Whereas visuomotor behaviors and visual object recognition have been studied in detail, we know relatively little about tactile object representations. We investigate a new model system for the tactile guidance of behavior, namely prey (cricket) capture by one of the smallest mammals, the Etruscan shrew, Suncus etruscus. Because of their high metabolic rate and nocturnal lifestyle, Etruscan shrews are forced to detect, overwhelm, and kill prey in large numbers in darkness. Crickets are exquisitely mechanosensitive, fast-moving prey, almost as big as the shrew itself. Shrews succeed in hunting by lateralized, precise, and fast attacks. Removal experiments demonstrate that both macrovibrissae and microvibrissae are required for prey capture, with the macrovibrissae being involved in attack targeting. Experiments with artificial prey replica show that tactile shape cues are both necessary and sufficient for evoking attacks. Prey representations are motion- and size-invariant. Shrews distinguish and memorize prey features. Corrective maneuvers and cricket shape manipulation experiments indicate that shrew behavior is guided by Gestalt-like prey descriptions. Thus, tactile object recognition in Etruscan shrews shares characteristics of human visual object recognition, but it proceeds faster and occurs in a 20,000-times-smaller brain.

Anjum, Farzana; Turni, Hendrik; Mulder, Paul G. H.; van der Burg, Johannes; Brecht, Michael

2006-01-01

30

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.

2013-01-01

31

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

32

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.

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

2011-01-01

33

The Force Driving Mating Behavior in the House Musk Shrew (Suncus murinus)  

Microsoft Academic Search

The mating behavior of the domesticated house musk shrew was observed in detail under laboratory conditions. The observations revealed that the house musk shrew has a series of behaviors before copulation. Tactile, auditory and chemical senses appear to function as flags for the recognition of conspecifics and to promote the development of an interaction between the sexes. The tactile senses

Osamu Matsuzaki

2002-01-01

34

Identification of Glyceraldehyde 3-Phosphate Dehydrogenase Sequence and Expression Profiles in Tree Shrew (Tupaia belangeri)  

PubMed Central

The tree shrews (Tupaia belangeri) diverged from the primate order (Primates) and are classified as Scandentia, a separate taxonomic group of mammals. The tree shrew has been suggested to use an animal model to study human disease but the genomic sequences of tree shrew is largely unidentified. Here we identified the full-length cDNA sequence of a housekeeping gene, Glyceraldehyde 3-phosphate Dehydrogenase (GAPDH), in tree shrew. We further constructed a phylogenetic family tree base on GAPDH molecules of various organisms and compared GAPDH sequences with human and other small experimental animals. These study revealed that tree shrew was closer to human than mouse, rat, rabbit and guinea pig. The Quantitative Reverse Transcription PCR and western blot analysis further demonstrated that GAPDH expressed in various tissues in tree shrew as a general conservative housekeeping proteins as in human. Our findings provide the novel genetic knowledge of the tree shrew and strong evidences that tree shrew can be an experimental model system to study human disorders.

Zheng, Yu; Wang, Yingjun; Smith, Wanli W.; Leng, Jing

2014-01-01

35

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

Microsoft Academic Search

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

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

2007-01-01

36

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

Microsoft Academic Search

Heart and lung mass, rate of oxygen consumption (V?O2), 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

Haya Mover; Amos Ar

1995-01-01

37

[Measurement and analysis of anatomical parameter values in tree shrews].  

PubMed

Anatomical parameter values in tree shrews are major biological characteristic indicators in laboratory animals. Body size, bones and mammilla, organ weights, coefficient intestinal canal and other anatomical data were measured and analyzed in laboratory domesticated tree shrews (7 to 9 months of age). Measurement of 31 anatomical parameters showed that body height, width of the right ear, ileum and colon had significant differences between males and females (P<0.05). Highly significant differences were also found in body slanting length, chest depth, torso length, left and right forelimb length, right hind limb length, left and right ear length, left ear width, keel bone length, left and right tibia length, duodenum and jejunum (P<0.01). With body length as the dependent variable, and tail length, torso length, right and left forelimb length, and left and right hind limb length as independent variables for stepwise regression analysis, the regression equation for body length = 13.90 + tail length × 0.16. The results of 37 organs weights between female and male tree shrews showed very significant differences (P<0.01) for weight of heart, lungs, spleen, left and right kidney, bladder, left and right hippocampus, left submandibular gland, and left and right thyroid gland, as well as significant (P<0.05) differences in the small intestine, right submandibular gland, and left adrenal gland. The coefficient of heart, lung, stomach, bladder, small and large intestine, brain, right hippocampus, and left adrenal gland showed highly significant differences (P<0.01), while differences in the right kidney, left hippocampus, left submandibular gland, right adrenal gland, and left and right thyroid gland were significant (P<0.05). With animal weight as the dependent variable and indicators of heart, lung, liver, spleen, left and right kidney and brain as independent variables for stepwise regression analysis, the regression equation showed that weight = 62.73 + left kidney × 79.21 + heart × 24.09. Female and male laboratory domesticated tree shrews showed certain influences in body size, organ weight and coefficient, and intestinal canal regarding anatomical parameters. This experiment provides basic data for studies on laboratory tree shrews and animal models. PMID:23572364

Li, Bo; Zhang, Rong-Ping; Li, Jin-Tao; He, Bao-Li; Zhen, Hong; Wang, Li-Mei; Jiao, Jian-Lin

2013-04-01

38

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.

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

2007-01-01

39

CXC Chemokine CXCL12 and Its Receptor CXCR4 in Tree Shrews (Tupaia belangeri): Structure, Expression and Function.  

PubMed

Chemokines are small secreted proteins functionally involved in the immune system's regulation of lymphocyte migration across numerous mammalian species. Given its growing popularity in immunological models, we investigated the structure and function of chemokine CXCL12 protein in tree shrews. We found that CXCL12 and its receptor CXCR4 in tree shrew had structural similarities to their homologous human proteins. Phylogenetic analysis supports the view that tree shrew is evolutionarily-close to the primates. Our results also showed that the human recombinant CXCL12 protein directly enhanced the migration of tree shrew's lymphocytes in vitro, while AMD3100 enhanced the mobilization of hematopoietic progenitor cells (HPCs) from bone marrow into peripheral blood in tree shrew in vivo. Collectively, these findings suggested that chemokines in tree shrews may play the same or similar roles as those in humans, and that the tree shrew is a viable animal model for studying human immunological diseases. PMID:24858548

Chen, Guiyuan; Wang, Wei; Meng, Shengke; Zhang, Lichao; Wang, Wenxue; Jiang, Zongmin; Yu, Min; Cui, Qinghua; Li, Meizhang

2014-01-01

40

CXC Chemokine CXCL12 and Its Receptor CXCR4 in Tree Shrews (Tupaia belangeri): Structure, Expression and Function  

PubMed Central

Chemokines are small secreted proteins functionally involved in the immune system's regulation of lymphocyte migration across numerous mammalian species. Given its growing popularity in immunological models, we investigated the structure and function of chemokine CXCL12 protein in tree shrews. We found that CXCL12 and its receptor CXCR4 in tree shrew had structural similarities to their homologous human proteins. Phylogenetic analysis supports the view that tree shrew is evolutionarily-close to the primates. Our results also showed that the human recombinant CXCL12 protein directly enhanced the migration of tree shrew's lymphocytes in vitro, while AMD3100 enhanced the mobilization of hematopoietic progenitor cells (HPCs) from bone marrow into peripheral blood in tree shrew in vivo. Collectively, these findings suggested that chemokines in tree shrews may play the same or similar roles as those in humans, and that the tree shrew is a viable animal model for studying human immunological diseases.

Meng, Shengke; Zhang, Lichao; Wang, Wenxue; Jiang, Zongmin; Yu, Min; Cui, Qinghua; Li, Meizhang

2014-01-01

41

Microchip-Associated Sarcoma in a Shrew (Suncus murinus)  

PubMed Central

A 16-mo-old female house musk shrew (Suncus murinus) with a 1-wk history of a rapidly growing subcutaneous mass in the interscapsular region was euthanized and submitted for necropsy. Macroscopic examination identified an irregular, well-demarcated, solid, tan-white subcutaneous mass. A small cavity containing a microchip device was present at the center of the mass. In addition, massive splenomegaly was evident grossly. Histologically, the subcutaneous mass comprised spindle cells arranged in a storiform pattern of interweaving bundles, consistent with a high-grade soft tissue sarcoma with multifocal necrosis. Immunohistochemical investigation suggested that the neoplastic cells were positive for neuron-specific enolase and (rarely) ?-smooth muscle actin and negative for cytokeratin, desmin, S100, and vimentin. In light of the mesenchymal histopathologic phenotype and the lack of specific immunoreactivity pattern, the mass was considered to be most consistent with a poorly differentiated sarcoma. To our knowledge, this is the first report of a microchip-associated soft tissue sarcoma in a shrew.

Schutt, Leah K; Turner, Patricia V

2010-01-01

42

Sex difference in Onuf's nucleus homologue in the Asian musk shrew.  

PubMed

Perineal muscles essential for copulatory functioning are innervated by Onuf's nucleus in humans and the spinal nucleus of the bulbocavernosus (SNB) and dorsolateral nucleus (DLN) in rats. These structures sexually differentiate as a result of developmental androgen exposure in most species examined. The homologous structure in the Asian musk shrew (Suncus murinus) is a single cluster in the lateral DLN/Onuf's position in the ventral horn of the spinal cord; these motoneurons innervate both the bulbocavernosus and ischiocavernosus muscles of the musk shrew. We found the expected sex difference in motoneuron number in the shrew DLN, but not in two neighboring motoneuron clusters, the retrodorsolateral nucleus (RDLN) and ventrolateral nucleus (VLN). Male musk shrews also have significantly larger soma areas in the VLN and DLN than females, and male DLN motoneurons have significantly larger nuclei than female. The sex difference in DLN motoneuron number was evident both in raw counts and after accounting for split nuclei error. PMID:20510680

Polak, Kathryn; Freeman, Louise M

2010-07-30

43

Sex difference in Onuf's nucleus homologue in the Asian musk shrew  

PubMed Central

Perineal muscles essential for copulatory functioning are innvervated by Onuf’s nucleus in humans and the spinal nucleus of the bulbocavernosus (SNB) and dorsolateral nucleus (DLN) in rats. These structures sexually differentiate as a result of developmental androgen exposure in most species examined. The homologous structure in the Asian musk shrew (Suncus murinus) is a single cluster in the lateral DLN/Onuf’s position in the ventral horn of the spinal cord; these motoneurons innervate both the bulbocavernosus and ischiocavernosus muscles of the musk shrew. We found the expected sex difference in motoneuron number in the shrew DLN, but not in two neighboring motoneuron clusters, the retrodorsolateral nucleus (RDLN) and ventrolateral nucleus (VLN). Male musk shrews also have significantly larger soma areas in the VLN and DLN than females, and male DLN motoneurons have significantly larger nuclei than female. The sex difference in DLN motoneuron number was evident both in raw counts and after accounting for split nuclei error.

Polak, Kathryn; Freeman, Louise M.

2010-01-01

44

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

PubMed Central

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. Images

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

1987-01-01

45

Livestock grazing intensity affects abundance of Common shrews (Sorex araneus) in two meadows in Denmark  

PubMed Central

Background Current nature conservation in semi-natural grasslands often includes grazing and hay cutting, as well as the abandonment of draining. Semi-natural grassland and in particular meadows constitute important habitat type for a large number of animal species in today's fragmented and intensively cultivated landscape of Europe. Here we focus on the population characteristics of Common shrews Sorex araneus in relation to livestock grazing intensity in two wet meadows in western Denmark. Results High grazing intensity had a significant negative effect on Common shrew number compared to low grazing intensity and no grazing. Common shrew abundance was generally, but not significantly, higher on the low grazing intensity plots than on the ungrazed controls. No differences in body mass, sex ratio, or reproductive output between Common shrew individuals from the various grazing treatments were found. Conclusion No negative effects of low intensity grazing on Common shrew abundance were found compared to the ungrazed control. Low intensity grazing thus seems a suitable management regime for Common shrews, when grazing is needed as part of the meadow management scheme. High intensity grazing on the other hand is not a suitable management tool.

Schmidt, Niels M; Olsen, Henrik; Leirs, Herwig

2009-01-01

46

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

47

Architectonic subdivisions of neocortex in the tree shrew (Tupaia belangeri)  

PubMed Central

Tree shrews are small mammals that bear some semblance to squirrels, but are actually close relatives of primates. Thus, they have been extensively studied as a model for the early stages of primate evolution. In the present study, subdivisions of cortex were reconstructed from brain sections cut in the coronal, sagittal or horizontal planes, and processed for parvalbumin (PV), SMI-32 immunopositive neurofilament protein epitopes, vesicle glutamate transporter 2 (VGluT2), free ionic zinc, myelin, cytochrome oxidase (CO) and Nissl substance. These different procedures revealed similar boundaries between areas, suggesting the detection of functionally relevant borders and allowed a more precise demarcation of cortical areal boundaries. Primary cortical areas were most clearly revealed by the zinc stain, due to the poor staining of layer 4, as thalamocortical terminations lack free ionic zinc. Area 17 (V1) was especially prominent, as the broad layer 4 was nearly free of zinc stain. However, this feature was less pronounced in primary auditory and somatosensory, cortex. In primary sensory areas, thalamocortical terminations in layer 4 densely express VGluT2. Auditory cortex consists of two architectonically distinct subdivisions, a primary core region (Ac), surrounded by a belt region (Ab) that had a slightly less developed koniocellular appearance. Primary motor cortex (M1) was identified by the absence of VGluT2 staining in the poorly developed granular layer 4 and the presence of SMI-32 labeled pyramidal cells in layers 3 and 5. The presence of well-differentiated cortical areas in tree shrews indicates their usefulness in studies of cortical organization and function.

Wong, Peiyan; Kaas, Jon H.

2010-01-01

48

Thermoregulatory correlates of nausea in rats and musk shrews  

PubMed Central

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.

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

2014-01-01

49

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

50

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

51

Colonization of Ireland: revisiting 'the pygmy shrew syndrome' using mitochondrial, Y chromosomal and microsatellite markers  

PubMed Central

There is great uncertainty about how Ireland attained its current fauna and flora. Long-distance human-mediated colonization from southwestern Europe has been seen as a possible way that Ireland obtained many of its species; however, Britain has (surprisingly) been neglected as a source area for Ireland. The pygmy shrew has long been considered an illustrative model species, such that the uncertainty of the Irish colonization process has been dubbed ‘the pygmy shrew syndrome'. Here, we used new genetic data consisting of 218 cytochrome (cyt) b sequences, 153 control region sequences, 17 Y-intron sequences and 335 microsatellite multilocus genotypes to distinguish between four possible hypotheses for the colonization of the British Isles, formulated in the context of previously published data. Cyt b sequences from western Europe were basal to those found in Ireland, but also to those found in the periphery of Britain and several offshore islands. Although the central cyt b haplotype in Ireland was found in northern Spain, we argue that it most likely occurred in Britain also, from where the pygmy shrew colonized Ireland as a human introduction during the Holocene. Y-intron and microsatellite data are consistent with this hypothesis, and the biological traits and distributional data of pygmy shrews argue against long-distance colonization from Spain. The compact starburst of the Irish cyt b expansion and the low genetic diversity across all markers strongly suggests a recent colonization. This detailed molecular study of the pygmy shrew provides a new perspective on an old colonization question.

McDevitt, A D; Vega, R; Rambau, R V; Yannic, G; Herman, J S; Hayden, T J; Searle, J B

2011-01-01

52

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.

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

2012-01-01

53

[Morphological characteristics and cryodamage of Chinese tree shrew (Tupaia belangeri chinensis) sperm].  

PubMed

The tree shrew (Tupaia belangeri chinensis) is a small non-rodent mammal, which is a relatively new experimental animal in medicine due to its close evolutionary relationship to primates and its rapid propagation. Sperm characteristics and cryopreservation in the tree shrew were the main contents of our spermatological research. Epididymal sperm were surgically harvested from male tree shrews captured from the Kunming area. The rate of testis weight to body weight was (1.05±0.07)%, volume of both testis was (1.12 ± 0.10) mL, total sperm from epididymis and vas deferens were 2.2-8.8×10(7), and sperm motility and acrosome integrity were (68.8 ± 3.9)% and (90.0 ± 2.1)%, respectively. Sperm ultrastructure of the tree shrew was examined by scanning electron microscopy and transmission electron microscopy. Tree shrew sperm had a round or oval shaped head of approximately 6.65×5.82 ?m, and midpiece, principal piece, tail, and total sperm lengths were 13.39, 52.35, 65.74, and 73.05 ?m, respectively. The mitochondria in the midpiece consisted of approximately 48 gyres and had a 9+9+2 axonemal pattern. After freezing and thawing, sperm showed partly intact acrosomes and plasma membrane defects, and sperm breakages, twists, and swellings were found. The tree shrew had similar ultrastructure with other mammalians except for the mitochondria number and the sperm size. Ultrastructural alteration is still the main cause resulting in poor sperm after cryopreservation. PMID:22345005

Zhang, Yuan-Xu; Ping, Shu-Huang; Yang, Shi-Hua

2012-02-01

54

Ultrastructural localization of tyrosine hydroxylase in tree shrew nucleus accumbens core and shell.  

PubMed

Many behavioral, physiological, and anatomical studies utilize animal models to investigate human striatal pathologies. Although commonly used, rodent striatum may not present the optimal animal model for certain studies due to a lesser morphological complexity than that of non-human primates, which are increasingly restricted in research. As an alternative, the tree shrew could provide a beneficial animal model for studies of the striatum. The gross morphology of the tree shrew striatum resembles that of primates, with separation of the caudate and putamen by the internal capsule. The neurochemical anatomy of the ventral striatum, specifically the nucleus accumbens, has never been examined. This major region of the limbic system plays a role in normal physiological functioning and is also an area of interest for human striatal disorders. The current study uses immunohistochemistry of calbindin and tyrosine hydroxylase (TH) to determine the ultrastructural organization of the nucleus accumbens core and shell of the tree shrew (Tupaia glis belangeri). Stereology was used to quantify the ultrastructural localization of TH, which displays weaker immunoreactivity in the core and denser immunoreactivity in the shell. In both regions, synapses with TH-immunoreactive axon terminals were primarily symmetric and showed no preference for targeting dendrites versus dendritic spines. The results were compared to previous ultrastructural studies of TH and dopamine in rat and monkey nucleus accumbens. Tree shrews and monkeys show no preference for the postsynaptic target in the shell, in contrast to rats which show a preference for synapsing with dendrites. Tree shrews have a ratio of asymmetric to symmetric synapses formed by TH-immunoreactive terminals that is intermediate between rats and monkeys. The findings from this study support the tree shrew as an alternative model for studies of human striatal pathologies. PMID:24769226

McCollum, L A; Roberts, R C

2014-06-20

55

The rostral nasal anatomy of two elephant shrews.  

PubMed Central

The nasal anatomy of Elephantulus brachyrhynchus and E. myurus shows adaptations needed for a long, mobile snout with no special chemosensory features. Olfactory and vomeronasal neuroepithelia do not extend rostral to the nasal opening of the incisive ducts. Their fine structure presents no unusual features. Separate dorsal, lateral and ventral cartilages and fenestrations in the septal cartilage permit snout flexibility. Dorsal and ventral tubular glands extend the whole length of the snout under the dermis but only release their secretions at the tip, together with the products of the nasolacrimal and lateral nasal gland ducts. These secretions may protect the bare rostral epithelium from the chemical defences of termites and ants, which are major food items. A ventral groove in the snout communicates directly with the sulcus of the incisive papilla on the rostral palate. The oral openings of the incisive ducts also lie within the sulcus. Variability in the relation of the vomeronasal duct to the incisive duct and in the presence of taste buds on the incisive papilla in the two species of Elephantulus studied here limit their value as evidence of relationships between elephant shrews and other insectivores and prosimians. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5

Kratzing, J E; Woodall, P F

1988-01-01

56

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

57

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.

Durrwald, Ralf; Kolodziejek, Jolanta; Weissenbock, Herbert; Nowotny, Norbert

2014-01-01

58

2-arachidonoylglycerol interferes with lithium-induced vomiting in the house musk shrew, Suncus murinus.  

PubMed

The role of the endocannabinoid system in vomiting has been previously studied using several animal species. These investigations have clearly demonstrated an anti-emetic role for the eCB, anandamide, in these animal models; however, research concerning the role of 2-arhachidonoylglycerol (2AG) has been less clear. The aim of the present study was to assess the effects of exogenous 2AG administration in the house musk shrew, Suncus murinus. In Experiment 1, shrews were injected with vehicle or 2AG (1, 2, 5, 10 mg/kg) 15 min prior to behavioral testing in which the frequency of vomiting episodes was observed. In Experiment 2, shrews were pre-treated with 2AG (2, 5 mg/kg) prior to being administered the emetic drug, lithium chloride (LiCl). It was found that 2AG alone did not induce emesis, but interfered with vomiting in response to LiCl administration. The anti-emetic effects of 2AG in Suncus murinus do not appear to be mediated by CB1 receptors, as concomitant pretreatment with the CB1 receptor antagonist, SR141716, did not reverse the suppressive effects of 2AG. These results confirm that manipulations that increase levels of 2AG exert anti-emetic effects in the house musk shrew. PMID:23958470

Sticht, M A; Rock, E M; Parker, L A

2013-08-15

59

Pliocene and Pleistocene diversiWcation and multiple refugia in a Eurasian shrew (Crocidura suaveolens group)  

Microsoft Academic Search

We sequenced 998 base pairs (bp) of mitochondrial DNA cytochrome b and 799 bp of nuclear gene BRCA1 in the Lesser white-toothed shrew (Crocidura suaveolens group) over its geographic range from Portugal to Japan. The aims of the study were to identify the main clades within the group and respective refugia resulting from Pleistocene glaciations. Analyses revealed the Asian lesser

Sylvain Dubey; Mikhail Zaitsev; Jean-François Cosson; Ablimit Abdukadier; Peter Vogel

60

Taste preferences for amino acids in the house musk shrew, Suncus murinus.  

PubMed

Taste preferences in house musk shrews for amino acids as well as NaCl, sucrose, quinine hydrochloride, HCl and saccharin Na were studied by employing the two-bottle preference technique. Shrews showed a preference for 0.2--05. M sucrose but a moderate rejection to NaCl and a strong rejection to quinine, HCl and saccharin. They exhibited a marked preference for many naturally occurring L-alpha-amino acids with aliphatic side chains at both 0.02 and 0.2 M. Increase in the aliphatic side chain length of DL-alpha-amino acids resulted in both lowering of the preference threshold and increase in the preference magnitude. Amino acids with side chains containing sulfur atoms, basic groups and Phe at 0.02 M were preferred to water, but Cys and Arg at 0.2 M was rejected. Shrews showed neither preference nor rejection to Trp, Asn, Gln and monosodium glutamate at 0.02 M, but rejected strongly Asp and Glu. D-Met from 0.001 to 0.1 M was preferred as well as L-Met, while D-Phe was more preferred than L-Phe. Such preferences for a wide variety of amino acids in shrews could be attributed to their food habit of predating on various kinds of insects and worms. PMID:7100283

Iwasaki, K; Sato, M A

1982-05-01

61

Interhemispheric connections of cortical sensory areas in tree shrews.  

PubMed

Interhemispheric connections were studied in tree shrews (Tupaia belangeri) after multiple injections of horseradish peroxidase or horseradish peroxidase conjugated to wheat germ agglutinin into the cortex of one cerebral hemisphere. After an appropriate survival period, the areal pattern of connections was revealed by flattening the other hemisphere, cutting sections parallel to the cortical surface, and staining with tetramethylbenzidine. Architectonic boundaries were identified by using sections stained for myelinated fibers. Labeled cells and axon terminations formed largely overlapping distributions that covaried in density, although labeled cells appeared to be more evenly distributed than labeled terminations. Connections were concentrated along the border of area 17 (V-I) with area 18 (V-II). However, connections also extended as far as 2 mm into area 17 to include cortex representing parts of the visual field 10 degrees or more from the zero vertical meridian. Clusters of dense connections spanned the width of area 18, where they alternated with regions of fewer connections. These clusters roughly corresponded in location to regions with heavier myelination. In the visually responsive temporal cortex, connections were also unevenly distributed. The organization of most of this cortex is not understood, but one subdivision, the temporal dorsal area (TD), has been identified on the basis of reciprocal connections with area 17. The central part of the TD had few interhemispheric connections, while most of the outer border had dense connections. The auditory cortex had dense and patchy connections throughout. The pattern in the primary somatosensory cortex (S-I) varied according to the representation of body parts, so that the cortex related to the forepaw had sparse connections, while connections were dense but uneven over much of the representation of the face, nose, and mouth. A focus of connections was found at the border of the forepaw and face representations, where the myelination of S-I cortex is interrupted. Dense, uneven connections also characterized the second somatosensory area, S-II. The motor cortex was densely connected, with only slightly fewer terminations rostral to the forepaw region of S-I. Other parts of frontal cortex had dense connections. The distribution of cortical connections varied with depth for at least some areas, so that clusters of cells and terminations were found in supragranular layers in S-I, S-II, and TD, while infragranular labeled cells were more evenly distributed.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3989001

Cusick, C G; MacAvoy, M G; Kaas, J H

1985-05-01

62

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.

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

2009-01-01

63

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.

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

2014-01-01

64

MORPHOLOGY OF THE INNER SIDE OF THE MANDIBLE IN MICROMAMMALS (MAMMALIA: INSECTIVORA, CHIROPTERA, RODENTIA) OF ROMANIA  

Microsoft Academic Search

In this paper, the inner side of the mandible of 39 Romanian micromammal species (Mammalia: Insectivora, Chiroptera, Rodentia) is described and illustrated. The author proposed the name of some structures observed on the inner side of the mandible as: fossa ramus mandibulae (FRM), processus angulus mandibulae (PAM), incisura mandibulae superior (IMS), incisura mandibulae inferior (IMI), crista ramus mandibulae (CRM), processus

Grigore Antipa

2007-01-01

65

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

66

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

67

Effect of cannabinoids on lithium-induced vomiting in the Suncus murinus (house musk shrew)  

Microsoft Academic Search

RationaleMarijuana has been reported to interfere with nausea and vomiting in chemotherapy patients. The principal cannabinoids found in marijuana include the psychoactive compound ?-9-tetrahydrocannabinol (THC) and the non-psychoactive compound cannabidiol (CBD). The experiments reported here evaluated the potential of THC and CBD to interfere with vomiting in the Suncus murinus (house musk shrew) produced by lithium chloride (LiCl), which is

Linda A. Parker; Magdalena Kwiatkowska; Page Burton; Raphael Mechoulam

2004-01-01

68

[Racial and population variability of phenotypic (cranial) characters in the common shrew Sorex araneus L., 1758].  

PubMed

Variability of the cranial properties of chromosomal races Serov, Manturovo and Pechora of the common shrew were studied. A consistent increase of scull size in the Serov race with moving from the plain to highlands and a skull size decrease from low to high latitudes was detected. Interpopulation variability among different races was shown to be comparable with interracial variability or to exceed it. This suggests microevolution at the level of local populations. PMID:21446185

Shchipanov, N A; Bobretsov, A V; Kupriianova, I F; Pavlova, S V

2011-01-01

69

Alternative reproductive tactics in male common shrews: relationships between mate-searching behaviour, sperm production, and reproductive success as revealed by DNA fingerprinting  

Microsoft Academic Search

The common shrew (Sorex araneus) is a solitary small mammal with a promiscuous mating system. Previous studies of this species suggest that females typically mate multiply, and that males may adopt alternative mate-searching tactics. We studied two generations of common shrews in a population near Oxford, England. Males were found to adopt two different mate-searching tactics. Those classed as type

P. Stockley; J. B. Searle; D. W. Macdonald; C. S. Jones

1994-01-01

70

Amphetamine and morphine produce a conditioned taste and place preference in the house musk shrew (Suncus murinus).  

PubMed

Rats have been shown to avoid consuming a flavor, but prefer a location, previously paired with amphetamine or morphine. A series of 4 experiments evaluated the hedonic properties of amphetamine and morphine in the house musk shrew (Suncus murinus), an insectivore that (unlike rats) is capable of vomiting when exposed to toxins. Unlike rats, amphetamine (20 mg/kg) and morphine (20 mg/kg) produced both a conditioned sucrose (0.3 M) and saccharin (0.1%) preference in shrews (administered intraperitoneally), when measured by both a 1- and a 2-bottle test. At the same dose, both drugs also produced a place preference in shrews. These results suggest that the potential of rewarding drugs to produce taste avoidance may vary on the basis of the ability of the species to vomit. PMID:11868236

Parker, Linda A; Corrick, Marion L; Limebeer, Cheryl L; Kwiatkowska, Magdalena

2002-01-01

71

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

72

[Life cycle of Maupasina weissi Seurat, 1913, Subuluroidea Nematode, parasite of the elephant shrew (author's transl)].  

PubMed

The life cycle of Maupasina weissi Seurat, 1913, the parasite of the elephant shrew, has been experimentally obtained from the intermediate host Locusta migratoria. The biology of this Nematoda is considered as being more primitive than the Subuluridae: -- egg maturation in external environment is in fact necessary to the Maupasina larvae to penetrate into the insect, -- The different localizations of the infective larvae, such as mesenteron regeneration crypta, fat body, demonstrate that the parasite is not completely adaptated to its intermediate host, -- the ontogenesis of cephalic structures is characterized by an hypertrophy of the archaic structures mainly from cuticular origin. PMID:550714

Quentin, J C; Verdier, J M

1979-01-01

73

Sex chromosome meiotic drive in hybrid males of the common shrew (Sorex araneus).  

PubMed

Patterns of sex chromosome segregation in six homozygous males of the common shrew (Sorex araneus LINNAEUS, 1758) belonging to two chromosomal races, as well as in 16 interracial hybrids were studied. Based on their karyotypes the hybrids can be subdivided into two groups: (a) complex heterozygotes, which form meiotic quadrivalents in chain and chain + ring configurations, and (b) complex heterozygotes, which form meiotic pentavalents in chain configurations. Random (1:1) segregation of sex chromosomes was found in homozygous as well as those heterozygous males which form meiotic complexes of four chromosomes. However, in some hybrids with meiotic pentavalents we observed a strong preferential segregation in favour of X chromosomes. PMID:19058534

Fedyk, Stanis?aw; Bajkowska, Urszula; Chetnicki, W?odzimierz

2005-01-01

74

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

PubMed

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

75

Does a nonprimate mammal, the northern tree shrew (Tupaia belangeri), exhibit paw preference in two forms of a grasping task?  

PubMed

Tree shrews represent a relevant model to study the evolution of primate manual laterality as they are phylogenetically close to primates, they are able to grasp despite having a nonopposable thumb, and they possess a well-developed visual system. In this study, we examined the paw laterality and grasping success rate of 30 Tupaia belangeri (15 males, 15 females) in 2 forced-food grasping tasks (i.e., in a forced-food grasping experiment, the animal has to use paws instead of mouth for food retrieval). We also attempted to determine whether paw usage would be affected by the availability of visual cues using both a visual task (transparent tube) and a nonvisual task (identical but opaque tube). In both tasks, tree shrews showed paw preferences at an individual but not at a population level. Paw laterality (direction and strength) did not differ between tasks. Moreover, in the specific task that we used, grasping success rate was not affected by an absence of visual cues, indicating that tree shrews did not rely on visual guidance to direct their grasps in this forced-food grasping experiment. Our findings suggest that, in contrast to primates, paw usage in tree shrews may result from a modification of a fixed motor pattern in which the preferred direction may be learned. This basic motor organization might be a first step in the evolution of manual laterality, which eventually became controlled by vision in the primate lineage. PMID:22866771

Maille, Audrey; Jäschke, Nathalie; Joly, Marine; Scheumann, Marina; Blois-Heulin, Catherine; Zimmermann, Elke

2013-02-01

76

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.

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

2014-01-01

77

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

78

Amphetamine and Morphine Produce a Conditioned Taste and Place Preference in the House Musk Shrew (Suncus murinus )  

Microsoft Academic Search

Rats have been shown to avoid consuming a flavor, but prefer a location, previously paired with amphetamine or morphine. A series of 4 experiments evaluated the hedonic properties of amphetamine and morphine in the house musk shrew (Suncus murinus), an insectivore that (unlike rats) is capable of vomiting when exposed to toxins. Unlike rats, amphetamine (20 mg\\/kg) and morphine (20

Linda A. Parker; Marion L. Corrick; Cheryl L. Limebeer; Magdalena Kwiatkowska

2002-01-01

79

The force driving mating behavior in the house musk shrew (Suncus murinus).  

PubMed

The mating behavior of the domesticated house musk shrew was observed in detail under laboratory conditions. The observations revealed that the house musk shrew has a series of behaviors before copulation. Tactile, auditory and chemical senses appear to function as flags for the recognition of conspecifics and to promote the development of an interaction between the sexes. The tactile senses and the use of the snout were particularly important in the mating sequence, and mutual contact appeared to give rise to driving the sequence to completion. The two sexes contacted each other 'politely', came to mounting by continuous following, and the male finished with a series of post-ejaculatory offensive behaviors and scent markings. The variation in the contact reduced once the female commenced tail-wagging. The ratio of the time spent in front-and-behind contact to that spent in multi-lateral contact increased when both sexes commenced following formation. This ratio was maintained until the male's post-ejaculatory offensive behavior finished. The series of mating behavior was completed by the continuous touching of both sexes and by changes in the manner of contact. PMID:12193801

Matsuzaki, Osamu

2002-08-01

80

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.

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

2012-01-01

81

Conditioned Flavor Preference and the US Postexposure Effect in the House Musk Shrew (Suncus Murinus)  

PubMed Central

The house musk shrew (Suncus murinus) is the only species of mammalian insectivore that can be domesticated and used as a laboratory animal, and is an interesting subject in terms of evolutionary and comparative aspects. The present study on the learning faculties of shrews examines the possibility of acquiring a conditioned flavor preference and the effects of US postexposure. Subjects were allowed to a drink sucrose solution with flavor A and tap water with flavor B during training. Two extinction tests were administered after every four conditioning trials, and a significant preference for flavor A was observed. After each test, the animals were divided into two groups. Subjects in Group US were presented with a sucrose solution without flavor, while those in Group Water were given tap water. After these trials, all subjects received choice tests where they were presented with water containing the two flavors. The preference ratio was lower in Group US than in Group Water, suggesting a postexposure effect. The findings were discussed in terms of habituation to the US.

Sawa, Kosuke; Ishii, Kiyoshi

2012-01-01

82

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

83

Angioarchitecture of the coeliac sympathetic ganglion complex in the common tree shrew (Tupaia glis)  

PubMed Central

The angioarchitecture of the coeliac sympathetic ganglion complex (CGC) of the common tree shrew (Tupaia glis) was studied by the vascular corrosion cast technique in conjunction with scanning electron microscopy. The CGC of the tree shrew was found to be a highly vascularised organ. It normally received arterial blood supply from branches of the inferior phrenic, superior suprarenal and inferior suprarenal arteries and of the abdominal aorta. In some animals, its blood supply was also derived from branches of the middle suprarenal arteries, coeliac artery, superior mesenteric artery and lumbar arteries. These arteries penetrated the ganglion at variable points and in slightly different patterns. They gave off peripheral branches to form a subcapsular capillary plexus while their main trunks traversed deeply into the inner part before branching into the densely packed intraganglionic capillary networks. The capillaries merged to form venules before draining into collecting veins at the peripheral region of the ganglion complex. Finally, the veins coursed to the dorsal aspect of the ganglion to drain into the renal and inferior phrenic veins and the inferior vena cava. The capillaries on the coeliac ganglion complex do not possess fenestrations.

PROMWIKORN, WARAPORN; THONGPILA, SAKPORN; PRADIDARCHEEP, WISUIT; MINGSAKUL, THAWORN; CHUNHABUNDIT, PANJIT; SOMANA, REON

1998-01-01

84

Habitat use and potential interactions between the house mouse and lesser white-toothed shrew on an island undergoing habitat restoration  

Microsoft Academic Search

To forecast the potential impact of plant community and dry-stone wall restoration on an insular population of the lesser\\u000a white-toothed shrewCrocidura suaveolens Pallas, 1811, shrew and house mouseMus musculus Linnaeus, 1758 abundances were assessed in 3 anthropogenic habitats on Béniguet Island, Brittany, France, by a standardised\\u000a annual trapping system checked yearly for 9 years and in 6 “natural” habitats by

Michel Pascal; Olivier Lorvelec; Frédéric Bioret; Pierre Yésou; Daniel Simberloff

2009-01-01

85

Effect of castration and oral administration of sex hormones on some specialised integumentary glands of the male musk shrew, Suncus murinus viridescens (Blyth)  

Microsoft Academic Search

Effect of castration and oral administration of sex hormones on the specialised apocrine sudoriferous glands of the perineal\\u000a region and the holocrine sebaceous glands of the flank and oral lip regions of the male musk shrew,Suncus murinus viridescens is investigated. Gonadectomy effected a significant regression and hypotrophy of the sudoriferous as well as sebaceous glandular\\u000a structures of the shrew. The

M Balakrishnan; K M Alexander

1980-01-01

86

Redescription of Pterygodermatites (Mesopectines) nycticebi (Mönnig, 1920) (Nematoda: Rictulariidae), a parasite of slow loris Nycticebus coucang (Mammalia: Primates)  

Microsoft Academic Search

Pterygodermatites (Mesopectines) nycticebi (Mönnig, 1920) (Nematoda: Spirurida: Rictulariidae) is redescribed based on immature and mature adults collected from the stomach and small intestine at autopsy of a slow loris, Nycticebus coucang (Boddaert, 1785) (Mammalia: Primates), in a zoological garden in Japan. It is first demonstrated that male possesses a minute telamon and a left lateral pore in the preanal part

Yatsukaho Ikeda; Akiko Fujisaki; Koichi Murat; Hideo Hasegawa

87

Novos materiais de Propraopus Ameghino, 1881 (Mammalia, Xenarthra, Cingulata) do Pleistoceno final, Rio Grande do Sul, Brasil  

Microsoft Academic Search

NEW FOSSIL MATERIAL OF PROPRAOPUS AMEGHINO, 1881 (MAMMALIA, XENARTHRA, CINGULATA) OF THE LATE PLEISTOCENE, RIO GRANDE DO SUL, BRAZIL Propraopus Ameghino, 1881 is a genus of Dasypodidae that was widely distributed during the Pleistocene times in South America. In Brazil it was recorded in many localities and distinct latitudes, between the Late Pleistocene and Early Holocene. This work discuss new

Vanessa Gregis Pitana; Ana Maria Ribeiro

88

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

89

Mandible asymmetry and genetic diversity in island populations of the common shrew, Sorex araneus.  

PubMed

Mandibles from 13 island and six mainland populations of common shrews from the west coast of Scotland were subjected to geometric morphometric analysis in order to investigate the relationship between genetic diversity and fluctuating asymmetry. Although population mean shape fluctuating asymmetry (FA) and size FA were significantly inversely correlated with population genetic diversity this result was substantially due to one island. Sanda, the smallest island with by far the lowest genetic diversity, also had the highest FA. When Sanda was removed from the analysis, the relationship was not significant. There was no relationship between genetic diversity and FA at the individual level, whether measured as mean locus heterozygosity or d(2). In general, if genetic variation affects FA at all, the effect is weak and may only be of biological interest in very small populations. PMID:18194233

White, T A; Searle, J B

2008-03-01

90

Female multiple mating behaviour in the common shrew as a strategy to reduce inbreeding.  

PubMed

Three hypotheses concerning potential genetic benefits of female multiple mating behaviour are evaluated for the common shrew. In a high-density population, many successful copulations took place between individuals estimated to be close relatives (e.g. full or half siblings). Juveniles resulting from such matings tended to be relatively small at weaning, and were generally less likely to survive to sexual maturity than more outbred individuals. Multiple paternity was discovered in eight of nine litters examined. The incidence of matings between close relatives, the cost of inbreeding, and the high incidence of multiple paternity presented are each consistent with the hypothesis that female multiple mating is a strategy to reduce inbreeding. That is, if females cannot always distinguish close kin, then they may copulate with several different males and so reduce the risk that all their offspring will be sired by a close relative. PMID:8108451

Stockley, P; Searle, J B; MacDonald, D W; Jones, C S

1993-12-22

91

Bartonella species in rodents and shrews in the greater Jakarta area.  

PubMed

In February 2004, we captured 221 rodents and shrews in the Greater Jakarta area as part of a study to determine the prevalence of rodent-associated vector-borne infections. Microscopic examination of blood smears revealed 6% (13/218) to be positive for Bartonella spp. The corresponding DNA samples, either from blood blots or frozen spleen pieces and from fleas collected on these animals, were tested for evidence of Bartonella infection by PCR, targeting the portions: 378bp and 930bp of the citrate synthase gene (g/tA). The sequences from our sample clusters with a Peruvian entity, B. phoceensis, B. rattimassiliensis and B. elizabethae, the latter species has been associated with endocarditis and neuroretinitis in humans. As previous analyses have shown, there appears to be little geographic or host consistency with phylogenetic placement. The public health significance of these findings remains to be determined. PMID:16610656

Winoto, Imelda L; Goethert, Heidi; Ibrahim, Ima Nurisa; Yuniherlina, Ikke; Stoops, Craig; Susanti, Ika; Kania, Winny; Maguire, Jason D; Bangs, Michael J; Telford, Sam R; Wongsrichanalai, Chansuda

2005-11-01

92

Species Interactions during Diversification and Community Assembly in an Island Radiation of Shrews  

PubMed Central

Background Closely 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 Findings Using a combination of tools, we test the hypothesis that the distributions of shrew (Crocidura) species in the Philippines are the result of competitive exclusion preventing secondary invasion of occupied islands. We first compare ecological niche models between two widespread, allopatric species and find statistical support for their ecological similarity, implying that competition for habitat between these species is possible. We then examine dispersion patterns among sympatric species and find some signal for overdispersion of body size, but not for phylogenetic branch length. Finally, we simulate the process of inter-island colonization under a stochastic model of dispersal lacking ecological forces. Results are dependent on the geographic scope and colonization probability employed. However, some combinations suggest that the number of inter-island dispersal events necessary to populate the archipelago may be much higher than the minimum number of colonization events necessary to explain current estimates of species richness and phylogenetic relationships. If our model is appropriate, these results imply that alternative factors, such as competitive exclusion, may have influenced the process of inter-island colonization and subsequent cladogenesis. Conclusions/Significance We interpret the combined results as providing tenuous evidence that similarity in body size may prevent co-occurrence in Philippine shrews and that competitive exclusion among ecologically similar species, rather than an inability to disperse among islands, may have limited diversification in this group, and, possibly other clades endemic to island archipelagos.

Esselstyn, Jacob A.; Maher, Sean P.; Brown, Rafe M.

2011-01-01

93

Microbial pathogens in ticks, rodents and a shrew in northern Gyeonggi-do near the DMZ, Korea.  

PubMed

A total of 1,618 ticks [420 individual (adults) and pooled (larvae and nymphs) samples], 369 rodents (Apodemus agrarius, Rattus norvegicus, Tscherskia triton, Mus musculus, and Myodes regulus), and 34 shrews (Crocidura lasiura) that were collected in northern Gyeonggi-do near the Demilitarized Zone (DMZ) of Korea during 2004-2005, were assayed by PCR for selected zoonotic pathogens. From a total of 420 individual and pooled tick DNA samples, Anaplasma (A.) phagocytophilum (16), A. platys (16), Ehrlichia (E.) chaffeensis (63), Borrelia burgdorferi (16), and Rickettsia spp. (198) were detected using species-specific PCR assays. Out of 403 spleens from rodents and shrews, A. phagocytophilum (20), A. platys (34), E. chaffeensis (127), and Bartonella spp. (24) were detected with species-specific PCR assays. These results suggest that fevers of unknown causes in humans and animals in Korea should be evaluated for infections by these vector-borne microbial pathogens. PMID:18716449

Chae, Joon Seok; Yu, Do Hyeon; Shringi, Smriti; Klein, Terry A; Kim, Heung Chul; Chong, Sung Tae; Lee, In Yong; Foley, Janet

2008-09-01

94

Morphological and sequence analysis of Mycoplasma sp. isolated from the oral cavity of a house musk shrew (Suncus murinus).  

PubMed

Mycoplasma sp. strain EDS-4 was isolated from the oral cavity of EDS line of a house musk shrew (Suncus murinus) originated from Bangladesh, and was distinguished from all previously described mollicutes. It lacks a cell wall; ferments glucose; does not produce film and spots; and does not hydrolyse arginine and urea. The strain could be distinguished from all previously described mollicutes by 16S rRNA gene sequence comparisons. The results suggest that the isolate is new species of mollicutes originated from the shrew. The strain EDS-4 has been deposited with Japan collection of Microorganisms, Bioresource Center, RIKEN in Japan (JCM15930). The 16S rRNA gene sequence of strain EDS-4 is available through the DDBJ under accession number (AB469852). PMID:19915329

Goto, Kazuo; Yasuda, Masahiko; Hayashimoto, Nobuhito; Ebukuro, Susumu

2010-01-01

95

Immunocompetence and helminth community of the white-toothed shrew, Crocidura russula from the Montseny Natural Park, Spain  

Microsoft Academic Search

Host immunocompetence assessed by spleen size and response to phytohaemagglutinin (PHA) injection may give some indications\\u000a on the control of parasite infection and on host mediation effect, through immunity, on parasite community structure. We investigated\\u000a the helminth community and immunocompetence of the white-toothed shrew in a small area to test the relationship between immunocompetence\\u000a and intensity of helminth infection. At

Joëlle Goüy de Bellocq; Alexis Ribas; Juan Carlos Casanova; Serge Morand

2007-01-01

96

Postglacial Recolonization of Continental Europe by the Pygmy Shrew ( Sorex minutus ) Inferred From Mitochondrial and Y Chromosomal DNA Sequences  

Microsoft Academic Search

\\u000a The postglacial recolonization of the pygmy shrew (Sorex minutus, n?=?68) across continental Europe was examined using control region sequences (342 bp) and concatenated sequences (2,939 bp)\\u000a of four paternally inherited introns, specific for the Y chromosome. Phylogenetic analysis (NJ, MP, ML, and Bayesian inference)\\u000a of the control region retrieved five major lineages (Northern, Western, Italian, Balkan, and Spanish) in Europe,

Allan D. McDevitt; Glenn Yannic; Ramugondo V. Rambau; Thomas J. Hayden; Jeremy B. Searle

97

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

98

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

PubMed

In theory, competition among species in a shared habitat results in niche separation. In the case of small recondite mammals such as shrews, little is known about their autecologies, leaving open questions regarding the degree to which closely related species co-occur and how or whether ecological niches are partitioned. The extent to which species are able to coexist may depend on the degree to which they exploit different features of their habitat, which may in turn influence our ability to recognize them as species. We explored these issues in a biodiversity hotspot, by surveying shrew (genus Crocidura) diversity on the Indonesian island of Java. We sequenced portions of nine unlinked genes in 100-117 specimens of Javan shrews and incorporated homologous data from most known Crocidura species from other parts of island South-East Asia. Current taxonomy recognizes four Crocidura species on Java, including two endemics. However, our phylogenetic, population genetic and species delimitation analyses identify five species on the island, and all are endemic to Java. While the individual ranges of these species may not overlap in their entirety, we found up to four species living syntopically and all five species co-occurring on one mountain. Differences in species' body size, use of above ground-level habitats by one species and habitat partitioning along ecological gradients may have facilitated species diversification and coexistence. PMID:24010862

Esselstyn, Jacob A; Maharadatunkamsi; Achmadi, Anang S; Siler, Cameron D; Evans, Ben J

2013-10-01

99

A fossil aardvark (Mammalia, Tubulidentata) from the lower Pliocene of Chad  

NASA Astrophysics Data System (ADS)

The Mission Paléoanthropologique Franco-Tchadienne (MPFT) found a new species of Orycteropodidae (Mammalia, Tubulidentata) in the Kollé fossiliferous sector, northern Chad. After Orycteropus abundulafus [Journal of Vertebrate Paleontology 20 (1) (2000) 205-209; Lehmann, T., Vignaud, P., Likius A., Brunet M., in press. A new Orycteropodidae (Mammalia, Tubulidentata) in the Mio-Pliocene of Northern Chad. Zool. J. Linnean Soc.], this specimen is the second complete skeleton of fossil aardvark found in the Djurab desert. It is the first complete representative of an Orycteropus species found in the Pliocene of Africa. In regard to the Miocene fossil aardvarks, this new taxon, Orycteropus djourabensis nov. sp., shows more affinities with the extant O. afer. The main differences are the larger teeth and the shorter hand in the fossil form. Kossom Bougoudi and Kollé represent a chronological series that gives a unique opportunity for studying the evolution of the African Tubulidentata around the Mio-Pliocene boundary (5.5-4 My). The new species is distinct from the older Chadian Orycteropodid from KB and it embodies the taxonomic turnover that took place within the order Tubulidentata around this boundary in Africa. Moreover, this new species is the oldest known Orycteropus species that clearly belongs to the modern forms including the extant aardvark.

Lehmann, Thomas; Vignaud, Patrick; Mackaye, Hassane Taïsso; Brunet, Michel

2004-12-01

100

Modulation of Glycosaminoglycan Levels in Tree Shrew Sclera during Lens-Induced Myopia Development and Recovery  

PubMed Central

Purpose In juvenile tree shrews, positioning a negative-power lens in front of an eye produces a hyperopic shift in refractive state and causes a compensatory increase in axial length over several days so that the eye is myopic when the lens is removed. During negative lens compensation, the scleral extracellular matrix is remodeled. A biomechanical property of the sclera, creep rate, increases; during recovery from induced myopia, the creep rate decreases below normal levels. Changes in glycosaminoglycan (GAG) levels, including those of hyaluronan, may participate in these changes in creep rate and, in turn, participate in controlling the axial length and refractive state. This study investigated the unsulfated and sulfated GAG composition of the sclera during compensation for a -5 diopter (D) lens and during recovery. Methods Capillary electrophoresis was used to assess the relative levels (ng/mg dry scleral weight) of unsulfated GAGs (hyaluronan [HA] and chondroitin [C0S]), sulfated GAGs (chondroitin-4-sulfate [C4S], chondroitin-6-sulfate [C6S], and dermatan sulfate [DS]) in the sclera of groups of tree shrews (n = 5 per group) that wore a monocular -5 D lens for 1, 2, 4, or 11 days or had 11 days of -5 D lens wear followed by 1, 2, or 4 days of recovery from lens wear. The fellow eye served as an untreated control. Groups of normal and plano lens-treated animals provided age-matched values. Results Expressed as a fraction of dry weight, levels of HA were lower after 1, 4, and 11 days of -5 D lens wear. Levels of C0S, C6S, and C4S were significantly lower after 4 and 11 days of lens wear. After 1 and 2 days of recovery, GAG levels in the treated eyes were not significantly different from those in control eyes. After 4 recovery days, HA levels were lower, but the levels of all other GAGs were not different in the recovering and control eyes. Some binocular changes also occurred. Conclusions The rapid differential decrease in HA levels during negative lens compensation and the absence of any difference after just 1 day of recovery suggest that HA levels may play a previously unrecognized early role in regulating the biomechanical property (creep rate) of the sclera. The reduced levels of the other GAGs, which occur when creep rate is at its peak elevation, and their rapid return to normal after 1 day of recovery suggest that they may also participate in regulating this biomechanical property of the sclera.

Moring, Anisha G.; Baker, John R.; Norton, Thomas T.

2007-01-01

101

Sticky snack for sengis: The Cape rock elephant-shrew, Elephantulus edwardii (Macroscelidea), as a pollinator of the Pagoda lily, Whiteheadia bifolia (Hyacinthaceae)  

NASA Astrophysics Data System (ADS)

Following the recent discovery of rodent pollination in the Pagoda lily, Whiteheadia bifolia (Hyacinthaceae) in South Africa, now the Cape rock elephant-shrew, Elephantulus edwardii (Macroscelidea, Afrotheria) is reported as an additional pollinator. Elephant-shrews, live-trapped near W. bifolia plants, were released in two terraria, containing the plants. The animals licked nectar with their long and slender tongues while being dusted with pollen and touching the stigmas of the flowers with their long and flexible noses. The captured elephant-shrews had W. bifolia pollen in their faeces, likely as a result of grooming their fur as they visited the flowers without eating or destroying them. The animals mostly preferred nectar over other food. This is the first record of pollination and nectar consumption in the primarily insectivorous E. edwardii, contributing to the very sparse knowledge about the behaviour of this unique clade of African mammals, as well as pollination by small mammals.

Wester, Petra

2010-12-01

102

Food restriction, refeeding, and gastric fill fail to affect emesis in musk shrews.  

PubMed

Nausea and emesis are common side effects of gastrointestinal disease. Reports indicate that ghrelin and endocannabinoids, agents that stimulate appetite, also reduce emesis evoked by chemotherapy treatment, which suggests that stimulation of feeding inhibits the emetic system. In the following study we conducted a more direct test of this hypothesis by determining the impact of manipulating the motivation to eat on emesis, using food restriction and refeeding. Emesis was induced in musk shrews, a commonly used animal model for emesis research, using the cancer chemotherapy agent cisplatin (20 mg/kg ip), nicotine (2 mg/kg sc), or motion (1 Hz, horizontal, 4-cm displacement), because these treatments are known to target separate emetic pathways: gut vagal afferents, area postrema, and vestibular pathways, respectively. Twenty-four hours of food restriction was sufficient to stimulate food intake, and 1 h of refeeding filled the stomach. The results indicate that food restriction, refeeding, and gastric fill had no significant effects on the amount of emesis produced by any of the emetic treatments tested here. This suggests that, although activation of the emetic system might have prominent effects on food intake, neural controls for feeding behavior do not significantly affect the neural pathways for emesis. These results may have implications for how we treat patients who experience a constellation of side effects, including nausea and emesis, since stimulating appetite may not necessarily inhibit emetic pathways. PMID:19892939

Horn, Charles C; Still, Liz; Fitzgerald, Christiana; Friedman, Mark I

2010-01-01

103

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

104

[Soricinia sawadai sp. n. (Cyclophyllidea: Hymenolepididae), a new cestode species from the shrews of Sakhalin Island].  

PubMed

A new species Soricinia sawadai sp. n. parasitizing shrews of Sakhalin Island (Sores unguiculatus and S. caecutiens) is described. The new species differs from other species of the genus Soricinia Spassky et Spasskaja, 1954 in having specific armament and size of the cirrus. Soricinia sawadai sp. n. differs from S. aurita (Irzhavsky et al., 2005) in having half size of the ovary (0.076-0.08 x 0.03-0.038 versus 0.135-0.14 x 0.037-0.04) and the cirrus bursa extending into the aporal fraction of the middle part of segment. The new species differs from S. quarta (Karpenko, 1983) in having half size of the cirrus (0.025-0.026 versus 0.05-0.055) and half number of hexacants in uterine segments (20-22 versus 40-45). The new species differs from S. infirma (Zarnowski, 1955) in having other cirrus armament, larger number of segments and lesser number of hexacants. The species Insectivorolepis macracetobulosa Sawada et Koyasu, 1991 parasitizing Sorex unguiculatus on Hokkaido Island is synonymized with Soricinia quarta. The species Insectivorolepis macracetobulosa sensu Sawada et Harada, 1993 parasitizing Sorex shinto shinto on Honshu Island is described as a separate species Soricinia haradai sp. n. PMID:20795487

Zubova, O A; Guliaev, V D; Kornienko, S A

2010-01-01

105

Food restriction, refeeding, and gastric fill fail to affect emesis in musk shrews  

PubMed Central

Nausea and emesis are common side effects of gastrointestinal disease. Reports indicate that ghrelin and endocannabinoids, agents that stimulate appetite, also reduce emesis evoked by chemotherapy treatment, which suggests that stimulation of feeding inhibits the emetic system. In the following study we conducted a more direct test of this hypothesis by determining the impact of manipulating the motivation to eat on emesis, using food restriction and refeeding. Emesis was induced in musk shrews, a commonly used animal model for emesis research, using the cancer chemotherapy agent cisplatin (20 mg/kg ip), nicotine (2 mg/kg sc), or motion (1 Hz, horizontal, 4-cm displacement), because these treatments are known to target separate emetic pathways: gut vagal afferents, area postrema, and vestibular pathways, respectively. Twenty-four hours of food restriction was sufficient to stimulate food intake, and 1 h of refeeding filled the stomach. The results indicate that food restriction, refeeding, and gastric fill had no significant effects on the amount of emesis produced by any of the emetic treatments tested here. This suggests that, although activation of the emetic system might have prominent effects on food intake, neural controls for feeding behavior do not significantly affect the neural pathways for emesis. These results may have implications for how we treat patients who experience a constellation of side effects, including nausea and emesis, since stimulating appetite may not necessarily inhibit emetic pathways.

Still, Liz; Fitzgerald, Christiana; Friedman, Mark I.

2010-01-01

106

Bibliography of studies on hybrid zones of the common shrew chromosome races distributed in Russia  

PubMed Central

Abstract The common shrew, Sorex araneus Linnaeus, 1758, has become a model species for cytogenetic and evolutionary studies after discovery of extraordinary Robertsonian polymorphism at the within-species level. Development of differential staining techniques (Q-, R-and G-banding) made it possible to identify the chromosomal arms and their combination in racial karyotypes. Entering into contact with each other, the chromosomal races might form hybrid zones which represent a great interest for understanding of the process of speciation. Until recently all known hybrid zones of S. araneus were localized in Western Europe and only one was identified in Siberia (Russia) between Novosibirsk and Tomsk races (Aniskin and Lukianova 1989, Searle and Wójcik 1998, Polyakov et al. 2011). However, a rapidly growing number of reports on discovery of interracial hybrid zones of Sorex araneus in the European part of Russia and neighboring territories appeared lately. The aim of the present work is to compile the bibliography of all studies covering this topic regardless of the original language and the publishing source which hopefully could make research data more accessible to international scientists. It could also be a productive way to save current history of Sorex araneus researches in full context of the ISACC (International Sorex araneus Cytogenetics Committee) heritage (Searle et al. 2007, Zima 2008).

Nadjafova, Rena S.

2013-01-01

107

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.

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

108

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

109

Structure of the ovaries of the Nimba otter shrew, Micropotamogale lamottei, and the Madagascar hedgehog tenrec, Echinops telfairi.  

PubMed

The otter shrews are members of the subfamily Potamogalinae within the family Tenrecidae. No description of the ovaries of any member of this subfamily has been published previously. The lesser hedgehog tenrec, Echinops telfairi, is a member of the subfamily Tenrecinae of the same family and, although its ovaries have not been described, other members of this subfamily have been shown to have ovaries with non-antral follicles. Examination of these two species illustrated that non-antral follicles were characteristic of the ovaries of both species, as was clefting and lobulation of the ovaries. Juvenile otter shrews range from those with only small follicles in the cortex to those with 300- to 400-microm follicles similar to those seen in non-pregnant and pregnant adults. As in other species, most of the growth of the oocyte occurred when follicles had one to two layers of granulosa cells. When larger follicles became atretic in the Nimba otter shrew, hypertrophy of the theca interna produced nodules of glandular interstitial tissue. In the tenrec, the hypertrophying theca interna cells in most large follicles appeared to undergo degeneration. Both species had some follicular fluid in the intercellular spaces between the more peripheral granulosa cells. It is suggested that this fluid could aid in separation of the cumulus from the remaining granulosa at ovulation. The protruding follicles in lobules and absence of a tunica albuginea might also facilitate ovulation of non-antral follicles. Ovaries with a thin-absent tunica albuginea and follicles with small-absent antra are widespread within both the Eulipotyphla and in the Afrosoricida, suggesting that such features may represent a primitive condition in ovarian development. Lobulated and deeply crypted ovaries are found in both groups but are not as common in the Eulipotyphla making inclusion of this feature as primitive more speculative. PMID:16046864

Enders, A C; Carter, A M; Künzle, H; Vogel, P

2005-01-01

110

The transfer of radiolabelled n-6 essential fatty acids by the mammary system of the tree-shrew (Tupia tana).  

PubMed

The fatty acid content of tree-shrew milk has been determined from analysis of the stomach content of infants immediately after suckling. Comparison of the n-6 fatty acid composition of the stomach contents, liver and brain demonstrate a striking increment in the ratio of arachidonic to linoleic acid. Feeding radioactively labelled linoleic acid to the mother 24 hr prior to suckling showed that 12-20% was transferred to the milk. Evidence from the appearance of the radioactivity administered as linoleic acid into arachidonic acid indicates that this species is able to desaturate linoleic acid. PMID:3595091

Williams, G; Crawford, M A

1987-01-01

111

Preliminary data on the biodiversity of rodents and insectivores (Mammalia) in the periphery of Kisangani (D. R. Congo)  

Microsoft Academic Search

This study presents the species diversity of rodents and insectivores s.l. as observed in the forests around Kisangani (D.R. Congo) between 1979 and 2003. 7736 specimens were collected using Victor snap traps, Sherman live traps and pitfalls. In total, 49 small mammals species (36 rodents and 18 shrews) were identified of which 42 were actually captured and 7 more were

I. Mukinzi; P. G. B. Katuala; J. Kennis; M. Gambalemoke; N. Kadange; A. M. Dudu

2005-01-01

112

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

113

Morphological adaptation of the skull for various behaviors in the tree shrews.  

PubMed

Skull size and shape were examined among 14 species of the tree shrews (Tupaia montana, T. picta, T. splendidula, T. mulleri, T. longipes, T. glis, T. javanica, T. minor, T. gracilis, T. dorsalis, T. tana, Dendrogale melanura, D. murina, and Ptilocercus lowii). The bones of face were rostro-caudally longer in T. tana and T. dorsalis, contrasting with T. minor and T. gracilis, D. melanura, D. murina and P. lowii which have smaller facial length ratios. The arbo-terrestrial species (T. longipes and T. glis) were similar to terrestrial species in length ratios of bones of face unlike the other arbo-terrestrial species (T. montana, T. picta, T. splendidula, and T. mulleri). We propose that T. longipes and T. glis have adapted to foraging for termites and ants as have T. tana and T. dorsalis. Additionally small body size in T. javanica may be the result of being isolated in Java. We separated the species into 5 groups from the measurment values of skulls: 1) Terrestrial species; T. tana and T. dorsalis, 2) Arboreal species; T. minor and T. gracilis, 3) Arbo-terrestrial species group 1: T. montana, T. splendidula, T. picta and T. mulleri, and T. javanica, 4) Arbo-terrestrial species group 2: T. glis and T. longipes, 5) Arboreal species of Dendrogale and Ptilocercus. Principal component analysis separated species into 8 clusters as follows: 1) T. tana, 2) T. dorsalis, 3) T. montana, T. splendidula, T. picta and T. mulleri, 4) T. glis and T. longipes, 5) T. javanica, 6) T. minor and T. gracilis, 7) D. melanura and D. murina, and 8) P. lowii. We suggest that these clusters correspond to behavioral strategies and peculiarities observed in foraging, feeding and locomotion in each species. PMID:12951419

Endo, Hideki; Hikida, Tsutomu; Motokawa, Masaharu; Chou, Loke Ming; Fukuta, Katsuhiro; Stafford, Brian J

2003-08-01

114

Neural regulation of esophageal striated muscle in the house musk shrew (Suncus murinus).  

PubMed

In the present study, we characterized the neural regulation of esophageal striated muscle in Suncus murinus (a house musk shrew; "suncus" used as a laboratory name), which was compared with that in the rat. The tunica muscularis consists of striated muscle in the suncus esophagus. An isolated segment of the suncus esophagus was placed in an organ bath and the contractile responses were recorded using a force transducer. Electrical stimulations to vagus nerves induced contractile responses in the esophageal segment. Treatment with ?-bungarotoxin, a blocker of nicotinic acetylcholine receptors, blocked the vagally mediated contractions of the suncus esophagus. D-tubocurarine and succinylcholine, typical antagonists of nicotinic acetylcholine receptors, also inhibited the suncus esophageal contractions, while higher concentrations of the agents were required rather than concentrations for producing an equivalent block in the rat. We used capsaicin, a stimulator of small-caliber afferent neurons, for activating the peripheral neural network. The reagent inhibited the vagally mediated twitch contractions of striated muscle in the suncus esophagus, which was reversed by pretreatment with a nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methyl ester. Application of a nitric oxide donor, diethylamine NONOate diethylammonium salt, mimicked capsaicin-induced inhibition. The results suggest that motility of the suncus esophagus, which consists of striated muscles, is regulated by vagal cholinergic neurons. The local neural network including capsaicin-sensitive neurons and intrinsic nitrergic neurons can modify the vagally mediated motility in the suncus esophagus. In addition, nicotinic acetylcholine receptors of the suncus esophagus might be pharmacologically distinct from those of rodent esophagi. PMID:22285704

Shiina, Takahiko; Shima, Takeshi; Suzuki, Yuji; Wörl, Jürgen; Shimizu, Yasutake

2012-05-21

115

Homeostatic maintenance in excitability of tree shrew hippocampal CA3 pyramidal neurons after chronic stress.  

PubMed

The experience of chronic stress induces a reversible regression of hippocampal CA3 apical neuron dendrites. Although such postsynaptic membrane reduction will obviously diminish the possibility of synaptic input, the consequences for the functional membrane properties of these cells are not well understood. We tested the hypothesis that chronic stress affects the input-output characteristics and excitability of CA3 pyramidal cells. Somatic whole-cell current-clamp recording with parallel intracellular biocytin labeling was performed on CA3 neurons from in vitro hippocampal slices from male tree shrews, which were collected after 28 days of psychosocial stress exposure and compared to recordings obtained from control animals. Post hoc morphometric analysis of biocytin-labeled CA3 cells revealed branch regression, by fewer dendritic crossings and length, limited to a distance of approximately 280-340 microm from the soma only. The results from whole-cell recording indicate that chronic stress surprisingly reduced the apparent membrane time constant and input resistance 20-25%, accompanied by increased amplitude of the hyperpolarization-induced voltage "sag." All active membrane properties, including depolarization-induced action potential kinetics, complex spiking patterns, and afterhyperpolarization voltages, were indistinguishable from control recordings. Although linear association analysis confirmed that differences in geometry, such as apical length or branch number, were correlated to functional variability in properties of the AP current and voltage threshold, these changes were too marginal to be reflected in the group differences. However, the individual adrenal hormone status was associated significantly with the selective changes in subthreshold excitability. Taken together, the data provide evidence that despite long-term stress induces morphological changes, upregulates cortisol release and shifts the intrinsic membrane properties, the efficacy of somatic excitability of CA3 pyramidal neurons is largely preserved. PMID:15318332

Kole, Maarten H P; Czéh, Boldizsár; Fuchs, Eberhard

2004-01-01

116

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.

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

117

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

118

Low cholesteryl ester transfer protein and phospholipid transfer protein activities are the factors making tree shrew and beijing duck resistant to atherosclerosis  

PubMed Central

Background Tree shrew and beijing duck are regarded as animal models resistant to atherosclerosis (AS). This study was carried out to discover the potential mechanism. Methods Blood samples were collected from healthy men and male animals. Plasma lipid profile and activities of cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) were measured, compared and analyzed in human, tree shrew, and Beijing duck. Results The results showed that there were species differences on plasma lipid profile and activities of CETP and PLTP in the three species. Compared with human, tree shrew and beijing duck had higher high density lipoprotein cholesterol (HDL-C)/total cholesterol (TC) and HDL-C/low density lipoprotein cholesterol (LDL-C) ratios, but lower CETP and PLTP activities. In the three species, CETP and PLTP activities were negatively related with the ratio of HDL-C/LDL-C. Conclusions The present study suggested that low plasma CETP and PLTP activities may lead to a high HDL-C/LDL-C ratio and a high resistance to AS finally in tree shrew and beijing duck. Moreover, low PLTP activity may also make the animals resistant to AS by the relative high vitamin E content of apoB-containing lipoproteins and high anti-inflammatory and antioxidative properties of HDL particles. A detailed study in the future is recommended.

2010-01-01

119

The distribution of crossed and uncrossed optic fibers in the different layers of the lateral geniculate nucleus in the tree shrew ( Tupaia glis )  

Microsoft Academic Search

The laminar distribution of crossed and uncrossed optic fibers was studied in the lateral geniculate nucleus (LGN) in the tree shrew (Tupaia glis) following unilateral enucleation. For the investigation of the termination of optic fibers the transneuronal degeneration method and experimental EM were employed. By using formvar film-coated slot grids, all six layers of the LGN could be studied in

Ferenc Hajdu; Rolf Hassler; Aleksander Wagner

1982-01-01

120

Do geological or climatic processes drive speciation in dynamic archipelagos? The tempo and mode of diversification in Southeast Asian shrews.  

PubMed

Geological and climatic processes potentially alter speciation rates by generating and modifying barriers to dispersal. In Southeast Asia, two processes have substantially altered the distribution of land. Volcanic uplift produced many new islands during the Miocene-Pliocene and repeated sea level fluctuations during the Pleistocene resulted in intermittent land connections among islands. Each process represents a potential driver of diversification. We use a phylogenetic analysis of a group of Southeast Asian shrews (Crocidura) to examine geographic and temporal processes of diversification. In general, diversification has taken place in allopatry following the colonization of new areas. Sulawesi provides an exception, where we cannot reject within-island speciation for a clade of eight sympatric and syntopic species. We find only weak support for temporally declining diversification rates, implying that neither volcanic uplift nor sea level fluctuations had a strong effect on diversification rates. We suggest that dynamic archipelagos continually offer new opportunities for allopatric diversification, thereby sustaining high speciation rates over long periods of time, or Southeast Asian shrews represent an immature radiation on a density-dependent trajectory that has yet to fill geographic and ecological space. PMID:19500148

Esselstyn, Jacob A; Timm, Robert M; Brown, Rafe M

2009-10-01

121

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.

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

2011-01-01

122

A novel 26RFa peptide containing both analgesic and anti-inflammatory functions from Chinese tree shrew.  

PubMed

26RFa is one of neuroendocrine peptide groups in the RFamide peptide family containing conserved Arg-Phe/Tyr-NH2 motif at their C-terminus. They exert multiple biological functions in vertebrates. A novel 26RFa peptide (TC26RFa) with unique structure is identified from the tree shrew of Tupaia belangeri chinensis in the present study. In structure, different from other 26RFa peptides containing conserved Phe-Arg-Phe-NH2 motif at their C-terminus, there is a Phe-Arg-Tyr-NH2 C-terminus in TC26RFa. It has been found that TC26RFa of intraperitoneal injection exerts strong analgesic activities in several mice models including acetic acid-induced abdominal writhing, formalin-induced paw licking, and thermal pain-induced tail withdrawal. It shows comparable analgesic ability with morphine. In addition, this peptide has been found to inhibit inflammatory factor secretion (including tumor necrosis factor-?, interleukin-6, and interleukin-1?) induced by lipopolysaccharides (LPS). Furthermore, it stimulates secretion of the anti-inflammatory factor, interleukin-10. In addition to the identification of a novel 26RFa peptide from tree shrew, a new type of function (anti-inflammation) involved in 26RFa peptide is discovered. PMID:24632209

Zhu, Yuqin; Duan, Zilei; Mo, Guoxiang; Shen, Chuanbin; Lv, Longbao; Chen, Wenlin; Lai, Ren

2014-07-01

123

Identification of aflatoxin M1-N7-guanine in liver and urine of tree shrews and rats following administration of aflatoxin B1.  

PubMed

Epidemiological studies have shown that exposure to aflatoxin B(1) (AFB(1)) and concurrent infection with hepatitis B lead to a multiplicative risk of developing liver cancer. This chemical-viral interaction can be recapitulated in the tree shrew (Tupia belangeri chinensis). As an initial characterization of this model, the metabolism of AFB(1) in tree shrews has been examined and compared to a sensitive bioassay species, the rat. Utilizing LC/MS/MS, an unreported product, aflatoxin M(1)-N(7)-guanine (AFM(1)-N(7)-guanine), was detected in urine and hepatic DNA samples 24 h after administration of 400 microg/kg AFB(1). In hepatic DNA isolated from tree shrews, AFM(1)-N(7)-guanine was the predominant adduct, 0.74 +/- 0.14 pmol/mg DNA, as compared to 0.37 +/- 0.07 pmol/mg DNA of AFB(1)-N(7)-guanine. Conversely, in rat liver, 6.56 +/- 2.41 pmol/mg DNA of AFB(1)-N(7)-guanine and 0.42 +/- 0.13 pmol/mg DNA of AFM(1)-N(7)-guanine were detected. Rats excreted 1.00 +/- 0.21 pmol AFB(1)-N(7)-guanine/mg creatinine and 0.29 +/- 0.10 pmol AFM(1)-N(7)-guanine/mg creatinine as compared to 0.60 +/- 0.12 pmol AFB(1)-N(7)-guanine/mg creatinine and 0.69 +/- 0.16 pmol AFM(1)-N(7)-guanine/mg creatinine excreted by the tree shrew. Furthermore, tree shrew urine contained 40 times more of the hydroxylated metabolite, AFM(1), than was excreted by rats. In vitro experiments confirmed this difference in oxidative metabolism. Hepatic microsomes isolated from tree shrews failed to produce aflatoxin Q(1) or aflatoxin P(1) but formed a significantly greater amount of AFM(1) than rat microsomes. Bioassays indicated that the tree shrew was considerably more resistant than the rat to AFB(1) hepatocarcinogenesis, which may reflect the significant differences in metabolic profiles of the two species. PMID:12971806

Egner, Patricia A; Yu, Xiang; Johnson, Jesse K; Nathasingh, Christopher K; Groopman, John D; Kensler, Thomas W; Roebuck, Bill D

2003-09-01

124

Rediscovery of Meristaspis lateralis (Kolenati) (Acari: Mesostigmata: Spinturnicidae) parasitizing the Egyptian fruit bat, Rousettus aegyptiacus (Geoffroy) (Mammalia: Chiroptera), with a key to mites of bats in Egypt.  

PubMed

Faunistic information about bat mites in Egypt is scarce. Collection records of parasitic mites, Meristaspis lateralis (Kolenati, 1856) (Mesostigmata: Spinturnicidae), are reported from the Egyptian fruit bat, Rousettus aegyptiacus (Geoffroy, 1810) (Mammalia: Chiroptera) in Assiut Governorate, Egypt. Seven species of bat mites are recognized from Egypt to date. A host-parasite checklist and an identification key to these species are presented. PMID:24961009

Negm, Mohamed W; Fakeer, Mahmoud M

2014-04-01

125

Endocrine correlates of reproductive development in the male tree-shrew (Tupaia belangeri) and the effects of infantile exposure to exogenous androgens.  

PubMed

The developmental life-history of tree-shrews conforms with the general primate pattern. Consequently, elucidation of the tree-shrew's neuroendocrine reproductive axis could shed light on the mechanisms that underlie human pubertal development. In the present study, we examined plasma gonadotropin concentrations in male tree-shrews from birth to sexual maturity, and related them to changes in the androgenic and gametogenic status of the testis. A hypogonadotropic infantile phase, during which a stable population of primordial cells is established, extended from birth to approximately Day 30. Following a short juvenile phase (Days 30-40), a pubertal phase of accelerated reproductive development was initiated between Days 40-55. At this time, FSH and LH levels rose and testosterone concentrations reached peak levels coincident with the descent of the testes, accelerated growth in the reproductive tract and the onset of spermatogenesis. To test whether this developmental peak in testosterone secretion is an important determinant in the normal onset of puberty, we exposed male tree-shrews prematurely to high circulating androgen levels for various periods and then examined the impact on key components of the developing reproductive axis. The testosterone implants failed to initiate spermatogenesis and the testes remained in an infantile state for the duration of the treatment, whereas implant removal led to the development of full spermatogenic activity. In both normal and experimental situations, low levels of FSH were associated with a lack of spermatogenic activity while the progression of germ cell development was precisely correlated with rising FSH levels. Taken together, these data establish a comprehensive picture of reproductive development in the male tree-shrew, and also provide support for the hypothesis that FSH plays a primary role in the initiation of spermatogenesis. PMID:17686481

Collins, Peter M; Tsang, Wai Ning; Urbanski, Henryk F

2007-01-01

126

Redescription of Pterygodermatites (Mesopectines) nycticebi (Mönnig, 1920) (Nematoda: Rictulariidae), a parasite of slow loris Nycticebus coucang (Mammalia: Primates).  

PubMed

Pterygodermaties (Mesopectines) nycticebi (Mönnig, 1920) (Nematoda: Spirurida: Rictulariidae) is redescribed based on immature and mature adults collected from the stomach and small intestine at autopsy of a slow loris, Nycticebus coucang (Boddaert, 1785) (Mammalia: Primates), in a zoological garden in Japan. It is first demonstrated that male possesses a minute telamon and a left lateral pore in the preanal part of body. The cause of death of the slow loris is strongly surmised to be related to the nematode infection, which was apparently acquired under captivity in the zoological garden. PMID:14560972

Ikeda, Yatsukaho; Fujisaki, Akiko; Murata, Koichi; Hasegawa, Hideo

2003-06-01

127

Chemical features of monoaminergic and non-monoaminergic neurons in the brain of laboratory shrew ( Suncus murinus) are changed by systemic administration of monoamine precursors  

Microsoft Academic Search

5-Hydroxy-l-tryptophan (5-HTP) and l-3,4-dihydroxyphenylalanine (l-DOPA) were injected intraperitoneally (i.p.) into the laboratory shrew (Suncus murinus). Immunocytochemical and immunofluorescence studies were carried out on serial or same sections of the brain, which were reacted with specific antisera to dopamine (DA) or serotonin (5-HT) produced in our laboratory. We observed that cell bodies and nerve terminals of many catecholaminergic (CAnergic) neurons exhibited

Nobuyuki Karasawa; Ryohachi Arai; Genzoh Isomura; Toshiharu Nagatsu; Ikuko Nagatsu

1995-01-01

128

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

Microsoft Academic Search

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

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

2005-01-01

129

[Identification of a novel WART-like chromosome rearrangement in complex heterozygotes in an interracial hybrid zone of the common shrew Sorex araneus L].  

PubMed

Karyotypes uncharacteristic of pure races or hybrids were identified in the interracial hybrid zones of the common shrew Sorex araneus L. that were recently discovered in the European part of Russia. This suggests the actual existence in natural populations of WART-like rearrangements (whole-arm reciprocal translocations) along with Robertsonian fusions of acrocentrics. Demonstration of new and still rare chromosome variants is the aim of this communication. PMID:21061632

Pavlova, S V; Bulatova, N Sh

2010-09-01

130

Distribution of Borna disease virus antigen and RNA in tissues of naturally infected bicolored white-toothed shrews, Crocidura leucodon, supporting their role as reservoir host species.  

PubMed

Borna disease is a severe viral-induced disorder of the central nervous system of horses, sheep, and a few other animal species, occurring in certain areas of central Europe. Pathogenesis and epidemiology of natural Borna disease virus (BDV) infections are still not fully understood; several unique epidemiologic features, however, point toward the existence of BDV reservoir populations other than the final hosts. In this study, 69 mice and 12 shrews were trapped and examined. The virus distribution was investigated in detail in 2 BDV-positive bicolored white-toothed shrews, Crocidura leucodon, by immunohistochemistry and TaqMan real-time reverse transcription polymerase chain reaction (RT-PCR). RT-PCR amplification products were sequenced, and the sequences were compared. These shrews had been collected in a BDV-endemic geographical region using live traps and did not show obvious clinical or pathological disease signs. BDV antigen and nucleic acid were identified in several organs, including the brain, mainly in nerve tissue and neurons, respectively, but also in parenchymal cells (eg, hepatocytes, Leydig cells) and epithelial cells, particularly of the respiratory and urogenital tract. PMID:20133953

Puorger, M E; Hilbe, M; Müller, J-P; Kolodziejek, J; Nowotny, N; Zlinszky, K; Ehrensperger, F

2010-03-01

131

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

132

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

133

The morphological and histological characters of the male external genitalia of the house musk shrew, Suncus murinus.  

PubMed

External genitalia are the reproductive organs necessary for efficient copulation and internal fertilization in various mammalian species. Their morphogeneses display significant morphological and developmental differences among species. The house musk shrew, Suncus murinus (hereafter described as suncus) is a species of the order Insectivora, which has been considered as primitive and one of the earliest eutheria phylogenetically. Comparative anatomical analyses of phylogenetically different mammals will contribute to the better understanding of morphological diversity of external genitalia. This study performed various anatomical and histological analyses concerning the organization of the external genitalia of male suncus. It was shown that the external genitalia of suncus possessed a muscular structure, which we proposed as musculus ischiocavernosus dorsalis of suncus. The musculus ischiocavernosus dorsalis is originated from the inner surface of the tuber ischiadicum and was allocated adjacent to the corpus cavernosum penis. In addition, a pair of alpha-smooth muscle actin positive muscles was located bilaterally to the urethra. This unique morphology of the external genitalia of suncus males may provide a unique model system to investigate genital morphogenesis. PMID:15846055

Kamikawa-Miyado, Mami; Ogi, Hidenao; Ogino, Yukiko; Katoh, Hironori; Suzuki, Kentaro; Uemura, Masanori; Kitoh, Junzoh; Oda, Sen-Ichi; Yamada, Gen

2005-04-01

134

Multilocus phylogeny and cryptic diversity in Asian shrew-like moles (Uropsilus, Talpidae): implications for taxonomy and conservation  

PubMed Central

Background The genus Uropsilus comprises a group of terrestrial, montane mammals endemic to the Hengduan and adjacent mountains. These animals are the most primitive living talpids. The taxonomy has been primarily based on cursory morphological comparisons and the evolutionary affinities are little known. To provide insight into the systematics of this group, we estimated the first multi-locus phylogeny and conducted species delimitation, including taxon sampling throughout their distribution range. Results We obtained two mitochondrial genes (~1, 985 bp) and eight nuclear genes (~4, 345 bp) from 56 specimens. Ten distinct evolutionary lineages were recovered from the three recognized species, eight of which were recognized as species/putative species. Five of these putative species were found to be masquerading as the gracile shrew mole. The divergence time estimation results indicated that climate change since the last Miocene and the uplift of the Himalayas may have resulted in the diversification and speciation of Uropsilus. Conclusions The cryptic diversity found in this study indicated that the number of species is strongly underestimated under the current taxonomy. Two synonyms of gracilis (atronates and nivatus) should be given full species status, and the taxonomic status of another three potential species should be evaluated using extensive taxon sampling, comprehensive morphological, and morphometric approaches. Consequently, the conservation status of Uropsilus spp. should also be re-evaluated, as most of the species/potential species have very limited distribution.

2013-01-01

135

Dental microwear in relation to changes in the direction of mastication during the evolution of Myodonta (Rodentia, Mammalia)  

NASA Astrophysics Data System (ADS)

Observations of dental microwear are used to analyse the correlation between changes in molar tooth crown morphology and the direction of masticatory movement during the evolution of Myodonta (Rodentia, Mammalia). The studied sample includes 36 specimens representing both superfamilies of Myodonta (Muroidea and Dipodoidea) spanning 16 dipodoid and 9 muroid species. Microscopic scratches on occlusal surfaces resulting from contact between opposite teeth during mastication are analysed. Using these features, we determine the direction of masticatory movements. Microwear patterns display diverse orientations among Dipodoidea: oblique in Sicistinae, Euchoreutinae and Zapodinae, propalinal in Dipodinae and intermediary in Allactaginae. Similarly, Muroidea exhibit the following orientations: oblique in Cricetinae and propalinal in Arvicolinae, Cricetomyinae, Gerbillinae and Murinae. These various chewing types illustrate different evolutionary grades within the superfamilies. Acquisition of the antero-posterior masticatory movement in Dipodoidea is related to flattening of the molar occlusal surface. However, in some muroid subfamilies, this direction of mastication is associated with low-crowned and cuspidate molars (Cricetomyinae, Murinae).

Charles, Cyril; Jaeger, Jean-Jacques; Michaux, Jacques; Viriot, Laurent

2007-01-01

136

Natural infection of Didelphis aurita (Mammalia: Marsupialia) with Leishmania infantum in Brazil  

PubMed Central

Background The opossum Didelphis have been considered as natural hosts of Leishmania parasites in the New World, suggesting an important role in the epidemiology of Visceral Leishmaniasis (VL). Among six extant species that belong to the genus Didelphis, only two (D. marsupialis and D. albiventris), have been mentioned as natural hosts of Leishmania infantum in Brazil and Colombia. In the present paper, it is reported for the first time, the observation of intracellular parasites (amastigotes) in tissues of Didelphis aurita naturally infected with Leishmania infantum in Brazil. We also discuss some aspects associated to the relationship between L. infantum and the geographical distribution of some species of the genus Didelphis. Methods The opossums studied were caught by wire traps (Tomahawk) in Barra de Guaratiba, a peri-urban area in Rio de Janeiro. The opossums were killed with an overdose of Thiopental sodium.At necropsy, macroscopic alterations were examined and samples from liver, spleen, lymph nodes, ear, abdominal skin, scent glands and bone marrow were collected for parasitological and molecular diagnoses. Results Forty-eight opossums were captured in an AVL endemic region, 30 being caught in a mangrove area and eighteen animals in a forest area near to some residential-yards. Among the thirty opossums trapped in the mangrove area, all of them were negative by both imprint and sera samples assayed on Dipstick Tests, that is a test based on a combination of protein-A colloidal gold conjugate and rk39 Leishmania antigen to detect anti-Leishmania antibody in serum or plasma. At the macroscopic examination one out of eighteen opossums, caught close to the forest, presented alterations compatible with spleen hypertrophy and three were positive by Dipstick Tests (16.6%) and presented amastigotes in the spleen and in one of them, the parasites were also observed in a submandibular lymph node. Leishmania infantum infections were confirmed through dot blot hybridization using a L. infantum-specific biotinylated probe. Conclusions In the present paper we present the first report of amastigotes in the tissues of Didelphis aurita (Mammalia: Marsupialia) naturally infected with Leishmania infantum. We also attempt to claim the particular role of some opossum species as hosts of Leishmania infantum, contributing at least in part on the description of potential sylvatic reservoirs.

2012-01-01

137

Mechanism of Ghrelin-Induced Gastric Contractions in Suncus murinus (House Musk Shrew): Involvement of Intrinsic Primary Afferent Neurons  

PubMed Central

Here, we have reported that motilin can induce contractions in a dose-dependent manner in isolated Suncus murinus (house musk shrew) stomach. We have also shown that after pretreatment with a low dose of motilin (10?10 M), ghrelin also induces gastric contractions at levels of 10?10 M to 10?7 M. However, the neural mechanism of ghrelin action in the stomach has not been fully revealed. In the present study, we studied the mechanism of ghrelin-induced contraction in vitro using a pharmacological method. The responses to ghrelin in the stomach were almost completely abolished by hexamethonium and were significantly suppressed by the administration of phentolamine, prazosin, ondansetron, and naloxone. Additionally, N-nitro-l-arginine methylester significantly potentiated the contractions. Importantly, the mucosa is essential for ghrelin-induced, but not motilin-induced, gastric contractions. To evaluate the involvement of intrinsic primary afferent neurons (IPANs), which are multiaxonal neurons that pass signals from the mucosa to the myenteric plexus, we examined the effect of the IPAN-related pathway on ghrelin-induced contractions and found that pretreatment with adenosine and tachykinergic receptor 3 antagonists (SR142801) significantly eliminated the contractions and GR113808 (5-hydroxytryptamine receptor 4 antagonist) almost completely eliminated it. The results indicate that ghrelin stimulates and modulates suncus gastric contractions through cholinergic, adrenergic, serotonergic, opioidergic neurons and nitric oxide synthases in the myenteric plexus. The mucosa is also important for ghrelin-induced gastric contractions, and IPANs may be the important interneurons that pass the signal from the mucosa to the myenteric plexus.

Mondal, Anupom; Aizawa, Sayaka; Sakata, Ichiro; Goswami, Chayon; Oda, Sen-ichi; Sakai, Takafumi

2013-01-01

138

Thalamic Burst Firing Propensity: a Comparison of the Dorsal Lateral Geniculate and Pulvinar Nuclei in the Tree Shrew  

PubMed Central

Relay neurons in dorsal thalamic nuclei can fire high frequency bursts of action potentials that ride the crest of voltage-dependent transient (T-type) calcium currents (low threshold spike; LTS). To explore potential nucleus-specific burst features, we compared the membrane properties of dorsal lateral geniculate nucleus (dLGN) and pulvinar nucleus relay neurons using in vitro whole cell recording in juvenile and adult tree shrew (Tupaia) tissue slices. We injected current ramps of variable slope into neurons that were sufficiently hyperpolarized to de-inactivate T-type calcium channels. In a small percentage of juvenile pulvinar and dLGN neurons, an LTS could not be evoked. In the remaining juvenile neurons, and in all adult dLGN neurons, a single LTS could be evoked by current ramps. However, in the adult pulvinar, current ramps evoked multiple LTSs in over 70% of recorded neurons. Using immunohistochemistry, western blot techniques, unbiased stereology, confocal and electron microscopy, we found that pulvinar neurons expressed more T-type calcium channels (Cav 3.2) and more small conductance potassium channels (SK2) than dLGN neurons and that the pulvinar nucleus contained a higher glia-to-neuron ratio than the dLGN. Hodgkin-Huxley type compartmental models revealed that the distinct firing modes could be replicated by manipulating T-type calcium and SK2 channel density, distribution, and kinetics. The intrinsic properties of pulvinar neurons that promote burst firing in the adult may be relevant to the treatment of conditions that involve the adult onset of aberrant thalamocortical interactions.

Wei, Haiyang; Bonjean, Maxime; Petry, Heywood M.; Sejnowski, Terrence J.; Bickford, Martha E.

2011-01-01

139

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

140

Mechanism of ghrelin-induced gastric contractions in Suncus murinus (house musk shrew): involvement of intrinsic primary afferent neurons.  

PubMed

Here, we have reported that motilin can induce contractions in a dose-dependent manner in isolated Suncus murinus (house musk shrew) stomach. We have also shown that after pretreatment with a low dose of motilin (10(-10) M), ghrelin also induces gastric contractions at levels of 10(-10) M to 10(-7) M. However, the neural mechanism of ghrelin action in the stomach has not been fully revealed. In the present study, we studied the mechanism of ghrelin-induced contraction in vitro using a pharmacological method. The responses to ghrelin in the stomach were almost completely abolished by hexamethonium and were significantly suppressed by the administration of phentolamine, prazosin, ondansetron, and naloxone. Additionally, N-nitro-l-arginine methylester significantly potentiated the contractions. Importantly, the mucosa is essential for ghrelin-induced, but not motilin-induced, gastric contractions. To evaluate the involvement of intrinsic primary afferent neurons (IPANs), which are multiaxonal neurons that pass signals from the mucosa to the myenteric plexus, we examined the effect of the IPAN-related pathway on ghrelin-induced contractions and found that pretreatment with adenosine and tachykinergic receptor 3 antagonists (SR142801) significantly eliminated the contractions and GR113808 (5-hydroxytryptamine receptor 4 antagonist) almost completely eliminated it. The results indicate that ghrelin stimulates and modulates suncus gastric contractions through cholinergic, adrenergic, serotonergic, opioidergic neurons and nitric oxide synthases in the myenteric plexus. The mucosa is also important for ghrelin-induced gastric contractions, and IPANs may be the important interneurons that pass the signal from the mucosa to the myenteric plexus. PMID:23565235

Mondal, Anupom; Aizawa, Sayaka; Sakata, Ichiro; Goswami, Chayon; Oda, Sen-ichi; Sakai, Takafumi

2013-01-01

141

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.

Badyaev, A V; Foresman, K R

2000-01-01

142

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.

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

2003-01-01

143

Measuring airborne components of seismic body vibrations in a Middle-Asian sand-dwelling Insectivora species, the piebald shrew (Diplomesodon pulchellum).  

PubMed

Self-produced seismic vibrations have been found for some subterranean rodents but have not been reported for any Insectivora species, although seismic sensitivity has been confirmed for blind sand-dwelling chrysochlorid golden moles. Studying the vocal behaviour of captive piebald shrews, Diplomesodon pulchellum, we documented vibrations, apparently generated by the whole-body wall muscles, from 11 (5 male, 6 female) of 19 animals, placed singly on a drum membrane. The airborne waves of the vibratory drumming were digitally recorded and then analysed spectrographically. The mean frequency of vibration was 160.5 Hz. This frequency matched the periodicity of the deep sinusoidal frequency modulation (159.4 Hz) found in loud screech calls of the same subjects. The body vibration was not related to thermoregulation, hunger-related depletion of energy resources or fear, as it was produced by well-fed, calm animals, at warm ambient temperatures. We hypothesize that in the solitary, nocturnal, digging desert piebald shrew, body vibrations may be used for seismic exploration of substrate density, to avoid energy-costly digging of packed sand for burrowing and foraging. At the same time, the piercing quality of screech calls due to the deep sinusoidal frequency modulation, matching the periodicity of body vibration, may be important for agonistic communication in this species. PMID:22837458

Volodin, Ilya A; Zaytseva, Alexandra S; Ilchenko, Olga G; Volodina, Elena V; Chebotareva, Anastasia L

2012-08-15

144

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

145

Neoskrjabinolepis nuda n. sp. from shrews on Sakhalin Island, Russia, with a taxonomic review of Neoskrjabinolepis Spasskii, 1947 (Cestoda: Cyclophyllidea: Hymenolepididae).  

PubMed

Neoskrjabinolepis (Neoskrjabinolepidoides) nuda n. sp. is described from the shrews Sorex unguiculatus (type-host), S. gracillimus, S. isodon and S. caecutiens on Sakhalin Island, Russia. The new species is characterised by: rostellar hooks 40-44 microm long and provided with small epiphyseal thickening of the handle; a long (95-100 microm) cirrus consisting of basal region with claw-shaped spines, a parabasal region with thin needle-shaped spines and an unarmed distal region; a cirrus-sac extending well into the median field; and 15-22 eggs per gravid uterus. A review of the species of Neoskrjabinolepis Spasskii, 1947 is presented. Currently, this genus includes nine species and is divided in two subgenera on the basis of strobilar development, which is gradual in the subgenus Neoskrjabinolepis (four species) and serial in the subgenus Neoskrjabinolepidoides Kornienko, Gulyaev & Mel'nikova, 2006 (five species). An amended generic diagnosis and an identification key to Neoskrjabinolepis spp. are presented. PMID:18427960

Kornienko, Svetlana A; Gulyaev, Vladimir D; Mel'nikova, Yulia A; Georgiev, Boyko B

2008-06-01

146

Conservation throughout mammalia and extensive protein-encoding capacity of the highly repeated DNA long interspersed sequence one.  

PubMed

We report an investigation of the structure, evolutionary history, and function of the highly repeated DNA family named Long Interspersed Sequence One (L1). Hybridization studies show, first, that L1 is present throughout marsupial and placental mammalian orders. Second, L1 is more homologous within these species than between them, which suggests that it has undergone concerted evolution within each mammalian lineage. Third, on the whole L1 diverges in accordance with the fossil record. This suggests that it arose in each lineage rather by inheritance from a common ancestral family, which was present in the progenitor to mammals, than by cross-species transmission. Alignment of 1.6 X 10(3) bases of primate and mouse L1 DNA sequences shows a predominance of silent mutations within aligned long open reading frames, indicating that at least this part of L1 has produced functional protein. The observation of additional long open reading frames in further unaligned DNA sequences suggests that a minimum of 3.2 X 10(3) bases or at least half of the L1 structure is a protein-coding sequence. Thus L1, which contains about 100,000 members in mouse, is by far the most repetitive family of which a subset comprises functional protein-encoding genes. The ability of the putative protein-encoding regions of mouse L1 to hybridize to L1 homologs throughout the Mammalia implies that these sequences have been subject to conservative selection upon protein function in all mammalian lineages, rather than in a few. L1 is therefore a highly repeated family of genes with both a widespread and an ancient history of function in mammals. PMID:3009828

Burton, F H; Loeb, D D; Voliva, C F; Martin, S L; Edgell, M H; Hutchison, C A

1986-01-20

147

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

148

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

149

A microsatellite study in the ??gucki M?yn/Popielno hybrid zone reveals no genetic differentiation between two chromosome races of the common shrew (Sorex araneus).  

PubMed

This study investigated a chromosome hybrid zone between two chromosomal races of the common shrew (Sorex araneus). Gene flow and genetic structure of the hybrid zone, located in the northeast of Poland, were studied using seven polymorphic autosomal microsatellite loci (L9, L14, L33, L45, L67, L68, L97) and a Y-linked microsatellite locus (L8Y). Seventy-five animals (46 of the ??gucki M?yn race and 29 of the Popielno race) from nine different localities were examined and the data were analyzed using hierarchical AMOVA and F-statistic. The studied microsatellite loci and races (divided into nine geographical populations) were characterized by observed heterozygosity (H(O)), expected heterozygosities within (H(S)), and between (H(T)) populations, inbreeding coefficient (F(IS)), fixation index (F(ST)), and average allelic richness (A). We found that genetic structuring within and between the two chromosome races were weak and non-significant. This finding and unconstrained gene flow between the races indicates a high level of migration within the ??gucki M?yn/Popielno hybrid zone, suggesting that evolutionarily important genetic structuring does not occur in interracial zones where races which are not genetically distinct come into contact. PMID:21475705

Moska, Magdalena; Wierzbicki, Heliodor; Macierzy?ska, Anna; Strza?a, Tomasz; Ma?lak, Robert; Warcha?owski, Marcin

2011-04-01

150

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. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 304-315, 2014. © 2014 Wiley Periodicals, Inc. PMID:24895181

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

2014-07-01

151

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.

Matveevsky, Sergey N.; Pavlova, Svetlana V.; Maret M. Acaeva; Oxana L. Kolomiets

2012-01-01

152

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

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

153

[Molecular variability in the commom shrew Sorex araneus L. from European Russia and Siberia inferred from the length polymorphism of DNA regions flanked by short interspersed elements (Inter-SINE PCR) and the relationships between the Moscow and Seliger chromosome races].  

PubMed

Genetic exchange among chromosomal races of the common shrew Sorex araneus and the problem of reproductive barriers have been extensively studied by means of such molecular markers as mtDNA, microsatellites, and allozymes. In the present study, the interpopulation and interracial polymorphism in the common shrew was derived, using fingerprints generated by amplified DNA regions flanked by short interspersed repeats (SINEs)-interSINE PCR (IS-PCR). We used primers, complementary to consensus sequences of two short retroposons: mammalian element MIR and the SOR element from the genome of Sorex araneus. Genetic differentiation among eleven populations of the common shrew from eight chromosome races was estimated. The NP and MJ analyses, as well as multidimensional scaling showed that all samples examined grouped into two main clusters, corresponding to European Russia and Siberia. The bootstrap support of the European Russia cluster in the NJ and MP analyses was respectively 76 and 61%. The bootstrap index for the Siberian cluster was 100% in both analyses; the Tomsk race, included into this cluster, was separated with the bootstrap support of NJ/MP 92/95%. PMID:16871777

Bannikova, A A; Bulatova, N Sh; Kramerov, D A

2006-06-01

154

The taming of the shrew  

PubMed Central

Transposons are mobile genetic elements that can be harmful for the host when mobilized. However, they are also genomic reservoirs for novel genes that can be evolutionarily beneficial. There are many examples of domesticated transposases, which play important roles in the hosts. In most cases domesticated transposases have lost their endonuclease activities and the hosts utilize their DNA-binding properties. However, some other domesticated transposases perform endonuclease activities for host biological processes. Because such a catalytically active transposase is potentially harmful for the integrity of the host genome, its activity should be tightly regulated. The catalytically active domesticated piggyBac transposase Tpb2p catalyzes programmed DNA elimination in the ciliate Tetrahymena. Here, we discuss the regulatory mechanism that prevents unintended DNA cleavage by Tpb2p and compare it to another well-studied catalytically active domesticated transposase, the RAG recombinase in V(D)J recombination. The regulatory mechanisms involve the temporarily regulated expression of the transposases, the target sequence preference of the endonuclease, and the recruitment of the transposases to locally restricted chromatin environments.

Vogt, Alexander; Mochizuki, Kazufumi

2014-01-01

155

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.

Springer, Mark S.; Meredith, Robert W.; Janecka, Jan E.; Murphy, William J.

2011-01-01

156

Automating analog design: Taming the shrew  

NASA Technical Reports Server (NTRS)

The pace of progress in the design of integrated circuits continues to amaze observers inside and outside of the industry. Three decades ago, a 50 transistor chip was a technological wonder. Fifteen year later, a 5000 transistor device would 'wow' the crowds. Today, 50,000 transistor chips will earn a 'not too bad' assessment, but it takes 500,000 to really leave an impression. In 1975 a typical ASIC device had 1000 transistors, took one year to first samples (and two years to production) and sold for about 5 cents per transistor. Today's 50,000 transistor gate array takes about 4 months from spec to silicon, works the first time, and sells for about 0.02 cents per transistor. Fifteen years ago, the single most laborious and error prone step in IC design was the physical layout. Today, most IC's never see the hand of a layout designer: and automatic place and route tool converts the engineer's computer captured schematic to a complete physical design using a gate array or a library of standard cells also created by software rather than by designers. CAD has also been a generous benefactor to the digital design process. The architect of today's digital systems creates the design using an RTL or other high level simulator. Then the designer pushes a button to invoke the logic synthesizer-optimizer tool. A fault analyzer checks the result for testability and suggests where scan based cells will improve test coverage. One obstinate holdout amidst this parade of progress is the automation of analog design and its reduction to semi-custom techniques. This paper investigates the application of CAD techniques to analog design.

Barlow, A.

1990-01-01

157

SHORT REPORT  

PubMed Central

SUMMARY Recent discovery of genetically distinct hantaviruses in shrews and moles (order Soricomorpha, family Soricidae and Talpidae) has challenged the conventional view that rodents serve as the principal reservoir hosts. Nova virus (NVAV), previously identified in archival liver tissue of a single European mole (Talpa europaea) from Hungary, represents one of the most highly divergent hantaviruses identified to date. To ascertain the spatial distribution and genetic diversity of NVAV, we employed RT–PCR to analyse lungs from 94 moles, captured in two locations in France, during October 2012 to March 2013. NVAV was detected in more than 60% of moles at each location, suggesting efficient enzootic virus transmission and confirming that this mole species serves as the reservoir host. Although the pathogenic potential of NVAV is unknown, the widespread geographical distribution of the European mole might pose a hantavirus exposure risk for humans.

Gu, S. H.; Dormion, J.; Hugot, J.-P.; Yanagihara, R.

2014-01-01

158

Complete mitochondrial genome sequence of Nectogale elegans.  

PubMed

Abstract The elegant water shrew (Nectogale elegans) belongs to the family Soricidae, and distributes in northern South Asia, central and southern China and northern Southeast Asia. In this study, the complete mitochondrial genome of N. elegans was sequenced. It was determined to be 17,460 bases, and included 13 protein-coding genes (PCGs), 22 tRNA genes, 2 ribosomal RNA genes and one non-coding region, which is similar to other mammalian mitochondrial genomes. Bayesian inference and maximum likelihood methods were used to construct phylogenetic trees based on 12 heavy-strand concatenated PCGs. Phylogenetic analyses further confirmed that Crocidurinae diverged prior to Soricinae, and Sorex unguiculatus differentiated earlier than N. elegans. PMID:23795853

Huang, Ting; Yan, Chaochao; Tan, Zheng; Tu, Feiyun; Yue, Bisong; Zhang, Xiuyue

2014-08-01

159

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

160

The entotympanic in late fetal Artiodactyla (Mammalia).  

PubMed

The entotympanic is a neomorphic component of the bulla tympanica of placental mammals. Ontogenetically, its rostral component seems to be derived from the tubal cartilage, whereas its caudal component is normally connected with the sheath of the tympanohyal; the present study indicates additional sources of the caudal entotympanic. The entotympanics develop in late fetal or early postnatal life as cartilaginous structures, but in most taxa they ossifiy endochondrally as "os bullae". This skeletal element is absent only in a few placental orders, among them the Artiodactyla. Because it is present in their sister taxa within the Scrotifera, it is likely to be reduced secondarily in the even-toed mammals. The study of histological serial sections of late fetal stages of several artiodactyl species shows that vestigial cartilaginous homologues of the entotympanics are invariably present, contrary to statements in the literature. In a few perinatal stages even secondary ossifications or calcifications of the entotympanic cartilages can be observed. The tubal cartilage of artiodactyls also continues into an anterior tegmen tympani (new term) that forms the floor of the fossa muscularis major. PMID:23625465

Maier, Wolfgang

2013-08-01

161

Identification of Ebola virus sequences present as RNA or DNA in organs of terrestrial small mammals of the Central African Republic.  

PubMed

The life cycle of the Ebola (EBO) virus remains enigmatic. We tested for EBO virus in the organs of 242 small mammals captured during ecological studies in the Central African Republic. EBO virus glycoprotein or polymerase gene sequences were detected by reverse transcription PCR in RNA extracts of the organs of seven animals and by PCR in DNA extract of one animal. Neither live virus nor virus antigen was detected in any organ sample. Direct sequencing of amplicons identified the virus as being of the Zaire/Gabon subtype. Virus-like nucleocapsids were observed by electron microscopy in the cytoplasm of the spleen cells of one animal. The animals belonged to two genera of rodents (Muridae; Mus setulosus, Praomys sp1 and P. sp2) and one species of shrew (Soricidae; Sylvisorex ollula). These preliminary results provide evidence that common terrestrial small mammals living in peripheral forest areas have been in contact with the EBO virus and demonstrate the persistence of EBO virus RNA and DNA in the organs of the animals. Our findings should lead to better targeting of research into the life cycle of the EBO virus. PMID:10580275

Morvan, J M; Deubel, V; Gounon, P; Nakouné, E; Barrière, P; Murri, S; Perpète, O; Selekon, B; Coudrier, D; Gautier-Hion, A; Colyn, M; Volehkov, V

1999-12-01

162

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

163

Skeletal indicators of ecological specialization in pika (Mammalia, Ochotonidae).  

PubMed

Pika species generally fall into two ecotypes, meadow-dwelling (burrowing) or talus-dwelling, a classification that distinguishes a suite of different ecological, behavioral, and life history traits. Despite these differences, little morphological variation has previously been documented to distinguish among ecotypes. The aim of this study was to test whether postcranial features related to burrowing are present in meadow-dwelling species and whether talus-dwelling species exhibit postcranial modifications related to frequent leaping between rocks. To test this, the scapula, humerus, ulna, radius, innominate, femur, tibia, and calcaneus of 15 species were studied and measured. Twenty-three measurements were taken on 199 skeletons, and 19 indices were constructed from these measurements. Indices were compared between the two ecotypes using Student's t-test. Comparisons among ecotypes, species, and subgenera were made using one-way ANOVA with the Tukey honest significant difference post hoc test. Multivariate results were generated using principal components analyses. Thirteen forelimb and hind limb indices proved significant in distinguishing the meadow-dwelling, talus-dwelling, and intermediate forms. A number of these indices are associated with burrowing or leaping in other mammals, providing some support for the hypothesis that postcranial modifications in pika are related to locomotor differences. This evidence of morphological responses to ecological specialization will be useful for reconstructing the paleobiology of extinct taxa, assessing the behavioral variability of extant species, and improving our understanding of the evolutionary history of pikas. PMID:23381921

Reese, Aspen T; Lanier, Hayley C; Sargis, Eric J

2013-05-01

164

Phylogenetic Relationships of Hedgehogs and Gymnures (Mammalia: Insectivora: Erinaceidae).  

National Technical Information Service (NTIS)

Contributions to Zoology, number 518, 69 pages, 12 figures, 19 plates, 8 tables, 1991.--Using 81 transformation series containing 172 characters of osteology, dentition, and external morphology, the phylogeny of recent erinaceids is investigated using sta...

D. R. Frost R. S. Hoffmann W. C. Wozencraft

1991-01-01

165

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

166

Trends of karyotypic evolution in the genus Hipposideros (Chiroptera: Mammalia).  

PubMed

The karyotypes of Hipposideros speroris, H. pomona, H. lankadiva, H. ceneraceus, H. ater and H. fulvus were analysed using conventional and banding technqiues. All six species exhibited the same 2n (32) and FN (60). The genus is remarkable for its apparent karyotypic stability. These species have only biarmed autosomes, one of which is a submetacentric marker chromosome with an achromatic gap. G-banded autosomes showed that most have remained conservative in the course of evolution of the species. Structural changes seemed to have occurred more frequently in the sex elements of the karyotypes rather than in the autosomes, and non-Robertsonian changes had an appreciable role to play in karyotypic evolution. This trend is probably dictated by the maximization of the biarmed condition which reflects the formation of stabilised linkage groups from the inception of the genus. It is proposed that the ancestral lineage of the genus Hipposideros was derived from a Rhinolophoid ancester whose karyotype was akin to Rhinolophus luctus. PMID:8375193

Sreepada, K S; Naidu, K N; Gururaj, M E

1993-01-01

167

Evolutionary morphology of the Tenrecoidea (Mammalia) hindlimb skeleton.  

PubMed

The tenrecs of Central Africa and Madagascar provide an excellent model for exploring adaptive radiation and functional aspects of mammalian hindlimb form. The pelvic girdle, femur, and crus of 13 tenrecoid species, and four species from the families Solenodontidae, Macroscelididae, and Erinaceidae, were examined and measured. Results from qualitative and quantitative analyses demonstrate remarkable diversity in several aspects of knee and hip joint skeletal form that are supportive of function-based hypotheses, and consistent with studies on nontenrecoid eutherian postcranial adaptation. Locomotor specialists within Tenrecoidea exhibit suites of characteristics that are widespread among eutherians with similar locomotor behaviors. Furthermore, several characters that are constrained at the subfamily level were identified. Such characters are more indicative of postural behavior than locomotor behavior. PMID:19107938

Salton, Justine A; Sargis, Eric J

2009-03-01

168

Evolutionary Morphology of the Tenrecoidea (Mammalia) Forelimb Skeleton  

Microsoft Academic Search

Functional morphology of the mammalian forelimb skeleton and the details of its joints have been explored and discussed in\\u000a great depth relative to other postcranial regions, despite potential difficulties with interpreting the morphology of this\\u000a region. The mammalian forelimb performs a variety of biological roles, including postural, locomotor, feeding, exploratory,\\u000a grooming, and defense related behaviors. Detailed morphology might therefore reflect

Justine A. Salton; Eric J. Sargis

169

Eocene archaeohyracids (Mammalia: Notoungulata: Hegetotheria) from the Puna, northwest Argentina  

NASA Astrophysics Data System (ADS)

A new genus and species of basal hegetothere mammal, Punahyrax bondesioi, is described from the middle-late? Eocene Geste Formation of northwestern (Catamarca and Salta provinces) Argentina. The new species is based on isolated teeth and mandibles and represents the first well-identified archaeohyracid from northwestern Argentina, and the earliest extra-Patagonian record of the family. It is characterized by its small-size and a short talonid on the molars. Though still poorly documented, this new taxon may provide key-data for the problem of the origin and basal of hegetotheres phylogeny. These fossils show the importance of northwestern Argentina (Puna area) in the early evolution of the extinct order Notoungulata and the poor state of our knowledge there.

Reguero, Marcelo A.; Croft, Darin C.; López, Guillermo M.; Alonso, Ricardo N.

2008-09-01

170

A morphological assessment of Myosorex zinki, an endemic shrew on Mount Kilimanjaro  

Microsoft Academic Search

The specific status of Myosorex zinki is analyzed based on recently collected material from Mt. Kili- manjaro. M. zinki historically has been viewed as a subspecies of M. blarina, but is distinct from M. blarina in sev- eral cranial dimensions. The recently collected series exhibits no sexual dimorphism. Contrary to what past records have indicated, M. zinki is not restricted

W. T. Stanley; M. A. Rogers; R. Hutterer

171

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

172

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...

173

The use of albendazole for the treatment of trematodiasis in two tree shrews (Tupala glis)  

USGS Publications Warehouse

Albendazole is a broad-spectrum anthelmintic of the benzimidazole group which has been tested in several rodents and domestic animals. Albendazole has been used effectively to treat trematodes in sheep, cattle, dogs, and cats. The use of this anthelmintic in exotic small mammals has not been reported to the authors' knowledge.

Beehler, B. A.; Tuggle, B. N.

1983-01-01

174

Flying lemurs - The 'flying tree shrews'? Molecular cytogenetic evidence for a Scandentia-Dermoptera sister clade  

PubMed Central

Background Flying lemurs or Colugos (order Dermoptera) represent an ancient mammalian lineage that contains only two extant species. Although molecular evidence strongly supports that the orders Dermoptera, Scandentia, Lagomorpha, Rodentia and Primates form a superordinal clade called Supraprimates (or Euarchontoglires), the phylogenetic placement of Dermoptera within Supraprimates remains ambiguous. Results To search for cytogenetic signatures that could help to clarify the evolutionary affinities within this superordinal group, we have established a genome-wide comparative map between human and the Malayan flying lemur (Galeopterus variegatus) by reciprocal chromosome painting using both human and G. variegatus chromosome-specific probes. The 22 human autosomal paints and the X chromosome paint defined 44 homologous segments in the G. variegatus genome. A putative inversion on GVA 11 was revealed by the hybridization patterns of human chromosome probes 16 and 19. Fifteen associations of human chromosome segments (HSA) were detected in the G. variegatus genome: HSA1/3, 1/10, 2/21, 3/21, 4/8, 4/18, 7/15, 7/16, 7/19, 10/16, 12/22 (twice), 14/15, 16/19 (twice). Reverse painting of G. variegatus chromosome-specific paints onto human chromosomes confirmed the above results, and defined the origin of the homologous human chromosomal segments in these associations. In total, G. variegatus paints revealed 49 homologous chromosomal segments in the HSA genome. Conclusion Comparative analysis of our map with published maps from representative species of other placental orders, including Scandentia, Primates, Lagomorpha and Rodentia, suggests a signature rearrangement (HSA2q/21 association) that links Scandentia and Dermoptera to one sister clade. Our results thus provide new evidence for the hypothesis that Scandentia and Dermoptera have a closer phylogenetic relationship to each other than either of them has to Primates.

Nie, Wenhui; Fu, Beiyuan; O'Brien, Patricia CM; Wang, Jinhuan; Su, Weiting; Tanomtong, Alongkoad; Volobouev, Vitaly; Ferguson-Smith, Malcolm A; Yang, Fengtang

2008-01-01

175

Molecular Anatomy of Tupaia (Tree Shrew) adenovirus Genome; Evolution of Viral Genes and Viral Phylogeny  

Microsoft Academic Search

Adenoviruses are globally spread and infect species in all five taxons of vertebrates. Outstanding attention is focused on adenoviruses because of their transformation potential, their possible usability as vectors in gene therapy and their applicability in studies dealing with, e.g. cell cycle control, DNA replication, transcription, splicing, virus–host interactions, apoptosis, and viral evolution. The accumulation of genetic data provides the

Udo Bahr; Eva Schöndorf; Michaela Handermann; Gholamreza Darai

2003-01-01

176

Patterns of infestation by adult Dermacentor variabilis (Acari: Ixodidae) in a mark-recapture study of raccoons (Mammalia: Carnivora) and Virginia opossums (Mammalia: Didelphimorphia) in Tennessee.  

PubMed

A mark-recapture study of raccoons (Procyon lotor L.) and Virginia opossums (Didelphis virginiana Kerr) was conducted from February 1991 through April 1994 to determine host interactions with adult Dermacentor variabilis Say. We captured 1,293 raccoons and Virginia opossums during the 3-yr study (140 individual raccoons and 160 individual Virginia opossums) with 1,895 adult D. variabilis collected. Raccoons had a significantly higher mean intensity and higher prevalence of adult ticks than Virginia opossums (Mann-Whitney Z = 6.15, chi 2 = 51.9, P < 0.001). Mean intensity follows Margolis et al. (1982) as being the mean number of parasite species per infected host. Prevalence follows Margolis et al. (1982) as being the number of individuals of the host species infected with a parasite species divided by the number of hosts examined. The time required for a higher prevalence and mean intensity of ticks to occur on raccoons than Virginia opossums was < 7 d. No significant differences occurred between the mean intensity or prevalence of D. variabilis between sexes or among age classes of raccoons. Significant differences in prevalence and mean intensity of ticks occurred between sexes and among age classes of Virginia opposums. Infestation increased by 0.64 ticks per day on Virginia opossums and 1.77/d on raccoons during the first 7 d. The base host finding rate (ticks per host per day) of adult D. variabilis on Virginia opossums was 0.064 and 0.053 on raccoons. Tick interactions with hosts are quantified and may reflect behavioral differences between sexes and among age groups intraspecifically, and host preferences of adult D. variabilis interspecifically. PMID:10337094

Kollars, T M; Ladine, T A

1999-05-01

177

Low-rate TCP-targeted denial of service attacks: the shrew vs. the mice and elephants  

Microsoft Academic Search

Denial of Service attacks are presenting an increasing threat to the global inter-networking infrastructure. While TCP's congestion control algorithm is highly robust to diverse network conditions, its implicit assumption of end-system cooperation results in a well-known vulnerability to attack by high-rate non-responsive flows. In this paper, we investigate a class of low-rate denial of service attacks which, unlike high-rate attacks,

Aleksandar Kuzmanovic; Edward W. Knightly

2003-01-01

178

The FAAH inhibitor URB-597 interferes with cisplatin- and nicotine-induced vomiting in the Suncus murinus (house musk shrew)  

Microsoft Academic Search

Considerable evidence implicates the endocannabinoid system as a neuromodulator of nausea and vomiting. The action of anandamide (AEA) can be prolonged by inhibiting its degradation, through the use of URB597 (URB), a Fatty Acid Amide Hydrolase (FAAH) enzyme inhibitor. Here we present evidence that the FAAH inhibitor, URB, interferes with cisplatin- and nicotine-induced vomiting in the Suncus murinus. In Experiment

L. A. Parker; C. L. Limebeer; E. M. Rock; D. L. Litt; M. Kwiatkowska; D. Piomelli

2009-01-01

179

The differential antiemetic properties of GLP-1 receptor antagonist, exendin (9-39) in Suncus murinus (house musk shrew).  

PubMed

The use of glucagon-like peptide-1 (7-36) amide (GLP-1) receptor agonists for the treatment of type 2 diabetes mellitus is commonly associated with nausea and vomiting. Previous studies using Suncus murinus revealed that the GLP-1 receptor agonist, exendin-4, induces emesis via the brainstem and/or hypothalamus. The present study investigated the mechanism of exendin-4-induced emesis in more detail. Ondansetron (1 mg/kg, s.c.) and CP-99,994 (10 mg/kg, s.c) failed to reduce emesis induced by exendin-4 (3 nmol, i.c.v.), suggesting that 5-HT3 and NK1 receptors are not involved in the mechanism. In other studies, the GLP-1 receptor antagonist, exendin (9-39), antagonised emesis and c-Fos expression in the brainstem and the paraventricular hypothalamus induced by the chemotherapeutic drug cisplatin (30 mg/kg, i.p.; p < 0.05), but not the emesis induced by nicotine (5 mg/kg, s.c.; p > 0.05), or copper sulphate pentahydrate (120 mg/kg, p.o.; p > 0.05). GLP-1 receptors may therefore represent a potential target for drugs to prevent chemotherapy-induced emesis in situations where 5-HT3 and NK1 receptor antagonists fail. PMID:24726308

Chan, Sze Wa; Lu, Zengbing; Lin, Ge; Yew, David Tai Wai; Yeung, Chi Kong; Rudd, John A

2014-08-01

180

Separation of emetic and anorexic responses of exendin-4, a GLP-1 receptor agonist in Suncus murinus (house musk shrew).  

PubMed

The use of glucagon-like peptide-1 (7-36) amide (GLP-1) receptor agonists for the treatment of type 2 diabetes mellitus is commonly associated with nausea and vomiting. Therefore, the present studies investigated the potential of GLP-1 receptor ligands to modulate emesis and feeding in Suncus murinus. Exendin-4, a selective GLP-1 receptor agonist, was administered subcutaneously (1-30 nmol/kg) or intracerebroventricularly (0.03-3 nmol) after 12-h of fasting. In other studies, animals were pretreated with the GLP-1 receptor antagonist, exendin (9-39), or saline (5 ?l) 15 min prior to exendin-4 (3 nmol, i.c.v.). Behaviour of animals and food and water intake were then recorded for 1-2 h; c-Fos expression was also assessed in the brains of animals in the i.c.v. studies. The subcutaneous administration of exendin-4 reduced food and water intake (p < 0.001) and induced emesis in 40% of animals (p > 0.05). The intracerebroventricular administration of exendin-4 also prevented feeding, and induced emesis (p < 0.01). In these studies, exendin (9-39) (30 nmol, i.c.v.) antagonised emesis induced by exendin-4 and the increased c-Fos expressions in the brainstem and hypothalamus (p < 0.05), but it was ineffective in reversing the exendin-4-induced inhibition of food and water intake (p > 0.05). These data suggest that exendin-4 exerts its emetic effects in the brainstem and/or hypothalamus via GLP-1 receptors. The action of exendin-4 to suppress feeding may involve non-classical GLP-1 receptors or other mechanisms. PMID:23357334

Chan, Sze Wa; Lin, Ge; Yew, David Tai Wai; Yeung, Chi Kong; Rudd, John A

2013-07-01

181

Morphology of female genital tracts in Dasypodidae (Xenarthra, Mammalia): a comparative survey  

Microsoft Academic Search

Previous works about comparative spermatology in Dasypodidae determined that sperm morphology is a striking variable among genera. It was suggested that this sperm feature may be related to specific morphologies of the female reproductive tract. The present comparative study of the morphology of the female genital tract from seven species corresponding to six genera of Dasypodidae is aimed to determine

Pablo D. Cetica; Hernán J. Aldana Marcos; María Susana Merani

2005-01-01

182

Cutaneous eccrine glands of the foot pads of the rock hyrax (Procavia capensis, Hyracoidea, Mammalia).  

PubMed

In order to find correlations between skin gland morphology and specific ethological features, the cutaneous glands of the foot pads of Procavia capensis were studied by histological and various histochemical methods and by electron microscopy. In the foot pads, abundant specific eccrine skin glands occur, which consist of coiled tubular secretory portions and coiled ducts. The wall of the secretory part is composed of cuboidal glandular cells and myoepithelial cells. Among the glandular cells two types occur: clear and dark cells. Clear cells have numerous mitochondria and form a basal labyrinth, indicating fluid transport. Dark cells, which stain strongly with periodic acid-Schiff, contain a highly developed perinuclear Golgi apparatus, large amounts of rough endoplasmic reticulum and many secretory granules indicating production of glycoproteins. Cytokeratin (CK) 19 was found in secretory compartments and ducts, CK14 only in duct cells. Single cells of the secretory coils and ducts may be stained with antibodies against antimicrobial peptides. Some glandular cells contain proliferating cell nuclear antigen-positive nuclei especially in the ducts indicating an increased cell proliferation. Terminal transferase (TdT)-mediated d-UTP nick-end labeling-positive nuclei can be detected predominantly in the secretory coils and rarely in the transitional portions between ducts and end pieces. We suppose that proliferating cells migrate from the ducts to the secretory coils. The secretory product of the eccrine cutaneous glands seems to improve the traction between the foot pads of these animals and the steep and smooth rock formations among which they live. PMID:12097843

Stumpf, P; Welsch, U

2002-01-01

183

Dental microwear patterns of extant and extinct Muridae (Rodentia, Mammalia): ecological implications.  

PubMed

Extant species of Muridae occupy a wide array of habitats and have diverse dietary habits. Consequently, their dental microwear patterns represent a potential clue to better understand the paleoecology of their extinct relatives, which are abundant in many Old World Neogene localities. In this study, dental microwear is investigated for specimens of 17 extant species of murine and deomyine rodents in order to test the reliability of this method and infer dietary preferences on the fossil species Saïdomys afarensis. This extinct form comes from a mid-Pliocene site (AL 327) located at the Hadar Formation (Ethiopia) known to have delivered many hominid specimens of Australopithecus afarensis. A significant correlation between microwear patterns and diet is detected. Thus, grass, fruit, and insect eaters display, respectively, high amounts of fine scratches, wide scratches, and large pits. Moreover, some aspects of the paleoecology of S. afarensis, including feeding habits, could be assessed in regard to its dental microwear pattern. Indeed, it probably had feeding habits similar to that of living grass eaters. These results concur with the presence of open to woodland areas covered by an herbaceous vegetal layer, including monocotyledons, in the vicinity of this mid-Pliocene locality. PMID:19127354

Rodrigues, Helder Gomes; Merceron, Gildas; Viriot, Laurent

2009-04-01

184

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.

2010-01-01

185

Comparative study of notoungulate (Placentalia, Mammalia) bony labyrinths and new phylogenetically informative inner ear characters.  

PubMed

The phylogenetic relationships of notoungulates, an extinct group of predominantly South American herbivores, remain poorly resolved with respect to both other placental mammals and among one another. Most previous phylogenetic analyses of notoungulates have not included characters of the internal cranium, not least because few such features, including the bony labyrinth, have been described for members of the group. Here we describe the inner ears of the notoungulates Altitypotherium chucalensis (Mesotheriidae), Pachyrukhos moyani (Hegetotheriidae) and Cochilius sp. (Interatheriidae) based on reconstructions of bony labyrinths obtained from computed tomography imagery. Comparisons of the bony labyrinths of these taxa with the basally diverging notoungulate Notostylops murinus (Notostylopidae), an isolated petrosal from Itaboraí, Brazil, referred to Notoungulata, and six therian outgroups, yielded an inner ear character matrix of 25 potentially phylogenetically informative characters, 14 of them novel to this study. Two equivocally optimized character states potentially support a pairing of Mesotheriidae and Hegetotheriidae, whereas four others may be diagnostic of Notoungulata. Three additional characters are potentially informative for diagnosing more inclusive clades: one for crown Placentalia; another for a clade containing Kulbeckia, Zalambdalestes, and Placentalia; and a third for Eutheria (crown Placentalia plus stem taxa). Several other characters are apomorphic for at least one notoungulate in our study and are of potential interest for broader taxonomic sampling within Notoungulata to clarify currently enigmatic interrelationships. Measures of the semicircular canals were used to infer agility (e.g. capable of quick movements vs. lethargic movements) of these taxa. Agility scores calculated from these data generally corroborate interpretations based on postcranial remains of these or closely related species. We provide estimates of the low-frequency hearing limits in notoungulates based on the ratio of radii of the apical and basal turns of the cochlea. These limits range from 15?Hz in Notostylops to 149?Hz in Pachyrukhos, values comparable to the Asian elephant (Elephas maximus) and the California sea lion (Zalophus californianus) when hearing in air, respectively. PMID:24102069

Macrini, Thomas E; Flynn, John J; Ni, Xijun; Croft, Darin A; Wyss, André R

2013-11-01

186

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. Anat Rec, 297:1532-1535, 2014. © 2014 Wiley Periodicals, Inc. PMID:24920139

Rodrigues, Fernanda Rosa; da Silva, Vera Maria Ferreira; Marques Barcellos, José Fernando

2014-08-01

187

A nearly complete skeleton of Ernanodon (Mammalia, Palaeanodonta) from Mongolia: morphofunctional analysis  

Microsoft Academic Search

Ernanodon, one of the most enigmatic Asian fossil mammals, was previously known by a single specimen from the late Paleocene (Nongshanian) of China. Here we document the first record of Ernanodon from Mongolia, represented by a nearly complete skeleton from the late Paleocene (Gashatan) of the Naran Bulak locality. The new material provides an opportunity to understand the lifestyle and

Peter Kondrashov; Alexandre K. Agadjanian

2012-01-01

188

Evolutionary and developmental dynamics of the dentition in Muroidea and Dipodoidea (Rodentia, Mammalia).  

PubMed

When it comes to mouse evo-devo, the fourth premolar-first molar (P4-M1) dental complex becomes a source of longstanding controversies among paleontologists and biologists. Muroidea possess only molar teeth but with additional mesial cusps on their M1. Developmental studies tend to demonstrate that the formation of such mesial cusps could result from the integration of a P4 germ into M1 during odontogenesis. Conversely, most Dipodoidea conserve their fourth upper premolars and those that lost these teeth can also bear additional mesial cusps on their first upper molars. The aim of this study is to assess this developmental model in both Muroidea and Dipodoidea by documenting the morphological evolution of the P4-M1 complex across 50?Ma. Fourteen extinct and extant species, including abnormal and mutant specimens were investigated. We found that, even if their dental evolutionary pathways strongly differ, Dipodoidea and Muroidea retain common developmental characteristics because some of them can present similar dental morphological trends. It also appears that the acquisition of a mesial cusp on M1 is independent from the loss of P4 in both superfamilies. Actually, the progressive decrease of the inhibitory effect of P4, consequent to its regression, could allow the M1 to lengthen and mesial cusps to grow in Muroidea. Apart from these developmental explanations, patternings of the mesial part of first molars are also deeply constrained by morpho-functional requirements. As there is no obvious evidence of such mechanisms in Dipodoidea given their more variable dental morphologies, further developmental investigations are needed. PMID:21740509

Rodrigues, Helder Gomes; Charles, Cyril; Marivaux, Laurent; Vianey-Liaud, Monique; Viriot, Laurent

2011-01-01

189

Early Eocene lagomorph (Mammalia) from Western India and the early diversification of Lagomorpha  

PubMed Central

We report the oldest known record of Lagomorpha, based on distinctive, small ankle bones (calcaneus and talus) from Early Eocene deposits (Middle Ypresian equivalent, ca 53?Myr ago) of Gujarat, west-central India. The fossils predate the oldest previously known crown lagomorphs by several million years and extend the record of lagomorphs on the Indian subcontinent by 35?Myr. The bones show a mosaic of derived cursorial adaptations found in gracile Leporidae (rabbits and hares) and primitive traits characteristic of extant Ochotonidae (pikas) and more robust leporids. Together with gracile and robust calcanei from the Middle Eocene of Shanghuang, China, also reported here, the Indian fossils suggest that diversification within crown Lagomorpha and possibly divergence of the family Leporidae were already underway in the Early Eocene.

Rose, Kenneth D; DeLeon, Valerie Burke; Missiaen, Pieter; Rana, R.S; Sahni, Ashok; Singh, Lachham; Smith, Thierry

2008-01-01

190

Karyotype comparison and phylogenetic relationships of Pipistrellus -like bats (Vespertilionidae; Chiroptera; Mammalia)  

Microsoft Academic Search

Detailed karyotype descriptions of 20 Pipistrellus-like bat species belonging to the family Vespertilionidae are presented. For the first time, chromosomal complements of four species, i.e. Pipistrellus stenopterus (2n=32), P. javanicus (2n=34), Hypsugo eisentrauti (2n=42) and H. crassulus (2n=30) are reported. A Pipistrellus kuhlii-like species from Madagascar represents a separate species distinguished from the European Pipistrellus kuhlii (2n=44) by a diploid

M. Volleth; G. Bronner; M. C. Göpfert; K.-G. Heller; O. von Helversen; H.-S. Yong

2001-01-01

191

Characterisation of glycoconjugate sugar residues in the vomeronasal organ of the armadillo Chaetophractus villosus (Mammalia, xenarthra)  

PubMed Central

Conventional carbohydrate histochemistry and the binding patterns of 21 lectins were analysed to characterise the glycoconjugate content in the components of the vomeronasal organ of the armadillo Chaetophractus villosus. The mucomicrovillous complex of the sensory epithelium bound most of the lectins studied. No reaction was observed with Con A, PSA, S-Con A and SBA, and the sustentacular cells were stained with UEA-I, DSL, LEL, STL and Con A. The vomeronasal receptor neurons were labelled with S-WGA, WGA, PNA, UEA-I, STL, Con A, S-Con A, ECL and RCA120. The basal cell layer reacted with S-WGA, WGA, LCA, UEA-I, DSL, LEL, STL, Con A, JAC and VVA. The nonsensory epithelium exhibited a differential staining in relation to the different components. The mucociliary complex stained with ECL, DBA, JAC, RCA120, STL, LCA, PHA-E, PHA-L, LEL, BSL-I and VVA. However, SJA and UEA-I stained the mucus complex lining a subpopulation of columnar cells. The cytoplasm and cell membranes of columnar cells was labelled with DBA, DSL and LCA. The apical region of these cells exhibited moderate reactivity with LEL and SJA. None of the lectins bound specifically to secretory granules of the nonsecretory cells. Basal cells of the nonsensory epithelium were labelled with DSL, LEL, LCA, BSL-I and STL. The vomeronasal glands showed a positive reaction with WGA, DSL, LEL, LCA, DBA, PNA, RCA120 and SBA. Subpopulations of acinar cells were observed with ECL, S-WGA, Con A, S-Con A and DBA. PNA and RCA120 stained the cells lining the glandular ducts. In comparison with previous results obtained in the olfactory mucosa of the same group of armadillos, the carbohydrate composition of the vomeronasal organ sensory epithelium differed from the olfactory sensory epithelium. This is probably related to the different nature of molecules involved in the perireceptor processes.

CARMANCHAHI, P. D.; FERRARI, C. C.; ALDANA MARCOS, H. J.; AFFANNI, J. M.; SONEZ, C. A.; PAZ, D. A.

2000-01-01

192

New species of Agriotherium (Mammalia, Carnivora) from the late Miocene to early Pliocene of central Myanmar  

NASA Astrophysics Data System (ADS)

Here we describe a new species of giant short-faced fossil bears, Agriotheriummyanmarensis sp. nov. (Ursidae, Carnivora), from the latest Miocene to early Pliocene Irrawaddy sediments in the Chaingzauk area, central Myanmar. A. myanmarensis has a short mandible and a deep premasseteric fossa, both of which are the typical feature of Agriotherium. There are two specimens discovered so far: in the type specimen the inferior border of the mandibular corpus is rectilinearly-shaped, the m1 talonid is rather reduced, m1 metaconid larger than the entoconid-entoconulid ridge, the diastema between canine and p4 is very short, and the postcanine teeth are so reduced that existing cheek teeth are very crowded. Agriotherium had been widely distributed from the late Miocene through Pleistocene in Europe, East Asia (China), North America, and South Africa, but no fossil record has been reported from Southeast Asia. Except its extreme short snout, A. myanmarensis is most similar to that of the European form, Agriotheriuminsigne, rather than to the Asian species from Siwalik or China, such as Agriotheriumpalaeindicus, Agriotheriumsivalensis, and Agriotheriuminexpetans, suggesting the phylogenetic closeness to the European rather than to the South/East Asian forms.

Ogino, Shintaro; Egi, Naoko; Zin-Maung-Maung-Thein; Thaung-Htike; Takai, Masanaru

2011-08-01

193

Sexual dimorphism of the internal mandibular chamber in Fayum Pliohyracidae (Mammalia)  

USGS Publications Warehouse

An internal mandibular fenestra and chamber are found in many fossil hyracoids. The internal mandibular fenestra is located on the lingual surface of the mandibular corpus and opens into a chamber within the mandible. The mandibular chamber is maximally developed in late Eocene Thyrohyrax meyeri and early Oligocene Thyrohyrax domorictus from the Fayum Province of Egypt. The function of this chamber is unknown as it is not found in extant hyraxes, nor is it known to occur in any other mammal. In Thyrohyrax, this feature appears to be sexually dimorphic because it is confined to roughly one half of the specimens that otherwise cannot be separated by dental characteristics or measurements. It has been suggested that the chamber is found in females based on the presumed distribution of this character in other fossil hyracoids. Fossils from Fayum Quarry L-41, preserving the sexually dimorphic anterior dentition, show that, in Thyrohyrax meyeri and Thyrohyrax domorictus, the internal mandibular chamber is found in males. In Thyrohyrax litholagus, an internal mandibular fenestra and inflated mandibular chamber occurs in males whereas females show the variable presence of an internal mandibular fossa or fenestra but lack an expanded chamber. Other genera show differing patterns of sexual variation in which some Fayum hyracoids have an internal mandibular fenestra in both sexes but with the greatest development of the mandibular chamber occurring in males. We review functions proposed for the internal mandibular chamber and suggest that it housed a laryngeal air sac that may have had a vocal function by acting as a resonating chamber. ?? 2006 by the Society of Vertebrate Paleontology.

de, Blieux, D. D.; Baumrind, M. R.; Simons, E. L.; Chatrath, P. S.; Meyer, G. E.; Attia, Y. S.

2006-01-01

194

The taxonomic status of the Yucatan brown brocket, Mazama pandora (Mammalia: Cervidae)  

USGS Publications Warehouse

The Yucatan brown brocket deer, described as Mazama pandora, is now treated as a subspecies of either the common brown brocket, Mazama gouazoubira, or of the red brocket, M. americana. Analysis of brocket deer from Mexico and Central and South America, reveals that the Yucatan brown brocket is sympatric with the red brocket in Mexico and, while similar to M. gouazoubira, warrents recognition as a separate species.

Medellin, R.A.; Gardner, A.L.; Aranda, J.M.

1998-01-01

195

Cranial and dental anatomy of Antilohyrax pectidens: a Late Eocene hyracoid (Mammalia) from the Fayum, Egypt  

Microsoft Academic Search

The hyracoid Antilohyrax pectidens Rasmussen and Simons, 2000 from quarry L-41 in the Fayum, Egypt displays many interesting features, including a comb-like, pectinate lower first incisor similar to that of the dermopteran Cynocephalus. Antilohyrax was originally described as lacking upper incisors, and having retracted nasal bones and selenodont cheek teeth, functionally resembling characters found in bovid artiodactyls. Analysis of cranial

Donald D. De Blieux; Elwyn L. Simons

2002-01-01

196

Enamel microstructure of Tribosphenomys (Mammalia, glires): Character analysis and systematic implications  

Microsoft Academic Search

Enamel distribution on the upper and lower incisors ofTribosphenomys minutus (from Late Paleocene-Early Eocene of Inner Mongolia of China) is typically rodent-like, i.e., primarily confined to the anterior surface throughout these transversely compressed, evergrowing teeth. AlthoughTribosphenomys incisor enamel is differentiated into two layers, it does not possess Hunter-Schreger bands (HSB). The incisor and molar enamels are radial in type, a

Jin Meng; André R. Wyss

1994-01-01

197

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.

Horacek, Ivan; Knitlova, Marketa; Wagner, Jan; Kordos, Laszlo; Nadachowski, Adam

2013-01-01

198

Phylogeography, population history and conservation genetics of jaguars (Panthera onca, Mammalia, Felidae).  

PubMed

The jaguar (Panthera onca), the largest felid in the American Continent, is currently threatened by habitat loss, fragmentation and human persecution. We have investigated the genetic diversity, population structure and demographic history of jaguars across their geographical range by analysing 715 base pairs of the mitochondrial DNA (mtDNA) control region and 29 microsatellite loci in approximately 40 individuals sampled from Mexico to southern Brazil. Jaguars display low to moderate levels of mtDNA diversity and medium to high levels of microsatellite size variation, and show evidence of a recent demographic expansion. We estimate that extant jaguar mtDNA lineages arose 280 000-510 000 years ago (95% CI 137 000-830 000 years ago), a younger date than suggested by available fossil data. No strong geographical structure was observed, in contrast to previously proposed subspecific partitions. However, major geographical barriers such as the Amazon river and the Darien straits between northern South America and Central America appear to have restricted historical gene flow in this species, producing measurable genetic differentiation. Jaguars could be divided into four incompletely isolated phylogeographic groups, and further sampling may reveal a finer pattern of subdivision or isolation by distance on a regional level. Operational conservation units for this species can be defined on a biome or ecosystem scale, but should take into account the historical barriers to dispersal identified here. Conservation strategies for jaguars should aim to maintain high levels of gene flow over broad geographical areas, possibly through active management of disconnected populations on a regional scale. PMID:11251788

Eizirik, E; Kim, J H; Menotti-Raymond, M; Crawshaw, P G; O'Brien, S J; Johnson, W E

2001-01-01

199

Phylogeography, population history and conservation genetics of jaguars (Panthera onca, Mammalia, Felidae)  

Microsoft Academic Search

The jaguar ( Panthera onca ), the largest felid in the American Continent, is currently threatened by habitat loss, fragmentation and human persecution. We have investigated the genetic diversity, population structure and demographic history of jaguars across their geographical range by analysing 715 base pairs of the mitochondrial DNA (mtDNA) control region and 29 microsatellite loci in ? ? ?

Eduardo Eizirik; Jae-Heup Kim; Marilyn Menotti-Raymond; Peter G. Crawshaw JR.; Stephen J. O'Brien; Warren E. Johnson

2001-01-01

200

The highly specialized vocal tract of the male Mongolian gazelle (Procapra gutturosa Pallas, 1777 - Mammalia, Bovidae)  

PubMed Central

The entire head and neck of a wild adult male Mongolian gazelle (Procapra gutturosa) was dissected with special reference to its enlarged larynx. Two additional adult male specimens taken from the wild were analysed by computer tomography. The sternomandibularis, omohyoideus, thyrohyoideus and hyoepiglotticus muscles are particularly enlarged and improve laryngeal suspension and stabilization. The epiglottis is exceptionally large. A permanent laryngeal descent is associated with the evolution of an unpaired palatinal pharyngeal pouch. A certain momentary descent seems to occur during vocalization. The high lateral walls of the thyroid cartilage are ventrally connected by a broad keel. The large thyroarytenoid muscle is divided into two portions: a rostral ventricularis and a caudal vocalis muscle. A paired lateral laryngeal ventricle projects between these two muscles. The massive vocal fold is large and lacks any rostrally directed flexible structures. It is supported by a large cymbal-like fibroelastic pad. Vocal tract length was measured in the course of dissection and in computer tomographic images. Two representative spectrograms, one of an adult male and one of a juvenile, recorded in the natural habitat of the Mongolian gazelle are presented. In the spectrograms, the centre frequency of the lowest band is about 500 Hz in the adult male and about 790 Hz in the juvenile. The low pitch of the adult male's call is ascribed to the evolutionary mass increase and elongation of the vocal folds. In the habitat of P. gutturosa a call with a low pitch and, thus, with an almost homogeneous directivity around the head of the vocalizing animal may be optimally suited for multidirectional advertisement calls during the rut. The signal range of an adult male's call in its natural habitat can therefore be expected to be larger than the high-pitched call of a juvenile.

Frey, R; Gebler, A

2003-01-01

201

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.

Higdon, Jeff W; Bininda-Emonds, Olaf RP; Beck, Robin MD; Ferguson, Steven H

2007-01-01

202

Dental microwear patterns of extant and extinct Muridae (Rodentia, Mammalia): ecological implications  

NASA Astrophysics Data System (ADS)

Extant species of Muridae occupy a wide array of habitats and have diverse dietary habits. Consequently, their dental microwear patterns represent a potential clue to better understand the paleoecology of their extinct relatives, which are abundant in many Old World Neogene localities. In this study, dental microwear is investigated for specimens of 17 extant species of murine and deomyine rodents in order to test the reliability of this method and infer dietary preferences on the fossil species Saïdomys afarensis. This extinct form comes from a mid-Pliocene site (AL 327) located at the Hadar Formation (Ethiopia) known to have delivered many hominid specimens of Australopithecus afarensis. A significant correlation between microwear patterns and diet is detected. Thus, grass, fruit, and insect eaters display, respectively, high amounts of fine scratches, wide scratches, and large pits. Moreover, some aspects of the paleoecology of S. afarensis, including feeding habits, could be assessed in regard to its dental microwear pattern. Indeed, it probably had feeding habits similar to that of living grass eaters. These results concur with the presence of open to woodland areas covered by an herbaceous vegetal layer, including monocotyledons, in the vicinity of this mid-Pliocene locality.

Gomes Rodrigues, Helder; Merceron, Gildas; Viriot, Laurent

2009-04-01

203

Biology and impacts of Pacific island invasive species 9. Capra hircus, the feral goat, (Mammalia: Bovidae)  

USGS Publications Warehouse

Domestic goats, Capra hircus, were intentionally introduced to numerous oceanic islands beginning in the sixteenth century. The remarkable ability of C. hircus to survive in a variety of conditions has enabled this animal to become feral and impact native ecosystems on islands throughout the world. Direct ecological impacts include consumption and trampling of native plants, leading to plant community modification and transformation of ecosystem structure. While the negative impacts of feral goats are well-known and effective management strategies have been developed to control this invasive species, large populations persist on many islands. This review summarizes the impacts of feral goats on Pacific island ecosystems, and the management strategies available to control this invasive species.

Chynoweth, Mark W.; Litton, Creighton M.; Lepczyk, Christopher A.; Hess, Steve A.; Cordell, Susan

2013-01-01

204

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.

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

205

Evolutionary history of the African soricid Myosorex (Insectivora, Mammalia) out of Africa  

Microsoft Academic Search

The species Myosorex meini Jammot, 1977 was a nomen nudum because it was named in an unpublished dissertation. The species is here revised using the new material found in the Late Pliocene fissure infillings of Almenara-Casablanca 1 and 4 (province of Castelló, East of Spain) and from the Tollo de Chiclana localities 1B, 3, 10, and 10B in the Guadix

Marc Furió; Andrés Santos-Cubedo; Jordi Agustí; Raef Minwer-Barakat

2007-01-01

206

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

207

Notes on the typology of the skull of the Myrmecophagidae (Mammalia, Edentata).  

PubMed

The skulls of Myrmecophaga, Tamandua, and Cyclopes are klinorhynch; the upper jaw is situated rostral to the neurocranium and to a varying degree ventral to the plane of the median basis cranii. The median part of the base of the neurocranium is the structure to which the anatomical modifications in the median plane are referred. The kyphosis, which determines the situation of the upper jaw, is prebasically located either within the upper jaw (Myrmecophaga, Tamandua) or at its basis (Cyclopes). PMID:3197936

Hofer, H O

1988-01-01

208

The Phylogeny of the Myrmecophagidae (Mammalia, Xenarthra, Vermilingua) and the Relationship of Eurotamandua to the Vermilingua  

Microsoft Academic Search

A cladistic investigation of the phylogenetic relationships among the three extant anteater genera and the three undoubted extinct myrmecophagid genera is performed based upon osteological characteristics of the skull and postcranial skeleton. One hundred seven discrete morphological characters are analyzed using the computer program PAUP. Characters are polarized via comparison to the successive xenarthran outgroups Tardigrada (represented by the living

Timothy J. Gaudin; Daniel G. Branham

1998-01-01

209

Placentation and fetal membrane development in the South American coati, Nasua nasua (Mammalia, Carnivora, Procyonidae)  

PubMed Central

Background Placental research in carnivores has concentrated on domestic species, which have zonary, labyrinthine placentas with an endotheliochorial barrier. Although the coati, Nasua nasua, is a widely distributed species in South America, data on the development of the placenta and the fetal membranes in this species are very sparse. Findings Four placentas from mid-gestation to near term were collected from wild individuals and were investigated based on gross morphology, histology, immunohistochemistry and electron microscopy. The available data support the concept that the ancestral condition of placentation in carnivores is phylogenetically characterized by a zonary and labyrinthine placental type with an endotheliochorial fetomaternal barrier, comprising extended epitheliochorial and haemochorial zones, such as hemophagous organs for iron supply and histiotrophe uptake and a yolk sac placenta. Conclusions Because of the foundational mechanisms that lead to the considerable complexity of fetomaternal contact zones in carnivores have not been studied, carnivores are interesting animal models for interhaemal barrier differentiation.

2014-01-01

210

Thermal energetics and torpor in the common pipistrelle bat, Pipistrellus pipistrellus (Vespertilionidae: Mammalia)  

Microsoft Academic Search

Rate of metabolism and body temperature were studied between ?6°C and 38°C in the common pipistrelle bat Pipistrellus pipistrellus (Vespertilionidae), a European species lying close to the lower end of the mammalian size range (body mass 4.9±0.8g, N=28). Individuals maintained only occasionally a normothermic body temperature averaging 35.4±1.1°C (N=4) and often showed torpor during metabolic runs. The thermoneutral zone was

Michel Genoud; Philippe Christe

2011-01-01

211

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...

212

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.

Jacobs, David S.; Babiker, Hassan; Bastian, Anna; Kearney, Teresa; van Eeden, Rowen; Bishop, Jacqueline M.

2013-01-01

213

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

214

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

215

First detailed reconstruction of the karyotype of Trachypithecus cristatus (Mammalia: Cercopithecidae)  

PubMed Central

Background The chromosomal homologies of human (Homo sapiens = HSA) and silvered leaf monkey (Trachypithecus cristatus = TCR) have been previously studied by classical chromosome staining and by fluorescence in situ hybridization (FISH) applying chromosome-specific DNA probes of all human chromosomes in the 1980s and 1990s, respectively. Results However, as the resolution of these techniques is limited we used multicolor banding (MCB) at an ~250-band level, and other selected human DNA probes to establish a detailed chromosomal map of TCR. Therefore it was possible to precisely determine evolutionary conserved breakpoints, orientation of segments and distribution of specific regions in TCR compared to HSA. Overall, 69 evolutionary conserved breakpoints including chromosomal segments, which failed to be resolved in previous reports, were exactly identified and characterized. Conclusions This work also represents the first molecular cytogenetic one characterizing a multiple sex chromosome system with a male karyotype 44,XY1Y2. The obtained results are compared to other available data for old world monkeys and drawbacks in hominoid evolution are discussed.

2013-01-01

216

Evolution and taxonomy of the wild species of the genus Ovis (Mammalia, Artiodactyla, Bovidae).  

PubMed

New insights for the systematic and evolution of the wild sheep are provided by molecular phylogenies inferred from Maximum parsimony, Bayesian, Maximum likelihood, and Neighbor-Joining methods. The phylogeny of the wild sheep was based on cytochrome b sequences of 290 samples representative of most of the sub-species described in the genus Ovis. The result was confirmed by a combined tree based on cytochrome b and nuclear sequences for 79 Ovis samples representative of the robust clades established with mitochondrial data. Urial and mouflon, which are either considered as a single or two separate species, form two monophyletic groups (O. orientalis and O. vignei). Their hybrids appear in one or the other group, independently from their geographic origin. The European mouflon O. musimon is clearly in the O. orientalis clade. The others species, O. dalli, O. canadensis, O. nivicola, and O. ammon are monophyletic. The results support an Asiatic origin of the genus Ovis, followed by a migration to North America through North-Eastern Asia and the Bering Strait and a diversification of the genus in Eurasia less than 3 million years ago. Our results show that the evolution of the genus Ovis is a striking example of successive speciation events occurring along the migration routes propagating from the ancestral area. PMID:19897045

Rezaei, Hamid Reza; Naderi, Saeid; Chintauan-Marquier, Ioana Cristina; Taberlet, Pierre; Virk, Amjad Tahir; Naghash, Hamid Reza; Rioux, Delphine; Kaboli, Mohammad; Pompanon, François

2010-02-01

217

Molecular systematics and phylogeography of the tribe Myonycterini (Mammalia, Pteropodidae) inferred from mitochondrial and nuclear markers.  

PubMed

The tribe Myonycterini comprises five fruit bat species of the family Pteropodidae, which are endemic to tropical Africa. Previous studies have produced conflicting results about their interspecific relationships. Here, we performed a comparative phylogeographic analysis based on 148 complete cytochrome b gene sequences from the three species distributed in West Africa and Central Africa (Myonycteris torquata, Lissonycteris angolensis and Megaloglossus woermanni). In addition, we investigated phylogenetic relationships within the tribe Myonycterini, using a matrix including 29 terminal taxa and 7235 nucleotide characters, corresponding to an alignment of two mitochondrial genes and seven nuclear introns. Our phylogenetic analyses confirmed that the genus Megaloglossus belongs to the tribe Myonycterini. Further, the genus Rousettus is paraphyletic, with R. lanosus, sometimes placed in the genus Stenonycteris, being the sister-group of the tribes Myonycterini and Epomophorini. Our phylogeographic results showed that populations of Myonycteris torquata and Megaloglossus woermanni from the Upper Guinea Forest are highly divergent from those of the Congo Basin Forest. Based on our molecular data, we recommended several taxonomic changes. First, Stenonycteris should be recognized as a separate genus from Rousettus and composed of S. lanosus. This genus should be elevated to a new tribe, Stenonycterini, within the subfamily Epomophorinae. This result shows that the evolution of lingual echolocation was more complicated than previously accepted. Second, the genus Lissonycteris is synonymised with Myonycteris. Third, the populations from West Africa formerly included in Myonycteris torquata and Megaloglossus woermanni are now placed in two distinct species, respectively, Myonycteris leptodon and Megaloglossus azagnyi sp. nov. Our molecular dating estimates show that the three phases of taxonomic diversification detected within the tribe Myonycterini can be related to three distinct decreases in tree cover vegetation, at 6.5-6, 2.7-2.5, and 1.8-1.6Ma. Our results suggest that the high nucleotide distance between Ebolavirus Côte d'Ivoire and Ebolavirus Zaire can be correlated with the Plio/Pleistocene divergence between their putative reservoir host species, i.e., Myonycteris leptodon and Myonycteris torquata, respectively. PMID:23063885

Nesi, Nicolas; Kadjo, Blaise; Pourrut, Xavier; Leroy, Eric; Pongombo Shongo, Célestin; Cruaud, Corinne; Hassanin, Alexandre

2013-01-01

218

Blood parasites of mound-building mouse, Mus spicilegus Petényi, 1882 (Mammalia, Rodentia).  

PubMed

Mound-building mice, Mus spicilegus, were studied for the blood parasites in Eastern Slovakia, vicinity Kechnec village near Kosice town (Kosická kotlina basin, 21 degrees 14' E, 48 degrees 33' N) during years 2002-2005. Overall, 251 specimens were examined. The parasites were detected using microhematokrit centrifugation technique and on the Giemsa's method stained blood smears and light microscopy. The parasites were found in 3.57% of specimens; 1.20% of mice were infected with Bartonella sp., 2.39% were infected with Babesia piroplasms. No Hepatozoon hemogregarines and trypanosomes were observed. The intensity of infection with Bartonella was low, less than 0.01% of erythrocytes were invaded, the percent of the erythrocytes with Babesia sp. was less than 0.01%. The morphological description and measurements of parasites were made using the "Analysis" software combined with a video camera and a microscope. The mean size of Bartonella sp. bacteria's were 0.8 x 0.3 microm, range 0.4-1.5 x 0.1-0.9 microm, Babesia sp. occurred in pear-shaped and ring-like forms, 1.00-1.27 microm in diameter, and 0.98-1.27 microm in size, respectively. The regular form of four cells--"maltese cross" was not noticed. This is the first record infection of Mus spicilegus with blood parasites. PMID:20450010

Karbowiak, Grzegorz; Fricová, Jana; Stanko, Michal; Hapunik, Joanna; Várfalvyová, Denisa

2010-01-01

219

The evolution of fossoriality and the adaptive role of horns in the Mylagaulidae (Mammalia: Rodentia)  

PubMed Central

Ceratogaulus, a member of the extinct fossorial rodent clade Mylagaulidae, is the only known rodent with horns and the smallest known horned mammal. The function of the large, dorsally projecting nasal horns on this burrowing animal has been the subject of wide speculation among palaeontologists; suggested uses range from sexual combat to burrowing. Mammals have evolved adaptations for digging repeatedly; horns and other cranial appendages have also evolved numerous times. These two adaptations co-occur in mammals extremely rarely: only two fossil genera (Ceratogaulus and the xenarthran Peltephilus) and no extant mammals are both horned and fossorial. Tracing the evolution of fossoriality in aplodontoid rodents (the larger clade to which Ceratogaulus belongs) reveals that Ceratogaulus descended from ancestors who dug by head-lifting. Whereas this suggests an obvious explanation for the horns of this rodent, evidence from functional morphology, anatomy, phylogeny and geologic context indicates that the horns in Ceratogaulus were used for defence, rather than digging, and evolved to offset increased predation costs associated with spending more time foraging above ground as body size increased.

Hopkins, Samantha S.B

2005-01-01

220

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

221

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

222

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

223

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

224

A Total Evidence Phylogeny of the Arctoidea (Carnivora: Mammalia): Relationships Among Basal Taxa  

Microsoft Academic Search

A total evidence phylogenetic analysis was performed for 14 extant and 18 fossil caniform genera using a data matrix of 5.6 kbp\\u000a of concatenated sequence data from six independent loci and 80 morphological characters from the cranium and dentition. Maximum\\u000a parsimony analysis recovered a single most parsimonious cladogram (MPC). The topology of the extant taxa in the MPC agreed\\u000a with previous

John A. Finarelli

2008-01-01

225

Swimming Mode Inferred from Skeletal Proportions in the Fossil Pinnipeds Enaliarctos and Allodesmus (Mammalia, Carnivora)  

Microsoft Academic Search

Swimming modes are crucial for understanding evolutionary transitions from land to sea, because locomotion affects many aspects\\u000a of an animal’s life. The modern pinniped families Otariidae (fur seals and sea lions), Phocidae (true seals), and Odobenidae\\u000a (walruses) are thought to share a common origin, but each differs in its primary mode of aquatic locomotion. Previous studies\\u000a of locomotor evolution in

Ryan M. Bebej

2009-01-01

226

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

227

Digital Cranial Endocast of Hyopsodus (Mammalia, “Condylarthra”): A Case of Paleogene Terrestrial Echolocation?  

Microsoft Academic Search

We here describe the endocranial cast of the Eocene archaic ungulate Hyopsodus lepidus AMNH 143783 (Bridgerian, North America) reconstructed from X-ray computed microtomography data. This represents the first complete cranial endocast known for Hyopsodontinae. The Hyopsodus endocast is compared to other known “condylarthran” endocasts, i. e. those of Pleuraspidotherium (Pleuraspidotheriidae), Arctocyon (Arctocyonidae), Meniscotherium (Meniscotheriidae), Phenacodus (Phenacodontidae), as well as to

Maeva J. Orliac; Christine Argot; Emmanuel Gilissen

2012-01-01

228

Bone Inner Structure Suggests Increasing Aquatic Adaptations in Desmostylia (Mammalia, Afrotheria)  

PubMed Central

Background The paleoecology of desmostylians has been discussed controversially with a general consensus that desmostylians were aquatic or semi-aquatic to some extent. Bone microanatomy can be used as a powerful tool to infer habitat preference of extinct animals. However, bone microanatomical studies of desmostylians are extremely scarce. Methodology/Principal Findings We analyzed the histology and microanatomy of several desmostylians using thin-sections and CT scans of ribs, humeri, femora and vertebrae. Comparisons with extant mammals allowed us to better understand the mode of life and evolutionary history of these taxa. Desmostylian ribs and long bones generally lack a medullary cavity. This trait has been interpreted as an aquatic adaptation among amniotes. Behemotops and Paleoparadoxia show osteosclerosis (i.e. increase in bone compactness), and Ashoroa pachyosteosclerosis (i.e. combined increase in bone volume and compactness). Conversely, Desmostylus differs from these desmostylians in displaying an osteoporotic-like pattern. Conclusions/Significance In living taxa, bone mass increase provides hydrostatic buoyancy and body trim control suitable for poorly efficient swimmers, while wholly spongy bones are associated with hydrodynamic buoyancy control in active swimmers. Our study suggests that all desmostylians had achieved an essentially, if not exclusively, aquatic lifestyle. Behemotops, Paleoparadoxia and Ashoroa are interpreted as shallow water swimmers, either hovering slowly at a preferred depth, or walking on the bottom, and Desmostylus as a more active swimmer with a peculiar habitat and feeding strategy within Desmostylia. Therefore, desmostylians are, with cetaceans, the second mammal group showing a shift from bone mass increase to a spongy inner organization of bones in their evolutionary history.

Hayashi, Shoji; Houssaye, Alexandra; Nakajima, Yasuhisa; Chiba, Kentaro; Ando, Tatsuro; Sawamura, Hiroshi; Inuzuka, Norihisa; Kaneko, Naotomo; Osaki, Tomohiro

2013-01-01

229

Red pandas (Mammalia, Carnivora: Parailurus) in the biomes of North Eurasia and North America  

NASA Astrophysics Data System (ADS)

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 with bamboo bushes were wide-spread in the Holarctic during the Neogene. During the Late Pliocene, due to a gradual cooling of the climate, altiplanation, and other factors, their habitat started disintegrating, and red pandas began dying out, surviving only in China.

Matishov, G. G.; Kalmykov, N. P.

2011-05-01

230

Building large trees by combining phylogenetic information: a complete phylogeny of the extant Carnivora (Mammalia).  

PubMed

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 deriving a complete phylogeny for all 271 extant species of the Carnivora from 177 literature sources. Beyond providing a 'consensus' estimate of carnivore phylogeny, the tree also indicates taxa for which the relationships remain controversial (e.g. the red panda; within canids, felids, and hyaenids) or have not been studied in any great detail (e.g. herpestids, viverrids, and intrageneric relationships in the procyonids). Times of divergence throughout the tree were also estimated from 74 literature sources based on both fossil and molecular data. We use the phylogeny to show that some lineages within the Mustelinae and Canidae contain significantly more species than expected for their age, illustrating the tree's utility for studies of macroevolution. It will also provide a useful foundation for comparative and conservational studies involving the carnivores. PMID:10396181

Bininda-Emonds, O R; Gittleman, J L; Purvis, A

1999-05-01

231

Phylogeny of the Carnivora (Mammalia): congruence vs incompatibility among multiple data sets.  

PubMed

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 and morphological character data. Conditional data combination analyses of the four independent data sets (transthyretin intron I, cytochrome b, partial 12S rRNA, and morphology) indicate that the phylogenetic results derived from each generally agree, with two exceptions. The first exception, signal heterogeneity in comparisons involving transthyretin and morphology, provides an example where phylogenetic conclusions drawn from total evidence analyses may differ from conclusions drawn from CDC analyses. The second exception demonstrates that while a CDC method may reject the null hypothesis of homogeneity for a particular partition, including that partition in combined analyses, may nevertheless provide an overall increase in phylogenetic signal, in terms of nodal support for most associations, without altering the topology derived from the combined homogeneous data partitions. Phylogenetic reconstruction among the feliform families supports a sister-group relationship between the hyaenas (Hyaenidae) and mongooses (Herpestidae) and places the African palm civet (Nandinia) as basal to all other living Feliformia. Among the caniform families, CDC analyses strongly support the previously enigmatic red panda (Ailurus) as a monotypic lineage that is sister to Musteloidea sensu stricto (mustelids plus procyonids), in addition to pinniped monophyly and a sister-group relationship between the walrus and sea lions. PMID:9667990

Flynn, J J; Nedbal, M A

1998-06-01

232

New Mesotheriidae (Mammalia, Notoungulata, Typotheria), geochronology and tectonics of the Caragua area, northernmost Chile  

NASA Astrophysics Data System (ADS)

Few mammal fossils were known from the Altiplano or adjoining parts of northern Chile until recently. We report a partial mesotheriid palate from the vicinity of Caragua (Huaylas Formation) in northernmost Chile. The new material helps resolve contradictory taxonomic assignments (and age implications) of the two mesotheriid specimens previously reported from the area. Herein we refer all three mesotheriid specimens to a new taxon, Caraguatypotherium munozi, which is closely related to Plesiotypotherium, Typotheriopsis, Pseudotypotherium, and Mesotherium. This phylogenetic placement permits a revised biochronologic estimate of a post-Friasian/pre-Huayquerian (˜15-9 Ma) age for the Huaylas Formation, consistent with new radioisotopic dates from the upper Huaylas Formation and its bracketing stratigraphic units. Improved geochronologic control for the Huaylas Formation has important implications for the timing of tectonic events in the Precordillera/Altiplano of northern Chile. Structural, stratigraphic, and temporal data suggest the onset of rapid, progressive deformation shortly after the deposition of the older Zapahuira Formation, continuing at least partly through deposition of the Huaylas Formation. Deposition of the Huaylas Formation was short lived (between ˜10-12 Ma), possibly stemming from activity on the Copaquilla-Tignámar Fault in the eastern Precordillera. This deformation is associated with the development of the Oxaya Anticline and activity of the Ausipar Fault west of the study region on the frontal limb of the anticline in the westernmost Precordillera. Faulting and folding occurred rapidly, beginning at ˜11.4 Ma (shortly after deposition of the youngest extrusives of the Zapahuira Formation) and before ˜10.7 Ma (the age of the gently dipping horizons within the upper Huaylas Formation that overlie the mammal fossils and an intraformational unconformity). Mesotheriids are the only Tertiary fossil mammals known from the Precordillera of northernmost Chile thus far; the group is common and diverse in faunas from the Altiplano of Bolivia (and a fauna recently recovered from the Chilean Altiplano), in contrast to most higher-latitude and tropical assemblages. This distinctiveness indicates that intermediate latitudes may have been biogeographically distinct and served as a center of diversification for mesotheriids and other groups of indigenous South American mammals.

Flynn, John J.; Croft, Darin A.; Charrier, Reynaldo; Wyss, André R.; Hérail, Gérard; García, Marcelo

2005-05-01

233

NEW LATE MIOCENE ELEPHANTOID (MAMMALIA: PROBOSCIDEA) FOSSILS FROM LEMUDONG'O, KENYA  

Microsoft Academic Search

The late Miocene marked a time of significant geographic dispersal and radiation for many mammalian taxa within Africa, including the proboscidean lineages. The ,6.1 Ma site of Lemudong'o, Kenya, yielded two elephantoid specimens. The first is a mandibular fragment with the third molar. This specimen represents a primitive member of the Anancus kenyensis lineage, with similarities to a specimen from

HARUO SAEGUSA; LESLEA J. HLUSKO

234

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

235

First Castorid (Mammalia, Rodentia) from the Middle Miocene of Southeast Asia  

NASA Astrophysics Data System (ADS)

Today and in the Tertiary, the geographical distribution of castorids is limited throughout all of the northern continents. Fossils of the Castoridae genus Steneofiber are abundant in many localities of Eurasia from the late Oligocene to Pliocene period. Recently, Steneofiber fossils were discovered in two localities of northern Thailand, Mae Moh and Chiang Muan coal mines, in layers of late middle Miocene age. These discoveries represent the first records of castorids from Southeast Asia and correspond to their southernmost known range. The focus of this study is to describe this new Thai species of Steneofiber and to define its wear stages from the molar occlusal surfaces by using micro-CT scan analysis. The CT scan technique permits the analysis of the virtual occlusal surface changes from wear, allowing easier comparison to related species of Steneofiber cheek teeth without destroying the teeth. The new species, Steneofiber siamensis n. sp., can be distinguished from the other species of Steneofiber by several distinct characters, longer mesostriid on p4, presence of premesostria and metastria on P4, which are smaller than most of the other known species. The occurrence of this new castorid also supports a subtropical to tropical paleoclimate for these two localities of northern Thailand.

Suraprasit, Kantapon; Chaimanee, Yaowalak; Martin, Thomas; Jaeger, Jean-Jacques

2011-04-01

236

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.

Faulkes, Chris G.

2014-01-01

237

Prey selection, food habits and dietary overlap between leopard Panthera pardus (Mammalia: Carnivora) and re-introduced tiger Panthera tigris (Mammalia: Carnivora) in a semi-arid forest of Sariska Tiger Reserve, Western India  

Microsoft Academic Search

After the extermination of tigers in Sariska Tiger Reserve, Western India in 2004, three tigers were re-introduced in Sariska during 2008–2009. The present study examined the prey selection and dietary overlap between leopard and tiger after re-introduction of tiger in the study area. Scat analysis revealed the presence of nine prey species in leopard scat (n?=?90 scats) and five prey

K. Mondal; S. Gupta; S. Bhattacharjee; Q. Qureshi; K. Sankar

2012-01-01

238

Expanded host diversity and geographic distribution of hantaviruses in sub-saharan Africa.  

PubMed

The recent discovery of hantaviruses in shrews and bats in West Africa suggests that other genetically distinct hantaviruses exist in East Africa. Genetic and phylogenetic analyses of newfound hantaviruses, detected in archival tissues from the Geata mouse shrew (Myosorex geata) and Kilimanjaro mouse shrew ( Myosorex zinki) captured in Tanzania, expands the host diversity and geographic distribution of hantaviruses and suggests that ancestral shrews and/or bats may have served as the original mammalian hosts of primordial hantaviruses. PMID:24741077

Kang, Hae Ji; Stanley, William T; Esselstyn, Jacob A; Gu, Se Hun; Yanagihara, Richard

2014-07-01

239

An overview of the host spectrum and distribution of Calodium hepaticum (syn. Capillaria hepatica): part 2-Mammalia (excluding Muroidea).  

PubMed

Calodium hepaticum (syn. Capillaria hepatica) is a globally distributed zoonotic nematode with low host specificity and a high affinity to the liver. Although murid rodents are the main definite hosts, various other mammals can be affected with hepatic capillariasis: non-murid rodents, Insectivora, Chiroptera, Lagomorpha, Artiodactyla, Perissodactyla, Hyracoidea, Marsupialia, Carnivora, and Primates. Overall, more than 180 mammalian species (including humans) are known as suitable hosts of this pathogen. This review gives an overview of the distribution and host spectrum of C. hepaticum in non-Muroidean mammals in wildlife and zoos as well as in domesticated and laboratory animals. Furthermore, the role of spurious infections in animals and the dissemination of C. hepaticum by mammalian and non-mammalian animals are summarized. PMID:24257974

Fuehrer, Hans-Peter

2014-02-01

240

Histology, histochemistry and fine structure of the lacrimal and nictitans gland in the South American armadillo Chaetophractus villosus (Xenarthra, Mammalia).  

PubMed

The anatomical, histological, histochemical and ultrastructural characteristics of the lacrimal gland (LG) and nictitans gland (NG) of the armadillo Chaetophractus villosus were described. The histochemical and histological features of both glands in male and female adult animals were compared. The tissues were processed with conventional techniques for light and transmission electron microscopy. Fixed specimens were submitted to a battery of tests for glycans, glycosaminglycans, glycoconjugates, proteins, and lipids. The LG of the armadillo may be considered within the set of glandulae lacrimales superior in which primates, carnivores, perisodactyls and artiodactyls are included. The localization of the NG was similar to that of other mammals. Lacrimal and NG were histologically and histochemically identical. The secretory endpieces consisted of three cell types: (1) Mucous cells (MC) with different types of mucous secretory granules with neutral and sialic acid-containing glycoconjugates (GCs). (2)Seromucous cells (SMC) showing a variety of moderately electron dense secretory granules with flocculent material with carboxylated acidic, neutral, and sialic acid-containing GCs. Intercellular canaliculi with junctional complexes and basolateral intercellular spaces were frequent. (3) Serous cells (SC) with electron dense secretory granules. Histochemically, they showed the strongest reaction for proteins and neutral, weakly acid and carboxylated acidic GCs. The epithelium of the intra- and inter-lobular excretory ducts showed secretory activity, junctional complexes, and wide basolateral intercellular spaces with lateral folds. The endpieces and ducts were surrounded by myoepithelial cells. The stroma was characterized by fenestrated endothelium, unmyelinated axons, and abundant plasma cells. MC, SMC, and the duct system were richly innervated by hypolemmal nerve terminals. PMID:12470975

Aldana Marcos, Hernán Javier; Cintia Ferrari, Carina; Cervino, Claudio; Affanni, Jorge Mario

2002-12-01

241

Updating the evolutionary history of Carnivora (Mammalia): a new species-level supertree complete with divergence time estimates  

PubMed Central

Background Although it has proven to be an important foundation for investigations of carnivoran ecology, biology and evolution, the complete species-level supertree for Carnivora of Bininda-Emonds et al. is showing its age. Additional, largely molecular sequence data are now available for many species and the advancement of computer technology means that many of the limitations of the original analysis can now be avoided. We therefore sought to provide an updated estimate of the phylogenetic relationships within all extant Carnivora, again using supertree analysis to be able to analyze as much of the global phylogenetic database for the group as possible. Results In total, 188 source trees were combined, representing 114 trees from the literature together with 74 newly constructed gene trees derived from nearly 45,000 bp of sequence data from GenBank. The greater availability of sequence data means that the new supertree is almost completely resolved and also better reflects current phylogenetic opinion (for example, supporting a monophyletic Mephitidae, Eupleridae and Prionodontidae; placing Nandinia binotata as sister to the remaining Feliformia). Following an initial rapid radiation, diversification rate analyses indicate a downturn in the net speciation rate within the past three million years as well as a possible increase some 18.0 million years ago; numerous diversification rate shifts within the order were also identified. Conclusions Together, the two carnivore supertrees remain the only complete phylogenetic estimates for all extant species and the new supertree, like the old one, will form a key tool in helping us to further understand the biology of this charismatic group of carnivores.

2012-01-01

242

Molecules, morphometrics and new fossils provide an integrated view of the evolutionary history of Rhinopomatidae (Mammalia: Chiroptera)  

PubMed Central

Background The Rhinopomatidae, traditionally considered to be one of the most ancient chiropteran clades, remains one of the least known groups of Rhinolophoidea. No relevant fossil record is available for this family. Whereas there have been extensive radiations in related families Rhinolophidae and Hipposideridae, there are only a few species in the Rhinopomatidae and their phylogenetic relationship and status are not fully understood. Results Here we present (a) a phylogenetic analysis based on a partial cytochrome b sequence, (b) new fossils from the Upper Miocene site Elaiochoria 2 (Chalkidiki, Greece), which represents the first appearance datum of the family based on the fossil record, and (c) discussion of the phylogeographic patterns in both molecular and morphological traits. We found deep divergences in the Rhinopoma hardwickii lineage, suggesting that the allopatric populations in (i) Iran and (ii) North Africa and the Middle East should have separate species status. The latter species (R. cystops) exhibits a shallow pattern of isolation by distance (separating the Middle East and the African populations) that contrasts with the pattern of geographic variation in the morphometrical traits. A deep genetic gap was also found in Rhinopoma muscatellum (Iran vs. Yemen). We found only minute genetic distance between R. microphyllum from the Levant and India, which fails to support the sub/species distinctness of the Indian form (R. microphyllum kinneari). Conclusion The mtDNA survey provided phylogenetic tree of the family Rhinopomatidae for the first time and revealed an unexpected diversification of the group both within R. hardwickii and R. muscatellum morphospecies. The paleobiogeographic scenario compiled in respect to molecular clock data suggests that the family originated in the region south of the Eocene Western Tethyan seaway or in India, and extended its range during the Early Miocene. The fossil record suggests a Miocene spread into the Mediterranean region, followed by a post-Miocene retreat. Morphological analysis compared with genetic data indicates considerable phenotypic plasticity in this group.

Hulva, Pavel; Horacek, Ivan; Benda, Petr

2007-01-01

243

Chewing through the Miocene: an examination of the feeding musculature in the ground sloth Hapalops from South America (Mammalia: Pilosa)  

PubMed Central

Hapalops, a smaller-sized and early sloth of the Megatheroidea, appeared in the middle Miocene Santa Cruz formation of Argentina. This genus is part of the group from which later, larger megatheroids arose, i.e., Nothrotheriops and Megatherium. Many cranial characters support this idea; however Hapalops is not merely a smaller antecedent of the later forms. Specifically, Hapalops retains short anterior caniniform teeth, and a temporomandibular joint elevated above the cheek tooth row; a combination distinct among sloths. An elevated temporomandibular joint occurs in Bradypus, a tree sloth with anterior chisel-shaped teeth instead of caniniforms, and the tree sloth Choloepus, which is aligned with the megalonychids, has anterior caniniforms. Hapalops has an elongated zygomatic ascending process that is reminiscent of that in Bradypus; however, the Bradypus skull is extremely foreshortened while that of Hapalops is elongated, as in nothrotheres, but not deepened as in megatheres. Previous work identified many sloth cranial character complexes, and functional limitations on skull feature combinations. The unique Hapalops character patterns indicate a selective feeder with a mediolaterally oriented grinding stroke during mastication.

Naples, Virginia L.; McAfee, Robert K.

2014-01-01

244

A New Genus of Aplodontid Rodent (Mammalia, Rodentia) from the Late Oligocene of Northern Junggar Basin, China  

PubMed Central

A new genus and species of aplodontid rodent, Proansomys dureensis, from the late Oligocene of the northern Junggar Basin of China is described. The new genus is referred to as Ansomyinae because the ectoloph on the upper cheek teeth, although not fully crested, has attained the same characteristic bucket-handle-shaped configuration as other members of the subfamily. It represents the earliest record of the subfamily yet discovered in Asia and is more plesiomorphic than species of the genus Ansomys in having a partly crested ectoloph, a lower degree of lophodonty, and less complex tooth basins (lacking accessory lophules). Proansomys has transitional features between Prosciurus and Ansomys, suggesting that the Ansomyinae derived from a group of aplodontids related to Prosciurus, as did other advanced aplodontid rodents. This provides new light on the paleobiogeography of the Ansomyinae.

Bi, Shundong; Meng, Jin; McLean, Sarah; Wu, Wenyu; Ni, Xijun; Ye, Jie

2013-01-01

245

Potential pitfalls of reconstructing deep time evolutionary history with only extant data, a case study using the canidae (mammalia, carnivora).  

PubMed

Reconstructing evolutionary patterns and their underlying processes is a central goal in biology. Yet many analyses of deep evolutionary histories assume that data from the fossil record is too incomplete to include, and rely solely on databases of extant taxa. Excluding fossil taxa assumes that character state distributions across living taxa are faithful representations of a clade's entire evolutionary history. Many factors can make this assumption problematic. Fossil taxa do not simply lead-up to extant taxa; they represent now-extinct lineages that can substantially impact interpretations of character evolution for extant groups. Here, we analyze body mass data for extant and fossil canids (dogs, foxes, and relatives) for changes in mean and variance through time. AIC-based model selection recovered distinct models for each of eight canid subgroups. We compared model fit of parameter estimates for (1) extant data alone and (2) extant and fossil data, demonstrating that the latter performs significantly better. Moreover, extant-only analyses result in unrealistically low estimates of ancestral mass. Although fossil data are not always available, reconstructions of deep-time organismal evolution in the absence of deep-time data can be highly inaccurate, and we argue that every effort should be made to include fossil data in macroevolutionary studies. PMID:24106995

Finarelli, John A; Goswami, Anjali

2013-12-01

246

The clavicles of Smilodon fatalis and Panthera atrox (Mammalia: Felidae) from Rancho La Brea, Los Angeles, California.  

PubMed

The Rancho La Brea collections at the George C. Page Museum in Los Angeles, California, contain the largest single inventory of Smilodon fatalis remains representing virtually every bone in the skeleton. Eighteen clavicles of two distinctive shapes have been recovered from historical and recent excavations at Rancho La Brea. In this study, we identify these specimens to species through comparison of their morphology and morphological variability with clavicles found in modern felids. This study includes a reevaluation of clavicles that have been previously assigned to S. fatalis, which are more likely to be those of Panthera atrox, and the description of pantherine cat clavicles. A previously undescribed sample of clavicles not only includes some of the same pantherine morph but also 10 specimens, herein assigned to S. fatalis, which are morphologically distinctive and significantly smaller than the previously described specimens. In addition, we report unexpected variations between clavicles of Panthera leo and P. tigris: the clavicles of P. leo closely resemble those of the large Rancho La Brea clavicle morph-which presumably belongs to P. atrox-thus supporting a P. leo/P. atrox clade. We report distinctive morphology of the clavicles of Acinonyx jubatus. Possible functional and phylogenic significance of felid clavicles is suggested. PMID:22592918

Hartstone-Rose, Adam; Long, Ryan C; Farrell, Aisling B; Shaw, Christopher A

2012-09-01

247

A new genus of aplodontid rodent (Mammalia, Rodentia) from the late Oligocene of northern Junggar Basin, China.  

PubMed

A new genus and species of aplodontid rodent, Proansomys dureensis, from the late Oligocene of the northern Junggar Basin of China is described. The new genus is referred to as Ansomyinae because the ectoloph on the upper cheek teeth, although not fully crested, has attained the same characteristic bucket-handle-shaped configuration as other members of the subfamily. It represents the earliest record of the subfamily yet discovered in Asia and is more plesiomorphic than species of the genus Ansomys in having a partly crested ectoloph, a lower degree of lophodonty, and less complex tooth basins (lacking accessory lophules). Proansomys has transitional features between Prosciurus and Ansomys, suggesting that the Ansomyinae derived from a group of aplodontids related to Prosciurus, as did other advanced aplodontid rodents. This provides new light on the paleobiogeography of the Ansomyinae. PMID:23359629

Bi, Shundong; Meng, Jin; McLean, Sarah; Wu, Wenyu; Ni, Xijun; Ye, Jie

2013-01-01

248

Geographic distribution of an extinct equid (Equus hydruntinus: Mammalia, Equidae) revealed by morphological and genetical analyses of fossils.  

PubMed

Equus hydruntinus inhabited Europe and the Middle East for more than 300 000 years. For a long time, palaeontological data failed to place E. hydruntinus into the equid phylogenetic tree, confronted with the fact that it shares primitive Equus characters with both zebras and asses, and derived characters with asses and hemiones. However, the study of a recently discovered skull points to a relationship with hemiones. Extraction of DNA from ancient samples from Crimea (E. hydruntinus) and Iran (E. cf. hydruntinus) yielded 134-288 bp of the mtDNA control region and 143 bp of the cytochrome b gene. This DNA analysis supports the proximity of E. hydruntinus and Equus hemionus suggested by skull and limb bone analyses, and rejects proximity to either Equus burchelli or the asses suggested by tooth morphology. Dental morphology may thus be of poor taxonomical value if used alone for establishing equid phylogenetic relationships. Furthermore, the small genetic distance between E. cf. hydruntinus of Iran and the classical E. hydruntinus of Crimea suggests that both samples belong to the same species. Accordingly, the geographic range of E. hydruntinus -- until now believed to be restricted to Europe, Israel, and Turkey -- can be extended towards East as far as Iran. PMID:16780426

Orlando, Ludovic; Mashkour, Marjan; Burke, Ariane; Douady, Christophe J; Eisenmann, Véra; Hänni, Catherine

2006-07-01

249

Evolutionary and biological implications of dental mesial drift in rodents: the case of the Ctenodactylidae (Rodentia, Mammalia).  

PubMed

Dental characters are importantly used for reconstructing the evolutionary history of mammals, because teeth represent the most abundant material available for the fossil species. However, the characteristics of dental renewal are presently poorly used, probably because dental formulae are frequently not properly established, whereas they could be of high interest for evolutionary and developmental issues. One of the oldest rodent families, the Ctenodactylidae, is intriguing in having longstanding disputed dental formulae. Here, we investigated 70 skulls among all extant ctenodactylid genera (Ctenodactylus, Felovia, Massoutiera and Pectinator) by using X-ray conventional and synchrotron microtomography in order to solve and discuss these dental issues. Our study clearly indicates that Massoutiera, Felovia and Ctenodactylus differ from Pectinator not only by a more derived dentition, but also by a more derived eruptive sequence. In addition to molars, their dentition only includes the fourth deciduous premolars, and no longer bears permanent premolars, conversely to Pectinator. Moreover, we found that these premolars are lost during adulthood, because of mesial drift of molars. Mesial drift is a striking mechanism involving migration of teeth allowed by both bone remodeling and dental resorption. This dental innovation is to date poorly known in rodents, since it is only the second report described. Interestingly, we noted that dental drift in rodents is always associated with high-crowned teeth favoring molar size enlargement. It can thus represent another adaptation to withstand high wear, inasmuch as these rodents inhabit desert environments where dust is abundant. A more accurate study of mesial drift in rodents would be very promising from evolutionary, biological and orthodontic points of view. PMID:23185576

Gomes Rodrigues, Helder; Solé, Floréal; Charles, Cyril; Tafforeau, Paul; Vianey-Liaud, Monique; Viriot, Laurent

2012-01-01

250

Germ cell differentiation and proliferation in the developing testis of the South American plains viscacha, Lagostomus maximus (Mammalia, Rodentia).  

PubMed

Cell proliferation and cell death are essential processes in the physiology of the developing testis that strongly influence the normal adult spermatogenesis. We analysed in this study the morphometry, the expression of the proliferation cell nuclear antigen (PCNA), cell pluripotency marker OCT-4, germ cell marker VASA and apoptosis in the developing testes of Lagostomus maximus, a rodent in which female germ line develops through abolished apoptosis and unrestricted proliferation. Morphometry revealed an increment in the size of the seminiferous cords with increasing developmental age, arising from a significant increase of PCNA-positive germ cells and a stable proportion of PCNA-positive Sertoli cells. VASA showed a widespread cytoplasmic distribution in a great proportion of proliferating gonocytes that increased significantly at late development. In the somatic compartment, Leydig cells increased at mid-development, whereas peritubular cells showed a stable rate of proliferation. In contrast to other mammals, OCT-4 positive gonocytes increased throughout development reaching 90% of germ cells in late-developing testis, associated with a conspicuous increase in circulating FSH from mid- to late-gestation. TUNEL analysis was remarkable negative, and only a few positive cells were detected in the somatic compartment. These results show that the South American plains viscacha displays a distinctive pattern of testis development characterized by a sustained proliferation of germ cells throughout development, with no signs of apoptosis cell demise, in a peculiar endocrine in utero ambiance that seems to promote the increase of spermatogonial number as a primary direct effect of FSH. PMID:21554773

Gonzalez, C R; Muscarsel Isla, M L; Fraunhoffer, N A; Leopardo, N P; Vitullo, A D

2012-08-01

251

Chewing through the Miocene: an examination of the feeding musculature in the ground sloth Hapalops from South America (Mammalia: Pilosa).  

PubMed

Hapalops, a smaller-sized and early sloth of the Megatheroidea, appeared in the middle Miocene Santa Cruz formation of Argentina. This genus is part of the group from which later, larger megatheroids arose, i.e., Nothrotheriops and Megatherium. Many cranial characters support this idea; however Hapalops is not merely a smaller antecedent of the later forms. Specifically, Hapalops retains short anterior caniniform teeth, and a temporomandibular joint elevated above the cheek tooth row; a combination distinct among sloths. An elevated temporomandibular joint occurs in Bradypus, a tree sloth with anterior chisel-shaped teeth instead of caniniforms, and the tree sloth Choloepus, which is aligned with the megalonychids, has anterior caniniforms. Hapalops has an elongated zygomatic ascending process that is reminiscent of that in Bradypus; however, the Bradypus skull is extremely foreshortened while that of Hapalops is elongated, as in nothrotheres, but not deepened as in megatheres. Previous work identified many sloth cranial character complexes, and functional limitations on skull feature combinations. The unique Hapalops character patterns indicate a selective feeder with a mediolaterally oriented grinding stroke during mastication. PMID:25075299

Naples, Virginia L; McAfee, Robert K

2014-01-01

252

The youngest species of the aquatic sloth Thalassocnus and a reassessment of the relationships of the nothrothere sloths (Mammalia: Xenarthra)  

Microsoft Academic Search

Two new specimens of the aquatic sloth Thalassocnus from the Pliocene of Peru are described, one of T. carolomartini McDonald and Muizon, 2002 and the other T. yaucensis, sp. nov. Comparisons with the type species of Thalassocnus, T. natans, demonstrates that T. carolomartini and T. yaucensis are more similar morphologically to each other than to other species of the genus

Christian De Muizon; H. Gregory Mcdonald; Rodolfo Salas; Mario Urbina

2004-01-01

253

A new early species of the aquatic sloth Thalassocnus (Mammalia, Xenarthra) from the Late Miocene of Peru  

Microsoft Academic Search

Thalassocnus antiquus, sp. nov., is a marine nothrothere from the late Miocene Aguada de Lomas vertebrate horizon (ca. 7 to 8 Ma) of the Pisco Formation in the Sacaco area of the southern coast of Peru. It is similar to the slightly younger latest Miocene Thalassocnus natans, but smaller and distinctly more gracile. The sloping morphology of the lateral border

Christian De Muizon; H. Gregory Mcdonald; Rodolfo Salas; Mario Urbina

2003-01-01

254

A new giant megatheriine ground sloth (Mammalia: Xenarthra: Megatheriidae) from the late Blancan to early Irvingtonian of Florida  

Microsoft Academic Search

The giant megatheriine ground sloth Eremotherium eomigrans is described based on remains from the late Blancan to early Irvingtonian (late Pliocene to early Pleistocene) of Florida. It resembles the other giant megatheriines E. laurillardi and Megatherium americanum in size, but is clearly distinguished by a pentadactyl manus. It is assigned to the genus Eremotherium based on two synapomorphies shared with

GERARDO DE IULIIS; CÁSTOR CARTELLE

1999-01-01

255

Relaxed clocks and inferences of heterogeneous patterns of nucleotide substitution and divergence time estimates across whales and dolphins (Mammalia: Cetacea).  

PubMed

Various nucleotide substitution models have been developed to accommodate among lineage rate heterogeneity, thereby relaxing the assumptions of the strict molecular clock. Recently developed "uncorrelated relaxed clock" and "random local clock" (RLC) models allow decoupling of nucleotide substitution rates between descendant lineages and are thus predicted to perform better in the presence of lineage-specific rate heterogeneity. However, it is uncertain how these models perform in the presence of punctuated shifts in substitution rate, especially between closely related clades. Using cetaceans (whales and dolphins) as a case study, we test the performance of these two substitution models in estimating both molecular rates and divergence times in the presence of substantial lineage-specific rate heterogeneity. Our RLC analyses of whole mitochondrial genome alignments find evidence for up to ten clade-specific nucleotide substitution rate shifts in cetaceans. We provide evidence that in the uncorrelated relaxed clock framework, a punctuated shift in the rate of molecular evolution within a subclade results in posterior rate estimates that are either misled or intermediate between the disparate rate classes present in baleen and toothed whales. Using simulations, we demonstrate abrupt changes in rate isolated to one or a few lineages in the phylogeny can mislead rate and age estimation, even when the node of interest is calibrated. We further demonstrate how increasing prior age uncertainty can bias rate and age estimates, even while the 95% highest posterior density around age estimates decreases; in other words, increased precision for an inaccurate estimate. We interpret the use of external calibrations in divergence time studies in light of these results, suggesting that rate shifts at deep time scales may mislead inferences of absolute molecular rates and ages. PMID:21926070

Dornburg, Alex; Brandley, Matthew C; McGowen, Michael R; Near, Thomas J

2012-02-01

256

Evolutionary Patterns in the Dentition of Duplicidentata (Mammalia) and a Novel Trend in the Molarization of Premolars  

PubMed Central

Background The cusp homology of Lagomorpha has long been problematic largely because their teeth are highly derived relative to their more typically tribosphenic ancestors. Within this context, the lagomorph central cusp has been particularly difficult to homologize with other tribosphenic cusps; authors have previously considered it the paracone, protocone, metacone, amphicone, or an entirely new cusp. Methodology/Principal Findings Here we present newly described fossil duplicidentates (Lagomorpha and Mimotonidae) in the context of a well-constrained phylogeny to establish a nomenclatural system for cusps based on the tribosphenic pattern. We show that the central cusp of lagomorphs is homologous with the metaconule of other mammals. We also show that the buccal acquisition of a second cusp on the premolars (molarization) within duplicidentates is atypical with respect to other mammalian lineages; within the earliest lagomorphs, a second buccal cusp is added mesially to an isolated buccal cusp. Conclusions/Significance The distal shift of the ‘ancestral’ paracone within early duplicidentates amounts to the changing of a paracone into a metacone in these lineages. For this reason, we support a strictly topological approach to cusp names, and suggest a discontinuity in nomenclature to capture the complexity of the interplay between evolutionary history and the developmental process that have produced cusp patterns in duplicidentates.

Kraatz, Brian P.; Meng, Jin; Weksler, Marcelo; Li, Chuankui

2010-01-01

257

Evolutionary and Biological Implications of Dental Mesial Drift in Rodents: The Case of the Ctenodactylidae (Rodentia, Mammalia)  

PubMed Central

Dental characters are importantly used for reconstructing the evolutionary history of mammals, because teeth represent the most abundant material available for the fossil species. However, the characteristics of dental renewal are presently poorly used, probably because dental formulae are frequently not properly established, whereas they could be of high interest for evolutionary and developmental issues. One of the oldest rodent families, the Ctenodactylidae, is intriguing in having longstanding disputed dental formulae. Here, we investigated 70 skulls among all extant ctenodactylid genera (Ctenodactylus, Felovia, Massoutiera and Pectinator) by using X-ray conventional and synchrotron microtomography in order to solve and discuss these dental issues. Our study clearly indicates that Massoutiera, Felovia and Ctenodactylus differ from Pectinator not only by a more derived dentition, but also by a more derived eruptive sequence. In addition to molars, their dentition only includes the fourth deciduous premolars, and no longer bears permanent premolars, conversely to Pectinator. Moreover, we found that these premolars are lost during adulthood, because of mesial drift of molars. Mesial drift is a striking mechanism involving migration of teeth allowed by both bone remodeling and dental resorption. This dental innovation is to date poorly known in rodents, since it is only the second report described. Interestingly, we noted that dental drift in rodents is always associated with high-crowned teeth favoring molar size enlargement. It can thus represent another adaptation to withstand high wear, inasmuch as these rodents inhabit desert environments where dust is abundant. A more accurate study of mesial drift in rodents would be very promising from evolutionary, biological and orthodontic points of view.

Gomes Rodrigues, Helder; Sole, Floreal; Charles, Cyril; Tafforeau, Paul; Vianey-Liaud, Monique; Viriot, Laurent

2012-01-01

258

Trypanosoma cruzi infection in neotropical wild carnivores (Mammalia: Carnivora): at the top of the T. cruzi transmission chain.  

PubMed

Little is known on the role played by Neotropical wild carnivores in the Trypanosoma cruzi transmission cycles. We investigated T. cruzi infection in wild carnivores from three sites in Brazil through parasitological and serological tests. The seven carnivore species examined were infected by T. cruzi, but high parasitemias detectable by hemoculture were found only in two Procyonidae species. Genotyping by Mini-exon gene, PCR-RFLP (1f8/Akw21I) and kDNA genomic targets revealed that the raccoon (Procyon cancrivorus) harbored TcI and the coatis (Nasua nasua) harbored TcI, TcII, TcIII-IV and Trypanosoma rangeli, in single and mixed infections, besides four T. cruzi isolates that displayed odd band patterns in the Mini-exon assay. These findings corroborate the coati can be a bioaccumulator of T. cruzi Discrete Typing Units (DTU) and may act as a transmission hub, a connection point joining sylvatic transmission cycles within terrestrial and arboreal mammals and vectors. Also, the odd band patterns observed in coatis' isolates reinforce that T. cruzi diversity might be much higher than currently acknowledged. Additionally, we assembled our data with T. cruzi infection on Neotropical carnivores' literature records to provide a comprehensive analysis of the infection patterns among distinct carnivore species, especially considering their ecological traits and phylogeny. Altogether, fifteen Neotropical carnivore species were found naturally infected by T. cruzi. Species diet was associated with T. cruzi infection rates, supporting the hypothesis that predator-prey links are important mechanisms for T. cruzi maintenance and dispersion in the wild. Distinct T. cruzi infection patterns across carnivore species and study sites were notable. Musteloidea species consistently exhibit high parasitemias in different studies which indicate their high infectivity potential. Mesocarnivores that feed on both invertebrates and mammals, including the coati, a host that can be bioaccumulator of T. cruzi DTU's, seem to take place at the top of the T. cruzi transmission chain. PMID:23861767

Rocha, Fabiana Lopes; Roque, André Luiz Rodrigues; de Lima, Juliane Saab; Cheida, Carolina Carvalho; Lemos, Frederico Gemesio; de Azevedo, Fernanda Cavalcanti; Arrais, Ricardo Corassa; Bilac, Daniele; Herrera, Heitor Miraglia; Mourão, Guilherme; Jansen, Ana Maria

2013-01-01

259

The sweet spot of a biological hammer: the centre of percussion of glyptodont (Mammalia: Xenarthra) tail clubs.  

PubMed

The importance of the centre of percussion (CP) of some hand-held sporting equipment (such as tennis rackets and baseball bats) for athletic performance is well known. In order to avoid injuries it is important that powerful blows are located close to the CP. Several species of glyptodont (giant armoured mammals) had tail clubs that can be modelled as rigid beams (like baseball bats) and it is generally assumed that these were useful for agonistic behaviour. However, the variation in tail club morphology among known genera suggests that a biomechanical and functional analysis of these structures could be useful. Here, we outline a novel method to determine the CP of the glyptodont tail clubs. We find that the largest species had the CP very close to the possible location of horny spikes. This is consistent with the inference that they were adapted to delivering powerful blows at that point. Our new analysis reinforces the case for agonistic use of tail clubs in several glyptodont species. PMID:19710060

Blanco, R Ernesto; Jones, Washington W; Rinderknecht, Andrés

2009-11-22

260

Genetic variability of Herpailurus yagouaroundi, Puma concolor and Panthera onca (Mammalia, Felidae) studied using Felis catus microsatellites  

Microsoft Academic Search

We used four microsatellite loci (Fca08, Fca45, Fca77 and Fca96) from the domestic cat, Felis catus, to investigate genetic variability in specimens of Herpailurus yagouaroundi (jaguarundi, otter cat, eyra), Puma concolor (cougar, mountain lion, puma) and Panthera onca (jaguar) held in various Brazilian zoos. Samples of DNA from the cats were PCR amplified and then sequenced before being analyzed using

Vanessa Roma Moreno; Alexéia Barufatti Grisolia; Francine Campagnari; Marcela Milazzotto; Cristina Harumi Adania; José Fernando Garcia; Edislane Barreiros de Souza

2006-01-01

261

Novel gene conversion between X-Y homologues located in the nonrecombining region of the Y chromosome in Felidae (Mammalia)  

PubMed Central

Genes located on the mammalian Y chromosome outside of the pseudoautosomal region do not recombine with those on the X and are predicted to either undergo selection for male function or gradually degenerate because of an accumulation of deleterious mutations. Here, phylogenetic analyses of X-Y homologues, Zfx and Zfy, among 26 felid species indicate two ancestral episodes of directed genetic exchange (ectopic gene conversion) from X to Y: once during the evolution of pallas cat and once in a common predecessor of ocelot lineage species. Replacement of the more rapidly evolving Y homologue with the evolutionarily constrained X copy may represent a mechanism for adaptive editing of functional genes on the nonrecombining region of the mammalian Y chromosome.

Pecon Slattery, Jill; Sanner-Wachter, Leslie; O'Brien, Stephen J.

2000-01-01

262

Postglacial colonization of northwestern North America by the forest-associated American marten ( Martes americana , Mammalia: Carnivora: Mustelidae)  

Microsoft Academic Search

Phylogeographic patterns were used to assess intraspecific diversification of American martens ( Martes americana ). Within martens, two morphological groups ( americana and caurina ) have been recognized, though the level of distinction between them has been debated. We examined mitochondrial cytochrome b gene haplotypes from 680 martens to explore the colonization history of the Pacific Northwest and found two

KAREN D. S TONE; R ODNEY W. F LYNN; JOSEPH A. C OOK

263

Mitochondrial DNA and karyotypic data confirm the presence of Mus indutus and Mus minutoides (Mammalia, Rodentia, Muridae, Nannomys) in Botswana  

PubMed Central

Abstract We use a combination of cytochrome b sequence data and karyological evidence to confirm the presence of Mus indutus and Mus minutoides in Botswana. Our data include sampling from five localities from across the country, including one site in northwestern Botswana where both species were captured in syntopy. Additionally, we find evidence for two mitochondrial lineages of M. minutoides in northwestern Botswana that differ by 5% in sequence variation. Also, we report that M. minutoides in Botswana have the 2n=34 karyotype with the presence of a (X.1) sex-autosome translocation.

McDonough, Molly M.; Sotero-Caio, Cibele G.; Ferguson, Adam W.; Lewis, Patrick J.; Tswiio, Matlhogonolo; Thies, Monte L.

2013-01-01

264

The northernmost record of Catagonus stenocephalus (Lund in Reinhardt, 1880) (Mammalia, Cetartiodactyla) and its palaeoenvironmental and palaeobiogeographical significance  

NASA Astrophysics Data System (ADS)

During fieldwork carried out in January 2009 at Aurora do Tocantins (Tocantins State, northern Brazil), we recovered a fragmentary right maxilla (UNIRIO-PM 1006) of Catagonus stenocephalus from a sedimentary deposit of presumed late Pleistocene age in a karstic cave. This paper aims to: (1) provide the first record of C. stenocephalus in the northern region of Brazil (and consequently, also the northernmost one); (2) update the geographic distribution of C. stenocephalus; (3) present a date for the specimen; and (4) discuss the palaeoenvironmental and palaeobiogeographical implications of the finding. The species C. stenocephalus (Lund) is known from the Bonaerian (middle Pleistocene) and Lujanian (late Pleistocene to earliest Holocene) ages in Argentina, Uruguay, Brazil and Bolivia. The new record presented here extends the geographical distribution of C. stenocephalus more than 1000 km north from the former northernmost record (caves of Lagoa Santa region). Peccaries of the genus Catagonus have several morphological features associated with cursorial habits in relatively open and dry environments. The new distributional range of C. stenocephalus is coincident with the Chacoan subregion, characterized by dry climates and open areas. As the studied material comes from the top of the carbonate layer, this may suggest that the deposition of the C. stenocephalus remains described here is synchronous with the onset of a wetter climate phase. This argument is also in accordance with the datation results, around 20 ky BP, just after the last glacial maximum. This increasingly wet climate, which may also be related to the climatic changes that occurred during the late Pleistocene/early Holocene, could be a factor in the extinction of C. stenocephalus in South America.

Avilla, Leonardo S.; Müller, Lisiane; Gasparini, German M.; Soibelzon, Leopoldo; Absolon, Bruno; Pêgo, Frederico Bonissoni; Silva, Rafael C.; Kinoshita, Angela; Graciano Figueiredo, Ana Maria; Baffa, Oswaldo

2013-03-01

265

Chromosome painting and molecular dating indicate a low rate of chromosomal evolution in golden moles (Mammalia, Chrysochloridae)  

Microsoft Academic Search

Golden moles (Chrysochloridae) are poorly known subterranean mammals endemic to Southern Africa that are part of the superordinal\\u000a clade Afrotheria. Using G-banding and chromosome painting we provide a comprehensive comparison of the karyotypes of five\\u000a species representing five of the nine recognized genera: Amblysomus hottentotus, Chrysochloris asiatica, Chrysospalax trevelyani, Cryptochloris zyli and Eremitalpa granti. The species are karyotypically highly conserved.

C. Gilbert; P. C. O’Brien; G. Bronner; F. Yang; A. Hassanin; M. A. Ferguson-Smith; T. J. Robinson

2006-01-01

266

Mixed infection in the anteater Tamandua tetradactyla (Mammalia: Pilosa) from Pará State, Brazil: Trypanosoma cruzi, T. rangeli and Leishmania infantum.  

PubMed

Some Trypanosoma and Leishmania species are multi-host parasites whose distribution overlaps in several parts of the Brazilian Amazon basin. Despite being a common trait among wild mammals, mixed infections and their consequences for the host's health and parasite transmission are still a poorly known phenomenon. Here we describe a triple mixed infection - Trypanosoma cruzi, T. rangeli and Leishmania infantum - in a bone marrow sample from an anteater Tamandua tetradactyla captured in a house backyard from the endemic Abaetetuba municipality in the Amazon basin. T. cruzi was also isolated from blood samples. The mini-exon multiplex PCR characterization detected the infection by T. rangeli and T. cruzi (TcI genotype), while L. infantum infection was confirmed by an ITS-PCR followed by amplicon sequencing. This is the first description of T. rangeli isolation from bone marrow and the first report of L. infantum infection in xenarthrans. The implications of this finding are discussed considering the influence of mixed infections in the role of this mammal species as a putative reservoir host of these 3 trypanosomatid species. PMID:23253893

De Araújo, Vitor Antônio L; Boité, Mariana C; Cupolillo, Elisa; Jansen, Ana Maria; Roque, André Luiz R

2013-04-01

267

Community Analysis of Muridae (Mammalia, Rodentia) Diversity in Guinea: A Special Emphasis on Mastomys Species and Lassa Fever Distributions  

Microsoft Academic Search

The Murid rodent diversity has been sampled following the 9th Meridian in the east of Guinea from the forest region to Sudanian savannas of southern Mali. This represents the first small\\u000a mammals survey in North Guinea. Murid diversity patterns have been researched using correspondence analysis and faunal comparisons.\\u000a A difference between southern forest communities and northern ones is observed. Mastomys

E. Lecompte; E. Calvet; M. D. Camara; A. Doré; K. Koulémou; F. Kourouma; B. Soropogui; O. Sylla; B. Allali-Kouadio; S. Kouassi-Kan; C. Akoua-Koffi; J. Meulen; L. Koivogui

268

The Adaptive Significance of Enamel Loss in the Mandibular Incisors of Cercopithecine Primates (Mammalia: Cercopithecidae): A Finite Element Modelling Study  

PubMed Central

In several primate groups enamel is reduced or absent from the lingual (tongue) side of the mandibular incisor crowns akin to other placental and marsupial mammalian groups such as rodents, lagomorphs and wombats. Here we investigate the presumed adaptation of crowns with unilateral enamel to the incision of tough foods in cercopithecines, an Old World monkey subfamily, using a simulation approach. We developed and validated a finite element model of the lower central incisor of the rhesus macaque (Macaca mulatta) with labial enamel only to compute three-dimensional displacements and maximum principal stresses on the crown subjected to compressive loads varying in orientation. Moreover, we developed a model of a macaque incisor with enamel present on both labial and lingual aspects, thus resembling the ancestral condition found in the sister taxon, the leaf-eating colobines. The results showed that, concomitant with experimental results, the cercopithecine crown with unilateral enamel bends predominantly towards the inside of the mouth, while displacements decreased when both labial and lingual enamel are present. Importantly, the cercopithecine incisor crown experienced lower maximum principal stress on the lingual side compared to the incisor with enamel on the lingual and labial aspects under non-axial loads directed either towards the inside or outside of the mouth. These findings suggest that cercopithecine mandibular incisors are adapted to a wide range of ingestive behaviours compared to colobines. We conclude that the evolutionary loss of lingual enamel in cercopithecines has conferred a safeguard against crown failure under a loading regime assumed for the ingestion (peeling, scraping) of tough-skinned fruits.

Kupczik, Kornelius; Lev-Tov Chattah, Netta

2014-01-01

269

Masticatory muscle architecture in the Laotian rock rat Laonastes aenigmamus (Mammalia, Rodentia): new insights into the evolution of hystricognathy  

PubMed Central

We present the first descriptive comparison of the skull, mandible and jaw muscles of the recently recovered Laotian rock rat Laonastes aenigmamus. The gross anatomy of five specimens captured in Laos and internal architecture of the jaw musculature were studied using dissections. The following muscles are described: temporal, masseter, pterygoids, digastric, mylohyoid, geniohyoid and transverse mandibular. The description of the masticatory apparatus of L. aenigmamus offers a rare opportunity to assess the order of establishment of the morphological characters during the evolution of Ctenohystrica. Striking convergences have occurred during the evolution of Diatomyidae and L. aenigmamus presents a unique combination of myological features that corresponds to a mixture of sciurognathous and hystricognathous characters. If L. aenigmamus is a sciurognathous rodent, we have to assume that it independently acquired a pars reflexa of the superficial masseter. We show for the first time that the development of this pars reflexa has occurred several times during the evolution of Ctenohystrica and can no longer be considered a synapomorphic feature of ‘Hystricognathi’. These results bring new insights into the evolution of hystricognathy and have profound implications for the interpretation of the fossil record of early hystricognath rodents.

Hautier, Lionel; Saksiri, Soonchan

2009-01-01

270

The action of post-dispersal beetles (Coleoptera: Scarabaeidae) and ants (Hymenoptera: Formicidae) on scats of Didelphis spp. (Mammalia: Didelphidae).  

PubMed

A two year study of dung beetles and ants acting on scats of two species of opossum (Didelphis spp.) was carried out. Scats were left in the field in order to detect post-dispersal agents. A portion of each scat (30 %) was examined for seeds in the laboratory. Beetles were recovered from burrows (51% of 84 faecal samples left in the field) where they either buried scats of opossums or were attracted, together with ants, to pitfalls (N = 10) baited with opossum scats. Dung beetles were the main post-dispersal agents of seeds found in scats of opossums, rolling the scats away or burying then on the site of deposition. They buried faeces at 4 to 15 cm in depth (N = 22 tunnels). The main dung beetles identified (medium to large size) were Eurysternus (28.7 % in pitfalls) and Dichotomius (13.7 %), Coprophanaeus (seen only directly on faeces), besides small-bodied beetles (< 10 mm; 57.6 %). The ant Acromirmex sp. transported some seeds from scats. This species was present in 25.5 % of all Formicidae samples (pitfall). These post-dispersal agents contribute to avert scat seed predators such as rodents, and to accelerate seed bank formation. PMID:18457158

Cáceres, Nilton Carlos; Monteiro-Filho, Emygdio L A

2006-12-01

271

Homeotic Evolution in the Mammalia: Diversification of Therian Axial Seriation and the Morphogenetic Basis of Human Origins  

Microsoft Academic Search

Background. Despite the rising interest in homeotic genes, little has been known about the course and pattern of evolution of homeotic traits across the mammalian radiation. An array of emerging and diversifying homeotic gradients revealed by this study appear to generate new body plans and drive evolution at a large scale. Methodology\\/Principal Findings. This study identifies and evaluates a set

Aaron G. Filler

2007-01-01

272

A comparison of the chromosome G-banding pattern in two Sorex species, S. satunini and S. araneus (Mammalia, Insectivora)  

PubMed Central

Abstract The G-banded karyotype of Sorex satunini was compared with the karyotype of Sorex araneus. Extensive homology was revealed. The major chromosomal rearrangements involved in the evolutionary divergence of these species have been identified as centric fusions and centromeric shifts. From the known palaeontological age of Sorex satunini it is obvious that the vast chromosomal polymorphism of the Sorex araneus group originated during the middle Pleistocene.

Borisov, Yuriy M.; Orlov, Victor N.

2012-01-01

273

Endocrine cells and nerve ganglia of the small intestine of the Opossum Didelphis aurita Wied-Neuwied, 1826 (Mammalia: Didelphidae).  

PubMed

The nervous and endocrine systems jointly control intestinal movements, secretions of their glands and also participate of the processes of nutrient digestion and absorption. Therefore, the central objective of this study was to verify the existence of a possible relationship between the number of nervous cells and ganglia of the submucosal and myenteric plexuses and the number of endocrine cells in the small intestine of adult D. aurita. The utilized staining techniques were Grimelius, modified Masson-Fontana, direct immunoperoxidase and H-E. Argyrophillic, argentaffin and insulin immunoreactive endocrine cells do not numerically vary between the initial, mid and final regions of the duodenum, jejunum and ileum (P>0.05), except for argyrophillic cells in the jejunum (P>0.05). No numerical relationship has yet been verified between the number of nerve ganglia and endocrine cells, and also between nervous and endocrine cells. We recommended the use of new immunohistochemical techniques to confirm the numerical correlation between the nervous and endocrine systems in the small intestine. The morphology and distribution of endocrine cells and the nerve ganglia studied were similar to those encountered in eutherian mammals. PMID:22801379

Freitas-Ribeiro, Gláucia M; Fonseca, Cláudio C; Sartori, Sirlene S R; Loures-Ribeiro, Alan; Neves, Clóvis A

2012-09-01

274

High-resolution chromosome painting reveals the first genetic signature for the chiropteran suborder Pteropodiformes (Mammalia: Chiroptera)  

Microsoft Academic Search

Up to now, the composition of synteny-conserved segments in chiropteran karyotypes was studied by cross-species chromosome\\u000a painting with probes derived from whole human (HSA) or chiropteran chromosomes only. Here, painting probes from the vespertilionid\\u000a bat Myotis myotis were hybridized, for the first time, onto human metaphase chromosomes. The segmental composition of bat karyotypes was further\\u000a refined by cross-species painting with

Marianne Volleth; Fengtang Yang; Stefan Müller

2011-01-01

275

Anatomy of the External Nasal Passages and Facial Complex in the Delphinidae (Mammalia: Cetacea): Smithsonian Contributions to Zoology, Number 207.  

National Technical Information Service (NTIS)

This study is concerned with the comparative anatomy of the external nasal passages and associated structures in delphinid odontocetes. It has been possible to assemble detailed anatomical information for nearly all of the delphinid genera. Comparative da...

J. G. Mead

1975-01-01

276

Cranial remain from Tunisia provides new clues for the origin and evolution of Sirenia (Mammalia, Afrotheria) in Africa.  

PubMed

Sea cows (manatees, dugongs) are the only living marine mammals to feed solely on aquatic plants. Unlike whales or dolphins (Cetacea), the earliest evolutionary history of sirenians is poorly documented, and limited to a few fossils including skulls and skeletons of two genera composing the stem family of Prorastomidae (Prorastomus and Pezosiren). Surprisingly, these fossils come from the Eocene of Jamaica, while stem Hyracoidea and Proboscidea--the putative sister-groups to Sirenia--are recorded in Africa as early as the Late Paleocene. So far, the historical biogeography of early Sirenia has remained obscure given this paradox between phylogeny and fossil record. Here we use X-ray microtomography to investigate a newly discovered sirenian petrosal from the Eocene of Tunisia. This fossil represents the oldest occurrence of sirenians in Africa. The morphology of this petrosal is more primitive than the Jamaican prorastomids' one, which emphasizes the basal position of this new African taxon within the Sirenia clade. This discovery testifies to the great antiquity of Sirenia in Africa, and therefore supports their African origin. While isotopic analyses previously suggested sirenians had adapted directly to the marine environment, new paleoenvironmental evidence suggests that basal-most sea cows were likely restricted to fresh waters. PMID:23342128

Benoit, Julien; Adnet, Sylvain; El Mabrouk, Essid; Khayati, Hayet; Ben Haj Ali, Mustapha; Marivaux, Laurent; Merzeraud, Gilles; Merigeaud, Samuel; Vianey-Liaud, Monique; Tabuce, Rodolphe

2013-01-01

277

Revision of the Wind River faunas, early Eocene of central Wyoming. IX - The oldest known hystricomorphous rodent (Mammalia: Rodentia)  

NASA Technical Reports Server (NTRS)

The rostral portion of the skull of a new genus and species of rodent, Armintomys tullbergi, from the earliest middle Eocene of the Wind River Basin (Wyoming) provides the geologically oldest known record of the hystricomorphous zygomasseteric structure. Armintomys also preserves the oldest known occurrence of incisor enamel that is transitional from pauciserial to uniserial. Other dental characters include: anteriorly grooved incisor, small premolars, and relatively primitive sciuravidlike molars. Analysis of this unique combination of characters implies that Armintomys is the oldest known myomorph rodent and the only known representative of a new family. Armintomyidae, which is referred, with question, to the myomorph superfamily Dipodoidea. Armintomys is more primitive, especially in premolar retention and structure, than the Bridgerian zapodid Elymys from Nevada, but adds to evidence from the latter for an early origin and radiation of dipodoid rodents.

Dawson, Mary R.; Krishtalka, Leonard; Stucky, Richard K.

1990-01-01

278

Three new karyotypes extend a Robertsonian fan in Ethiopian spiny mice of the genus Acomys I. Geoffroy, 1838 (Mammalia, Rodentia)  

PubMed Central

Abstract Three new karyotypes (2n=40, 44, 52) are described revealing what are probably new cryptic species of Ethiopian spiny mice. Two other diploid numbers have already been reported for the country (2n=36 and 68) and, overall, the five known karyotypic forms constitute a common lineage differentiated by a Robertsonian process. Such arrays of karyotypic forms are known as a ‘Robertsonian fan’. This view of the situation in Ethiopian Acomys I. Geoffroy, 1838 is based on standard chromosomal morphology that reveals a constant FN (68) and needs further investigation of chromosome homology by differential staining and/or molecular cytogenetic techniques as well as further molecular phylogenetic analysis.

Lavrenchenko, L.A.; Nadjafova, R.S.; Bulatova, N.Sh.

2011-01-01

279

Effect of ondansetron and Delta(9)-tetrahydrocannabinol on the establishment of lithium-induced conditioned taste avoidance in the house musk shrew (Suncus murinus)  

Microsoft Academic Search

Recent evidence suggests that toxin-induced taste avoidance in the non-emetic rat is not mediated by conditioned sickness. In contrast, it appears that toxin-induced taste avoidance in an emetic species is mediated by conditioned sickness. The present experiments evaluated the potential of the anti-emetic agents, ondansetron [OND; a serotonin receptor (5-HT3) antagonist] and Delta(9)-tetrahydrocannabinol [THC; a cannabinoid (CB 1) agonist] to

Magdalena Kwiatkowska

2004-01-01

280

[The Gongylonematid parasitic in the elephant shrew Elephantus rozeti (Macrocelidae) in Tunisia was identified as Gongylonema brevispiculum Seurat, 1914 (author's transl)].  

PubMed

Its larval form obtained from experimentally infected intermediate hosts, differs from those of other Gongylonematids. In the genus Gongylonema four types of larvae were recognized. They are characterized by the size and the cephalic and caudal structures of the larvae. The cellular reactions caused by the larvae of G. brevispiculum in the insect muscles are similar to those caused by infections with larvae of Acuarid nematodes. PMID:573088

Quentin, J C; Seureau, C

1978-01-01

281

Pituitary extract of the ricefield eel Monopterus albus (Synbranchidae, Teleostei) exhibits gonadotropic activity in the classes Mammalia, Aves, Reptilia and Amphibia.  

PubMed

Pituitary extract of the ricefield eel Monopterus albus demonstrated gonadotropic activity in mammals and non-mammalian vertebrates. Using the rat as the recipient, FSH activity was detected in Monopterus pituitaries in the HCG augmentation test and LH activity in the ovarian ascorbic acid depletion test. Cyclic AMP level in superovulated ovaries, ovarian lactate production and glucose uptake in vitro, plasma testosterone level in males, testicular enzymes, ventral prostate weight and other androgen-dependent parameters were stimulated after treatment with Monopterus pituitary extract. Testicular and ovarian 32P5+ uptake in the chick, testicular weight in the grass turtle Chinemys reevesi, and ovulation in the amphibians Xenopus laevis and Rana tigrina were enhanced. Both the FSH-like and LH-like activities in Monopterus pituitaries were sensitive to proteolytic enzymes and chemicals that attack the disulfide linkage, carbohydrate moiety, tyrosine, tryptophan and histidine residues. This constitutes the first report of dual gonadotropic activities elicited by a teleost pituitary extract in the mammal in vivo. PMID:2873938

Ng, T B; Lee, Y H; Chan, S T

1986-01-01

282

A New Machairodont from the Palmetto Fauna (Early Pliocene) of Florida, with Comments on the Origin of the Smilodontini (Mammalia, Carnivora, Felidae)  

PubMed Central

South-central Florida’s latest Hemphillian Palmetto Fauna includes two machairodontine felids, the lion-sized Machairodus coloradensis and a smaller, jaguar-sized species, initially referred to Megantereon hesperus based on a single, relatively incomplete mandible. This made the latter the oldest record of Megantereon, suggesting a New World origin of the genus. Subsequent workers variously accepted or rejected this identification and biogeographic scenario. Fortunately, new material, which preserves previously unknown characters, is now known for the smaller taxon. The most parsimonious results of a phylogenetic analysis using 37 cranio-mandibular characters from 13 taxa place it in the Smilodontini, like the original study; however, as the sister-taxon to Megantereon and Smilodon. Accordingly, we formally describe Rhizosmilodon fiteae gen. et sp. nov. Rhizosmilodon, Megantereon, and Smilodon (?=? Smilodontini) share synapomorphies relative to their sister-taxon Machairodontini: serrations smaller and restricted to canines; offset of P3 with P4 and p4 with m1; complete verticalization of mandibular symphysis; m1 shortened and robust with widest point anterior to notch; and extreme posterior “lean” to p3/p4. Rhizosmilodon has small anterior and posterior accessory cusps on p4, a relatively large lower canine, and small, non-procumbent lower incisors; all more primitive states than in Megantereon and Smilodon. The former also differs from Megantereon and Smilodon gracilis by having a very small mandibular flange. Rhizosmilodon is the oldest known member of the Smilodontini, suggesting that the tribe originated in North America. Two more derived, similar-sized species evolved in parallel during the Blancan, Megantereon hesperus and Smilodon gracilis. The former is rarer, known only from the north-central and northwestern US, and presumably dispersed into the Old World. The latter is known from the eastern and southern US, and dispersed into South America.

Wallace, Steven C.; Hulbert, Richard C.

2013-01-01

283

Feeding preferences of Gomphotherium subtapiroideum (Proboscidea, Mammalia) from the Miocene of Sandelzhausen (Northern Alpine Foreland Basin, southern Germany) through life and geological time: evidence from dental microwear analysis  

Microsoft Academic Search

The objective of this study is to estimate changes in feeding preferences of the proboscidean species Gomphotherium subtapiroideum (Schlesinger 1917) by means of dental microwear analyses. The dietary changes are first evaluated through the ontogeny of this species, between\\u000a juveniles and adults, and are then studied through geological time, from early Middle Miocene (MN5) to middle Late Miocene\\u000a (MN8–9) localities

Ivan CalandraUrsula; Ursula B. Göhlich; Gildas Merceron

2010-01-01

284

Coccidial dispersion across New World marsupials: Klossiella tejerai Scorza, Torrealba & Dagert, 1957 (Apicomplexa: Adeleorina) from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) (Mammalia: Didelphimorphia).  

PubMed

Klossiella tejerai Scorza, Torrealba & Dagert, 1957 is a primitive coccidian parasite reported from the New World marsupials Didelphis marsupialis (Linnaeus) and Marmosa demerarae (Thomas). The current work describes K. tejerai from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) in Southeastern Brazil, evidencing the coccidial dispersion across opossums of the same family. The sporocysts recovered from urine samples were ellipsoidal, 20.4 × 12.7 µm, with sporocyst residuum composed of scattered spherules and c.13 sporozoites per sporocyst, with refractile bodies and nucleus. Macrogametes, microgametes, sporonts, sporoblasts/sporocysts were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. Didelphis marsupialis should not have transmitted K. tejerai to D. aurita because they are not sympatric; however M. demerarae is sympatric with D. marsupialis and D. aurita. Therefore, D. aurita becomes the third host species for K. tejerai in South America. PMID:25079818

Dos Santos, Caroline Spitz; Berto, Bruno Pereira; do Bomfim Lopes, Bruno; Cordeiro, Matheus Dias; da Fonseca, Adivaldo Henrique; Filho, Walter Leira Teixeira; Lopes, Carlos Wilson Gomes

2014-09-01

285

The amino acid sequence of a lamprey ( Entosphenus japonicus) liver fatty acid-binding protein identified its close relationship to cardiac fatty acid-binding proteins of Mammalia  

Microsoft Academic Search

Fatty acid-binding proteins (FABPs) constitute a large, tissue-specific multigene family in animals. While liver FABPs of Aves, Reptilia, and Amphibia are close homologs of mammalian liver FABPs, the shark liver protein belongs to the mammalian heart FABP subfamily. We purified an FABP from the liver of lamprey, Entosphenus japonicus, by gel filtration and anion-exchange chromatography. Amino acid sequences determined for

Katsuya Baba; Yoshiaki Takahashi; Yutaka Aoyagi; Shoji Odani

1999-01-01

286

Systematic Palaeontology (Vertebrate Palaeontology) Meles iberica n. sp., a new Eurasian badger (Mammalia, Carnivora, Mustelidae) from Fonelas P-1 (Plio-Pleistocene boundary, Guadix Basin, Granada, Spain)  

Microsoft Academic Search

This paper reports a new species of ancient badger - Meles iberica n. sp. - discovered at the Fonelas P-1 Plio-Pleistocene site (Cuenca de Guadix, Granada, Spain). The anatomical features of its fossils, which identify it as a new species of Meles, include: the great robustness and small size of the specimens found, orbits nearly closed by well-developed zygomatic processes

Alfonso Arribas; Guiomar Garrido

2007-01-01

287

Meles iberica n. sp., a new Eurasian badger (Mammalia, Carnivora, Mustelidae) from Fonelas P-1 (Plio-Pleistocene boundary, Guadix Basin, Granada, Spain)  

Microsoft Academic Search

This paper reports a new species of ancient badger –Meles iberica n. sp. – discovered at the Fonelas P-1 Plio-Pleistocene site (Cuenca de Guadix, Granada, Spain). The anatomical features of its fossils, which identify it as a new species of Meles, include: the great robustness and small size of the specimens found, orbits nearly closed by well-developed zygomatic processes of

Alfonso Arribas; Guiomar Garrido

2007-01-01

288

Presence of the 54-chromosome common vole (Mammalia) on Olkhon Island (Lake Baikal, East Siberia, Russia), and the occurrence of an unusual X-chromosome variant.  

PubMed

We report a new finding of the 54-chromosome sibling species of the common vole in East Siberia - the first description from Olkhon Island (Lake Baikal). The karyotype of a male specimen revealed by routine staining and C-banding demonstrates the unambiguous presence of Microtus rossiaemeridionalis Ognev, 1924 (recently often regarded as as junior synonym of Microtus levis Miller, 1908). Comparison with conspecific specimens from the European part of the species range (from the left bank of the river Volga) shows that the vole of the island population has a smaller X-chromosome due to a reduced quantity of C-positive heterochromatin. This is just the third example of this type of X-chromosome variant with previous cases on an Arctic island (Svalbard) and the West Siberian lowland (Novosibirsk) and the only one on a lake island. Although Microtus rossiaemeridionalis is largely monomorphic in its karyotype, our data show that one specific type of X-chromosome variant is remarkably widespread, though rare. PMID:24260647

Pavlova, S V; Tchabovsky, A V

2011-01-01

289

A new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) from the dusky rice rat Melanomys caliginosus (Tomes) (Mammalia: Rodentia) in Costa Rica.  

PubMed

We collected faecal samples from 24 dusky rice rats, Melanomys caliginosus (Tomes) (Rodentia: Cricetidae: Sigmodontinae), in a Biological Reserve in Costa Rica, and found three (12.5%) to be infected with a species of Eimeria Schneider, 1875, which we describe here as new. Sporulated oöcysts of Eimeria caliginosa n. sp. are almost spheroidal and measure 16-21 × 17-20 (mean 19.6 × 18.2) ?m; micropyle, oöcyst residuum and polar granule are absent. Sporocysts are ovoidal, 9-13 × 6-8 (mean 11.2 × 6.7) ?m, with small Stieda and sub-Stieda bodies present, but a para-Stieda body is absent; the sporocyst residuum is a compact mass of c.11-15 granules, c.5 ?m wide. Sporozoites are crescent-shaped, 5-8 × 2-3 (mean 6.8 × 2.4) ?m. This is the third species of Eimeria described from the genus Melanomys Thomas. PMID:24832189

Chinchilla, Misael; Valerio, Idalia; Sánchez, Ronald; González, Antonieta; Duszynski, Donald W

2014-06-01

290

The Dasypodidae (Mammalia, Xenarthra) from the Urso Fóssil Cave (Quaternary), Parque Nacional de Ubajara, State of Ceará, Brazil: paleoecological and taxonomic aspects.  

PubMed

This paper deals with xenarthrans osteoderms assigned to Dasypus aff. D. novemcinctus, Euphractus sexcinctus and Cabassous sp. The material was collected in subsurface, from 0.10 to 0.60 m in the Urso Fóssil Cave, Parque Nacional de Ubajara, State of Ceará, northeastern Brazil. The ages of sediment samples from levels 4 and 5 (depths of 0.40 and 0.50 m) were determined by thermoluminescence technique, and indicated ages of 8,000 and 8,200 years BP for each layer respectively. The presence in these layers of early Holocene xenarthrans taxa can contribute to the understanding of the biotic evolution of the northwest region of Ceará during the last 10,000 years. Two of the three identified taxa still occur in the region: Dasypus novemcinctus and Euphractus sexcinctus. The Dasypodidae fauna here reported includes animals with generalist feeding habits and current wide geographical distribution. It is suggested, therefore, that the climatic and environmental conditions in the early Holocene were very similar the actual ones, and that the absence of Cabassous may be conditioned to other factors, such as anthropogenic action and loss of habitat by fragmentation of the vegetation. PMID:24519005

Oliveira, Paulo V; Ribeiro, Ana Maria; Oliveira, Edison V; Viana, Maria Somália S

2014-03-01

291

Presence of the 54-chromosome common vole (Mammalia) on Olkhon Island (Lake Baikal, East Siberia, Russia), and the occurrence of an unusual X-chromosome variant  

PubMed Central

Abstract We report a new finding of the 54-chromosome sibling species of the common vole in East Siberia - the first description from Olkhon Island (Lake Baikal). The karyotype of a male specimen revealed by routine staining and C-banding demonstrates the unambiguous presence of Microtus rossiaemeridionalis Ognev, 1924 (recently often regarded as as junior synonym of Microtus levis Miller, 1908). Comparison with conspecific specimens from the European part of the species range (from the left bank of the river Volga) shows that the vole of the island population has a smaller X-chromosome due to a reduced quantity of C-positive heterochromatin. This is just the third example of this type of X-chromosome variant with previous cases on an Arctic island (Svalbard) and the West Siberian lowland (Novosibirsk) and the only one on a lake island. Although Microtus rossiaemeridionalis is largely monomorphic in its karyotype, our data show that one specific type of X-chromosome variant is remarkably widespread, though rare.

Pavlova, S.V.; Tchabovsky, A.V.

2011-01-01

292

New Specimens of the Rare Taeniodont Wortmania (Mammalia: Eutheria) from the San Juan Basin of New Mexico and Comments on the Phylogeny and Functional Morphology of "Archaic" Mammals  

PubMed Central

Background Taeniodonta is a clade of Late Cretaceous – Paleogene mammals remarkable for their relatively extreme cranial, dental, and postcranial adaptations and notable for being among the first mammals to achieve relatively large size following the Cretaceous-Paleogene mass extinction. Previous workers have hypothesized that taeniodonts can be divided into two clades: Conoryctidae, a group of small-bodied taeniodonts with supposedly “generalized” postcranial skeletons, and Stylinodontidae, a group of large-bodied, robust animals with massive forelimbs and claws adapted for scratch-digging. However, many taeniodont taxa are poorly known and few are represented by postcranial material, leaving many details about their anatomy, biology, and evolution ambiguous. Methodology/Principal Findings In this paper, we describe three new specimens of the rare taxon Wortmaniaotariidens from the early Paleocene (Puercan) of New Mexico. Among these specimens is one that includes remarkably complete cranial and dental material, including associated upper and lower teeth, and another that consists of partial forelimbs. These specimens allow for an updated anatomical description of this unusual taxon, supply new data for phylogenetic analyses, and enable a more constrained discussion of taeniodont biology and functional morphology. Conclusions/Significance The new specimen of Wortmania that includes associated upper and lower teeth indicates that previous interpretations of the upper dentition of this taxon were not accurate and the taxon Robertschochiasullivani is a junior synonym of W. otariidens. New specimens that include partial forelimbs indicate that Wortmania is very similar to later, large-bodied taeniodonts, with marked and distinctive adaptations for scratch-digging. Comparisons with other taeniodont taxa that include postcranial material suggest that all taeniodonts may have had scratch-digging adaptations. A phylogenetic analysis shows that Schowalteria and Onychodectes are basal taeniodonts, Stylinodontidae (including Wortmania) is monophyletic, and a monophyletic Conoryctidae (but not including Onychodectes) is only recovered when certain characters are ordered.

Williamson, Thomas E.; Brusatte, Stephen L.

2013-01-01

293

New ontogenetic evidence on the septomaxilla of Tamandua and Choloepus (Mammalia, Xenarthra), with a reevaluation of the homology of the mammalian septomaxilla  

Microsoft Academic Search

An intramembranous ossification at the anterior end of the cartilaginous nasal capsule is described for the first time in prenatal specimens of the anteaterTamandua and the slothCholoepus and redescribed in prenatal specimens of the armadillosDasypus andZaedyus. From comparisons of this bone with the septomaxilla of monotremes and various Mesozoic mammals, it is concluded that (1) the bone inTamandua andCholoepus is

U. Zeller; J. R. Wible; M. Elsner

1993-01-01

294

Distribution and origin of vasoactive intestinal polypeptide (VIP)-immunoreactive, acetylcholinesterase-positive and adrenergic nerves of the cerebral arteries in the bent-winged bat (Mammalia: Chiroptera)  

Microsoft Academic Search

The overall distribution and origins of vasoactive intestinal polypeptide (VIP)-immunoreactive (IR), acetylcholinesterase (AChE)-positive and adrenergic nerves in the walls of the cerebral arteries were investigated in the bent-winged bat. VIP-IR and AChE-positive nerves innervating the bat cerebral vasculature appear to arise mainly from VIP-IR and AChE-positive cell bodies within microganglia found in the nerve bundle accompanying the sympathetic nerve bundle

K?ichi And?

1988-01-01

295

Differences in Tooth Microwear of Populations of Caribou ( Rangifer tarandus , Ruminantia, Mammalia) and Implications to Ecology, Migration, Glaciations and Dental Evolution  

Microsoft Academic Search

Tooth microwear was analyzed for a large sample of wild-shot barren-ground caribou (Rangifer tarandus groenlandicus) from the Kaminuriak population of eastern Canada. This sample was compared to the microwear of specimens from three Pleistocene\\u000a localities in North America (Alaska) and western Europe (Caune de l’Arago in France and Salzgitter in Germany). The results\\u000a show that the extant samples from eastern

Florent Rivals; Nikos Solounias

2007-01-01

296

Biochronological implications of the Arvicolidae (Rodentia, Mammalia) from the Lower Pleistocene hominid-bearing level of Trinchera Dolina 6 (TD6, Atapuerca, Spain)  

Microsoft Academic Search

Level TD6 of the Trinchera Dolina Section in the railway cutting of the Sierre de Atapuerca (Trinchera del Ferrocarril) has yielded a rich small mammal assemblage (26 species) in association with fossil human remains of Homo antecessor. The arvicolids of TD6 are identified as: Mimomys savini, Microtus seseae, Stenocranius gregaloides, Terricola arvalidens, Iberomys huescarensis, Allophaiomys chalinei, and Pliomys episcopalis. The

Gloria Cuenca-Bescós; César Laplana; Jose Ignacio Canudo

1999-01-01

297

Observations and larval descriptions of fleas (Siphonaptera: Ceratophyllidae, Ctenophthalmidae, Ishnopsyllidae) of the southern flying squirrel, little brown bat, and Brazilian free-tailed bat (Mammalia: Rodentia, Chiroptera).  

PubMed

Larvae of the four fleas infesting nests of the southern flying squirrel, Glaucomys volans colans (L.) [Conorhinopsylla stanfordi Stewart, Epitedia faceta (Rothschild), Opisodasys pseudarctomys (Baker), and Orchopeas howardi (Baker)], and of the bat fleas Myodopsylla insignis (Rothschild) and Sternopsylla distincta texana (C. Fox), associated with the bats Myotis lcifuigus (Le Conte) and Tadarida brasiliensis (I. Geof. St. Hilaire), respectively, are described. C. stanfordi has the second posterior-row seta on abdominal segments 1-5 at most one fourth the length of the first and third setae, but it is unique among the Leptopsyllini with five short setae in abdominal segment 9 anterior row. E. faceta has the straight line of anterior-row setae 2-5 on abdominal segment 1, which is diagnostic for Phalacropsyllini. O. howardi and O. pseudarctomys have three anterior-row setae on the anal comb, three ventrolateral setae on the anal segment (abdominal segment 10), and a narrow mandible with five or more teeth as other Ceratopyllinae, but O. pseudarctomys is distinguishable from O. howardi because the first setae on the posterior row of the head is long (greater than one half the length of the third posterior-row setae), the ventral setae on abdominal segment 7 are different sizes, and the third anterior-row setae on abdominal segment 8 does not extend past the spiracle posterior to it. Bat flea larvae have six posterior-row setae on abdominal segments 1-9 with the anal comb anterior row with two or more setae; M. insignis has eight mandible teeth and S. distincta texana three to four. PMID:18047188

Elbel, Robert E; Bossard, Robert L

2007-11-01

298

First report of Borrelia burgdorferi sensu lato in two threatened carnivores: the Marbled polecat, Vormela peregusna and the European mink, Mustela lutreola (Mammalia: Mustelidae)  

PubMed Central

Background Lyme disease is a widespread cosmopolitan zoonosis caused by species belonging to the genus Borrelia. It is transmitted from animal reservoir hosts to humans through hard - ticks of genus Ixodes which are vectors of the disease. Case presentation Borrelia burgdorferi sensu lato infection was identified in a marbled polecat, Vormela peregusna, and two European minks, Mustela lutreola, from Romania, by PCR. RFLP revealed the presence of a single genospecies, Borrelia burgdorferi sensu stricto. Conclusions This is the first report of the Lyme disease spirochetes in the two mentioned hosts.

2012-01-01

299

Allelic diversity at the Mhc-DQA locus in cotton rats ( Sigmodon hispidus ) and a comparison of DQA sequences within the family Muridae (Mammalia: Rodentia)  

Microsoft Academic Search

The cotton rat (Sigmodon hispidus) is a common murid rodent of the southern United States, Mexico, and Central America. Using single-stranded conformation\\u000a polymorphism analysis and DNA sequencing techniques, 11 DQA exon 2 alleles were detected among 180 S. hispidus from Caddo County, Oklahoma, USA. The alleles represent a single locus exhibiting a high level of polymorphism. Nucleotide\\u000a and amino acid

Russell S. Pfau; Ronald A. Van Den Bussche; Karen McBee; Robert L. Lochmiller

1999-01-01

300

Bat flies (Diptera: Streblidae, Nycteribiidae) parasitic on bats (Mammalia: Chiroptera) at Parque Estadual da Cantareira, São Paulo, Brazil: parasitism rates and host-parasite associations.  

PubMed

A total of 443 bat flies belonging to the families Nycteribiidae and Strelidae, were collected on 22 species of bats (Molossidae, Phyllostomidae, and Vespertilionidae) from Parque Estadual da Cantareira (São Paulo, Brazil), between January, 2000 and January, 2001. Eighteen new occurrences of bat flies were recorded on Anoura geoffroyi (Anastrebla caudiferae), Glossophaga soricina (A. caudiferae), Sturnira lilium (Trichobius phyllostomae, T. furmani, and Paraeuctenodes similis), Artibeus lituratus (A. caudiferae), A. fimbriatus (Megistopoda proxima), A. obscurus (Metelasmus pseudopterus), Myotis nigricans (M. proxima, M. aranea, Paratrichobius longicrus), M. ruber (Anatrichobius passosi, Joblingia sp.), M. levis (A. passosi), M. albescens (A. passosi, Basilia andersoni), and Histiotus velatus (M. aranea). Seven new occurrences were recorded for the state of São Paulo, increasing the range for T. tiptoni, T. furmani, M. proxima, Aspidoptera falcata, A. caudiferae, A. modestini and B. andersoni. The relationships between parasitism and host sex, reproductive stage, age hyperparasitism by fungi are discussed. PMID:15867959

Bertola, Patrícia Beloto; Aires, Caroline Cotrim; Favorito, Sandra Elisa; Graciolli, Gustavo; Amaku, Marcos; Pinto-da-Rocha, Ricardo

2005-02-01

301

[The role of different types of excretions in mediated chemo-communication of common palm civet, Paradoxurus hermaphroditus Pallas, 1777 (Mammalia, Carnivora)].  

PubMed

We studied scent marking behavior, olfactory response to various excretions (secretion of the perineal gland, urine, and feces), as well as the information content of these excretions in the common palm civet (Paradoxurus hermaphroditus Pallas, 1777). Six forms of scent marking behavior have been described. The activity and form's proportion of such behavior differ in males and females. Dragging the perineal gland and leaving the secretion on the substrate was most commonly observed in animals of both sexes. The olfactory response of the palm civet varied by duration and depended both on the sex and excretion type. The palm civet could distinguish animal species, sex, and familiar/unfamiliar individuals by the odor of the perineal gland secretion. Different olfactory response of the palm civet to feces was observed only for that of different species. The scent marks of the perineal gland were most significant in mediated communication by scent marks of the palm civet; they completely replicated the information of the urine marks. PMID:14994474

Rozhnov, V V; Rozhnov, Iu V

2003-01-01

302

Allelic diversity at the Mhc-DQA locus in cotton rats (Sigmodon hispidus) and a comparison of DQA sequences within the family muridae (Mammalia: Rodentia).  

PubMed

The cotton rat (Sigmodon hispidus) is a common murid rodent of the southern United States, Mexico, and Central America. Using single-stranded conformation polymorphism analysis and DNA sequencing techniques, 11 DQA exon 2 alleles were detected among 180 S. hispidus from Caddo County, Oklahoma, USA. The alleles represent a single locus exhibiting a high level of polymorphism. Nucleotide and amino acid distance values among DQA alleles of S. hispidus were higher than those within Mus musculus and species of Rattus. Although the distribution of polymorphic amino acid residues among alleles of S. hispidus was similiar to that of Mus and Rattus, some residues of the alpha-helix region were more variable in S. hispidus. Comparisons of nonsynonymous and synonymous substitutions indicated a trend toward higher numbers of nonsynonymous substitutions; however, this difference was not significant statistically among S. hispidus alleles. To examine evolution of DQA alleles within Muridae, we performed a phylogenetic analysis that included DQA alleles from S. hispidus, Peromyscus leucopus, M. musculus, R. norvegicus, and six Australian species of Rattus. Results depicted monophyly for each genus, and this concordance between species and gene trees represents a lack of evidence for trans-species persistence of alleles among these genera. PMID:10436183

Pfau, R S; Van Den Bussche, R A; McBee, K; Lochmiller, R L

1999-09-01

303

A new machairodont from the Palmetto Fauna (early Pliocene) of Florida, with comments on the origin of the Smilodontini (Mammalia, Carnivora, Felidae).  

PubMed

South-central Florida's latest Hemphillian Palmetto Fauna includes two machairodontine felids, the lion-sized Machairodus coloradensis and a smaller, jaguar-sized species, initially referred to Megantereon hesperus based on a single, relatively incomplete mandible. This made the latter the oldest record of Megantereon, suggesting a New World origin of the genus. Subsequent workers variously accepted or rejected this identification and biogeographic scenario. Fortunately, new material, which preserves previously unknown characters, is now known for the smaller taxon. The most parsimonious results of a phylogenetic analysis using 37 cranio-mandibular characters from 13 taxa place it in the Smilodontini, like the original study; however, as the sister-taxon to Megantereon and Smilodon. Accordingly, we formally describe Rhizosmilodon fiteae gen. et sp. nov. Rhizosmilodon, Megantereon, and Smilodon ( = Smilodontini) share synapomorphies relative to their sister-taxon Machairodontini: serrations smaller and restricted to canines; offset of P3 with P4 and p4 with m1; complete verticalization of mandibular symphysis; m1 shortened and robust with widest point anterior to notch; and extreme posterior "lean" to p3/p4. Rhizosmilodon has small anterior and posterior accessory cusps on p4, a relatively large lower canine, and small, non-procumbent lower incisors; all more primitive states than in Megantereon and Smilodon. The former also differs from Megantereon and Smilodon gracilis by having a very small mandibular flange. Rhizosmilodon is the oldest known member of the Smilodontini, suggesting that the tribe originated in North America. Two more derived, similar-sized species evolved in parallel during the Blancan, Megantereon hesperus and Smilodon gracilis. The former is rarer, known only from the north-central and northwestern US, and presumably dispersed into the Old World. The latter is known from the eastern and southern US, and dispersed into South America. PMID:23516394

Wallace, Steven C; Hulbert, Richard C

2013-01-01

304

Zegdoumyidae (Rodentia, Mammalia), stem anomaluroid rodents from the Early to Middle Eocene of Algeria (Gour Lazib, Western Sahara): new dental evidence  

Microsoft Academic Search

The Palaeogene fossil record of rodents in Africa is very poor compared to that of North America or Eurasia. Despite this, Africa has long appeared to be a centre of adaptive radiation for two distinct groups of Rodentia: Hystricognathi and Anomaluroidea. The >45-million-year-old enigmatic Zegdoumyidae is the oldest and only rodent family known of this age from Africa (Algeria and

Laurent Marivaux; Mohammed Adaci; Mustapha Bensalah; Helder Gomes Rodrigues; Lionel Hautier; M’hammed Mahboubi; Fateh Mebrouk; Rodolphe Tabuce; Monique Vianey-Liaud

2011-01-01

305

Boltimys broomi gen. nov., sp. nov. (Rodentia, Mammalia), nouveau Muridae d'affinité incertaine du Pliocène inférieur d'Afrique du Sud  

NASA Astrophysics Data System (ADS)

Boltimys broomi gen. nov., sp. nov., a Muridae of uncertain affinity in the Early Pliocene of South Africa. Boltimys broomi gen. nov., sp. nov. is reported from the Early Pliocene fauna of Waypoint 160, a fossiliferous locality in the area of Bolt's Farm (Province of Gauteng) near Krugersdorp in South Africa. The occlusal surface of the jugal teeth is characterized by a basin-shaped aspect due to the coalescence of the cusps which make the lobes of the molars. An accessory inner cusp is present on the first and second upper molars. A faint longitudinal crest is present only in the first lower molar. The new rodent is tentatively referred to the subfamily Myocricetodontinae.

Sénégas, Frank; Michaux, Jacques

2000-04-01

306

The earliest immigration of woolly rhinoceros ( Coelodonta tologoijensis, Rhinocerotidae, Mammalia) into Europe and its adaptive evolution in Palaearctic cold stage mammal faunas  

NASA Astrophysics Data System (ADS)

The cold adapted larger mammal faunas of Pleistocene Eurasia (the so-called Mammuthus- Coelodonta faunas) were mainly composed of autochthonous Palaearctic elements. Whereas the history of the immigration and evolution of European woolly mammoths has been exhaustively studied, comparable investigations for woolly rhinoceroses are lacking. Referring to the remains of European and Asian Coelodonta in general and the first skull to be found of a European woolly rhinoceros of early Middle Pleistocene age (from Bad Frankenhausen, Germany) in particular, the occurrence, dispersal, morphological evolution and ecological adaptation of early Coelodonta are reviewed. Coelodonta originated around 2.5 Myr BP north of the Himalayan-Tibetan uplift. The genus was restricted in its range to different types of steppe landscapes of continental Asia for more than two million years and it wasn't until MIS 12, when extended phases of low temperature and aridity prevailed in western Eurasia that woolly rhinoceroses comparable to Coelodonta tologoijensis spread westward towards Central Europe for the first time. Coelodonta entered Central and, in several cases, Western Europe during all of the subsequent Middle to Late Pleistocene cold stages. Morphological evolution, in particular, the elongation and narrowing of the head and successively its lower and more inclined posture, the shift of the orbits towards the rear of the skull, and changes in the position and morphology of the tooth row concurrently indicate progressive adaptations to an efficient grazer. During the course of their Plio-/Pleistocene evolution, Coelodonta rhinoceroses changed strikingly from cursorial mixed feeders of central Asian origin to graviportal, highly specialised grazers, inhabiting huge belts of tundra-steppe-like environments during dry and cool to cold periods, and thus becoming the only rhinocerotid to join the Eurasian mammoth faunas. The Bad Frankenhausen Coelodonta record dates the initial formation of a pan-Eurasian Mammuthus- Coelodonta faunal complex to about 460 kyr BP.

Kahlke, Ralf-Dietrich; Lacombat, Frédéric

2008-11-01

307

A New Basal Caniform (Mammalia: Carnivora) from the Middle Eocene of North America and Remarks on the Phylogeny of Early Carnivorans  

PubMed Central

Background Despite a long history of research, the phylogenetic origin and initial diversification of the mammalian crown-group Carnivora remain elusive. Well-preserved fossil materials of basal carnivorans are essential for resolving these issues, and for constraining the timing of the carnivoran origin, which constitutes an important time-calibration point in mammalian phylogenetics. Methodology/Principal Findings A new carnivoramorphan from the middle Eocene of southern California, Lycophocyon hutchisoni, is described. The new taxon exhibits stages of dental and basicranial evolution that are intermediate between earlier carnivoramorphans and the earliest representatives of canoid carnivorans. The evolutionary affinity of the new taxon was determined by a cladistic analysis of previously-published and newly-acquired morphological data for 30 Paleogene carnivoramorphans. The most-parsimonious trees identified L. hutchisoni as a basal caniform carnivoran, and placed (1) Tapocyon robustus, Quercygale angustidens, “Miacis” sylvestris, “M.” uintensis, and “M.” gracilis inside or outside the Carnivora, (2) nimravids within the Feliformia, and (3) the amphicyonid Daphoenus outside the crown-group Canoidea. Parsimony reconstructions of ancestral character states suggest that loss of the upper third molars and development of well-ossified entotympanics that are firmly fused to the basicranium (neither condition is observed in L. hutchisoni) are not associated with the origin of the Carnivora as traditionally thought, but instead occurred independently in the Caniformia and the Feliformia. A discriminant analysis of the estimated body weight and dental ecomorphology predicted a mesocarnivorous diet for L. hutchisoni, and the postcranial morphology suggests a scansorial habit. Conclusions/Significance Lycophocyon hutchisoni illuminates the morphological evolution of early caniforms leading to the origin of crown-group canoids. Considerable uncertainty remains with respect to the phylogenetic origin of the Carnivora. The minimum date of caniform-feliform divergence is provisionally suggested to be either 47 million years ago or 38 million years ago, depending on the position of “Miacis” sylvestris within or outside the Carnivora, respectively.

Tomiya, Susumu

2011-01-01

308

Experimental Scrub Typhus Immunogens.  

National Technical Information Service (NTIS)

This study arose from the conviction that an alternate method of rickettsial inactivation was requires. New data suggested that cell-mediated immunity (CMI), rather than antibody, was required for heterologous protection. Since the penetration of mammalia...

G. H. G. Eisenberg J. V. Osterman

1976-01-01

309

Polypeptide Derivatives of Parathyroid Hormone (PTH).  

National Technical Information Service (NTIS)

Novel parathyroid hormone (PTH) polypeptide derivatives are disclosed, as are pharmaceutical compositions containing said polypeptides, and synthetic and recombinant methods for producing said polypeptides. Also disclosed are methods for treating mammalia...

H. Juppner H. M. Kronenberg J. T. Potts T. J. Gardella

2005-01-01

310

Echinostome Infections in the Striped-Field Mouse, Apodemus agrarius, and the Ussuri White-Toothed Shrew, Crocidura lasiura, Caught Near the Demilitarized Zone, Gyeonggi-do (Province), Republic of Korea  

PubMed Central

A total of 1,498 small mammals (rodents and insectivores), including Apodemus agrarius (n = 1,366), Crocidura lasiura (54), Mus musculus (32), Micronytus fortis (28), Eothenomys regulus (9), Micronys minutes (6), and Cricetulus triton (3), were live-trapped in Gyeonggi-do (Province) (Paju-si, Pocheon-gun, and Yeoncheon-gun) near the demilitarized zone (DMZ) from December 2004 to September 2005. A. agrarius was found to be infected with 3 species of echinostomes (Echinostoma hortense, Echinostoma cinetorchis, and Euparyphium murinum), while C. lasiura was infected with 1 species (Echinochasmus japonicas) of echinostome. Other mammals were free from echinostome infections. Total 16 E. hortense were detected in 7 (0.5%) mice, 9 E. cinetorchis from 5 (0.4%), and 3 E. murinum from 2 (0.1%) out of 1.366 A. agrarius examined. E. japonicus was found only in 1 (1.9%; total 3 specimens) C. lasiura. These results demonstrate that A. agrarius and C. lasiura, inhabiting near the DMZ of Gyeonggi-do serve as the natural definitive hosts for several species of echinostomes, although their infection rates are low. This is the first record of natural infections of A. agrarius with E. cinetorchis and C. lasiura with E. japonicus in the Republic of Korea.

Park, Jae-Hwan; Jung, Bong-Kwang; Guk, Sang-Mee; Kim, Jae-Lip; Shin, Eun-Hee; Klein, Terry A.; Kim, Heung-Chul; Chong, Sung-Tae; Baek, Luck Ju; Song, Jin-Won

2009-01-01

311

Echinostome infections in the striped-field mouse, Apodemus agrarius, and the Ussuri white-toothed shrew, Crocidura lasiura, caught near the demilitarized zone, Gyeonggi-do (Province), Republic of Korea.  

PubMed

A total of 1,498 small mammals (rodents and insectivores), including Apodemus agrarius (n = 1,366), Crocidura lasiura (54), Mus musculus (32), Micronytus fortis (28), Eothenomys regulus (9), Micronys minutes (6), and Cricetulus triton (3), were live-trapped in Gyeonggi-do (Province) (Paju-si, Pocheon-gun, and Yeoncheon-gun) near the demilitarized zone (DMZ) from December 2004 to September 2005. A. agrarius was found to be infected with 3 species of echinostomes (Echinostoma hortense, Echinostoma cinetorchis, and Euparyphium murinum), while C. lasiura was infected with 1 species (Echinochasmus japonicas) of echinostome. Other mammals were free from echinostome infections. Total 16 E. hortense were detected in 7 (0.5%) mice, 9 E. cinetorchis from 5 (0.4%), and 3 E. murinum from 2 (0.1%) out of 1.366 A. agrarius examined. E. japonicus was found only in 1 (1.9%; total 3 specimens) C. lasiura. These results demonstrate that A. agrarius and C. lasiura, inhabiting near the DMZ of Gyeonggi-do serve as the natural definitive hosts for several species of echinostomes, although their infection rates are low. This is the first record of natural infections of A. agrarius with E. cinetorchis and C. lasiura with E. japonicus in the Republic of Korea. PMID:19724709

Chai, Jong-Yil; Park, Jae-Hwan; Jung, Bong-Kwang; Guk, Sang-Mee; Kim, Jae-Lip; Shin, Eun-Hee; Klein, Terry A; Kim, Heung-Chul; Chong, Sung-Tae; Baek, Luck Ju; Song, Jin-Won

2009-09-01

312

Parasitic and Phoretic Arthropods of the Oldfield Mouse (Peromyscus polionotus) from Burned Habitats with Additional Ectoparasite Records from the Eastern Harvest Mouse (Reithrodontomys humulis) and Southern Short-Tailed Shrew (Blarina carolinensis)  

Microsoft Academic Search

We recorded 12 species of parasitic or phoretic arthropods from 112 live-trapped oldfield mice (Peromyscus polionotus) in southeastern Georgia, U.S.A.: 1 species of sucking louse (Hoplopleura hesperomydis), 1 flea (Peromy- scopsylla scotti*), 1 bot (Cuterebra fontinella*), 2 ticks (Dermacentor variabilis and Ixodes scapularis), 3 mesostig- matid mites (Androlaelaps fahrenholzi, Haemogamasus liponyssoides,* and Haemogamasus longitarsus*), 2 fur mites (Glycyphagus hypudaei, Radfordia

Todd N. Nims; Lance A. Durden; C. Ray Chandler; Oscar J. Pung

2008-01-01

313

Look What the Cat Brought In.  

ERIC Educational Resources Information Center

The small, uneaten, slate-gray, pointed-nose animal that is distasteful to the cat because of foul-tasting scent glands is the shrew. Describes the short-tailed shrew's physical characteristics, lifespan, habitat, eating habits, and senses. (ERB)

Erslev, Carole

1984-01-01

314

Colugos: obscure mammals glide into the evolutionary limelight  

Microsoft Academic Search

Substantial molecular evidence indicates that tree-shrews, colugos and primates cluster together on the mammalian phylogenetic\\u000a tree. Previously, a sister-group relationship between colugos and primates seemed likely. A new study of colugo chromosomes\\u000a indicates instead an affinity between colugos and tree-shrews.

Robert D Martin

2008-01-01

315

Deamination of 5-Methylcytosine Residues in Mammalian Cells  

PubMed Central

DNA demethylation in mammalia occurs after fertilization and during embryogenesis and accompanies cell aging and cancer transformation. With the help of the primer extension reaction, MALDI MS and DNA cleavage by thymine DNA glycosylase deamination of 5-methylcytosine residues has been shown to take place when the model methylated DNA duplexes are treated with nuclear extracts from the cell lines CHO, HeLa, and Skov3. The hypothesis that deamination of 5-methylcytosine is the first stage of demethylation in mammalia has been postulated.

Gromenko, E.V.; Spirin, P.V.; Kubareva, E.A.; Romanova, E.A.; Prassolov, V.S.; Shpanchenko, O.V.

2009-01-01

316

Leptospira and Rodents in Cambodia: Environmental Determinants of Infection  

PubMed Central

We investigated infection of rodents and shrews by Leptospira spp. in two localities of Cambodia (Veal Renh, Kaev Seima) and in four types of habitat (forests, non-flooded lands, lowland rain-fed paddy fields, houses) during the wet and the dry seasons. Habitat preference was common, and rodent and shrew species were found only in houses or in rain-fed paddy fields or in forests. Among 649 small mammals trapped belonging to 12 rodent species and 1 shrew species, 71 of 642 animals tested were carriers of Leptospira according to the 16S ribosomal RNA marker used. Rodent infection was higher in low-slope locations, corresponding to rain-fed paddy fields, especially in the rainy season and in Kaev Seima. Rodents (Rattus exulans) and shrews (Suncus murinus) inhabiting households showed significantly low levels of infections, whereas rodents living in and near to forests (shrubby wasteland, orchards) showed high levels of infection.

Ivanova, Svilena; Herbreteau, Vincent; Blasdell, Kim; Chaval, Yannick; Buchy, Philippe; Guillard, Bertrand; Morand, Serge

2012-01-01

317

FEASIBILITY OF MICRONUCLEUS METHODS FOR MONITORING GENETIC DAMAGE IN TWO FERAL SPECIES OF SMALL MAMMALS  

EPA Science Inventory

Peromyscus leucopus (white-footed mouse) and Cryptotis parva (least shrew) possess desirable attributes for biomonitoring contamination of terrestrial ecoystems, but few studies have examined the potential use of these species for monitoring exposure to genotoxic contaminants. Th...

318

Leptospira and rodents in Cambodia: environmental determinants of infection.  

PubMed

We investigated infection of rodents and shrews by Leptospira spp. in two localities of Cambodia (Veal Renh, Kaev Seima) and in four types of habitat (forests, non-flooded lands, lowland rain-fed paddy fields, houses) during the wet and the dry seasons. Habitat preference was common, and rodent and shrew species were found only in houses or in rain-fed paddy fields or in forests. Among 649 small mammals trapped belonging to 12 rodent species and 1 shrew species, 71 of 642 animals tested were carriers of Leptospira according to the 16S ribosomal RNA marker used. Rodent infection was higher in low-slope locations, corresponding to rain-fed paddy fields, especially in the rainy season and in Kaev Seima. Rodents (Rattus exulans) and shrews (Suncus murinus) inhabiting households showed significantly low levels of infections, whereas rodents living in and near to forests (shrubby wasteland, orchards) showed high levels of infection. PMID:22665613

Ivanova, Svilena; Herbreteau, Vincent; Blasdell, Kim; Chaval, Yannick; Buchy, Philippe; Guillard, Bertrand; Morand, Serge

2012-06-01

319

Presence of the African Machairodont Megantereon whitei (Broom, 1937) (Felidae, Carnivora, Mammalia) in the Lower Pleistocene Site of Venta Micena (Orce, Granada, Spain), with some Considerations on the Origin, Evolution and Dispersal of the Genus  

Microsoft Academic Search

We have made a comparative analysis of dental morphometries of theMegantereonspecimens found in the Lower Pleistocene site at Venta Micena (Orce, Granada, Southeastern Spain) with representatives of the genus throughout the Old and New World. The methodologies used in the study include discriminant functions and principal component analysis. The results obtained point to the presence of three distinct species of

Paul Palmqvist

1995-01-01

320

Is parasite load dependent on host aggregation size? The case of the greater mouse-eared bat Myotis myotis (Mammalia: Chiroptera) and its parasitic mite Spinturnix myoti (Acari: Gamasida).  

PubMed

The risk of parasite infection grows with the size of host aggregations, which, in turn, may also depend on host sex and age and the quality of environmental resources. Herein, we studied the relationship between ectoparasitic infections with the wing mite (Spinturnix myoti) and the size of the breeding colonies, sex, age, and body condition index (BCI) of its host, the greater mouse-eared bat (Myotis myotis). The influence of environmental quality in the Carpathian Mountains (Poland) was also examined. We found significant differences in mite abundance and BCI between different breeding aggregations of the greater mouse-eared bat and also between the host sex/age categories. The most heavily infected bats were adult M. myotis females, while young males appeared to be the least infected. The BCI differed significantly between the sexes in young bats (males had a higher BCI than females) and also between colonies. No significant differences in the BCI were found for adult females. We did not find any relationship between the infestation rate of M. myotis, their colony size, the quality of environmental resources (percentage of forest cover around the colony), or the BCI. The prevalence of the various developmental stages of the mites did not differ between the host sex/age categories; however, differences were found in the sex ratios of deutonymphs and adult mites between adult M. myotis females. We predict that parasite load may not be dependent on colony size itself, but mainly on microclimatic factors, which are in turn directly correlated with colony size. PMID:24604385

Postawa, Tomasz; Szubert-Kruszy?ska, Agnieszka

2014-05-01

321

THE FLUCTUATING ASYMMETRY OF SOME MORPHOMETRIC CHARACTERS OF THE SKULL IN A POPULATION OF MUS SPICIL EGUS, PETENY, 1882 (MAMMALIA: RODENTIA) FROM A CROP OF WHEAT IN THE COUNTY OF BOTO?ANI  

Microsoft Academic Search

The aim of our paper is to emphasize the asymmetry of some cranial characters in the Mus spicilegus species due to the stress provoked by the agricultural workings. The statistical analysis has been realized on the measurements of three bilateral cranial characters: the coronoid, condylar and angular processes. The results of the statistical tests applied have shown different levels of

MARIANA POPOVICI; R. ZAMFIRESCU

322

Una nueva especie de Pachynolophus (Mammalia, Perissodactyla) de Zambrana (Álava, Región Vasco-Cantábrica). Análisis filogenético de Pachynolophus y primera cita en el Eoceno superior de la Península Ibérica  

Microsoft Academic Search

Recent fieldwork in the Late Eocene of Zambrana (Álava, Basque-Cantabrian Region) has yielded a new species of Pachynolophus: P. zambranensis nov. sp. According to the phylogenetic analysis made in this study, the Zambrana species is part of the monophyletic Pachynolophus, which is defined at least by three synapomorphies: significant progressive increase of the size in the M1\\/1-M3\\/3 series, being M3\\/3

Ainara Badiola; Xabier Pereda-Suberbiola; Miguel Angel Cuesta

2005-01-01

323

Discovery of Middle Jurassic mammals from Siberia  

Microsoft Academic Search

Mammal remains from the Middle Jurassic (Bathonian) Berezovsk Quarry on the south of Krasnoyarsk Territory, West Siberia, Russia are referred to Docodonta indet. (two edentulous fragmentary dentaries) and Mammalia indet. (a sin? gle?rooted tooth). The dentaries exemplify a unique combination of plesiomorphic characters found among stem mam? mals only in Docodonta and Morganucodon: well developed Meckel's groove, trough for postdentary

ALEXANDER O. AVERIANOV; ALEXEY V. LOPATIN; PAVEL P. SKUTSCHAS; NIKOLAI V. MARTYNOVICH; SERGEI V. LESHCHINSKIY; ANTON S. REZVYI; SERGEI A. KRASNOLUTSKII; ALEXEY V. FAYNGERTZ

324

Evolution of the mammary gland from the innate immune system?  

Microsoft Academic Search

Summary The mammary gland is a skin gland unique to the class Mammalia. Despite a growing molecular and histological understanding of the development and physiology of the mammarygland,itsfunctionalandmorphologicalorigins have remained speculative. Numerous theories on the origin of the mammary gland and lactation exist. The purpose of the mammary gland is to provide the newborn with copious amounts of milk, a

Claudia Vorbach; Mario R. Capecchi; Josef M. Penninger

2006-01-01

325

Aspects of carnivoran Evolution in Africa  

Microsoft Academic Search

This thesis concerns the evolution of African small carnivorans, with emphasis on East African Viverridae and Herpestidae (Carnivora, Mammalia). Viverridae and Herpestidae are two Old World feliform (belonging to the cat branch) carnivoran families with a confusing, and sometimes even misleading, taxonomic and systematic history, in addition to a scarce fossil record. A new genus and species from Fort Ternan,

Reihaneh Dehghani

2008-01-01

326

Ecomorphological study of large canids from the lower Pleistocene of southeastern Spain  

Microsoft Academic Search

An ecomorphological analysis of the skeletal remains of large canids, Canis ( Xenocyon ) falconeri and Canis etruscus (Mammalia, Carnivora, Canidae), preserved in an assemblage of large mam- mals from the lower Pleistocene site at Venta Micena (Guadix-Baza Basin, Orce, Granada, southeastern Spain) is reported. Mean body mass of adult individuals was estimated to be around 10 kg for C.

PAUL PALMQVIST; ALFONSO ARRIBAS; BIENVENIDO MARTÍNEZ-NAVARRO

2007-01-01

327

Tenrec Phylogeny and the Noninvasive Extraction of Nuclear DNA  

Microsoft Academic Search

Due in part to scarcity of material, no published study has yet cladistically addressed the systematics of living and fossil Tenrecidae (Mammalia, Afrotheria). Using a noninvasive technique for sampling nuclear DNA from museum specimens, we investigate the evolution of the Tenrecidae and assess the extent to which tenrecids fit patterns of relationships proposed for other terrestrial mammals on Madagascar. Application

Robert J. Asher; Michael Hofreiter

2006-01-01

328

Unexpected primitive rodents in the Quaternary of Argentina  

Microsoft Academic Search

This article describes the first fossils recorded in the Hernandarias Formation (Pleistocene) in Entre Ríos province (eastern Argentina). They are represented by three teeth assigned to the caviomorph rodents (Rodentia, Mammalia) Aenigmys diamantensis gen. et sp. nov. and Eumysops. To establish the phylogenetic affinities of the two most enigmatic teeth, their enamel microstructure was studied. Aenigmys diamantensis is considered the

María G. Vucetich; Emma C. Vieytes; Diego H. Verzi; Jorge I. Noriega; Eduardo P. Tonni

2005-01-01

329

Winter reduction in body mass in a very small, nonhibernating mammal: consequences for heat loss and metabolic rates.  

PubMed

Low temperatures in northern winters are energetically challenging for mammals, and a special energetic burden is expected for diminutive species like shrews, which are among the smallest of mammals. Surprisingly, shrews shrink their body size in winter and reduce body and brain mass, an effect known as Dehnel's phenomenon, which is suggested to lower absolute energy intake requirements and thereby enhance survival when food availability is low. Yet reduced body size coupled with higher body-surface-to-mass ratio in these tiny mammals may result in thermoregulatory heat production at a given temperature constituting a larger proportion of the total energy expenditure. To evaluate energetic consequences of reduced body size in winter, we investigated common shrews Sorex araneus in northeastern Poland. Average body mass decreased by 19.0% from summer to winter, and mean skull depth decreased by 13.1%. There was no difference in Dehnel's phenomenon between years despite different weather conditions. The whole-animal thermal conductance (proportional to absolute heat loss) in shrews was 19% lower in winter than in summer; the difference between the two seasons remained significant after correcting for body mass and was caused by improved fur insulation in winter. Thermogenic capacity of shrews, although much enhanced in winter, did not reach its full potential of increase, and this corresponded with relatively mild subnivean temperatures. These findings indicate that, despite their small body size, shrews effectively decrease their costs of thermoregulation. The recorded decrease in body mass from summer to winter resulted in a reduction of overall resting metabolic rate (in thermoneutrality) by 18%. This, combined with the reduced heat loss, should translate to food requirements that are substantially lower than would be the case if shrews did not undergo seasonal decrease in body mass. PMID:23303317

Taylor, Jan R E; Rychlik, Leszek; Churchfield, Sara

2013-01-01

330

Bioaccumulation of metals and effects of a landfill in small mammals Part III: Structural alterations.  

PubMed

The leachates from the Garraf landfill located in a protected site (NE Spain) contain several potentially toxic substances such as heavy metals. Here we report the histopathological alterations produced by this pollution in wild specimens of an omnivorous species, the wood mouse, Apodemus sylvaticus, and an insectivorous species, the greater white-toothed shrew, Crocidura russula. Hepatic tissue presented the most severe alterations in both the species, namely cell cycle arrest (apoptosis and necrosis), inflammation, preneoplasic nodules, vacuolation and microsteatosis. The kidneys were altered more in the mice (presenting tubular necrosis and dilatation, inflammation, and cylinders) than in the shrews, suggesting that different metabolic pathways render shrews more tolerant to renal toxicity induced by pollutants. No pollution-related alterations were observed in lung, spleen, pancreas, gonads, oesophagus, intestine, or adrenals. We conclude that the two species could be used in conjunction as bioindicators to assess the effects of environmental pollution at different trophic levels. PMID:19758588

Sánchez-Chardi, Alejandro; Peñarroja-Matutano, Cristina; Borrás, Miquel; Nadal, Jacint

2009-11-01

331

Effects of Experimental Manipulations of Course Woody Debris on Sorcids and Other Fauna  

SciTech Connect

The authors studied the relationship between the level of course woody debris in experimental plots of mature loblolly pine and the richness and abundance of shrews, reptiles and amphibians. Comparisons were made between plots in which all down and standing debris were removed and plots that were not treated. Removal of woody debris resulted in a week treatment effect. The capture of southeastern shrews declined through the period perhaps due to drought. The least common shrew demonstrated the strongest effects from removal.In sampling 37 species of amphibians were observed. The Carolina anole and the red salamander were captured more frequently on removal plots. No difference were found between removal and controls with regard to reptiles.

McCay, T.S.; Komoroski, M.J.; Ford, W.M.; Laerm, J.; Reitz, E.J.

2001-06-10

332

RESPONSE OF HERPETOFAUNA AND SORICIDS TO COARSE WOODY DEBRIS MANIPULATIONS IN UPLAND LOBLOLLY PINE STANDS.  

SciTech Connect

MS Thesis. University of Georgia, Athens, Georgia. 153 pp. Although use of coarse woody debris (CWD) by herpetofauna and shrew species has been well documented in the Pacific Northwest and southern Appalachian Mountain regions of the United States, little information exists regarding the importance of CWD to herpetofaunal and shrew assemblages in pine forests of the southeastern Coastal Plain. Furthermore, few manipulative studies have assessed response to increased CWD volume. The primary objective of my study was to assess the response of herpetofauna and shrews to CWD manipulations in upland loblolly pine (Pinus taeda) stands of the South Carolina Coastal Plain physiographic region as part of an interdisciplinary study undertaken to better understand the ecological role of CWD in southeastern pine forests.

Moseley, Kurtis, Rooks

2004-06-01

333

Dugong dugon  

NSDL National Science Digital Library

Species profile of the dugong, Dugong dugon, including taxonomic classification, geographic range, biogeographic region, habitat, physical description, diet, behavior, reproduction, economic importance to humans and conservation status. Selected references and glossary are provided. Classification feature provides links to descriptions of each taxon, e.g. Animalia, Mammalia, Sirenia, etc., including images and details on anatomical features used in differentiating at each level. Appropriate for grades 7 and up.

334

New and already known acanthocephalans mostly from mammals in Vietnam, with descriptions of two new genera and species in Archiacanthocephala.  

PubMed

Adults of 2 new species and 2 new genera of acanthocephalans in class Archiacanthocephala, collected between 1998 and 2004 in Vietnam from the intestines of mammals, are described, i.e., Cucullanorhynchus constrictruncatus n. gen., n. sp. (Oligacanthorhynchidae) from a leopard Panthera pardus (Linnaeus) (Mammalia: Felidae) and Paraprosthenorchis ornatus n. gen. n. sp. (Oligacanthorhynchidae) from the Chinese pangolin Manis pentadactyla (Linnaeus) (Mammalia: Manidae). Adult Sphaerechinorhynchus macropisthospinus Amin, Wongsawad, Marayong, Saehoong, Suwattanacoupt, and Sey, 1998 (Plagiorhynchidae) are described for the first time from 2 females collected from a tiger Panthera tigris (Linnaeus) (Mammalia: Felidae) and from 1 male from a water monitor Varanus salvator Laurenti (Reptilia: Varanidae). Characteristic features distinguishing the new species or genera from related taxa are as follows. The trunk of C. constrictruncatus has an anterior hood in both sexes and a posterior constriction in females. The anterior trunk of P. ornatus has many small festoons and proboscis hooks are inserted in elevated papillae separated by beady, near hexagonal, ornate grids. PMID:18372641

Amin, Omar M; Ha, Ngyuen Van; Heckmann, Richard A

2008-02-01

335

[Development of telencephalon in Agapornis roseicollis Vieillot (Psittacidae) and its relationship to the evolution of the telencephalon in vertebrates].  

PubMed

1. The cerebral anlage of Agapornis roseicollis was investigated in serially cut slices during the developmental stages before hatching (day 3-day 20) by light microscopical quantitative and qualitative methods. 2. During earlier stages of development, the brain anlage is divided in three dorsally and four ventrally situated, longitudinally oriented matrix zones (D1-D3, V1-V4 according to Kuhlenbeck). In this developing system, mainly the lateral part of the telencephalic wall including its dorsal extension is considered to establish special importance for the further ontogenetic development. 3. The quite simple structure of the epistriatum in Reptils occurs as the neo-hyperstriatum-complex in Birds; likewise, deriving from the neocortex primitivus in Reptils, in Mammalia this part obviously develops to the more and more expanding neocortex as can be followed from lower mammalia species up to the highly developed Primates. According to the first main criterion of Remane, the homology of these parts of the brain in different vertebrates is most evident because these brain parts occupy exactly the same position in the brain anlage of early embryonal stages. 4. In Reptils, the neocortex primitivus appears as the last during ontogenetic development. Likewise in Birds, the neohyperstriatum-complex that is homologeous to the neocortex in Mammalia, differentiates during the final stages. These facts again emphasize the homology of these structures. 5. Further evidence for homology is obtained by the observation that in Agapornides the primordium of the neo-hyperstriatumcomplex contains migrating matrix cells columns, which also in Mammalia arrange into the same manner. Moreover, the transient and heterochronuous occurrence of cell layers at the outer surface of the brain anlage reminds to the development of palaeocortex and neocortex in Reptils and Mammalia. 6. From the point of view of evolution biology, the process of the progressive evolution is considered to be based on the step by step addition of tiny new structure-function-units to the already present morphology going along with a full structural and functional integration of the added, thus to achive the new quality. This so-called "Additive Morphogenesis" was effective during millions of years, consisting of such microevolutionary processes, and finally caused the "Gestaltungswandel", the ever changing evolving variety of bodily forms (and functions) that is recapitulated during individual species ontogenesis. PMID:8308262

Kirsche, W; Kirsche, K

1993-01-01

336

Propelling Students into Active Grammar Participation  

ERIC Educational Resources Information Center

"O! this learning, what a thing it is." -W. Shakespeare, "The Taming of the Shrew." The aim of this action research was to find out if active grammar involvement amongst students might lead to better results. My approach was to activate my students during grammar instruction by using cooperative learning: that is a form of learning in which…

Jurhill, Dennis A.

2011-01-01

337

Large Mesozoic mammals fed on young dinosaurs  

Microsoft Academic Search

Mesozoic mammals are commonly portrayed as shrew- or rat-sized animals that were mainly insectivorous, probably nocturnal and lived in the shadow of dinosaurs. The largest known Mesozoic mammal represented by substantially complete remains is Repenomamus robustus, a triconodont mammal from the Lower Cretaceous of Liaoning, China. An adult individual of R. robustus was the size of a Virginia opossum. Here

Yaoming Hu; Jin Meng; Yuanqing Wang; Chuankui Li

2005-01-01

338

Rickettsia felis in Xenopsylla cheopis, Java, Indonesia.  

PubMed

Rickettsia typhi and R. felis, etiologic agents of murine typhus and fleaborne spotted fever, respectively, were detected in Oriental rat fleas (Xenopsylla cheopis) collected from rodents and shrews in Java, Indonesia. We describe the first evidence of R. felis in Indonesia and naturally occurring R. felis in Oriental rat fleas. PMID:16965716

Jiang, Ju; Soeatmadji, Djoko W; Henry, Katherine M; Ratiwayanto, Sutanti; Bangs, Michael J; Richards, Allen L

2006-08-01

339

Intrinsic hand proportions of euarchontans and other mammals: Implications for the locomotor behavior of plesiadapiforms  

Microsoft Academic Search

Arboreal primates have distinctive intrinsic hand proportions compared with many other mammals. Within Euarchonta, platyrrhines and strepsirrhines have longer manual proximal phalanges relative to metacarpal length than colugos and terrestrial tree shrews. This trait is part of a complex of features allowing primates to grasp small-diameter arboreal substrates. In addition to many living and Eocene primates, relative elongation of proximal

E. Christopher Kirk; Pierre Lemelin; Mark W. Hamrick; Doug M. Boyer; Jonathan I. Bloch

2008-01-01

340

Antimicrobial Resistance in Escherichia coli Isolates from Swine and Wild Small Mammals in the Proximity of Swine Farms and in Natural Environments in Ontario, Canada  

Microsoft Academic Search

Wild animals not normally exposed to antimicrobial agents can acquire antimicrobial agent-resistant bacteria through contact with humans and domestic animals and through the environment. In this study we assessed the frequency of antimicrobial resistance in generic Escherichia coli isolates from wild small mammals (mice, voles, and shrews) and the effect of their habitat (farm or natural area) on antimicrobial resistance.

Gosia K. Kozak; Patrick Boerlin; Nicol Janecko; Richard J. Reid-Smith; Claire Jardine

2009-01-01

341

Potential mammalian reservoirs in a bubonic plague outbreak focus in Mbulu District, northern Tanzania, in 2007  

Microsoft Academic Search

This study investigated mammalian involvement in an outbreak of bubonic plague in Mbulu District, northern Tanzania, in March 2007. Plague is a rodent-borne zoo- notic disease that spreads to humans through fleas infected with Yersinia pestis. Live trapping of rodents and shrews was conducted in fallow and crop fields, peri- domestic areas, houses and the neighboring forest reserve. Serum was

Rhodes H. Makundi; Loth S. Mulungu; Abdul Katakweba; Thomas J. Mbise; Georgies Mgode

2008-01-01

342

Mental Illness and Violent Crime.  

National Technical Information Service (NTIS)

Throughout history, most societies have strongly believed that mental disorder is linked with violence. The earliest recorded account is found in a dialog written by Plato. William Shakespeare wrote of such a connection in The Taming of the Shrew and Henr...

J. Monahan

1996-01-01

343

Effect of soil pollution with metallic lead pellets on lead bioaccumulation and organ\\/body weight alterations in small mammals  

Microsoft Academic Search

Using small mammals as bioindicators, the bioavailable status and ecotoxicity of lead was investigated in an acidic sandy soil environment polluted with metallic lead pellets from shotgun ammunition. Average concentrations of lead in kidney, liver and bone tissue of wood mice (Apodemus sylvaticus), bank voles (Clethrionomys glareolus), and shrews (Sorex araneus) were strongly elevated, compared to tissue levels of conspecifics

Wei-chun Ma

1989-01-01

344

Introduction to Shakespeare: English.  

ERIC Educational Resources Information Center

The "Introduction to Shakespeare" course in the Quinmester Program involves the careful study of the tragedy "Romeo and Juliet" and the comedy "The Taming of the Shrew," emphasizing language, development of character and theme. The course also includes the study of biographical data relevant to the evolution of Shakespeare's literary genius, and…

Hargraves, Richard

345

Hippocampal Neurogenesis in Adult Old World Primates  

Microsoft Academic Search

The production of new hippocampal neurons in adulthood has been well documented in rodents. Recent studies have extended these findings to other mammalian species, such as tree shrews and marmoset monkeys. However, hippocampal neurogenesis has not been demonstrated in adult Old World primates. To investigate this possibility, we injected 11 adult Old World monkeys of different ages (5-23 years) with

Elizabeth Gould; Alison J. Reeves; Mazyar Fallah; Patima Tanapat; Charles G. Gross; Eberhard Fuchs

1999-01-01

346

Effects of predator removal on vertebrate prey populations: birds of prey and small mammals  

Microsoft Academic Search

We studied the effects of removal of breeding nomadic avian predators (the kestrel, Falco tinnunculus and Tengmalm's owl, Aegolius funereus) on small mammals (voles of the genera Microtus and Clethrionomys and the common shrew, Sorex araneus) during 1989–1992 in western Finland to find out if these predators have a regulating or limiting impact on their prey populations. We removed potential

Kai Norrdahl; Erkki Korpimäki

1995-01-01

347

Resolution among major placental mammal interordinal relationships with genome data imply that speciation influenced their earliest radiations  

Microsoft Academic Search

BACKGROUND: A number of the deeper divergences in the placental mammal tree are still inconclusively resolved despite extensive phylogenomic analyses. A recent analysis of 200 kbp of protein coding sequences yielded only limited support for the relationships among Laurasiatheria (cow, dog, bat and shrew), probably because the divergences occurred only within a few million years from each other. It is

Björn M Hallström; Axel Janke

2008-01-01

348

Model of the Fate of Chemicals in Sludge-Amended Soils with Uptake in Vegetation and Soil-Dwelling Organisms  

Microsoft Academic Search

The BASL4 (Biosolids Amended Soil Level 4) soil biota models are described, applied, and discussed. The models simulate the fate of organic chemicals present in biosolids that are applied to a two-layer soil and address the processes of chemical degradation, volatilization, leaching, and sorption to decaying organic matter. Uptake in invertebrates (worms), small mammals (shrews), and vegetation is simulated involving

Lauren Hughes; Don Mackay

2011-01-01

349

Prolonged hematopoiesis in a primate bone marrow culture system: characteristics of stem cell production and hematopoietic microenvironment  

Microsoft Academic Search

Maintenance of myelopoiesis and pluripo- tential stem cell production for prolonged periods in vitro hitherto has been limited to mouse bone marrow culture. In an effort to adapt the system for use in higher species, particularly in human and non-human primates, studies were undertaken using the prosimian species, Tupaia gus (tree shrew). In a number of experiments the duration of

M. A. S. Moore; A. P. C. Sheridan; T. D. Allen; T. M. Dexter

1979-01-01

350

Biological monitors of pollution  

SciTech Connect

This article discusses the use of biological monitors to assess the biological consequences of toxicants in the environment, such as bioavailability, synergism, and bioaccumulation through the food web. Among the organisms discussed are fly larvae, worms, bees, shellfish, fishes, birds (starlings, owls, hawks, songbirds) and mammals (rabbits, field mice, shrews).

Root, M.

1990-02-01

351

Effects of a stand-replacing fire on small-mammal communities in montane forest  

Microsoft Academic Search

Wildfire, ubiquitous and recurring over thousands of years, is the most important natural disturbance in northern coniferous forest. Accordingly, forest fires may exert a strong influence on the structure and functioning of small-mammal communities. We compared the composition of rodent and shrew communities in burned and unburned patches of a Doug- las-fir (Pseudotsuga menziesii (Mirbel) Franco) - western larch (Larix

Rafa? Zwolak; Kerry R. Foresman

2007-01-01

352

Delta9-tetrahydrocannabinol and cannabidiol, but not ondansetron, interfere with conditioned retching reactions elicited by a lithium-paired context in Suncus murinus: An animal model of anticipatory nausea and vomiting  

Microsoft Academic Search

Chemotherapy patients report not only acute nausea and vomiting during the treatment itself, but also report anticipatory nausea and vomiting upon re-exposure to the cues associated with the treatment. We present a model of anticipatory nausea based on the emetic reactions of the Suncus murinus (musk shrew). Following three pairings of a novel distinctive contextual cue with the emetic effects

Linda A. Parker; Magdalena Kwiatkowska; Raphael Mechoulam

2006-01-01

353

Tiny cystine stones in the gallbladder of a patient with cholecystolithiasis complicating acute cholecystitis: a case report.  

PubMed

Cystine stones, the main component of which is cystine, are very common urinary calculi, but are rare in the gall bladder. In animals, there has been only one report of cystine gallstones in tree shrews, and to our knowledge, this is the first report of cystine gallstones in humans. PMID:22472465

Qiao, Tie; Ma, Rui-Hong; Luo, Xiao-Bing; Feng, Yu-Yang; Wang, Xing-Qiang; Zheng, Pei-Ming; Luo, Zhen-Liang

2012-01-01

354

Molecular phylogeny of the superorder Archonta.  

PubMed Central

The superorder Archonta has been hypothesized to include primates, tree shrews, bats, and flying lemurs as descendants of a common ancestor. More recently, a diphyletic origin for bats has been proposed. To evaluate these hypotheses, the nucleotide sequence of the mitochondrial cytochrome oxidase subunit II gene was determined from a bushbaby (Galago senegalensis), flying lemur (Cynocephalus variegatus), tree shrew (Tupaia glis), spear-nosed bat (Phyllostomus hastatus), rousette bat (Rousettus leschenaulti), and nine-banded armadillo (Dasypus novemcinctus) and was compared with published sequences of a human, cow, and mouse. Phylogenetic analyses of the sequences give evidence that primates, tree shrews, and flying lemurs have a recent common ancestor but that bats are genealogically distant. The monophyletic origin of bats is supported. Contrary to interpretations based on morphological data, tree shrews are shown to be no more closely affiliated with primates than are flying lemurs. Analyses of the cytochrome oxidase subunit II gene give marginally more support to a Dermoptera-Scandentia clade than to a Dermoptera-Primates clade.

Adkins, R M; Honeycutt, R L

1991-01-01

355

Chronic Stress Decreases the Number of Parvalbumin-Immunoreactive Interneurons in the Hippocampus: Prevention by Treatment with a Substance P Receptor (NK1) Antagonist  

Microsoft Academic Search

Previous studies have demonstrated that stress may affect the hippocampal GABAergic system. Here, we examined whether long-term psychosocial stress influenced the number of parvalbumin-containing GABAergic cells, known to provide the most powerful inhibitory input to the perisomatic region of principal cells. Adult male tree shrews were submitted to 5 weeks of stress, after which immunocytochemical and quantitative stereological techniques were

Boldizsár Czeh; Mária Simon; Marieke GC van der Hart; Barthel Schmelting; Mayke B Hesselink; Eberhard Fuchs

2005-01-01

356

Astroglial Plasticity in the Hippocampus is Affected by Chronic Psychosocial Stress and Concomitant Fluoxetine Treatment  

Microsoft Academic Search

Analysis of post-mortem tissue from patients with affective disorders has revealed a decreased number of glial cells in several brain areas. Here, we examined whether long-term psychosocial stress influences the number and morphology of hippocampal astrocytes in an animal model with high validity for research on the pathophysiology of major depression. Adult male tree shrews were submitted to 5 weeks

Boldizsár Czéh; Mária Simon; Barthel Schmelting; Christoph Hiemke; Eberhard Fuchs

2006-01-01

357

On the systematic position of Hymenolepis blarinae Rausch & Kuns, 1950 (Cestoda, Hymenolepididae), with a re-description of the holotype  

Microsoft Academic Search

The systematic position of the cestode Hymenolepis blarinae Rausch & Kuns, 1950, a parasite of shrews in North America, is reconsidered. The authors disagree with both Yamaguti (1959), who transferred H. blarinae to the genus Rodentolepis, and Schmidt (1986), who considered Rodentolepis to be a synonym of Vampirolepis and transferred this species to the latter genus. The morphological characters of

Vasilij V. Tkach; Vadim V. Kornyushin

1997-01-01

358

The Alpha2B Adrenoceptor in the Paraventricular Thalamic Nucleus is Persistently Upregulated by Chronic Psychosocial Stress  

Microsoft Academic Search

Stress has been reported to regulate adrenergic receptors but it is not known whether it has an impact on the alpha-2 adrenoceptor subtype B that is strongly expressed in distinct nuclei of the thalamus. So far little is known about effects of stress on the thalamus. Using the chronic psychosocial stress paradigm in male tree shrews we analyzed alpha-2B adrenoceptor

U. Heilbronner; M. van Kampen; G. Flügge

2004-01-01

359

Antidepressant treatment with tianeptine reduces apoptosis in the hippocampal dentate gyrus and temporal cortex  

Microsoft Academic Search

BackgroundRecent clinical and preclinical studies suggest that major depression may be related to impairments of structural plasticity. Consequently, antidepressants may act by restoring altered rates of cell birth or death. Here, we investigated whether the antidepressant tianeptine would affect apoptosis in an animal model of depression, the psychosocially stressed tree shrew.

Paul J Lucassen; Eberhard Fuchs; Boldizsár Czéh

2004-01-01

360

Case 3058. Arctocephalus F. Cuvier, 1826 and Callorhinus Gray, 1859 (Mammalia, Pinnipedia): proposed conservation by the designation of Phoca pusilla Schreber, [1775] as the type species of Arctocephalus; and Otaria Peron, 1816 and Eumetopias Gill, 1866: proposed conservation by the designation of Phoca leonina Molina, 1782 as the type species of Otaria  

USGS Publications Warehouse

The purpose of this application is to conserve the accustomed understanding and usage of the fur seal name Arctocephalus F. Cuvier, 1826 by the designation of Phoca pusilia Schreber, [1775] as the type species, thus conserving also the name Callorhinus Gray, 1859. At present Phoca ursina Linnaeus, 1758 is the valid type species of both Arctocephalus and Callorhinus. The name Arctocephalus relates to a genus of some seven fur seals from the southern hemisphere, while Callorhinus is used for the single species C. ursinus (Linnaeus) from the northern hemisphere. It is also proposed that the universal understanding of the names Otaria Peron, 1816 and Eumetopias Gill, 1866 should be conserved for the southern and northern sea lions respectively by designating Phoca leonina Molina, 1782 (for which the valid specific name is P. byronia de Blainville, 1820) as the type species of Otaria. At present Phoca jubata Schreber, [1776] is the type species of Otaria and the name Otaria is a senior subjective synonym of Eumetopias. The four genera Arctocephalus, Callorhinus, Otaria and Eumetopias are all placed in the family OTARIIDAE Gray, 1825.

Gardner, A.L.; Robbins, C.B.

1999-01-01

361

Eyes in Various Species Can Shorten to Compensate for Myopic Defocus  

PubMed Central

Purpose. We demonstrated that eyes of young animals of various species (chick, tree shrew, marmoset, and rhesus macaque) can shorten in the axial dimension in response to myopic defocus. Methods. Chicks wore positive or negative lenses over one eye for 3 days. Tree shrews were measured during recovery from induced myopia after 5 days of monocular deprivation for 1 to 9 days. Marmosets were measured during recovery from induced myopia after monocular deprivation, or wearing negative lenses over one or both eyes, or from wearing positive lenses over one or both eyes. Rhesus macaques were measured after recovery from induced myopia after monocular deprivation, or wearing negative lenses over one or both eyes. Axial length was measured with ultrasound biometry in all species. Results. Tree shrew eyes showed a strong trend to shorten axially to compensate for myopic defocus. Of 34 eyes that recovered from deprivation-induced myopia for various durations, 30 eyes (88%) shortened, whereas only 7 fellow eyes shortened. In chicks, eyes wearing positive lenses reduced their rate of ocular elongation by two-thirds, including 38.5% of eyes in which the axial length became shorter than before. Evidence of axial shortening in rhesus macaque (40%) and marmoset (6%) eyes also occurred when exposed to myopic defocus, although much less frequently than that in eyes of tree shrews. The axial shortening was caused mostly by the reduction in vitreous chamber depth. Conclusions. Eyes of chick, tree shrew, marmoset, and rhesus macaque can shorten axially when presented with myopic defocus, whether the myopic defocus is created by wearing positive lenses, or is the result of axial elongation of the eye produced by prior negative lens wear or deprivation. This eye shortening facilitates compensation for the imposed myopia. Implications for human myopia control are significant.

Zhu, Xiaoying; McBrien, Neville A.; Smith, Earl L.; Troilo, David; Wallman, Josh

2013-01-01

362

Positive selection neighboring functionally essential sites and disease-implicated regions of mammalian reproductive proteins  

PubMed Central

Background Reproductive proteins are central to the continuation of all mammalian species. The evolution of these proteins has been greatly influenced by environmental pressures induced by pathogens, rival sperm, sexual selection and sexual conflict. Positive selection has been demonstrated in many of these proteins with particular focus on primate lineages. However, the mammalia are a diverse group in terms of mating habits, population sizes and germ line generation times. We have examined the selective pressures at work on a number of novel reproductive proteins across a wide variety of mammalia. Results We show that selective pressures on reproductive proteins are highly varied. Of the 10 genes analyzed in detail, all contain signatures of positive selection either across specific sites or in specific lineages or a combination of both. Our analysis of SP56 and Col1a1 are entirely novel and the results show positively selected sites present in each gene. Our findings for the Col1a1 gene are suggestive of a link between positive selection and severe disease type. We find evidence in our dataset to suggest that interacting proteins are evolving in symphony: most likely to maintain interacting functionality. Conclusion Our in silico analyses show positively selected sites are occurring near catalytically important regions suggesting selective pressure to maximize efficient fertilization. In those cases where a mechanism of protein function is not fully understood, the sites presented here represent ideal candidates for mutational study. This work has highlighted the widespread rate heterogeneity in mutational rates across the mammalia and specifically has shown that the evolution of reproductive proteins is highly varied depending on the species and interacting partners. We have shown that positive selection and disease are closely linked in the Col1a1 gene.

2010-01-01

363

Abundance and distribution of Xenopsylla cheopis on small mammals collected in West Java, Indonesia during rodent-borne disease surveys.  

PubMed

During February 2004 and September 2005, Xenopsylla cheopis were collected from small mammal hosts during rodent-bone disease surveys in Jakarta and Bandung, Indonesia. During 4 trap nights in Jakarta, 4 rodent species (Rattus exulans, Rattus norvegicus, Rattus tanezumi and Mus musculus) and one shrew species (Suncus murinus) were collected. Rattus tanezumi had the highest X. cheopis load (128 X. cheopis from 84 R. tanezumi) but R. norvegicus had the highest flea index, 1.8. In Bandung, over 6 trap nights 3 rodent species were collected (R. norvegicus, R. tanezumi and M. musculus) and the shrew, S. murinus, were collected. Rattus norvegicus had the highest number of X. cheopis collected (407 X. cheopis from 181 R. norvegicus) but R. tanezumi had the highest flea index, 3.5. During both surveys, X. cheopis was the species of flea collected. PMID:17333735

Ibrahim, Ima Nurisa; Winoto, Imelda; Wongsrichanalai, Chansuda; Blair, Patrick; Stoops, Craig

2006-09-01

364

Circumventing the polydactyly 'constraint': the mole's 'thumb'  

PubMed Central

Talpid moles across all northern continents exhibit a remarkably large, sickle-like radial sesamoid bone anterior to their five digits, always coupled with a smaller tibial sesamoid bone. A possible developmental mechanism behind this phenomenon was revealed using molecular markers during limb development in the Iberian mole (Talpa occidentalis) and a shrew (Cryptotis parva), as shrews represent the closest relatives of moles but do not show these conspicuous elements. The mole's radial sesamoid develops later than true digits, as shown by Sox9, and extends into the digit area, developing in relation to an Msx2-domain at the anterior border of the digital plate. Fgf8 expression, marking the apical ectodermal ridge, is comparable in both species. Developmental peculiarities facilitated the inclusion of the mole's radial sesamoid into the digit series; talpid moles circumvent the almost universal pentadactyly constraint by recruiting wrist sesamoids into their digital region using a novel developmental pathway and timing.

Mitgutsch, Christian; Richardson, Michael K.; Jimenez, Rafael; Martin, Jose E.; Kondrashov, Peter; de Bakker, Merijn A. G.; Sanchez-Villagra, Marcelo R.

2012-01-01

365

Venomous mammals.  

PubMed

It is not widely appreciated that mammals can be venomous in the manner of snakes and lizards. However, it was first demonstrated scientifically 50 years ago in the case of the American short-tailed shrew. Subsequently, similar evidence has been obtained from European shrews and the Haitian solenodon, but research in this area has been almost completely neglected for the last 20 years. In complete contrast to what has been learned about other animal venoms, the identity and mode of action of mammal venom toxins are still unknown. This review draws attention once more to the pioneering work undertaken in the 1940s and 1950s, exploring in more detail than hitherto why the implications of mammal venom are just as important as the chemistry and pharmacology of the phenomenon itself. PMID:1641406

Dufton, M J

1992-01-01

366

Light levels, refractive development, and myopia--a speculative review.  

PubMed

Recent epidemiological evidence in children indicates that time spent outdoors is protective against myopia. Studies in animal models (chick, macaque, tree shrew) have found that light levels (similar to being in the shade outdoors) that are mildly elevated compared to indoor levels, slow form-deprivation myopia and (in chick and tree shrew) lens-induced myopia. Normal chicks raised in low light levels (50 lux) with a circadian light on/off cycle often develop spontaneous myopia. We propose a model in which the ambient illuminance levels produce a continuum of effects on normal refractive development and the response to myopiagenic stimuli such that low light levels favor myopia development and elevated levels are protective. Among possible mechanisms, elevation of retinal dopamine activity seems the most likely. Inputs from intrinsically-photosensitive retinal ganglion cells (ipRGCs) at elevated light levels may be involved, providing additional activation of retinal dopaminergic pathways. PMID:23680160

Norton, Thomas T; Siegwart, John T

2013-09-01

367

The new locality of Ixodes apronophorus Schulze, 1924 in Biebrza National Park, Poland.  

PubMed

The new locality of Ixodes apronophorus Schulze, 1924 in Biebrza National Park, Poland is recorded. The study was conducted in open wet-meadow habitat (Caricetum appropinquatae), in April 2007. The small mammals were caught in live-traps placed at permanent trap stations. The ectoparasites were collected from the fur using combing out method. The adult female, nymphs and larva of Ixodes apronophorus were found, feeding on the common shrew Sorex araneus. PMID:18441883

Karbowiak, Grzegorz; Wieczorek, Monika; Borowski, Zbigniew; Wita, Irena

2007-01-01

368

Maximum Likelihood Analysis of the Complete Mitochondrial Genomes of Eutherians and a Reevaluation of the Phylogeny of Bats and Insectivores  

Microsoft Academic Search

.   The complete mitochondrial genomes of two microbats, the horseshoe bat Rhinolophus pumilus, and the Japanese pipistrelle Pipistrellus abramus, and that of an insectivore, the long-clawed shrew Sorex unguiculatus, were sequenced and analyzed phylogenetically by a maximum likelihood method in an effort to enhance our understanding of\\u000a mammalian evolution. Our analysis suggested that (1) a sister relationship exists between moles

Masato Nikaido; Kuniko Kawai; Yin Cao; Masashi Harada; Satoru Tomita; Norihiro Okada; Masami Hasegawa

2001-01-01

369

SMALL MAMMAL RECOLONIZATION OF RECLAIMED COAL SURFACE-MINED LAND IN WYOMING1  

Microsoft Academic Search

Small mammal populations were compared on unmined rangeland and reclaimed coal surface- mined land reseeded 2 years and 3-5 years previously. Eight species of small mammals were present on the 3-5-year-old reclaimed areas compared with six on 2-year-old areas and five on unmined rangeland. The masked shrew (Sorex cinereus) and northern grasshopper mouse (Onychomys leucogaster) were captured almost exclusively on

TERRENCE M. HINGTGEN

370

Involution of the auditory neuro-epithelium in a tiger (Panthera tigris) and a jaguar (Panthera onca).  

PubMed

Numerical atrophy of the hair cells of the organ of Corti of the inner ear in a 14-year-old tiger and a 17-year-old jaguar is described. The decrease in number of sensory hair cells is considered to represent physiological atrophy caused by the process of ageing. The findings are compared with previous observations on man, guinea-pigs, shrews, and bats. The development of the physiological involution of the hearing neuro-epithelium is discussed. PMID:6699224

Ulehlová, L; Burda, H; Voldrich, L

1984-01-01

371

Studies on hantavirus infection in small mammals captured in southern and central highland area of Vietnam.  

PubMed

To investigate the distribution of hantaviruses among animals in Southern and Central Highland area of Vietnam, a total of 1311 serum samples were obtained from rats and Asian house shrews (Suncus murinus) captured at 11 locations between 2006 and 2009. A total of 1066 serum samples from rats were examined for IgG antibodies against Hantaan virus, and there were 30 antibody-positive serum samples from rats that had been captured mainly in a port area and urban area in Ho Chi Minh City (HCMC) (2.8%). All of the antibody-positive rats were Rattus norvegicus, and they had Seoul virus (SEOV) genome in their lungs. SEOV sequences detected from rats captured in Southern Vietnam belonged to the same lineage as those from rats captured at Haiphong Port and a market area in Hanoi City. SEOV strain CSG5 was isolated from a rat captured at Saigon Harbor. Strain CSG5 showed a cross-neutralization pattern almost the same as that of a representative strain of SEOV. A total of 245 Asian house shrews were captured in the Central Highland area and near HCMC. Sera were examined for IgG antibodies against Thottapalayam virus (TPMV), and 32 (13.1%) of the antibody-positive shrews were mainly from the Central Highland area and showed a neutralizing antibody against TPMV. These results indicated that SEOV is distributed among R. norvegicus inhabiting harbor and urban areas of Southern Vietnam and that TPMV or an antigenically related virus is distributed among Asian house shrews in Central Highland area. PMID:22673720

Luan, Vu Dinh; Yoshimatsu, Kumiko; Endo, Rika; Taruishi, Midori; Huong, Vo Thi; Dat, Dang Tuan; Tien, Pham Cong; Shimizu, Kenta; Koma, Takaaki; Yasuda, Shumpei P; Nhi, Le; Huong, Vu Thi Que; Arikawa, Jiro

2012-09-01

372

Pneumocystis carinii infections in zoo animals  

Microsoft Academic Search

Summary Pneumocystis carinii was found to be present in the lungs of twenty-three zoo animals in the Netherlands. The following species were represented: red kangaroo, common tree shrew, Senegal-Galago, Demidoff's-Galago, brown howler monkey, woolly monkey, long-haired spider monkey, white-eared marmoset, chimpanzee, three-toed sloth, palm squirrel, red panda, fennec fox, tree hyrax and large-toothed hyrax.

F. G. Poelma

1975-01-01

373

Pneumocystis carinii infections in zoo animals.  

PubMed

Pneumocystis carinii was found to be present in the lungs of twenty-three zoo animals in the Netherlands. The following species were represented: red kangaroo, common tree shrew, Senegal-Galago, Demidoff's-Galago, brown howler monkey, woolly monkey, long-haired spider monkey, white-eared marmoset, chimpanzee, three-toed sloth, palm squirrel, red panda, fennec fox, tree hyrax and large-toothed hyrax. PMID:1079994

Poelma, F G

1975-01-01

374

Posture Does Not Matter! Paw Usage and Grasping Paw Preference in a Small-Bodied Rooting Quadrupedal Mammal  

PubMed Central

Background Recent results in birds, marsupials, rodents and nonhuman primates suggest that phylogeny and ecological factors such as body size, diet and postural habit of a species influence limb usage and the direction and strength of limb laterality. To examine to which extent these findings can be generalised to small-bodied rooting quadrupedal mammals, we studied trees shrews (Tupaia belangeri). Methodology/Principal Findings We established a behavioural test battery for examining paw usage comparable to small-bodied primates and tested 36 Tupaia belangeri. We studied paw usage in a natural foraging situation (simple food grasping task) and measured the influence of varying postural demands (triped, biped, cling, sit) on paw preferences by applying a forced-food grasping task similar to other small-bodied primates. Our findings suggest that rooting tree shrews prefer mouth over paw usage to catch food in a natural foraging situation. Moreover, we demonstrated that despite differences in postural demand, tree shrews show a strong and consistent individual paw preference for grasping across different tasks, but no paw preference at a population level. Conclusions/Significance Tree shrews showed less paw usage than small-bodied quadrupedal and arboreal primates, but the same paw preference. Our results confirm that individual paw preferences remain constant irrespective of postural demand in some small-bodied quadrupedal non primate and primate mammals which do not require fine motoric control for manipulating food items. Our findings suggest that the lack of paw/hand preference for grasping food at a population level is a universal pattern among those species and that the influence of postural demand on manual lateralisation in quadrupeds may have evolved in large-bodied species specialised in fine manipulations of food items.

Joly, Marine; Scheumann, Marina; Zimmermann, Elke

2012-01-01

375

Allometry of left ventricular myocardial innervation.  

PubMed

Body mass (BM) of terrestrial mammalian species ranges from a few grams in the case of the Etruscan shrew to a few tonnes for an elephant. The mass-specific metabolic rate, as well as heart rate, decrease with increasing BM, whereas heart mass is proportional to BM. In the present study, we investigated the scaling behaviour of several compartments of the left ventricular myocardium, notably its innervation, capillaries and cardiomyocytes. Myocardial samples were taken from 10 mammalian species with BM between approximately 2 g and 900 kg. Samples were analysed by design-based stereology and electron microscopy and the resulting data were subjected to linear regression and correlation analyses. The total length of nerve fibres (axons) in the left ventricle increased from 0.017 km (0.020 km) in the shrew to 7237 km (13,938 km) in the horse. The innervation density was similar among species but the mean number of axons per nerve fibre profile increased with rising BM. The total length of capillaries increased from 0.119 km (shrew) to 10,897 km (horse). The volume of cardiomyocytes was 0.017 cm(3) in the shrew and 1818 cm(3) in the horse. Scaling of the data against BM indicated a higher degree of complexity of the axon tree in larger animals and an allometric relationship between total length of nerve fibres/axons and BM. In contrast, the density of nerve fibres is independent of BM. It seems that the structural components of the autonomic nervous system in the heart are related to BM and heart mass rather than to functional parameters such as metabolic rate. PMID:24325466

Schipke, Julia; Mayhew, Terry M; Mühlfeld, Christian

2014-04-01

376

Discovery of hantaviruses in bats and insectivores and the evolution of the genus Hantavirus.  

PubMed

Hantaviruses are among the most important zoonotic pathogens of humans, causing either hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS). From the period 1964-2006 almost all hantaviruses had been identified in rodents, with the exception of Thottapalayam virus (TPMV) isolated from shrews sampled in India. As a consequence, rodents were considered as the natural reservoir hosts. However, over the past seven years, most of the newly found hantavirus genotypes have been from either shrews or moles. Remarkably, in recent years divergent hantaviruses have also been identified in bats sampled from both Africa and Asia. All these data indicate that hantaviruses have a broad range of natural reservoir hosts. Phylogenetic analyses of the available sequences of hantaviruses suggest that hantaviruses might have first appeared in Chiroptera (bats) or Soricomorpha (moles and shrews), before emerging in rodent species. Although rodent hantaviruses cluster according to whether their hosts are members of the Murinae and Cricetidae, the phylogenetic histories of the viruses are not always congruent with those of their hosts, indicating that cross-species transmission events have occurred at all taxonomic levels. In sum, both cross-species transmission and co-divergence have produced the high genetic diversity of hantaviruses described to date. PMID:24509342

Zhang, Yong-Zhen

2014-07-17

377

[Hantaviruses in Germany: threat for zoo, pet, companion and farm animals?].  

PubMed

Hantaviruses are so-called "emerging" and "re-emerging" viruses because of the new and sudden nature of their appearance. Human infections can lead to two distinct disease patterns, the Haemorrhagic Fever with Renal Syndrome and the Hantavirus Cardiopulmonary Syndrome. All known human pathogenic hantaviruses are transmitted through rodent hosts. There are three rodent-associated hantaviruses in Germany. The bank vole-associated Puumala virus (PUUV) is responsible for most of the human hantavirus infections. The Dobrava-Belgrade virus (DOBV) associated with the striped field mouse is causing hantavirus disease in the North and Northeast of Germany. The human pathogenicity of Tula virus (TULV) is still controversially discussed--the virus has been mainly associated with the common vole as the reservoir, but was molecularly detected also in the field and the water vole. More recently, two shrew-borne hantaviruses were described in Germany, i. e. Seewis virus in the common shrew and Asikkala virus in the pygmy shrew. Systematic studies about hantavirus infections of zoo, pet, companion and farm animals are still lacking. Hence, the aim of this review article is to summarise the current knowledge on this topic and raise the attention of veterinarians to potentially overlooked clinical disease patterns. PMID:24511827

Ulrich, Rainer G; Imholt, Christian; Krüger, Detlev H; Krautkrämer, Ellen; Scheibe, Thomas; Essbauer, Sandra S; Pfeffer, Martin

2013-01-01

378

The evolution of micro-cursoriality in mammals.  

PubMed

In this study we report on the evolution of micro-cursoriality, a unique case of cursoriality in mammals smaller than 1 kg. We obtained new running speed and limb morphology data for two species of elephant-shrews (Elephantulus spp., Macroscelidae) from Namaqualand, South Africa, which we compared with published data for other mammals. Elephantulus maximum running speeds were higher than those of most mammals smaller than 1 kg. Elephantulus also possess exceptionally high metatarsal:femur ratios (1.07) that are typically associated with fast unguligrade cursors. Cursoriality evolved in the Artiodactyla, Perissodactyla and Carnivora coincident with global cooling and the replacement of forests with open landscapes in the Oligocene and Miocene. The majority of mammal species, though, remained non-cursorial, plantigrade and small (<1 kg). The extraordinary running speed and digitigrady of elephant-shrews was established in the Early Eocene in the earliest macroscelid Prodiacodon, but was probably inherited from Paleocene, Holarctic stem macroscelids. Micro-cursoriality in macroscelids evolved from the plesiomorphic plantigrade foot of the possum-like ancestral mammal earlier than in other mammalian crown groups. Micro-cursoriality evolved first in forests, presumably in response to selection for rapid running speeds facilitated by local knowledge, in order to avoid predators. During the Miocene, micro-cursoriality was pre-adaptive to open, arid habitats, and became more derived in the newly evolved Elephantulus and Macroscelides elephant-shrews with trail running. PMID:24436375

Lovegrove, Barry G; Mowoe, Metobor O

2014-04-15

379

Reproductive characteristics of the african pygmy hedgehog, atelerix albiventris.  

PubMed

To obtain further perspective on reproduction and particularly gamete function among so-called primitive mammals presently grouped in the Order Insectivora, we have examined the African hedgehog, Atelerix albiventris, in light of unusual features reported in shrews and moles. Atelerix proves to share many but not all of the characteristics seen in these other insectivores. The penis of Atelerix has a 'snail-like' form, but lacks the surface spines common in insectivores and a number of other mammals. Hedgehog spermatozoa display an eccentric insertion of the tail on the sperm head, and they manifest the barbs on the perforatorium that, in shrews, probably effect the initial binding of the sperm head to the zona pellucida. As a possible correlate, the structural matrix of the hedgehog acrosome comprises only two main components, as judged by immunoblotting, rather than the complex of peptides seen in the matrix of some higher mammals. The Fallopian tube of Atelerix is relatively simple; it displays only minor differences in width and in the arborized epithelium between the isthmus and ampulla, and shows no evidence of the unusual sperm crypts that characterize the isthmus or ampulla, depending on the species, in shrews and moles. In common with other insectivores, Atelerix appears to be an induced ovulator, as judged by the ovulation of some 6-8 eggs by about 23 h after injection of hCG. The dense cumulus oophorus appeared to have little matrix, in keeping with the modest dimensions of the tubal ampulla and, while it was not quite as discrete as that of soricids, it did show the same insensitivity to 0.5% (w/v) ovine or bovine hyaluronidase. PMID:11006156

Bedford, J M; Mock, O B; Nagdas, S K; Winfrey, V P; Olson, G E

2000-09-01

380

Tick-borne zoonotic bacteria in wild and domestic small mammals in northern Spain.  

PubMed

The prevalence and diversity of tick-borne zoonotic bacteria (Borrelia spp., Anaplasma phagocytophilum, Coxiella burnetii, and spotted fever group rickettsiae) infecting 253 small mammals captured in the Basque Country (Spain) were assessed using PCR and reverse line blot hybridization. Trapping sites were selected around sheep farms (study 1, 2000 to 2002) and recreational parks (study 2, 2003 to 2005). The majority of the studied mammals (162) were wood mice (Apodemus sylvaticus), but six other different species were also analyzed: yellow-necked mice (Apodemus flavicollis), shrews (Crocidura russula and Sorex coronatus), bank voles (Clethrionomys glareolus), domestic mice (Mus domesticus), and moles (Talpa europaea). The results showed an infection rate ranging from 10.7% to 68.8%, depending on the small mammal species. One C. russula shrew and one A. sylvaticus mouse gave positive reactions for A. phagocytophilum, and C. burnetii was detected in two domestic mice and one A. sylvaticus mouse in a farm. The DNA of Borrelia spp. was detected in 67 animals (26.5%), most of them presenting positive hybridization with the probe for Borrelia sp. strain R57, the new Borrelia species previously detected in small mammals in our region. Furthermore, a second PCR and reverse line blot hybridization specific for B. burgdorferi sensu lato revealed the presence of Borrelia afzelii in 6.3% of C. glareolus voles and 14.3% of S. coronatus shrews. All small mammals were negative for spotted fever group rickettsiae. These results highlight the relevance of small mammals as reservoirs of some zoonotic bacteria. PMID:17693556

Barandika, J F; Hurtado, A; García-Esteban, C; Gil, H; Escudero, R; Barral, M; Jado, I; Juste, R A; Anda, P; García-Pérez, A L

2007-10-01

381

Metal contamination in wildlife living near two zinc smelters  

USGS Publications Warehouse

Wildlife in an oak forest on Blue Mountain was studied 10 km upwind (Bake Oven Knob site) and 2 km downwind (Palmerton site) of two zinc smelters in eastern Pennsylvania, USA. Previous studies at sites near these smelters had shown changes in populations of soil microflora, lichens, green plants and litter-inhabiting arthropods. The 02 soil litter horizon at Palmerton was heavily contaminated with Pb (2700 mg kg-1), Zn (24000 mg kg-1), and Cd (710 mg kg-1), and to a lesser extent with Cu (440 mg kg-1). Various kinds of invertebrates (earthworms, slugs and millipedes) that feed on soil litter or soil organic matter were rare at, or absent from, the Palmerton site. Those collected at Bake Oven Knob tended to have much higher concentrations of metals than did other invertebrates. Frogs, toads and salamanders were very rare at, or absent from, the Palmerton site, but were present at Bake Oven Knob and at other sites on Blue Mountain farther from the smelters. Metal concentrations (dry wt) in different organisms from Palmerton were compared. Concentrations of Pb were highest in shrews (110 mg kg-1), followed by songbirds (56 mg kg-1), leaves (21 mg kg-1), mice (17 mg kg-1), carrion insects (14 mg kg-1), berries (4.0 mg kg-1), moths (4,3 mg kg-1) and fungi (3.7 mg kg-1). Concentrations of Cd, in contrast, were highest in carrion insects (25 mg kg-1 ),followed by fungi (9.8 mg kg-1), leaves (8.1 mg kg-1), shrews (7.3 mg kg-I), moths (4.9 mg kg-1), mice (2.6 mg kg -1), songbirds (2.5 mg kg -1) and berries (1.2 mg kg-1). Concentrations of Zn and Cu tended to be highest in the same organisms that had the highest concentrations of Cd. Only a small proportion of the metals in the soil became incorporated into plant foliage, and much of the metal contamination detected in the biota probably came from aerial deposition. The mice from both sites seemed to be healthy. Shrews had higher concentrations of metals than did mice, and one shrew showed evidence of Pb poisoning; its red blood cell ALAD activity was greatly reduced, one kidney contained acid-fast intranuclear inclusion bodies, and the other kidney had 280 mg kg-1 Pb (wet wt). The livers from two cuckoos from Palmerton had elevated Pb concentrations (18 and 25 mg kg-1, wet wt). Most of the songbirds seemed to be healthy.

Beyer, W.N.; Pattee, O.H.; Sileo, L.; Hoffman, D.J.; Mulhern, B.M.

1985-01-01

382

The monoclonal antibody H386F labels microglia in the retinal nerve fiber layer of several mammals.  

PubMed

The antibody H386F revealed microglia in the retinae of several species: owl monkey, slow loris, galago, ferret, raccoon, and tree shrew. The shape, size, and density of labeled microglia were identical to those labeled by OX-42 and OX-41, two antibodies specific for microglia, in both galago and owl monkey. The labeled microglia varied little in retinal location. There was remarkably little variability in density, shape, number, and size of the labeled microglia between species. All labeled microglia were evenly distributed across, but restricted to, the nerve fiber layer. Possible reasons for this restriction in location are discussed. PMID:9278995

Tumosa, N; Baker, J R

1997-01-01

383

[Studies of hereditary conditionality index on some morphological characters of Tupaia belangeri chinensis].  

PubMed

Tree shrew is a kind of excellent experimental animal resource in medical science and biology. In this paper, 35 Tupaia blangeri chinensises (TBCs) captured from Kunming,Yunnan province were investigated. We analyzed hereditary conditionality index about some morphological characters. According to Rife-Buranamanas law, we analyzed the appearance characteristics with hereditary conditionality including color of fur, orbit etc. The results showed the following: wild fur with seasonal red spot, white fur of abdomen, non-white orbit, flesh-color palm, non-cocked ear, round tip tail, and the line between the breasts of both sides in a vertical position with axis line. PMID:15640044

Yu, Yong-Mei; Wu, Yi-Qian; Qian, Geng-Sun; Chang, Hong

2004-07-01

384

Non-contiguous finished genome sequence and description of Bartonella florenciae sp. nov.  

PubMed Central

Bartonella florenciae sp. nov. strain R4T is the type strain of B. florenciae sp. nov., a new species within the genus Bartonella. This strain, whose genome is described here, was isolated in France from the spleen of the shrew Crocidura russula. B. florenciae is an aerobic, rod-shaped, Gram-negative bacterium. Here we describe the features of this organism, together with the complete genome sequence and its annotation. The 2,010,844 bp-long genome contains 1,909 protein-coding and 46 RNA genes, including two rRNA operons.

Mediannikov, Oleg; El Karkouri, Khalid; Robert, Catherine; Fournier, Pierre-Edouard; Raoult, Didier

2013-01-01

385

Development of the Human Breast  

PubMed Central

Mammalia are so named based on the presence of the mammary gland in the breast. The mammary gland is an epidermal appendage, derived from the apocrine glands. The human breast consists of the parenchyma and stroma, originating from ectodermal and mesodermal elements, respectively. Development of the human breast is distinctive for several reasons. The human breast houses the mammary gland that produces and delivers milk through development of an extensive tree-like network of branched ducts. It is also characterized by cellular plasticity, with extensive remodeling in adulthood, a factor that increases its susceptibility to carcinogenesis. Also, breast development occurs in distinct stages via complex epithelial–mesenchymal interactions, orchestrated by signaling pathways under the regulation of systemic hormones. Congenital and acquired disorders of the breast often have a basis in development, making its study essential to understanding breast pathology.

Javed, Asma; Lteif, Aida

2013-01-01

386

Regulation of the Mammalian elongation cycle by subunit rolling: a eukaryotic-specific ribosome rearrangement.  

PubMed

The extent to which bacterial ribosomes and the significantly larger eukaryotic ribosomes share the same mechanisms of ribosomal elongation is unknown. Here, we present subnanometer resolution cryoelectron microscopy maps of the mammalian 80S ribosome in the posttranslocational state and in complex with the eukaryotic eEF1A?Val-tRNA?GMPPNP ternary complex, revealing significant differences in the elongation mechanism between bacteria and mammals. Surprisingly, and in contrast to bacterial ribosomes, a rotation of the small subunit around its long axis and orthogonal to the well-known intersubunit rotation distinguishes the posttranslocational state from the classical pretranslocational state ribosome. We term this motion "subunit rolling." Correspondingly, a mammalian decoding complex visualized in substates before and after codon recognition reveals structural distinctions from the bacterial system. These findings suggest how codon recognition leads to GTPase activation in the mammalian system and demonstrate that in mammalia subunit rolling occurs during tRNA selection. PMID:24995983

Budkevich, Tatyana V; Giesebrecht, Jan; Behrmann, Elmar; Loerke, Justus; Ramrath, David J F; Mielke, Thorsten; Ismer, Jochen; Hildebrand, Peter W; Tung, Chang-Shung; Nierhaus, Knud H; Sanbonmatsu, Karissa Y; Spahn, Christian M T

2014-07-01

387

CEPiNS: Conserved Exon Prediction in Novel Species.  

PubMed

Exon structure is relatively well conserved among orthologs in several large clades of species (e.g. Mammalia, Diptera, Lepidoptera) across evolutionary distances of up to 80 million years. Thus, it should be straightforward to predict the exon structures in novel species based upon the known exon structures of species that have had their genomes sequenced and well assembled. Being able to predict the exon boundaries in the genes of novel species is important given the quickly growing numbers of transcriptome sequencing projects. CEPiNS is a new pipeline for mining exon boundaries of predicted gene sets from model species and then using this information to identify the exon boundaries in a novel species through codon based alignment. The pipeline uses the freeware SPIDEY, an exon boundary prediction tool, and BLAST (BLASTN, BLASTP, TBLASTX), both of which are part of NCBI's toolkit. CEPiNS provides an important tool to analyze the transcriptome of novel species. PMID:23519394

Hasan, Shihab; Wheat, Christopher W

2013-01-01

388

The delayed rise of present-day mammals.  

PubMed

Did the end-Cretaceous mass extinction event, by eliminating non-avian dinosaurs and most of the existing fauna, trigger the evolutionary radiation of present-day mammals? Here we construct, date and analyse a species-level phylogeny of nearly all extant Mammalia to bring a new perspective to this question. Our analyses of how extant lineages accumulated through time show that net per-lineage diversification rates barely changed across the Cretaceous/Tertiary boundary. Instead, these rates spiked significantly with the origins of the currently recognized placental superorders and orders approximately 93 million years ago, before falling and remaining low until accelerating again throughout the Eocene and Oligocene epochs. Our results show that the phylogenetic 'fuses' leading to the explosion of extant placental orders are not only very much longer than suspected previously, but also challenge the hypothesis that the end-Cretaceous mass extinction event had a major, direct influence on the diversification of today's mammals. PMID:17392779

Bininda-Emonds, Olaf R P; Cardillo, Marcel; Jones, Kate E; MacPhee, Ross D E; Beck, Robin M D; Grenyer, Richard; Price, Samantha A; Vos, Rutger A; Gittleman, John L; Purvis, Andy

2007-03-29

389

A review of experimental and natural infections of animals with monkeypox virus between 1958 and 2012  

PubMed Central

Monkeypox virus (MPXV) was discovered in 1958 during an outbreak in an animal facility in Copenhagen, Denmark. Since its discovery, MPXV has revealed a propensity to infect and induce disease in a large number of animals within the mammalia class from pan-geographical locations. This finding has impeded the elucidation of the natural host, although the strongest candidates are African squirrels and/or other rodents. Experimentally, MPXV can infect animals via a variety of multiple different inoculation routes; however, the natural route of transmission is unknown and is likely to be somewhat species specific. In this review we have attempted to compile and discuss all published articles that describe experimental or natural infections with MPXV, dating from the initial discovery of the virus through to the year 2012. We further discuss the comparative disease courses and pathologies of the host species.

Parker, Scott; Buller, R Mark

2013-01-01

390

Canid mating systems, social behavior, parental care and ontogeny: are they flexible?  

PubMed

Benson Ginsburg's early studies of canid socialization and wolf social and reproductive behavior were focused, in part, on the degree to which there was flexibility in social development and specifically whether there was a critical period during development after which wolf pups could not be socialized to humans. My focus was the degree to which differences in canid ecology and social structure were correlated with differences in the plasticity of social and reproductive behavior, including development. Canid species are unusual among the Mammalia in being primarily monogamous. Males may play an indirect or direct role in parental care, depending on a species degree of sociality. Canid species also differ in developmental parameters, and reproductive suppression is common in the group-living pack hunters. I review comparative studies of the social and reproductive behavior of three South American canids which vary in their degree of sociality and explore the degree to which the species are ecologically and socially flexible. PMID:21487689

Kleiman, Devra G

2011-11-01

391

Expression of histo-blood group antigens in vertebrate gonads.  

PubMed

The tissue expression of human histo-blood group antigens (HBGA) in vertebrates, as well as their evolutionary tendencies and relation to histogenesis, especially in the reproductive system, are not entirely understood.The present research comprises a large-scale immunohistochemical study of HBGA A and B expression in ovaries and testicles of 14 species belonging to six classes of free-living vertebrates from Chondrichtyes to Mammalia .We present novel data for ABH antigen reactivity in reproductive organs of vertebrates which have not been studied so far. Our results suggest that HBGA are evolutionary stable structures, most possibly related to vitellogenesis in oocytes with high yolk content. The tendency observed in A and B antigen expression is mostly associated with the processes of gamete differentiation and vitellogenesis, rather than with the evolutionary development of vertebrate species. PMID:20194100

Tomova, Elena S; Sarafian, Victoria S

2010-03-01

392

CEPiNS: Conserved Exon Prediction in Novel Species  

PubMed Central

Exon structure is relatively well conserved among orthologs in several large clades of species (e.g. Mammalia, Diptera, Lepidoptera) across evolutionary distances of up to 80 million years. Thus, it should be straightforward to predict the exon structures in novel species based upon the known exon structures of species that have had their genomes sequenced and well assembled. Being able to predict the exon boundaries in the genes of novel species is important given the quickly growing numbers of transcriptome sequencing projects. CEPiNS is a new pipeline for mining exon boundaries of predicted gene sets from model species and then using this information to identify the exon boundaries in a novel species through codon based alignment. The pipeline uses the freeware SPIDEY, an exon boundary prediction tool, and BLAST (BLASTN, BLASTP, TBLASTX), both of which are part of NCBI’s toolkit. CEPiNS provides an important tool to analyze the transcriptome of novel species.

Hasan, Shihab; Wheat, Christopher W

2013-01-01

393

Unexpected primitive rodents in the Quaternary of Argentina  

NASA Astrophysics Data System (ADS)

This article describes the first fossils recorded in the Hernandarias Formation (Pleistocene) in Entre Ríos province (eastern Argentina). They are represented by three teeth assigned to the caviomorph rodents (Rodentia, Mammalia) Aenigmys diamantensis gen. et sp. nov. and Eumysops. To establish the phylogenetic affinities of the two most enigmatic teeth, their enamel microstructure was studied. Aenigmys diamantensis is considered the most primitive taxon of a clade formed by Dinomyidae-Neoepiblemidae-Heptaxodontidae. Evidence of the close relationships among these families also is presented herein. The new fossils reinforce previous hypotheses about the survival of primitive Brazilian taxa after their extinction in the Pampas and Patagonia of southern South America. They also show that the diversity of caviomorph rodents during the Quaternary was greater than supposed and that an important Quaternary extinction, not previously detected, affected several lineages. With the available evidence, it is not possible to determine if these rodents indicate a warm pulse or a particular biogeographic situation in Entre Ríos.

Vucetich, María G.; Vieytes, Emma C.; Verzi, Diego H.; Noriega, Jorge I.; Tonni, Eduardo P.

2005-10-01

394

PhyloMarker--A Tool for Mining Phylogenetic Markers Through Genome Comparison: Application of the Mouse Lemur (Genus Microcebus) Phylogeny  

PubMed Central

Molecular phylogeny is a fundamental tool to understanding the evolution of all life forms. One common issue faced by molecular phylogeny is the lack of sufficient molecular markers. Here, we present PhyloMarker, a phylogenomic tool designed to find nuclear gene markers for the inference of phylogeny through multiple genome comparison. Around 800 candidate markers were identified by PhyloMarker through comparison of partial genomes of Microcebus and Otolemur. In experimental tests of 20 randomly selected markers, nine markers were successfully amplified by PCR and directly sequenced in all 17 nominal Microcebus species. Phylogenetic analyses of the sequence data obtained for 17 taxa and nine markers confirmed the distinct lineage inferred from previous mtDNA data. PhyloMarker has also been used by other projects including the herons (Ardeidae, Aves) phylogeny and the Wood mice (Muridae, Mammalia) phylogeny. All source code and sample data are made available at http://bioinfo-srv1.awh.unomaha.edu/phylomarker/.

Lei, Runhua; Rowley, Thaine W.; Zhu, Lifeng; Bailey, Carolyn A.; Engberg, Shannon E.; Wood, Mindy L.; Christman, Mary C.; Perry, George H.; Louis, Edward E.; Lu, Guoqing

2012-01-01

395

Long signal peptides of RGMa and DCBLD2 are dissectible into subdomains according to the NtraC model.  

PubMed

Targeting of proteins to the endoplasmic reticulum (ER) usually requires N-terminal signal peptides (SP) of approximately 22 amino acids in length. However, a substantial number of proteins contain exceptionally long SPs of 40 amino acids and more, an example being protein shrew-1/AJAP1. Using shrew-1's SP as example, the NtraC model has been developed by dissecting long SPs into two functionally distinct subdomains ("N" and "C") separated by a ?-turn rich transition area ("tra"). Further proteins have been identified by computational analysis complying with the NtraC model. Here we used the SPs of two of these proteins, DCBLD2 and RGMa (including three isoforms), to show that the NtraC model applies to a growing group of SPs. We demonstrate that the full-length SPs of RGMa and DCBLD2 are functional and furthermore that the C-domains are sufficient and essential for ER targeting, whereas the N-domains are dispensable. Thus, the N-domains are available for additional functions. PMID:21183991

Resch, Eduard; Hiss, Jan A; Schreiner, Alexander; Schneider, Gisbert; Starzinski-Powitz, Anna

2011-03-01

396

THE subfossil occurrence and paleoecological significance of small mammals at ankilitelo cave, southwestern Madagascar  

USGS Publications Warehouse

Small mammals are rarely reported from subfossil sites in Madagascar despite their importance for paleoenvironmental reconstruction, especially as it relates to recent ecological changes on the island. We describe the uniquely rich subfossil small mammal fauna from Ankilitelo Cave, southwestern Madagascar. The Ankilitelo fauna is dated to the late Holocene (???500 years ago), documenting the youngest appearances of the extinct giant lemur taxa Palaeopropithecus, Megaladapis, and Archaeolemur, in association with abundant remains of small vertebrates, including bats, tenrecs, carnivorans, rodents, and primates. The Ankilitelo fauna is composed of 34 mammalian species, making it one of the most diverse Holocene assemblages in Madagascar. The fauna comprises the 1 st report of the short-tailed shrew tenrec (Microgale brevicaudata) and the ring-tailed mongoose (Galidia elegans) in southwestern Madagascar. Further, Ankilitelo documents the presence of southwestern species that are rare or that have greatly restricted ranges today, such as Nasolo's shrew tenrec (M. nasoloi), Grandidier's mongoose (Galidictis grandidieri), the narrow-striped mongoose (Mungotictis decemlineata), and the giant jumping rat (Hypogeomys antimena). A simple cause for the unusual small mammal occurrences at Ankilitelo is not obvious. Synergistic interactions between climate change, recent fragmentation and human-initiated degradation of forested habitats, and community-level processes, such as predation, most likely explain the disjunct distributions of the small mammals documented at Ankilitelo. ?? 2009 American Society of Mammalogists.

Muldoon, K. M.; De Blieux, D. D.; Simons, E. L.; Chatrath, P. S.

2009-01-01

397

Stable carbon isotope values document how a Late Holocene expansion in grasslands impacted vertebrates in northwestern Madagascar  

NASA Astrophysics Data System (ADS)

Madagascar is home to some of the world's most distinctive plants and animals. Unfortunately, forest loss and habitat degradation has had a dramatic impact on both floral and faunal communities. Here we use carbon isotope values in radiocarbon-dated bones to examine how the vertebrate community at Anjohibe Cave, northwestern Madagascar, responded to a Late Holocene increase in C4 grass abundance. Our data demonstrate that major changes in the vegetation and animal community are recent phenomena at Anjohibe. Extinct lemurs and hippopotamuses were present until ca. 1500 years ago. These taxa relied exclusively on C3 resources. Locally extirpated fauna were present until 300 years ago. The majority of these species also relied on C3 resources. Their presence strongly suggests that the region surrounding the cave was more wooded than it is now, possibly as recently as 300 years ago. All introduced individuals are modern. Rats (Rattus sp.), shrews (Suncus murinus), and the giant frog Hoplobatrachus cf. tigrinus, have remarkably high carbon isotope values, implicating substantial ingestion of C4 foods. It is possible that grass abundance has increased dramatically in the past 100 years. Alternatively, opportunistically granivorous rats and shrews may selectively consume seeds from C4 grasses. In agreement with previous studies, stable isotope data reveal details of vegetation and faunal turnover in Northwestern Madagascar. Grasses have increased, forest dwelling species have vanished, and introduced taxa are exploiting a novel niche.

Crowley, B. E.; Samonds, K.

2012-12-01

398

Hantaviruses: Rediscovery and new beginnings.  

PubMed

Virus and host gene phylogenies, indicating that antigenically distinct hantaviruses (family Bunyaviridae, genus Hantavirus) segregate into clades, which parallel the molecular evolution of rodents belonging to the Murinae, Arvicolinae, Neotominae and Sigmodontinae subfamilies, suggested co-divergence of hantaviruses and their rodent reservoirs. Lately, this concept has been vigorously contested in favor of preferential host switching and local host-specific adaptation. To gain insights into the host range, spatial and temporal distribution, genetic diversity and evolutionary origins of hantaviruses, we employed reverse transcription-polymerase chain reaction to analyze frozen, RNAlater(®)-preserved and ethanol-fixed tissues from 1546 shrews (9 genera and 47 species), 281 moles (8 genera and 10 species) and 520 bats (26 genera and 53 species), collected in Europe, Asia, Africa and North America during 1980-2012. Thus far, we have identified 24 novel hantaviruses in shrews, moles and bats. That these newfound hantaviruses are geographically widespread and genetically more diverse than those harbored by rodents suggests that the evolutionary history of hantaviruses is far more complex than previously conjectured. Phylogenetic analyses indicate four distinct clades, with the most divergent comprising hantaviruses harbored by the European mole and insectivorous bats, with evidence for both co-divergence and host switching. Future studies will provide new knowledge about the transmission dynamics and pathogenic potential of these newly discovered, still-orphan, non-rodent-borne hantaviruses. PMID:24412714

Yanagihara, Richard; Gu, Se Hun; Arai, Satoru; Kang, Hae Ji; Song, Jin-Won

2014-07-17

399

New Paleocene skeletons and the relationship of plesiadapiforms to crown-clade primates  

PubMed Central

Plesiadapiforms are central to studies of the origin and evolution of primates and other euarchontan mammals (tree shrews and flying lemurs). We report results from a comprehensive cladistic analysis using cranial, postcranial, and dental evidence including data from recently discovered Paleocene plesiadapiform skeletons (Ignacius clarkforkensis sp. nov.; Dryomomys szalayi, gen. et sp. nov.), and the most plesiomorphic extant tree shrew, Ptilocercus lowii. Our results, based on the fossil record, unambiguously place plesiadapiforms with Euprimates and indicate that the divergence of Primates (sensu lato) from other euarchontans likely occurred before or just after the Cretaceous/Tertiary boundary (65 Mya), notably later than logistical model and molecular estimates. Anatomical features associated with specialized pedal grasping (including a nail on the hallux) and a petrosal bulla likely evolved in the common ancestor of Plesiadapoidea and Euprimates (Euprimateformes) by 62 Mya in either Asia or North America. Our results are consistent with those from recent molecular analyses that group Dermoptera with Scandentia. We find no evidence to support the hypothesis that any plesiadapiforms were mitten-gliders or closely related to Dermoptera.

Bloch, Jonathan I.; Silcox, Mary T.; Boyer, Doug M.; Sargis, Eric J.

2007-01-01

400

The Celtic fringe of Britain: insights from small mammal phylogeography  

PubMed Central

Recent genetic studies have challenged the traditional view that the ancestors of British Celtic people spread from central Europe during the Iron Age and have suggested a much earlier origin for them as part of the human recolonization of Britain at the end of the last glaciation. Here we propose that small mammals provide an analogue to help resolve this controversy. Previous studies have shown that common shrews (Sorex araneus) with particular chromosomal characteristics and water voles (Arvicola terrestris) of a specific mitochondrial (mt) DNA lineage have peripheral western/northern distributions with striking similarities to that of Celtic people. We show that mtDNA lineages of three other small mammal species (bank vole Myodes glareolus, field vole Microtus agrestis and pygmy shrew Sorex minutus) also form a ‘Celtic fringe’. We argue that these small mammals most reasonably colonized Britain in a two-phase process following the last glacial maximum (LGM), with climatically driven partial replacement of the first colonists by the second colonists, leaving a peripheral geographical distribution for the first colonists. We suggest that these natural Celtic fringes provide insight into the same phenomenon in humans and support its origin in processes following the end of the LGM.

Searle, Jeremy B.; Kotlik, Petr; Rambau, Ramugondo V.; Markova, Silvia; Herman, Jeremy S.; McDevitt, Allan D.

2009-01-01

401

A look through 'lens' cubic mitochondria  

PubMed Central

Cell membranes may fold up into three-dimensional nanoperiodic cubic structures in biological systems. Similar geometries are well studied in other disciplines such as mathematics, physics and polymer chemistry. The fundamental function of cubic membranes in biological systems has not been uncovered yet; however, their appearance in specialized cell types indicates a role as structural templates or perhaps direct physical entities with specialized biophysical properties. The mitochondria located at the inner segment of the retinal cones of tree shrew (Tupaia glis and Tupaia belangeri) contain unique patterns of concentric cristae with a highly ordered membrane arrangement in three dimensions similar to the photonic nanostructures observed in butterfly wing scales. Using a direct template matching method, we show that the inner mitochondrial membrane folds into multi-layered (8 to 12 layers) gyroid cubic membrane arrangements in the photoreceptor cells. Three-dimensional simulation data demonstrate that such multi-layer gyroid membrane arrangements in the retinal cones of a tree shrew's eye can potentially function as: (i) multi-focal lens; (ii) angle-independent interference filters to block UV light; and (iii) a waveguide photonic crystal. These theoretical results highlight for the first time the significance of multi-layer cubic membrane arrangements to achieve near-quasi-photonic crystal properties through the simple and reversible biological process of continuous membrane folding.

Almsherqi, Zakaria; Margadant, Felix; Deng, Yuru

2012-01-01

402

Response to enrichment, type and timing: small mammals vary in their response to a springtime cicada but not a carbohydrate pulse.  

PubMed

1. Masting events in the autumn provide a carbohydrate-rich pulse of resources that can influence the dynamics of small mammals and their natural enemies. Similar patterns are observed with the periodical cicada emergence which provides a protein-rich pulse in the spring, but comparisons are confounded by timing and food type. 2. We compared the influence of a naturally occurring spring pulse of cicadas with an experimental spring pulse of carbohydrate-rich seeds. We used a replicated population level field experiment and capture-mark-recapture techniques to record the vital rates, demographics, and abundance of Peromyscus leucopus (the white-footed mouse), as well as other small mammals and their parasites. 3. The density of P. leucopus on grids where cicadas emerged was 55% higher than controls as a consequence of early breeding. This was followed by an increase in the prevalence of the nematode Pterygodermatities peromysci, reduced breeding and decreased recruitment rates. Other small mammals including Tamias striatus (eastern chipmunk) and Blarina brevicauda (short-tailed shrew), increased in density, but there was no affect on Sorex cinereus (masked shrew). 4. In contrast to the presence of cicadas, there was no influence of sunflower seed supplementation on small mammal density, vital rates, or reproduction with the exception of an increase in B. brevicauda density. The response of small mammals to seasonal pulses depends on timing, food type, and species. PMID:18684131

Vandegrift, Kurt J; Hudson, Peter J

2009-01-01

403

Hosts, seasonal occurrence and life cycle of Rhipicentor nuttalli (Acari: Ixodidae).  

PubMed

There are only two species worldwide within the genus Rhipicentor, namely Rhipicentor bicornis and Rhipicentor nuttalli and both occur only in Africa. Rhipicentor nuttali has a widespread distribution in South Africa and the present investigation was initiated to elucidate its host preference, seasonality and life cycle. Rock elephant shrews, Elephantulus myurus were examined for ticks at four localities in the Free State Province, one in Gauteng Province and two in Limpopo Province, South Africa. Cape elephant shrews, Elephantulus edwardii were examined at two places in the Western Cape Province, and a single specimen of the bushveld elephant shrew, Elephantulus intufi was examined in central Namibia. Small mammals of other species were also examined at two of these localities. The majority of E. myurus at two sites in the Free State, at the locality in Gauteng and both sites in Limpopo Province were infested with larvae and/or nymphs of R. nuttalli, while the single E. edwardii examined at one site in the Western Cape Province and the single E. intufi examined in Namibia were infested with nymphs of this tick. Not one of the other small animals was infested. Although larvae and nymphs of R. nuttalli were present on E. myurus throughout the year, the former were generally most numerous during the period March to September, and the latter during May to October. The preferred hosts of the adults are domestic dogs, leopards, Panthera pardus and South African hedgehogs, Atelerix frontalis. Adult females engorged on Atelerix frontalis in 16-32 days and, after a preoviposition period of 2-4 days, produced approximately 170,00 eggs during the following 60-70 days. The average incubation period of the eggs was 59 days. Larvae engorged on E. myurus in 4-10 days and moulted to nymphs 12-20 days later. Nymphs required 11-15 days to engorge on E. myurus and moulted to adults 32-47 days later. Allowing 14 days for the exoskeletons and mouthparts of each of the three parasitic stages to harden before they can attach to a host, the life cycle took approximately 214 days to complete in the laboratory. The length of this period, considered in conjunction with the times of maximum seasonal occurrence of the immature stages, indicates that the life cycle probably takes a year to complete in the field. PMID:12356163

Fourie, L J; Horak, I G; Kok, D J; Van Zyl, W

2002-09-01

404

Inhibition of monoacylglycerol lipase attenuates vomiting in Suncus murinus and 2-arachidonoyl glycerol attenuates nausea in rats  

PubMed Central

BACKGROUND AND PURPOSE To evaluate the role of 2-arachidonoyl glycerol (2AG) in the regulation of nausea and vomiting using animal models of vomiting and of nausea-like behaviour (conditioned gaping). EXPERIMENTAL APPROACH Vomiting was assessed in shrews (Suncus murinus), pretreated with JZL184, a selective monoacylglycerol lipase (MAGL) inhibitor which elevates endogenous 2AG levels, 1 h before administering the emetogenic compound, LiCl. Regulation of nausea-like behaviour in rats by exogenous 2AG or its metabolite arachidonic acid (AA) was assessed, using the conditioned gaping model. The role of cannabinoid CB1 receptors, CB2 receptors and cyclooxygenase (COX) inhibition in suppression of vomiting or nausea-like behaviour was assessed. KEY RESULTS JZL184 dose-dependently suppressed vomiting in shrews, an effect prevented by pretreatment with the CB1 receptor inverse agonist/antagonist, AM251. In shrew brain tissue, JZL184 inhibited MAGL activity in vivo. In rats, 2AG suppressed LiCl-induced conditioned gaping but this effect was not prevented by AM251 or the CB2 receptor antagonist, AM630. Instead, the COX inhibitor, indomethacin, prevented suppression of conditioned gaping by 2AG or AA. However, when rats were pretreated with a high dose of JZL184 (40 mg·kg?1), suppression of gaping by 2AG was partially reversed by AM251. Suppression of conditioned gaping was not due to interference with learning because the same dose of 2AG did not modify the strength of conditioned freezing to a shock-paired tone. CONCLUSIONS AND IMPLICATIONS Our results suggest that manipulations that elevate 2AG may have anti-emetic or anti-nausea potential. LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7

Sticht, Martin A; Long, Jonathan Z; Rock, Erin M; Limebeer, Cheryl L; Mechoulam, Raphael; Cravatt, Benjamin F; Parker, Linda A

2012-01-01

405

Euarchontan affinity of Paleocene Afro-European adapisoriculid mammals and their origin in the late Cretaceous Deccan Traps of India  

NASA Astrophysics Data System (ADS)

The controversial family Adapisoriculidae, a group of shrew-sized Paleocene mammals, had proposed relationships with insectivores, marsupials and more recently to plesiadapiforms. Adapisoriculid remains are numerous in the early Paleocene locality of Hainin, Belgium, and allow us a test of these different phylogenetic hypotheses. Here, we identify the first tarsal bones of adapisoriculid mammals. The highly specialised bones indicate an arboreal mode of life with euarchontan affinity. Moreover, the tarsal bones are morphologically very close to those of the late Cretaceous Deccanolestes from the Deccan intertrappean beds of India, and also share several characters with the Paleocene plesiadapiforms and the extant cynocephalid dermopterans. The adapisoriculid affinities of Deccanolestes are also confirmed by tooth morphology, indicating that Deccanolestes is a primitive member of this family. These phylogenetic affinities suggest a paleobiogeographic scenario for the family with dispersal either via East Africa or across the Tethys area.

Smith, Thierry; de Bast, Eric; Sigé, Bernard

2010-04-01

406

Spontaneous Squamous Cell Carcinomas in 13 Baboons, a First Report in a Spider Monkey, and a Review of the Nonhuman Primate Literature  

PubMed Central

Background Squamous cell carcinoma (SCC) is a neoplastic proliferation of epithelial cells undergoing squamous differentiation and represents a diagnostic challenge in nonhuman primates (NHP), especially in baboons with perineal SCC. Methods Fourteen SCC (13 baboons, 1 spider monkey) were identified over a 20-year period. A literature search identified 86 additional published cases of spontaneous NHP SCC. Results SCC was most commonly reported in macaques, baboons, marmosets, and squirrel monkeys. Metastasis occurred in 23%, of NHP. The most frequently reported primary locations were the oral cavity, integument, esophagus, and cervix-uterus. Perineal SCC occurred mainly in baboons. All reported SCC in marmosets occurred in the head. Nasal cavity SCC was only reported in male marmosets. All reported pulmonary SCC occurred in males, mostly in tree shrews. Conclusions SCC is a common neoplasm in NHP and exhibits species differences. NHPs may provide a useful SCC animal model.

Haddad, Jamie L.; Dick, Edward J.; Guardado-Mendoza, Rodolfo; Hubbard, Gene B.

2010-01-01

407

Characterization of monoclonal antibodies for identification of Borrelia japonica, isolates from Ixodes ovatus.  

PubMed

Monoclonal antibodies for identification of Borrelia japonica isolated from tick, Ixodes ovatus and long-tailed shrew, Sorex unguiculatus in Japan and Borrelia related to Lyme disease (Borrelia burgdorferi sensu lato) were prepared and characterized. All isolates belonging to B. japonica and isolates from I. dentatus and cottontail rabbit in North America reacted with MAb O1441b against flagellin which was prepared from immunized mice with strain HO14, type strain of B. japonica, but isolates from I. persulcatus, patient, and wood mouse, Apodemus speciosus ainu, in Japan, and isolates belonging to B. burgdorferi, B. garinii and B. afzelii from North America and Europe did not. Strains used in this study reacted with MAb P62 against common antigen which was prepared from immunized mice with strain NT24 isolated from I. persulcatus in Japan, but B. japonica did not. These MAbs are useful for identification and differentiation of B. japonica and B. burgdorferi sensu lato in Japan. PMID:7935066

Masuzawa, T; Kawabata, H; Beppu, Y; Miyamoto, K; Nakao, M; Sato, N; Muramatsu, K; Sato, N; Johnson, R C; Yanagihara, Y

1994-01-01

408

The biological significance of ?-oxidation of fatty acids  

PubMed Central

The author focuses on the biological significance of ?-oxidation of fatty acids. Early studies revealed that there is a subsidiary pathway for ?-oxidation of fatty acids when ?-oxidation is blocked. Many studies demonstrated that the ?-oxidation serves to provide succinyl-CoA for the citric acid cycle and for gluconeogenesis under conditions of starvation and diabetes. Acylglucosylceramides which are composed of linoleic acid, long chain ?-hydroxy fatty acids, eicosasphingenine (or trihydroxyeicosasphingenine) and glucose, are responsible for normal epidermal permeability function in the skin. It is observed that ?- and (?-1)-oxidation of fatty acids are related to energy metabolism in some laboratory animals such as musk shrews and Mongolian gerbils. Studies confirmed that ?- and (?-1)-oxidation of fatty acids play crucial roles in the production of insect pheromones of honeybees and in the formation of biopolyesters of higher plants. In addition, the biological significance of ?-oxidation of prostaglandins and leukotrienes is described.

MIURA, Yoshiro

2013-01-01

409

Making a Scene: Shakespeare in the Classroom  

NSDL National Science Digital Library

The Folger Shakespeare Company can help readers brush up on their Taming of the Shrew and much, much more. This lovely blog is designed to help teachers utilize Shakespeare in the classroom via posts on suggested activities and conversations about scenes from Romeo and Juliet, the Merchant of Venice, and many other works by the Immortal Bard. The posts are written by teachers from all around the United States and recent posts include "Finding a Shakespeare Hook" and "Hamlet's Ophelia: How Imagery Supports Characterization.â Users can add their own comments and also look through posts by topic. A useful word cloud of search items is also presented on the site and will help with exploration of possible topics.

410

Responses of Mammalian Insectivores, Amphibians, and Reptiles to Broad-Scale Manipulation of Coarse Woody Debris  

SciTech Connect

Sampled shrews at 9.3 ha plots from logs manually removed and control plots in loblolly pine forests of the Southeastern Coastal Plain. Capture rates of Cryptotis parva were lower at plots from which deadwood was removed whereas capture rates of Blarina cavolinensis and Sorex longirostris did not differ between control and removal plots. Cryptotis may have been most sensitive to removal plots due to low population density, hence poor ability to move into areas of low reproduction. (Second Abstract, p. 37)Presentation of evidence that juvenile amphibians including Ambystomatid salamanders may disperse hundreds of meter from their natal wetlands within the weeks to months following metamorphosis. Data indicates Ambystoma trigrinum metamorphs can take at least six months to disperse and en route use non-polar lipid reserves garnished as larvae. Report suggests a land management regime that allows for both juvenile amphibian dispersal and also the consumptive use of the surrounding landscape.

McCay, T.S.; Forschler, B.T.; Komoroski, M.J.; Ford, W.M.

2002-03-10

411

Coarse woody debris manipulations and the response of soricid and herpetofaunal communities in mature loblolly pine (Pinus taeda) stands.  

SciTech Connect

Coarse woody debris (CWD) may increase abundance of forest-floor dwelling fauna. Understanding the role of CWD in ecosystem function is necessary to manage species that rely on it, however, the extent to which soricids and herpetofauna use CWD is not understood. This research took a large- and small-scale approach to investigate the response of soricids and herpetofauna to CWD manipulations in the southeastern Coastal Plain. The results suggest that the addition of CWD can increase abundance and activity of the southeastern shrew. However, herpetofauna exhibited little response to CWD manipulations. Many Coastal Plain species may be adapted to burrowing in soil or under leaf litter because of naturally low levels of CWD, although these species may use and benefit from CWD. Overall the results suggest that CWD, at least of early to moderate decay, is not a critical habitat component for most soricids and herpetofauna in the southeastern Coastal Plain.

Owens, Audrey, K.

2006-04-01

412

Thottapalayam Virus, a Prototype Shrewborne Hantavirus  

PubMed Central

Thottapalayam virus (TPMV) has been placed in the genus Hantavirus of the family Bunyaviridae by virtue of its morphologic features and overall genetic similarities to well-characterized rodentborne hantaviruses. This virus has been isolated from the Asian house shrew (Suncus murinus); however, whether TPMV is naturally harbored by an insectivore host or represents spillover from a rodent reservoir host is unknown. Our analysis of published and unpublished data on the experimental host range, genetics, and molecular phylogeny of TPMV supports coevolution of TPMV with its nonrodent reservoir host. Future studies on the epizootiology of TPMV and investigations of new shrewborne hantaviruses will provide additional insights into the evolutionary origin of hantaviruses in their rodent and insectivore reservoir hosts. Such investigations may also provide clues about determinants of hantavirus pathogenicity and virulence.

Song, Jin-Won; Baek, Luck Ju; Schmaljohn, Connie S.

2007-01-01

413

Mammalian mitogenomic relationships and the root of the eutherian tree  

PubMed Central

The strict orthology of mitochondrial (mt) coding sequences has promoted their use in phylogenetic analyses at different levels. Here we present the results of a mitogenomic study (i.e., analysis based on the set of protein-coding genes from complete mt genomes) of 60 mammalian species. This number includes 11 new mt genomes. The sampling comprises all but one of the traditional eutherian orders. The previously unrepresented order Dermoptera (flying lemurs) fell within Primates as the sister group of Anthropoidea, making Primates paraphyletic. This relationship was strongly supported. Lipotyphla (“insectivores”) split into three distinct lineages: Erinaceomorpha, Tenrecomorpha, and Soricomorpha. Erinaceomorpha was the basal eutherian lineage. Sirenia (dugong) and Macroscelidea (elephant shrew) fell within the African clade. Pholidota (pangolin) joined the Cetferungulata as the sister group of Carnivora. The analyses identified monophyletic Pinnipedia with Otariidae (sea lions, fur seals) and Odobenidae (walruses) as sister groups to the exclusion of Phocidae (true seals).

Arnason, Ulfur; Adegoke, Joseph A.; Bodin, Kristina; Born, Erik W.; Esa, Yuzine B.; Gullberg, Anette; Nilsson, Maria; Short, Roger V.; Xu, Xiufeng; Janke, Axel

2002-01-01

414

Acute hepatotoxicity induced by hepatotoxins in Suncus murinus  

SciTech Connect

A comparative study was conducted to contrast the hepatotoxicity of several chemicals in the musk shrew (Suncus murinus) versus other common laboratory species (mouse or rat), and the following results were obtained from serum enzymes (SGOT and SGPT) and histopathological findings of liver specimens. (1) The sensitivity of Suncus liver to CCl/sub 4/ was different from that of mouse liver. (2) The sensitivity of Suncus liver to ..beta..-D-galactosamine was weaker than that of rat liver. (3) The sensitivity of Suncus liver to ethanol was stronger than that of mouse liver. After a single oral administration of ethanol (99.5% v/v, 0.1 ml/50 g body weight), the gallbladder of Suncus became enlarged and dark blue in color. (4) A striking fatty degeneration was seen 24 h after a single ip administration of amethopterin at 50 mg/kg in Suncus liver.

Lin, S.; Saito, H.; Yohro, T.; Shiga, J.

1986-01-01

415

Hunter-gatherers and other primates as prey, predators, and competitors of snakes.  

PubMed

Relationships between primates and snakes are of widespread interest from anthropological, psychological, and evolutionary perspectives, but surprisingly, little is known about the dangers that serpents have posed to people with prehistoric lifestyles and nonhuman primates. Here, we report ethnographic observations of 120 Philippine Agta Negritos when they were still preliterate hunter-gatherers, among whom 26% of adult males had survived predation attempts by reticulated pythons. Six fatal attacks occurred between 1934 and 1973. Agta ate pythons as well as deer, wild pigs, and monkeys, which are also eaten by pythons, and therefore, the two species were reciprocally prey, predators, and potential competitors. Natural history data document snake predation on tree shrews and 26 species of nonhuman primates as well as many species of primates approaching, mobbing, killing, and sometimes eating snakes. These findings, interpreted within the context of snake and primate phylogenies, corroborate the hypothesis that complex ecological interactions have long characterized our shared evolutionary history. PMID:22160702

Headland, Thomas N; Greene, Harry W

2011-12-2