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Sample records for osilae rodentia cricetidae

  1. Taxonomy of the Phyllotis osilae species group in Argentina; the status of the "Rata de los nogales" (Phyllotis nogalaris Thomas, 1921; Rodentia: Cricetidae).

    PubMed

    Jayat, J Pablo; Ortiz, Pablo E; D'elía, Guillermo

    2016-01-01

    The taxonomic status of populations of the genus Phyllotis from northwestern Argentina (NWA) has undergone recent changes, with the addition of two species (P. alisosiensis and P. anitae) to the traditionally recognized forms (P. caprinus, P. xanthopygus, and P. osilae). Three of these species (P. anitae, P. osilae, and P. alisosiensis) were included within the Phyllotis osilae species group. Most authors recognized three subspecies of P. osilae for NWA: P. osilae osilae, P. o. nogalaris, and P. o. tucumanus. Morphological, morphometric, and molecular studies based on recently collected specimens suggest that current classification does not reflect the diversity of this group in NWA, revealing the need of some taxonomic reallocations and new distributional delimitations. Here we propose that P. nogalaris must be recognized as a valid species and the restriction of P. osilae to southern Peru and central Bolivia. Following our results, we expect an outstanding improvement in the taxonomic knowledge of the Phyllotis osilae species group in the coming years.

  2. A new karyotype for Rhipidomys (Rodentia, Cricetidae) from Southeastern Brazil

    PubMed Central

    de Carvalho, Ana Heloisa; Lopes, Maria Olímpia Garcia; Svartman, Marta

    2012-01-01

    Abstract In this work we present a new karyotype for Rhipidomys Tschudi, 1845 (Cricetidae, Rodentia) from Brazil. Our chromosome analyses included GTG- and CBG-banding patterns, the localization of the nucleolus organizer regions after silver staining (Ag-NORs) and fluorescence in situ hybridization (FISH) with a telomere probe. The new karyotype is composed of 44 chromosomes and has a fundamental number (number of autosomal arms) of 48. Most Rhipidomys species already karyotyped presented similar complements with 2n=44, but their fundamental numbers varied from FN=46 to 80, a variation that has been mainly attributed to pericentric inversions. The comparison of this new karyotype to those of other Rhipidomys already reported allowed us to conclude that it is a distinctive chromosome complement, which can be of great use as a tool for the very complicated taxonomic identification in this genus. PMID:24260664

  3. A new genus and species of lungworm (Nemata: Metastrongyloidea) from Akodon mollis Thomas, 1894 (Rodentia: Cricetidae) in Peru.

    PubMed

    Morales, Maria Elizabeth; Ubelaker, John E; Gardner, Scott L

    2012-06-01

    Akodonema luzsarmientae n.g., n.sp. (Nemata: Metastrongyloidea) is described from the pulmonary arteries and heart from several individuals of "soft grass mouse," Akodon mollis (Rodentia: Cricetidae), collected in the region of Ancash, Peru. The new genus and species is distinguished by a reduction of the dorsal ray to 2 small widely separated papillae. PMID:22746394

  4. DNA barcoding of Murinae (Rodentia: Muridae) and Arvicolinae (Rodentia: Cricetidae) distributed in China.

    PubMed

    Li, Jing; Zheng, Xin; Cai, Yansen; Zhang, Xiuyue; Yang, Min; Yue, Bisong; Li, Jing

    2015-01-01

    Identification of rodents is very difficult mainly due to high similarities in morphology and controversial taxonomy. In this study, mitochondrial cytochrome oxidase subunit I (COI) was used as DNA barcode to identify the Murinae and Arvicolinae species distributed in China and to facilitate the systematics studies of Rodentia. In total, 242 sequences (31 species, 11 genera) from Murinae and 130 sequences (23 species, 6 genera) from Arvicolinae were investigated, of which 90 individuals were novel. Genetic distance, threshold method, tree-based method, online BLAST and BLOG were employed to analyse the data sets. There was no obvious barcode gap. The average K2P distance within species and genera was 2.10% and 12.61% in Murinae, and 2.86% and 11.80% in Arvicolinae, respectively. The optimal threshold was 5.62% for Murinae and 3.34% for Arvicolinae. All phylogenetic trees exhibited similar topology and could distinguish 90.32% of surveyed species in Murinae and 82.60% in Arvicolinae with high support values. BLAST analyses yielded similar results with identification success rates of 92.15% and 93.85% for Murinae and Arvicolinae, respectively. BLOG successfully authenticated 100% of detected species except Leopoldamys edwardsi based on the latest taxonomic revision. Our results support the species status of recently recognized Micromys erythrotis, Eothenomys tarquinius and E. hintoni and confirm the important roles of comprehensive taxonomy and accurate morphological identification in DNA barcoding studies. We believe that, when proper analytic methods are applied or combined, DNA barcoding could serve as an accurate and effective species identification approach for Murinae and Arvicolinae based on a proper taxonomic framework.

  5. An introduction to the systematics of Akodon orophilus Osgood, 1913 (Rodentia: Cricetidae) with the description of a new species.

    PubMed

    Jiménez, Carlos F; Pacheco, Víctor; Vivas, Dan

    2013-01-01

    The genus Akodon is one of the most species-rich rodent lineages in South America. In Peru, this genus contains 14 species subdivided in two groups: aerosus and boliviensis. Akodon orophilus Osgood, 1913 (Rodentia: Cricetidae) is a member of the Akodon aerosus group that inhabits the northern Peruvian montane forest, but is poorly characterized and its distribution is vaguely known. We review the status of the species based on morphology, morphometric and karyology, and compared with all members of the Akodon aerosus clade from Peruvian montane forests. As a result, we provide a complete redescription of A. orophilus, present new information on its natural history, restrict its distribution to the east of Río Marai6n, and describe a new species of Akodon from Huánuco Department, central Peru, a population previously assigned to A. orophilus. PMID:26312340

  6. Evolutionary story of a satellite DNA from Phodopus sungorus (Rodentia, Cricetidae).

    PubMed

    Paço, Ana; Adega, Filomena; Meštrović, Nevenka; Plohl, Miroslav; Chaves, Raquel

    2014-10-21

    With the goal to contribute for the understanding of satellite DNA evolution and its genomic involvement, in this work it was isolated and characterized the first satellite DNA (PSUcentSat) from Phodopus sungorus (Cricetidae). Physical mapping of this sequence in P. sungorus showed large PSUcentSat arrays located at the heterochromatic (peri)centromeric region of five autosomal pairs and Y-chromosome. The presence of orthologous PSUcentSat sequences in the genomes of other Cricetidae and Muridae rodents was also verified, presenting however, an interspersed chromosomal distribution. This distribution pattern suggests a PSUcentSat-scattered location in an ancestor of Muridae/Cricetidae families, that assumed afterwards, in the descendant genome of P. sungorus a restricted localization to few chromosomes in the (peri)centromeric region. We believe that after the divergence of the studied species, PSUcentSat was most probably highly amplified in the (peri)centromeric region of some chromosome pairs of this hamster by recombinational mechanisms. The bouquet chromosome configuration (prophase I) possibly displays an important role in this selective amplification, providing physical proximity of centromeric regions between chromosomes with similar size and/or morphology. This seems particularly evident for the acrocentric chromosomes of P. sungorus (including the Y-chromosome), all presenting large PSUcentSat arrays at the (peri)centromeric region. The conservation of this sequence in the studied genomes and its (peri)centromeric amplification in P. sungorus strongly suggests functional significance, possibly displaying this satellite family different functions in the different genomes. The verification of PSUcentSat transcriptional activity in normal proliferative cells suggests that its transcription is not stage-limited, as described for some other satellites.

  7. Evolutionary Story of a Satellite DNA from Phodopus sungorus (Rodentia, Cricetidae)

    PubMed Central

    Paço, Ana; Adega, Filomena; Meštrović, Nevenka; Plohl, Miroslav; Chaves, Raquel

    2014-01-01

    With the goal to contribute for the understanding of satellite DNA evolution and its genomic involvement, in this work it was isolated and characterized the first satellite DNA (PSUcentSat) from Phodopus sungorus (Cricetidae). Physical mapping of this sequence in P. sungorus showed large PSUcentSat arrays located at the heterochromatic (peri)centromeric region of five autosomal pairs and Y-chromosome. The presence of orthologous PSUcentSat sequences in the genomes of other Cricetidae and Muridae rodents was also verified, presenting however, an interspersed chromosomal distribution. This distribution pattern suggests a PSUcentSat-scattered location in an ancestor of Muridae/Cricetidae families, that assumed afterwards, in the descendant genome of P. sungorus a restricted localization to few chromosomes in the (peri)centromeric region. We believe that after the divergence of the studied species, PSUcentSat was most probably highly amplified in the (peri)centromeric region of some chromosome pairs of this hamster by recombinational mechanisms. The bouquet chromosome configuration (prophase I) possibly displays an important role in this selective amplification, providing physical proximity of centromeric regions between chromosomes with similar size and/or morphology. This seems particularly evident for the acrocentric chromosomes of P. sungorus (including the Y-chromosome), all presenting large PSUcentSat arrays at the (peri)centromeric region. The conservation of this sequence in the studied genomes and its (peri)centromeric amplification in P. sungorus strongly suggests functional significance, possibly displaying this satellite family different functions in the different genomes. The verification of PSUcentSat transcriptional activity in normal proliferative cells suggests that its transcription is not stage-limited, as described for some other satellites. PMID:25336681

  8. Rediscovery and New Morphological Data on Two Hassalstrongylus (Nematoda: Heligmonellidae) Coparasitic in the Marsh Rat Holochilus chacarius (Rodentia: Cricetidae) from Argentina.

    PubMed

    Digiani, María Celina; Notarnicola, Juliana; Navone, Graciela T

    2015-10-01

    Two species of Hassalstrongylus Durette-Desset, 1971, coparasitic in Holochilus chacarius Thomas (Rodentia, Cricetidae) and not recorded since their original description in 1937, were newly found in their type host and locality. Hassalstrongylus mazzai (Freitas, Lent and Almeida, 1937) and Hassalstrongylus argentinus (Freitas, Lent and Almeida, 1937) were obtained from Ho. chacarius from 2 different populations: one from Salta Province (northwest Argentina) and another from Chaco Province (northeast Argentina). The species described as Heligmonoides mazzai Freitas, Lent and Almeida, 1937 had been transferred to Hassalstrongylus even though its synlophe had never been studied. We provide the first descriptions and illustrations of the synlophe of males and females of Hassalstrongylus mazzai and the female of H. argentinus and account for morphological and metrical variability. We confirm, through the study of the synlophe, the placement of Hassalstrongylus mazzai in the genus Hassalstrongylus and designate neotypes for the species because the type material deposited by the authors could not be found. Females of both species were morphologically very similar, and a principal components analysis (PCA) performed on some morphometrical characters showed that the body length, uterus length, and an unexpected character as the number of eggs were useful characters in the discrimination of both species.

  9. Rediscovery and New Morphological Data on Two Hassalstrongylus (Nematoda: Heligmonellidae) Coparasitic in the Marsh Rat Holochilus chacarius (Rodentia: Cricetidae) from Argentina.

    PubMed

    Digiani, María Celina; Notarnicola, Juliana; Navone, Graciela T

    2015-10-01

    Two species of Hassalstrongylus Durette-Desset, 1971, coparasitic in Holochilus chacarius Thomas (Rodentia, Cricetidae) and not recorded since their original description in 1937, were newly found in their type host and locality. Hassalstrongylus mazzai (Freitas, Lent and Almeida, 1937) and Hassalstrongylus argentinus (Freitas, Lent and Almeida, 1937) were obtained from Ho. chacarius from 2 different populations: one from Salta Province (northwest Argentina) and another from Chaco Province (northeast Argentina). The species described as Heligmonoides mazzai Freitas, Lent and Almeida, 1937 had been transferred to Hassalstrongylus even though its synlophe had never been studied. We provide the first descriptions and illustrations of the synlophe of males and females of Hassalstrongylus mazzai and the female of H. argentinus and account for morphological and metrical variability. We confirm, through the study of the synlophe, the placement of Hassalstrongylus mazzai in the genus Hassalstrongylus and designate neotypes for the species because the type material deposited by the authors could not be found. Females of both species were morphologically very similar, and a principal components analysis (PCA) performed on some morphometrical characters showed that the body length, uterus length, and an unexpected character as the number of eggs were useful characters in the discrimination of both species. PMID:26193068

  10. The Cricetidae (Rodentia, Mammalia) from the Ulantatal area (Inner Mongolia, China): New data concerning the evolution of Asian cricetids during the Oligocene

    NASA Astrophysics Data System (ADS)

    Gomes Rodrigues, Helder; Marivaux, Laurent; Vianey-Liaud, Monique

    2012-08-01

    The Oligocene fossil deposits of Ulantatal in Inner Mongolia show an amazing faunal richness, comparable to the highly diversified contemporaneous faunas from the Valley of Lakes in Central Mongolia. To date, only a few taxa have been described. The present study consists of the description of 13 species of cricetid rodents from seven localities ranging in age from the late Early Oligocene to the Late Oligocene epoch. Most of them are new and belong to Eucricetodontinae, the dominating cricetid group at Ulantatal. These taxa give new information regarding the evolution of the Cricetidae in Central and Eastern Asia during the Oligocene. Four new species, Eucricetodon jilantaiensis nov. sp., Eucricetodon bagus nov. sp., Bagacricetodon tongi nov. gen., nov. sp. and Plesiodipus wangae nov. sp., show noticeable evolutionary trends. These species display more derived dental characters than their European contemporaries, in which they are much more comparable to Miocene forms. This observation reinforces the assumed early diversification of cricetids in this part of Asia. A striking case of sympatric evolution is indicated by the similarity of size and dental morphology of two sibling species, Eucricetodon asiaticus and Eucricetodon jilantaiensis nov. sp. Other taxa such as Witenia yolua nov. sp., Pseudocricetops matthewi nov. gen., nov. sp. and a primitive Tachyoryctoidinae, are scarcely represented and present unusual morphologies. The Cricetidae from Ulantatal also provide evidence suggesting faunal exchanges between Asia and Europe through the Paratethyan pathway during the second half of the Paleogene.

  11. Chromosomal evolution in Rodentia.

    PubMed

    Romanenko, S A; Perelman, P L; Trifonov, V A; Graphodatsky, A S

    2012-01-01

    Rodentia is the most species-rich mammalian order and includes several important laboratory model species. The amount of new information on karyotypic and phylogenetic relations within and among rodent taxa is rapidly increasing, but a synthesis of these data is currently lacking. Here, we have integrated information drawn from conventional banding studies, recent comparative painting investigations and molecular phylogenetic reconstructions of different rodent taxa. This permitted a revision of several ancestral karyotypic reconstructions, and a more accurate depiction of rodent chromosomal evolution.

  12. [Revision of the Taxonomic Position of the Olkhon Mountain Vole (Rodentia, Cricetidae)].

    PubMed

    Bodrov, S Yu; Kostygov, A Yu; Rudneva, L V; Abramson, N I

    2016-01-01

    An analysis of the phylogenetic position of the Olkhon mountain vole (Alticolaolchonensis Litvinov 1960) using the sequences of four nuclear (BRCA, GHR, LCAT, and IRBP) and one mitochondrial (cyt. b) genes was undertaken. It was noted that, until recently, multiple studies of the systematic position of this vole had been based exclusively on morphological data, while the major taxonomic traits contained contradictory information regarding both the subgeneric status of this species and its genus. It was established that the molecular data and morphology data allow us to attribute the Lake Baikal vole unambiguously to the nominative subgenus Alticola instead of Aschizomys.

  13. Cytokine mRNA expression in Peromyscus yucatanicus (Rodentia: Cricetidae) infected by Leishmania (Leishmania) mexicana.

    PubMed

    Loria-Cervera, Elsy Nalleli; Sosa-Bibiano, Erika Ivett; Van Wynsberghe, Nicole Raymonde; Saldarriaga, Omar Abdul; Melby, Peter C; Andrade-Narvaez, Fernando Jose

    2016-07-01

    Peromyscus yucatanicus, the main reservoir of Leishmania (Leishmania) mexicana in the Yucatan peninsula of Mexico, reproduces clinical and histological pictures of LCL in human as well as subclinical infection. Thus, we used this rodent as a novel experimental model. In this work, we analyzed cytokine mRNA expression in P. yucatanicus infected with L. (L.) mexicana. Animals were inoculated with either 2.5×10(6) or 1×10(2) promastigotes and cytokine expressions were analyzed by real-time RT-PCR in skin at 4 and 12weeks post-infection (wpi). Independently of the parasite inoculum none of the infected rodents had clinical signs of LCL at 4wpi and all expressed high IFN-γ mRNA. All P. yucatanicus inoculated with 2.5×10(6) promastigotes developed signs of LCL at 12wpi while the mice inoculated with 1×10(2) remained subclinical. At that time, both IFN-γ and IL-10 were expressed in P. yucatanicus with clinical and subclinical infections. Expressions of TNF-α and IL-4 were significantly higher in clinical animals (2.5×10(6)) compared with subclinical ones (1×10(2)). High TGF-β expression was observed in P. yucatanicus with clinical signs when compared with healthy animals. Results suggested that the clinical course of L. (L.) mexicana infection in P. yucatanicus was associated with a specific local pattern of cytokine production at 12wpi. PMID:27155064

  14. Karyotypic variation in the Andean rodent Phyllotis xanthopygus (Waterhouse, 1837) (Rodentia, Cricetidae, Sigmodontinae)

    PubMed Central

    Labaroni, Carolina Alicia; Malleret, Matías Maximiliano; Novillo, Agustina; Ojeda, Agustina; Rodriguez, Daniela; Cuello, Pablo; Ojeda, Ricardo; Dardo Martí; Lanzone, Cecilia

    2014-01-01

    Abstract Phyllotis xanthopygus (Waterhouse, 1837) is an Andean rodent endemic to South America. Despite its wide geographical distribution in Argentina, few individuals have been studied on the cytogenetic level and only through conventional staining. In this work, chromosome characterization of Argentine samples of this species was performed using solid staining, C-banding and base-specific fluorochromes. Twenty two specimens were analyzed, collected in the provinces of Jujuy, Catamarca, and the north and south of Mendoza. All studied specimens showed 2n=38, having mostly the bi-armed autosomes, metacentric or submetacentric. Fundamental Number varied between 70 and 72. These changes were due to the presence of chromosome heteromorphisms in individuals from southern Mendoza and Jujuy. C-banding revealed pericentromeric blocks of constitutive heterochromatin in most chromosomes. Acrocentric chromosomes involved in heteromorphisms showed high variation in the amount of heterochromatin within and among populations. Additionally, banding with fluorochromes (DAPI and chromomycin A3) revealed homologous localization of AT and GC rich regions among chromosomes of the different populations analyzed. Comparisons among heteromorphic pairs suggested, however, that the variation might be the result of complex chromosome rearrangements, involving possibly amplifications and/or deletions of heterochromatic segments. These results are in accordance with molecular studies that indicate genetic variability within and among the populations of this taxon. PMID:25610549

  15. Chromosomal variation in Argentine populations of Akodon montensis Thomas, 1913 (Rodentia, Cricetidae, Sigmodontinae)

    PubMed Central

    Malleret, Matías Maximiliano; Labaroni, Carolina Alicia; García, Gabriela Verónica; Ferro, Juan Martín; Martí, Dardo Andrea; Lanzone, Cecilia

    2016-01-01

    Abstract The genus Akodon Meyen, 1833 is one of the most species-rich among sigmodontine rodents and has great chromosome variability. Akodon montensis has a relatively broad distribution in South America, and Argentine populations are located in the southernmost region of its range. Brazilian populations have important chromosomal variability, but cytogenetic data from Argentina are scarce. We performed a chromosome characterization of natural populations of Akodon montensis using conventional staining, C-banding, Ag-NORs and base-specific fluorochromes. A total of 31 specimens from five localities of Misiones Province, in Argentina, were analyzed. The 2n=24 chromosomes was the most frequently observed karyotype. However, five individuals presented 25 chromosomes due to a supernumerary B-chromosome; and one individual had 2n=26 due to one B plus a trisomy for chromosome 11. Additionally, two XY females and two variants of the X chromosomes were found. C-positive centromeric bands occurred in all chromosomes; additional C-bands were observed in some autosomes, the X, Y and B chromosomes. Ag-NORs were observed in five autosomes, and the B chromosome was frequently marked. Fluorochrome banding was similar among karyotypes of the analyzed populations. Comparisons of cytogenetic data among populations of Argentina and Brazil showed the presence of high intraspecific variability in Akodon montensis and some differences among regions. PMID:27186343

  16. Reservoir competence of Microtus pennsylvanicus (Rodentia: Cricetidae) for the Lyme disease spirochete, Borrelia burgdorferi

    USGS Publications Warehouse

    Markowski, D.; Ginsberg, H.S.; Hyland, K.E.; Hu, R.

    1998-01-01

    The reservoir competence of the meadow vole, Microtus pennsylvanicus Ord, for the Lyme disease spirochete, Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner was established on Patience Island, RI. Meadow voles were collected from 5 locations throughout Rhode Island. At 4 of the field sites, M. pennsylvanicus represented only 4.0% (n = 141) of the animals captured. However, on Patience Island, M. pennsylvanicus was the sole small mammal collected (n = 48). Of the larval Ixodes scapularis Say obtained from the meadow voles on Patience Island, 62% (n = 78) was infected with B. burgdorferi. Meadow voles from all 5 locations were successfully infected with B. burgdorferi in the laboratory and were capable of passing the infection to xenodiagnostic I. scapularis larvae for 9 wk. We concluded that M. pennsylvanicus was physiologically capable of maintaining B. burgdorferi infection. However, in locations where Peromyscus leucopus (Rafinesque) is abundant, the role of M. pennsylvanicus as a primary reservoir for B. burgdorferi was reduced.

  17. [Revision of the Taxonomic Position of the Olkhon Mountain Vole (Rodentia, Cricetidae)].

    PubMed

    Bodrov, S Yu; Kostygov, A Yu; Rudneva, L V; Abramson, N I

    2016-01-01

    An analysis of the phylogenetic position of the Olkhon mountain vole (Alticolaolchonensis Litvinov 1960) using the sequences of four nuclear (BRCA, GHR, LCAT, and IRBP) and one mitochondrial (cyt. b) genes was undertaken. It was noted that, until recently, multiple studies of the systematic position of this vole had been based exclusively on morphological data, while the major taxonomic traits contained contradictory information regarding both the subgeneric status of this species and its genus. It was established that the molecular data and morphology data allow us to attribute the Lake Baikal vole unambiguously to the nominative subgenus Alticola instead of Aschizomys. PMID:27396178

  18. Nitric oxide production by Peromyscus yucatanicus (Rodentia) infected with Leishmania (Leishmania) mexicana

    PubMed Central

    Loría-Cervera, Elsy Nalleli; Sosa-Bibiano, Erika Ivett; Villanueva-Lizama, Liliana Estefanía; Van Wynsberghe, Nicole Raymonde; Canto-Lara, Silvia Beatriz; Batún-Cutz, José Luis; Andrade-Narváez, Fernando José

    2013-01-01

    Peromyscus yucatanicus (Rodentia: Cricetidae) is a primary reservoir of Leishmania (Leishmania) mexicana (Kinetoplastida: Trypanosomatidae). Nitric oxide (NO) generally plays a crucial role in the containment and elimination of Leishmania. The aim of this study was to determine the amount of NO produced by P. yucatanicus infected with L. (L.) mexicana. Subclinical and clinical infections were established in P. yucatanicus through inoculation with 1 x 102 and 2.5 x 106 promastigotes, respectively. Peritoneal macrophages were cultured alone or co-cultured with lymphocytes with or without soluble Leishmania antigen. The level of NO production was determined using the Griess reaction. The amount of NO produced was significantly higher (p ≤ 0.0001) in co-cultured macrophages and lymphocytes than in macrophages cultured alone. No differences in NO production were found between P. yucatanicus with subclinical L. (L.) mexicana infections and animals with clinical infections. These results support the hypothesis that the immunological mechanisms of NO production in P. yucatanicus are similar to those described in mouse models of leishmaniasis and, despite NO production, P. yucatanicus is unable to clear the parasite infection. PMID:23579796

  19. Characterization of the satellite DNA Msat-160 from species of Terricola (Microtus) and Arvicola (Rodentia, Arvicolinae).

    PubMed

    Acosta, Manuel J; Marchal, Juan A; Fernández-Espartero, Cecilia; Romero-Fernández, Ismael; Rovatsos, Michail T; Giagia-Athanasopoulou, Eva B; Gornung, Ekaterina; Castiglia, Riccardo; Sánchez, Antonio

    2010-10-01

    In the subfamily Arvicolinae (Cricetidae, Rodentia) the satellite DNA Msat-160 has been so far described in only some species from the genus Microtus and in one species from another genus, Chionomys nivalis. Here we cloned and characterized this satellite in two new arvicoline species, Microtus (Terricola) savii and Arvicola amphibius (terrestris). We have also demonstrated, by PCR and FISH, its existence in the genomes of several other species from both genera. These results suggest that Msat-160 already occurred in the common ancestor of the four genera/subgenera of Arvicolinae (Microtus, Chionomys, Arvicola, and Terricola). In Arvicola and Terricola, Msat-160 showed the basic monomer length of 160 bp, although a higher-order repeat (HORs) of 640 bp could have been probably replacing the original monomeric unit in A. a. terrestris. Msat-160 was localized by FISH mostly on the pericentromeric regions of the chromosomes, but the signal intensity and the number of carrier chromosomes varied extremely even between closely related species, resulting in a species-specific pattern of chromosomal distribution of this satellite. Such a variable pattern most likely is a consequence of a rapid amplification and contraction of particular repeats in the pericentromeric regions of chromosomes. In addition, we proposed that the rapid variation of pericentromeric repeats is strictly related to the prolific species radiation and diversification of karyotypes that characterize Arvicolinae lineage. Finally, we performed phylogenetic analysis in this group of related species based on Msat-160 that results to be in agreement with previously reported phylogenies, derived from other molecular markers.

  20. Analysis of meiotic chromosome structure and behavior in Robertsonian heterozygotes of Ellobius tancrei (Rodentia, Cricetidae): a case of monobrachial homology

    PubMed Central

    Matveevsky, Sergey; Bakloushinskaya, Irina; Tambovtseva, Valentina; Romanenko, Svetlana; Kolomiets, Oxana

    2015-01-01

    Abstract Synaptonemal complex (SC) chains were revealed in semisterile intraspecific F1 hybrids of Ellobius tancrei Blasius, 1884 (2n = 49, NF=56 and 2n=50, NF=56), heterozygous for Robertsonian (Rb) translocations. Chains were formed by Rb submetacentrics with monobrachial homology. Chromosome synapsis in spermatocytes of these hybrids was disturbed, apparently because of the problematic release of the chromosomes from the SC chains. These hybrids suffer from low fertility, and our data support the opinion that this is because a formation of Rb metacentrics with monobrachial homology within different races of the same species might be an initial event for the divergence of chromosomal forms. PMID:26752380

  1. Shippingport, Kentucky, is the type locality for the white-footed mouse, Peromyscus leucopus (Rafinesque, 1818) (Mammalia: Rodentia: Cricetidae)

    USGS Publications Warehouse

    Woodman, Neal

    2015-01-01

    The white-footed mouse, Musculus leucopus Rafinesque, 1818 (= Peromyscus leucopus), is a common small mammal that is widespread in the eastern and central United States. Its abundance in many habitats renders it ecologically important, and its status as a reservoir for hantavirus and Lyme disease gives the species medical and economic significance. The recognition of two cytotypes and up to 17 morphological subspecies of P. leucopus indicates considerable variation in the species, and to understand this variation, it is important that the nominate subspecies be adequately defined so as to act as a standard for comparison. Relevant to this standard for the white-footed mouse is its type locality, which has generally been accepted to be either the vague "pine barrens of Kentucky" or the mouth of the Ohio River. Newly assembled information regarding the life and travels of Constantine S. Rafinesque, the North American naturalist who described P. leucopus, establishes that Rafinesque observed this species in July 1818 while visiting Shippingport, Kentucky, which is now within the city limits of Louisville, Jefferson Co., Kentucky. Shippingport is therefore the actual type locality for this species.

  2. Bionomics of Cuterebra austeni (Diptera: Cuterebridae) and its association with Neotoma albigula (Rodentia: Cricetidae) in the southwestern United States.

    PubMed

    Baird, C R

    1997-11-01

    Cuterebra austeni Sabrosky causes cutaneous myiasis in white-throated woodrats, Neotoma albigula, in the southwestern United States. In central and southern Arizona and southwestern New Mexico, this species is bivoltine. Adult flies are active at hilltop aggregation sites from early spring through mid-May and again to a lesser extent in the fall months. Eggs produced from laboratory matings of adult flies hatched in response to warm breath (34-36 degrees C) 6-8 d after oviposition. Oviposition takes place around burrow entrances and near the bases of Opuntia cacti. In the wild, myiasis occurs in woodrats primarily during the spring months, with a small second peak during the fall. Larvae develop in cutaneous warbles in the sternal and the ventral cervical area of N. albigula and complete development in 33 d. Woodrats do not appear to be affected seriously by the presence of 1-5 larvae. Morphological changes in larvae and pupae are described through to adult eclosion.

  3. A new genus and species of chigger mite (Trombidiformes: Trombiculidae) from Loxodontomys pikumche (Rodentia: Cricetidae) in Chile.

    PubMed

    Fuente, María Carolina Silva-de La; Casanueva, María Eugenia; Salas, Lucila Moreno; González-Acuña, Daniel

    2016-01-01

    The family Trombiculidae is one of the most diverse and cosmopolitan (Walter et al. 2009). In Chile, the family Trombiculidae is represented by six genera associated with reptiles: Eutrombicula Ewing; Microtrombicula Ewing; Paratrombicula Goff & Whitaker; Whartonacarus (Brennan & Jones); Diaguitacarus Stekolnikov & González-Acuña and Proschoengastia Vercammen-Grandjean and two genera associated with rodents Chilacarus Webb, Bennett & Loomis and Poliremotus Brennan & Goff (Stekolnikov & González-Acuña 2015). PMID:27394465

  4. New species of Arostrilepis (Eucestoda: Hymenolepididae) in members of Cricetidae and Geomyidae (Rodentia) from the western Nearctic.

    PubMed

    Makarikov, Arseny A; Gardner, Scott L; Hoberg, Eric P

    2012-06-01

    Abstract : Specimens originally identified as Arostrilepis horrida from the Nearctic are revised, contributing to the recognition of a complex of cryptic species distributed across the Holarctic region. Previously unrecognized species are described based on specimens in cricetid (Neotominae) and geomyid rodents. Arostrilepis mariettavogeae n. sp. in Peromyscus californicus from Monterey County, California and Arostrilepis schilleri n. sp. in Thomomys bulbivorus from Corvallis, Oregon are characterized. Consistent with recent studies defining diversity in the genus, form, size, and spination (pattern, shape, and size) of the cirrus are diagnostic; species are further distinguished by the relative position and length of the cirrus sac and arrangement of the testes. Species of Arostrilepis have not previously been described in rodents outside of the Arvicolinae or from localities in the Nearctic. These studies emphasize the need for routine deposition of archival specimens and information, from survey, ecological, and biogeographic studies, in museum collections to serve as self-correcting records for biodiversity at local, regional, and continental scales. PMID:22097959

  5. Phylogeography of Trichuris populations isolated from different Cricetidae rodents.

    PubMed

    Callejón, Rocío; De Rojas, Manuel; Feliú, Carlos; Balao, Francisco; Marrugal, Angela; Henttonen, Heikki; Guevara, Diego; Cutillas, Cristina

    2012-11-01

    The phylogeography of Trichuris populations (Nematoda) collected from Cricetidae rodents (Muroidea) from different geographical regions was studied. Ribosomal DNA (Internal Transcribed Spacers 1 and 2, and mitochondrial DNA (cytochrome c- oxidase subunit 1 partial gene) have been used as molecular markers. The nuclear internal transcribed spacers (ITSs) 1 and 2 showed 2 clear-cut geographical and genetic lineages: one of the Nearctic region (Oregon), although the second was widespread throughout the Palaearctic region and appeared as a star-like structure in the minimum spanning network. The mitochondrial results revealed that T. arvicolae populations from the Palaearctic region were separated into 3 clear-cut geographical and genetic lineages: populations from Northern Europe, populations from Southern (Spain) and Eastern Europe (Croatia, Belarus, Kazahstan), and populations from Italy and France (Eastern Pyrénean Mountains). Phylogenetic analysis obtained on the basis of ITS1-5·8S-ITS2 rDNA sequences did not show a differential geographical structure; however, these markers suggest a new Trichuris species parasitizing Chionomys roberti and Cricetulus barabensis. The mitochondrial results revealed that Trichuris populations from arvicolinae rodents show signals of a post-glacial northward population expansion starting from the Pyrenees and Italy. Apparently, the Pyrenees and the Alps were not barriers to the dispersal of Trichuris populations.

  6. Encephalitozoon infections in Rodentia and Soricomorpha in Japan.

    PubMed

    Tsukada, Ryusuke; Tsuchiyama, Atsuko; Sasaki, Mizuki; Park, Chun-Ho; Fujii, Yoshito; Takesue, Masataka; Hatai, Hitoshi; Kudo, Noboru; Ikadai, Hiromi

    2013-11-15

    Encephalitozoon is an obligate intracellular microsporidian parasite that infects a wide range of mammalian hosts. In this study, we used nested PCR to investigate the presence of Encephalitozoon infection in Rodentia and Soricomorpha in Japan. We attempted to amplify and sequence Encephalitozoon-specific DNA from brain and viscera samples of 180 animals collected between 2008 and 2010. Forty-three samples (23.9%) from the orders Rodentia and Soricomorpha were positive for Encephalitozoon. This study is the first report of Encephalitozoon infection in Rodentia and Soricomorpha in Japan, and our findings suggest that these hosts may play a role in the spread of microsporidian spores in the environment.

  7. Pterygodermatites (Paucipectines) baiomydis n. sp. (Nematoda: Rictulariidae), a parasite of Baiomys taylori (Cricetidae)

    PubMed Central

    Lynggaard, Christina; García-Prieto, Luis; Guzmán-Cornejo, Carmen; Osorio-Sarabia, David

    2014-01-01

    Pterygodermatites (Paucipectines) baiomydis n. sp., an intestinal parasite of the northern pygmy mouse, Baiomys taylori (Cricetidae), collected in La Yerbabuena, Colima, Mexico, is described herein. Specimens were studied using light and scanning electronic microscopy. This is the 19th species of the subgenus Paucipectines described worldwide and the fourth collected in Mexico. It is differentiated from the remaining species in the subgenus by having 25 perioral denticles, arranged in a triangle (seven on each lateroventral margin, and eleven on the dorsal margin), and 10 pairs of caudal papillae. PMID:25375029

  8. Pterygodermatites (Paucipectines) baiomydis n. sp. (Nematoda: Rictulariidae), a parasite of Baiomys taylori (Cricetidae).

    PubMed

    Lynggaard, Christina; García-Prieto, Luis; Guzmán-Cornejo, Carmen; Osorio-Sarabia, David

    2014-01-01

    Pterygodermatites (Paucipectines) baiomydis n. sp., an intestinal parasite of the northern pygmy mouse, Baiomys taylori (Cricetidae), collected in La Yerbabuena, Colima, Mexico, is described herein. Specimens were studied using light and scanning electronic microscopy. This is the 19th species of the subgenus Paucipectines described worldwide and the fourth collected in Mexico. It is differentiated from the remaining species in the subgenus by having 25 perioral denticles, arranged in a triangle (seven on each lateroventral margin, and eleven on the dorsal margin), and 10 pairs of caudal papillae.

  9. Systematic studies of the genus Aegialomys Weksler, Percequillo and Voss, 2006 (Rodentia: Cricetidae: Sigmodontinae): Annotated catalogue of the types of the species-group taxa.

    PubMed

    Prado, Joyce Rodrigues Do; Percequillo, Alexandre Reis

    2016-01-01

    The genus Aegialomys was described to encompass the former Oryzomys xanthaeolus group, and includes nowadays two species: A. xanthaeolus and A. galapagoensis. Although not very confusing, the taxonomic history of the genus is long, comprising the description of five nominal taxa along the last 180 years: Mus galapagoensis Waterhouse, 1839; Oryzomys bauri Allen, 1892; Oryzomys xanthaeolus Thomas, 1894; Oryzomys  baroni Allen, 1897; and Oryzomys  xanthaeolus ica Osgood, 1944. Here we gathered and documented all available information about the type material of Aegialomys on which the species names were based, re-described their morphometric and morphological characters, commented their synonyms and taxonomic history, and compiled information about type localities. Additionally, we established a neotype for O. bauri in order to define the nominal taxon objectively. PMID:27470869

  10. Taxonomic revision of the Andean leaf-eared mouse, Phyllotis andium Thomas 1912 (Rodentia: Cricetidae), with the description of a new species.

    PubMed

    Rengifo, Edgardo M; Pacheco, Víctor

    2015-01-01

    The Andean Leaf-eared mouse, Phyllotis andium Thomas 1912, has been considered a widespread medium-size sigmodontine rodent (230 mm of total length and 35 grams approximately) that occurs from Tungurahua, Ecuador, through the Andes, to Lima, Peru. Previous studies performed on Phyllotis noted evidence of morphological geographical variation within the species, which is likely because of the several potential geographical barriers that exist within the distribution range of P. andium. We carried out a taxonomic revision of this species based on qualitative and quantitative morphological analyses of 330 specimens from 92 localities. This included appropriate comparisons with other species of the andium/amicus group and performed molecular analysis based on cytochrome b sequences. As a result, morphologic qualitative analysis suggested the recognition of three different taxa, which are supported by morphologic quantitative and molecular analyses. The three taxa here identified have allopatric distributional ranges separated by important geographic barriers. Following these identification criteria, P. andium is now recognized for the samples from Tungurahua, Ecuador to Huánuco, Peru, and includes melanius and fruticicolus as synonymous; the southern populations from the Ancash and Lima departments, in the western Peruvian Andes, are proposed to represent a new species; and we recognize P. stenops as a valid species with tamborum as a synonym. Finally, we postulate that the diversification of these three species is related to key events in the Andean orogeny. PMID:26624045

  11. Comparative chromosome mapping of the rRNA genes and telomeric repeats in three Italian pine voles of the Microtus savii s.l. complex (Rodentia, Cricetidae)

    PubMed Central

    Gornung, Ekaterina; Bezerra, Alexandra M. R.; Castiglia, Riccardo

    2011-01-01

    Abstract The Microtus (Terricola) savii s. l. complex is a group of five species/subspecies of the Italian pine voles, which diverged at different times either with or without chromosomal differentiation. The evidence of chromosomal diversification has so far concerned the shape of the sex chromosomes, especially the X chromosome. Three taxa of the group, Microtus savii savii, Microtus savii nebrodensis, and Microtus savii tolfetanus have identical karyotypes with metacentric X chromosomes. The X chromosomes of Microtus brachycercus and Microtus brachycercus niethammericus are, respectively, subtelocentric and acrocentric in shape. The Microtus savii complex has been long an object of conventional karyological studies, but comparative molecular cytogenetic data were completely missing. Therefore, we conducted a comparative chromosomal mapping of rRNA genes (rDNA) and telomeric repeats in three of the five taxa of the group: Microtus savii savii, Microtus savii nebrodensis, and Microtus brachycercus niethammericus, each of which belongs to a distinct mitochondrial clade.The survey revealed that differentiation of the clades was accompanied by remarkable changes with regard to the number and locations of the rDNA sites. Thus, Microtus savii savii and Microtus savii nebrodensis have especially high numbers of rDNA sites, which are located in the centromeric regions of, correspondingly, 18 and 13 chromosome pairs, whereas Microtus brachycercus niethammericus shows variable (8–10) and heteromorphic rDNA sites on both centromeric and telomeric regions. Interstitial telomeric sites (ITS), which are believed to indicate possible breakpoints of recurring chromosomal rearrangements, are present on the largest biarmed chromosomes and on the metacentric X chromosomes in Microtus savii savii and Microtus savii nebrodensis. These preliminary results are discussed in the context of recent advances in phylogeny of the group, as well as the rDNA genomic organization and X chromosome rearrangements in the genus Microtus. PMID:24260633

  12. Comparative chromosome mapping of the rRNA genes and telomeric repeats in three Italian pine voles of the Microtus savii s.l. complex (Rodentia, Cricetidae).

    PubMed

    Gornung, Ekaterina; Bezerra, Alexandra M R; Castiglia, Riccardo

    2011-01-01

    The Microtus (Terricola) savii s. l. complex is a group of five species/subspecies of the Italian pine voles, which diverged at different times either with or without chromosomal differentiation. The evidence of chromosomal diversification has so far concerned the shape of the sex chromosomes, especially the X chromosome. Three taxa of the group, Microtus savii savii, Microtus savii nebrodensis, and Microtus savii tolfetanus have identical karyotypes with metacentric X chromosomes. The X chromosomes of Microtus brachycercus and Microtus brachycercus niethammericus are, respectively, subtelocentric and acrocentric in shape. The Microtus savii complex has been long an object of conventional karyological studies, but comparative molecular cytogenetic data were completely missing. Therefore, we conducted a comparative chromosomal mapping of rRNA genes (rDNA) and telomeric repeats in three of the five taxa of the group: Microtus savii savii, Microtus savii nebrodensis, and Microtus brachycercus niethammericus, each of which belongs to a distinct mitochondrial clade.The survey revealed that differentiation of the clades was accompanied by remarkable changes with regard to the number and locations of the rDNA sites. Thus, Microtus savii savii and Microtus savii nebrodensis have especially high numbers of rDNA sites, which are located in the centromeric regions of, correspondingly, 18 and 13 chromosome pairs, whereas Microtus brachycercus niethammericus shows variable (8-10) and heteromorphic rDNA sites on both centromeric and telomeric regions. Interstitial telomeric sites (ITS), which are believed to indicate possible breakpoints of recurring chromosomal rearrangements, are present on the largest biarmed chromosomes and on the metacentric X chromosomes in Microtus savii savii and Microtus savii nebrodensis. These preliminary results are discussed in the context of recent advances in phylogeny of the group, as well as the rDNA genomic organization and X chromosome rearrangements in the genus Microtus.

  13. [Polymorphism and Genetic Structure of Microtus maximowiczii (Schrenck, 1858) (Rodentia, Cricetidae) from the Middle Amur River Region as Inferred from Sequencing of the mtDNA Control Region].

    PubMed

    Sheremetyeva, I N; Kartavtseva, I V; Frisman, L V; Vasil'eva, T V; Adnagulova, A V

    2015-10-01

    The genetic variability of the mitochondrial DNA control region sequences was estimated for the Maximowicz's vole Microtus maximowiczii from the Middle Amur River region located between the confluence of Amur River with Ussuri River and Zeya River. The species as a whole was characterized by a high level of genetic variability. For each individual sample, low nucleotide diversity was observed, except for two samples in which a more than twofold increase in this index was revealed. The presence of the contact zone of two genetically distinct populations in the area between Bira and Bidzhan rivers is suggested. PMID:27169230

  14. Complete mitochondrial genome sequence of Marmota himalayana (Rodentia: Sciuridae) and phylogenetic analysis within Rodentia.

    PubMed

    Chao, Q J; Li, Y D; Geng, X X; Zhang, L; Dai, X; Zhang, X; Li, J; Zhang, H J

    2014-04-14

    This is the first report of a complete mitochondrial genome sequence from Himalayan marmot (Marmota himalayana, class Marmota). We determined the M. himalayana mitochondrial (mt) genome sequence by using long-PCR methods and a primer-walking sequencing strategy with genus-specific primers. The complete mt genome of M. himalayana was 16,443 bp in length and comprised 13 protein-coding genes, 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a typical control region (CR). Gene order and orientation were identical to those in mt genomes of most vertebrates. The heavy strand showed an overall A+T content of 63.49%. AT and GC skews for the mt genome of the M. himalayana were 0.012 and -0.300, respectively, indicating a nucleotide bias against T and G. The control region was 997 bp in size and displayed some unusual features, including absence of repeated motifs and two conserved sequence blocks (CSB2 and CSB3), which is consistent with observations from two other rodent species, Sciurus vulgaris and Myoxus glis. Phylogenetic analysis of complete mt DNA sequences without the control region including 30 taxa of Rodentia was performed with Maximum-Likelihood (ML) and Bayesian Inference (BI) methods and provided strong support for Sciurognathi polyphyly and Hystricognathi monophyly. This analysis also provided evidence that M. himalayana mt DNA was closely related to that from Sciurus vulgaris (Sciuridae) and was similar to mt DNA from Myoxus glis.

  15. Epizootiology of Tacaribe serocomplex viruses (Arenaviridae) associated with neotomine rodents (Cricetidae, Neotominae) in southern California.

    PubMed

    Milazzo, Mary Louise; Cajimat, Maria N B; Mauldin, Matthew R; Bennett, Stephen G; Hess, Barry D; Rood, Michael P; Conlan, Christopher A; Nguyen, Kiet; Wekesa, J Wakoli; Ramos, Ronald D; Bradley, Robert D; Fulhorst, Charles F

    2015-02-01

    The objective of this study was to advance our knowledge of the epizootiology of Bear Canyon virus and other Tacaribe serocomplex viruses (Arenaviridae) associated with wild rodents in California. Antibody (immunoglobulin G [IgG]) to a Tacaribe serocomplex virus was found in 145 (3.6%) of 3977 neotomine rodents (Cricetidae: Neotominae) captured in six counties in southern California. The majority (122 or 84.1%) of the 145 antibody-positive rodents were big-eared woodrats (Neotoma macrotis) or California mice (Peromyscus californicus). The 23 other antibody-positive rodents included a white-throated woodrat (N. albigula), desert woodrat (N. lepida), Bryant's woodrats (N. bryanti), brush mice (P. boylii), cactus mice (P. eremicus), and deer mice (P. maniculatus). Analyses of viral nucleocapsid protein gene sequence data indicated that Bear Canyon virus is associated with N. macrotis and/or P. californicus in Santa Barbara County, Los Angeles County, Orange County, and western Riverside County. Together, analyses of field data and antibody prevalence data indicated that N. macrotis is the principal host of Bear Canyon virus. Last, the analyses of viral nucleocapsid protein gene sequence data suggested that the Tacaribe serocomplex virus associated with N. albigula and N. lepida in eastern Riverside County represents a novel species (tentatively named "Palo Verde virus") in the genus Arenavirus. PMID:25700047

  16. Climatic niche conservatism and ecological opportunity in the explosive radiation of arvicoline rodents (Arvicolinae, Cricetidae).

    PubMed

    Lv, Xue; Xia, Lin; Ge, Deyan; Wu, Yongjie; Yang, Qisen

    2016-05-01

    Climatic niche conservatism shapes patterns of diversity in many taxonomic groups, while ecological opportunity (EO) can trigger rapid speciation that is less constrained by the amount of time a lineage has occupied a given habitat. These two processes are well studied, but limited research has considered their joint and relative roles in shaping diversity patterns. We characterized climatic and biogeographic variables for 102 species of arvicoline rodents (Arvicolinae, Cricetidae), testing the effects of climatic niche conservatism and EO on arvicoline diversification as lineages transitioned between biogeographic regions. We found that the amount of time a lineage has occupied a precipitation niche is positively correlated with diversity along a precipitation gradient, suggesting climatic niche conservatism. In contrast, shift in diversification rate explained diversity patterns along a temperature gradient. Our results suggest that an indirect relationship exists between temperature and diversification that is associated with EO as arvicoline rodents colonized warm Palearctic environments. Climatic niche conservatism alone did not fully explain diversity patterns under density-dependence, highlighting the additional importance of EO-related processes in promoting the explosive radiation in arvicoline rodents and shaping diversity pattern among biogeographic regions and along climatic gradients.

  17. Epizootiology of Tacaribe Serocomplex Viruses (Arenaviridae) Associated with Neotomine Rodents (Cricetidae, Neotominae) in Southern California

    PubMed Central

    Milazzo, Mary Louise; Cajimat, Maria N. B.; Mauldin, Matthew R.; Bennett, Stephen G.; Hess, Barry D.; Rood, Michael P.; Conlan, Christopher A.; Nguyen, Kiet; Wekesa, J. Wakoli; Ramos, Ronald D.; Bradley, Robert D.

    2015-01-01

    Abstract The objective of this study was to advance our knowledge of the epizootiology of Bear Canyon virus and other Tacaribe serocomplex viruses (Arenaviridae) associated with wild rodents in California. Antibody (immunoglobulin G [IgG]) to a Tacaribe serocomplex virus was found in 145 (3.6%) of 3977 neotomine rodents (Cricetidae: Neotominae) captured in six counties in southern California. The majority (122 or 84.1%) of the 145 antibody-positive rodents were big-eared woodrats (Neotoma macrotis) or California mice (Peromyscus californicus). The 23 other antibody-positive rodents included a white-throated woodrat (N. albigula), desert woodrat (N. lepida), Bryant's woodrats (N. bryanti), brush mice (P. boylii), cactus mice (P. eremicus), and deer mice (P. maniculatus). Analyses of viral nucleocapsid protein gene sequence data indicated that Bear Canyon virus is associated with N. macrotis and/or P. californicus in Santa Barbara County, Los Angeles County, Orange County, and western Riverside County. Together, analyses of field data and antibody prevalence data indicated that N. macrotis is the principal host of Bear Canyon virus. Last, the analyses of viral nucleocapsid protein gene sequence data suggested that the Tacaribe serocomplex virus associated with N. albigula and N. lepida in eastern Riverside County represents a novel species (tentatively named “Palo Verde virus”) in the genus Arenavirus. PMID:25700047

  18. Climatic niche conservatism and ecological opportunity in the explosive radiation of arvicoline rodents (Arvicolinae, Cricetidae).

    PubMed

    Lv, Xue; Xia, Lin; Ge, Deyan; Wu, Yongjie; Yang, Qisen

    2016-05-01

    Climatic niche conservatism shapes patterns of diversity in many taxonomic groups, while ecological opportunity (EO) can trigger rapid speciation that is less constrained by the amount of time a lineage has occupied a given habitat. These two processes are well studied, but limited research has considered their joint and relative roles in shaping diversity patterns. We characterized climatic and biogeographic variables for 102 species of arvicoline rodents (Arvicolinae, Cricetidae), testing the effects of climatic niche conservatism and EO on arvicoline diversification as lineages transitioned between biogeographic regions. We found that the amount of time a lineage has occupied a precipitation niche is positively correlated with diversity along a precipitation gradient, suggesting climatic niche conservatism. In contrast, shift in diversification rate explained diversity patterns along a temperature gradient. Our results suggest that an indirect relationship exists between temperature and diversification that is associated with EO as arvicoline rodents colonized warm Palearctic environments. Climatic niche conservatism alone did not fully explain diversity patterns under density-dependence, highlighting the additional importance of EO-related processes in promoting the explosive radiation in arvicoline rodents and shaping diversity pattern among biogeographic regions and along climatic gradients. PMID:27061935

  19. Arthropod symbiotes of Laonastes aenigmamus (Rodentia:Diatomyidae).

    PubMed

    Bochkov, A V; Abramov, A V; Durden, L A; Apanaskevich, D A; Stekolnikov, A A; Stanyukovich, M K; Gnophanxay, S; Tikhonov, A N

    2011-04-01

    Arthropod symbiotes of the Laotian rock-rat, Laonastes aenigmamus (Rodentia:Diatomyidae), from Laos are examined. This host is a member of Diatomyidae previously thought to have gone extinct >10 million yr ago. Permanent symbiotes are represented by 2 species, a new species of sucking louse, Polyplax sp., near rhizomydis (Phthiraptera:Polyplacidae), and a new species of fur mite, Afrolistrophorus sp., near maculatus (Acariformes:Listrophoridae). The temporary parasites are represented by 18 species, i.e., 1 mesostigmatan species, i.e., a new species of Androlaelaps near casalis (Parasitiformes:Laelapidae); immature stages of 2 tick species, Ixodes granulatus and Haemaphysalis sp. (Parasitiformes:Ixodidae); and a rich fauna of chiggers (Acariformes:Trombiculidae) comprising 8 genera and 15 species. It is hypothesized that this host completely lost its initial fauna of ectosymbiotes and that ancestors of the recorded symbiotes switched to this host from rodents of the superfamily Muroidea.

  20. The complete mitochondrial genome of Ictidomys tridecemlineatus (Rodentia: Sciuridae).

    PubMed

    Zhang, Leping; Storey, Kenneth B; Yu, Dan-Na; Hu, Yizhong; Zhang, Jia-Yong

    2016-07-01

    The complete mitochondrial genome of the thirteen-lined ground squirrel, Ictidomys tridecemlineatus (Rodentia: Sciuridae) was sequenced to analyze the gene arrangement. It is a circular molecule of 16,458 bp in length including 37 genes typically found in other squirrels. The AT content of the overall base composition is 63.7% and the length of the control region is 1016 bp with 63.0% AT content. In BI and ML phylogenetic trees, I. tridecemlineatus is a sister clade to the genus Cynomys, and Tamias sibiricus is a sister clade to (Marmota himalayana + (I. tridecemlineatus + (C. leucurus + C. ludovicianus))). Ratufinae is well supported as the basal clade of Sciuridae. The monophyly of the family Sciuridae and its subfamilies Callosciurinae, Xerinae and Sciurinae are well supported. PMID:26024127

  1. The complete mitochondrial genome of Ictidomys tridecemlineatus (Rodentia: Sciuridae).

    PubMed

    Zhang, Leping; Storey, Kenneth B; Yu, Dan-Na; Hu, Yizhong; Zhang, Jia-Yong

    2016-07-01

    The complete mitochondrial genome of the thirteen-lined ground squirrel, Ictidomys tridecemlineatus (Rodentia: Sciuridae) was sequenced to analyze the gene arrangement. It is a circular molecule of 16,458 bp in length including 37 genes typically found in other squirrels. The AT content of the overall base composition is 63.7% and the length of the control region is 1016 bp with 63.0% AT content. In BI and ML phylogenetic trees, I. tridecemlineatus is a sister clade to the genus Cynomys, and Tamias sibiricus is a sister clade to (Marmota himalayana + (I. tridecemlineatus + (C. leucurus + C. ludovicianus))). Ratufinae is well supported as the basal clade of Sciuridae. The monophyly of the family Sciuridae and its subfamilies Callosciurinae, Xerinae and Sciurinae are well supported.

  2. Amphimerus bragai n. sp. (Digenea: Opisthorchiidae), a parasite of the rodent Nectomys squamipes (Cricetidae) from Minas Gerais, Brazil.

    PubMed

    de Moraes Neto, A H; Thatcher, V E; Lanfredi, R M

    1998-01-01

    Amphimerus bragai n.sp. (Digenea, Opisthorchiidae) from the bile ducts of a rodent from the State of Minas Gerais, Brazil, Nectomys squamipes (Cricetidae), is described. The new species as studied by both light and scanning electron microscopy. A table is presented comparing the measurements of the new species with those of A. lancea (Diesing, 1850) and A. vallecaucensis Thatcher; 1970, parasites of dolphins and marsupials, respectively. The new species is similar in size and body form to A. vallecaucensis from which it differs in having a vitellarium that extends to the acetabulum while that of the former species are limited to the posterior one-third of the body. Additionally, the new species is from a rodent.

  3. A Transitional Gundi (Rodentia: Ctenodactylidae) from the Miocene of Israel.

    PubMed

    López-Antoñanzas, Raquel; Gutkin, Vitaly; Rabinovich, Rivka; Calvo, Ran; Grossman, Aryeh

    2016-01-01

    We describe a new species of gundi (Rodentia: Ctenodactylidae: Ctenodactylinae), Sayimys negevensis, on the basis of cheek teeth from the Early Miocene of the Rotem Basin, southern Israel. The Rotem ctenodactylid differs from all known ctenodactylid species, including Sayimys intermedius, which was first described from the Middle Miocene of Saudi Arabia. Instead, it most resembles Sayimys baskini from the Early Miocene of Pakistan in characters of the m1-2 (e.g., the mesoflexid shorter than the metaflexid, the obliquely orientated hypolophid, and the presence of a strong posterolabial ledge) and the upper molars (e.g., the paraflexus that is longer than the metaflexus). However, morphological (e.g., presence of a well-developed paraflexus on unworn upper molars) and dimensional (regarding, in particular, the DP4 and M1 or M2) differences between the Rotem gundi and Sayimys baskini distinguish them and testify to the novelty and endemicity of the former. In its dental morphology, Sayimys negevensis sp. nov. shows a combination of both the ultimate apparition of key-characters and incipient features that would be maintained and strengthened in latter ctenodactylines. Thus, it is a pivotal species that bridges the gap between an array of primitive ctenodactylines and the most derived, Early Miocene and later, gundis.

  4. New karyotypes of Atlantic tree rats, genus Phyllomys (Rodentia: Echimyidae).

    PubMed

    Araújo, Naiara Pereira; Loss, Ana Carolina; Cordeiro-Junior, Dirceu A; da Silva, Kátia Regina; Leite, Yuri L R; Svartman, Marta

    2014-01-01

    Phyllomys (Echimyidae, Rodentia) is a genus of Neotropical rodents with available cytogenetic data restricted to six out of 13 species, mainly based on simple staining methods, without detailed analyses. In this work, we present new karyotypes for Phyllomys lamarum (diploid number 2n = 56, fundamental number or number of autosomal arms FN = 102) and Phyllomys sp. (2n = 74, FN = 140) from the state of Minas Gerais, southeastern Brazil. We provide the first GTG- and CBG-banding patterns, silver-staining of the nucleolar organizer regions (Ag-NORs), and fluorescence in situ hybridization (FISH) with telomeric and 45S rDNA probes of Phyllomys. In addition to examining their chromosomes and phenotypic characters, we sequenced mitochondrial DNA from the specimens analyzed to confirm their taxonomic identification. The comparison of the distinctive chromosome complements of our specimens with those of other species of Phyllomys already published allowed us to conclude that chromosome data may be very useful for the taxonomy of the genus, as no two species analyzed presented the same diploid and fundamental numbers (2n and FN).

  5. A Transitional Gundi (Rodentia: Ctenodactylidae) from the Miocene of Israel

    PubMed Central

    López-Antoñanzas, Raquel; Gutkin, Vitaly; Rabinovich, Rivka; Calvo, Ran; Grossman, Aryeh

    2016-01-01

    We describe a new species of gundi (Rodentia: Ctenodactylidae: Ctenodactylinae), Sayimys negevensis, on the basis of cheek teeth from the Early Miocene of the Rotem Basin, southern Israel. The Rotem ctenodactylid differs from all known ctenodactylid species, including Sayimys intermedius, which was first described from the Middle Miocene of Saudi Arabia. Instead, it most resembles Sayimys baskini from the Early Miocene of Pakistan in characters of the m1-2 (e.g., the mesoflexid shorter than the metaflexid, the obliquely orientated hypolophid, and the presence of a strong posterolabial ledge) and the upper molars (e.g., the paraflexus that is longer than the metaflexus). However, morphological (e.g., presence of a well-developed paraflexus on unworn upper molars) and dimensional (regarding, in particular, the DP4 and M1 or M2) differences between the Rotem gundi and Sayimys baskini distinguish them and testify to the novelty and endemicity of the former. In its dental morphology, Sayimys negevensis sp. nov. shows a combination of both the ultimate apparition of key-characters and incipient features that would be maintained and strengthened in latter ctenodactylines. Thus, it is a pivotal species that bridges the gap between an array of primitive ctenodactylines and the most derived, Early Miocene and later, gundis. PMID:27049960

  6. A Transitional Gundi (Rodentia: Ctenodactylidae) from the Miocene of Israel.

    PubMed

    López-Antoñanzas, Raquel; Gutkin, Vitaly; Rabinovich, Rivka; Calvo, Ran; Grossman, Aryeh

    2016-01-01

    We describe a new species of gundi (Rodentia: Ctenodactylidae: Ctenodactylinae), Sayimys negevensis, on the basis of cheek teeth from the Early Miocene of the Rotem Basin, southern Israel. The Rotem ctenodactylid differs from all known ctenodactylid species, including Sayimys intermedius, which was first described from the Middle Miocene of Saudi Arabia. Instead, it most resembles Sayimys baskini from the Early Miocene of Pakistan in characters of the m1-2 (e.g., the mesoflexid shorter than the metaflexid, the obliquely orientated hypolophid, and the presence of a strong posterolabial ledge) and the upper molars (e.g., the paraflexus that is longer than the metaflexus). However, morphological (e.g., presence of a well-developed paraflexus on unworn upper molars) and dimensional (regarding, in particular, the DP4 and M1 or M2) differences between the Rotem gundi and Sayimys baskini distinguish them and testify to the novelty and endemicity of the former. In its dental morphology, Sayimys negevensis sp. nov. shows a combination of both the ultimate apparition of key-characters and incipient features that would be maintained and strengthened in latter ctenodactylines. Thus, it is a pivotal species that bridges the gap between an array of primitive ctenodactylines and the most derived, Early Miocene and later, gundis. PMID:27049960

  7. Taxonomic position of Eothenomys wardi (Arvicolinae: Cricetidae) based on morphological and molecular analyses with a detailed description of the species.

    PubMed

    Zeng, Tao; Jin, Wei; Sun, Zhi Yu; Liu, Yang; Murphy, Robert W; Fu, Jian Rong; Wang, Xin; Hou, Quan Fen; Tu, Fei Yun; Liao, Rui; Liu, Shao Ying; Yue, Bi Song

    2013-01-01

    Ward's Red-backed Vole (Eothenomys wardi) is a rodent from the family Cricetidae. This endemic species occurs only in extreme northwestern Yunnan province, China in the Mekong and Salween river divide. It occupies steep cliffs at 2,800 to 4,250 m above sea level on the remote Qinghai-Tibetan plateau. The validity of E. wardi is controversial and no specimens exist apart from the nominal series. In 2010, we collected 38 topotypes of E. wardi from Meri Snow Mountain. The results of our phylogenetic analyses based on nucleotide sequences of the mitochondrial genes cytochrome b (cytb) and cytochrome c oxidase subunit one (COI) suggest that E. wardi is the sister group of E. custos, against its previously presumed sister species or conspecific species E. chinensis. In addition, seven out of 34 morphological characters differentiate E. wardi from other members of the genus Eothenomys. Therefore, we consider E. wardi to be a valid species and we provide its detailed morphological description.

  8. Hymenolepis folkertsi n. sp. (Eucestoda: Hymenolepididae) in the oldfield mouse Peromyscus polionotus (Wagner) (Rodentia: Cricetidae: Neotominae) from the southeastern Nearctic with comments on tapeworm faunal diversity among deer mice.

    PubMed

    Makarikov, Arseny A; Nims, Todd N; Galbreath, Kurt E; Hoberg, Eric P

    2015-06-01

    A previously unrecognized species of hymenolepidid cestode attributable to Hymenolepis is described based on specimens in Peromyscus polionotus, oldfield mouse, from Georgia near the southeastern coast of continental North America. Specimens of Hymenolepis folkertsi n. sp. differ from those attributed to most other species in the genus by having testes arranged in a triangle and a scolex with a prominent rostrum-like protrusion. The newly recognized species is further distinguished by the relative position and length of the cirrus sac, shape of seminal receptacle, and relative size of external seminal vesicle and seminal receptacle. Hymenolepidid cestodes have sporadically been reported among the highly diverse assemblage of Peromyscus which includes 56 distinct species in the Nearctic. Although the host genus has a great temporal duration and is endemic to the Nearctic, current evidence suggests that tapeworm faunal diversity reflects relatively recent assembly through bouts of host switching among other cricetid, murid, and geomyid rodents in sympatry.

  9. Hymenolepis folkertsi n. sp. (Eucestoda: Hymenolepididae) in the oldfield mouse Peromyscus polionotus (Wagner) (Rodentia: Cricetidae: Neotominae) from the southeastern Nearctic with comments on tapeworm faunal diversity among deer mice.

    PubMed

    Makarikov, Arseny A; Nims, Todd N; Galbreath, Kurt E; Hoberg, Eric P

    2015-06-01

    A previously unrecognized species of hymenolepidid cestode attributable to Hymenolepis is described based on specimens in Peromyscus polionotus, oldfield mouse, from Georgia near the southeastern coast of continental North America. Specimens of Hymenolepis folkertsi n. sp. differ from those attributed to most other species in the genus by having testes arranged in a triangle and a scolex with a prominent rostrum-like protrusion. The newly recognized species is further distinguished by the relative position and length of the cirrus sac, shape of seminal receptacle, and relative size of external seminal vesicle and seminal receptacle. Hymenolepidid cestodes have sporadically been reported among the highly diverse assemblage of Peromyscus which includes 56 distinct species in the Nearctic. Although the host genus has a great temporal duration and is endemic to the Nearctic, current evidence suggests that tapeworm faunal diversity reflects relatively recent assembly through bouts of host switching among other cricetid, murid, and geomyid rodents in sympatry. PMID:25762188

  10. Description of Litomosoides ysoguazu n. sp. (Nematoda, Onchocercidae), a parasite of the tuft-toed rice rat Sooretamys angouya (Fischer) (Rodentia: Cricetidae), and a first record of L. esslingeri Bain, Petit & Berteaux, 1989 in Paraguay.

    PubMed

    Notarnicola, Juliana; de la Sancha, Noé Ulises

    2015-06-01

    Paraguay is a small landlocked country whose mammalian fauna is among the least studied in South America, as well as their parasites. As a result of a study of the effects of habitat fragmentation on small mammal biodiversity in eastern Paraguay, we have collected some parasites of cricetid rodents. Herein, we describe a new species of Litomosoides Chandler, 1931 parasitising the body cavity of the tuft-toed rice rat Sooretamys angouya (Fischer) and Litomosoides esslingeri Bain, Petit & Diagne, 1989 parasitising Oligoryzomys nigripes (Olfers), thus expanding its geographical distribution into Paraguay. Litomosoides ysoguazu n. sp. is characterised by the large size of the females (92.2-117.6 mm long) and by having buccal capsule with an anterior widening with rounded edges on the chitinous segment and a rounded widening at the base; male tail with a single pair of adcloacal papillae, three to five pairs of asymmetrical postcloacal papillae, and one or two unpaired papillae in the median ventral line; spicules corresponding to the "sigmodontis" species group; and microfilaria with a sheath stuck to the body and visible in the anterior extremity. We also describe a fourth-stage female larva. Oligoryzomys nigripes is a new host record of L. esslingeri; this enlarges the host record to eight species highlighting the low specificity of this species. PMID:25962465

  11. Description of Litomosoides ysoguazu n. sp. (Nematoda, Onchocercidae), a parasite of the tuft-toed rice rat Sooretamys angouya (Fischer) (Rodentia: Cricetidae), and a first record of L. esslingeri Bain, Petit & Berteaux, 1989 in Paraguay.

    PubMed

    Notarnicola, Juliana; de la Sancha, Noé Ulises

    2015-06-01

    Paraguay is a small landlocked country whose mammalian fauna is among the least studied in South America, as well as their parasites. As a result of a study of the effects of habitat fragmentation on small mammal biodiversity in eastern Paraguay, we have collected some parasites of cricetid rodents. Herein, we describe a new species of Litomosoides Chandler, 1931 parasitising the body cavity of the tuft-toed rice rat Sooretamys angouya (Fischer) and Litomosoides esslingeri Bain, Petit & Diagne, 1989 parasitising Oligoryzomys nigripes (Olfers), thus expanding its geographical distribution into Paraguay. Litomosoides ysoguazu n. sp. is characterised by the large size of the females (92.2-117.6 mm long) and by having buccal capsule with an anterior widening with rounded edges on the chitinous segment and a rounded widening at the base; male tail with a single pair of adcloacal papillae, three to five pairs of asymmetrical postcloacal papillae, and one or two unpaired papillae in the median ventral line; spicules corresponding to the "sigmodontis" species group; and microfilaria with a sheath stuck to the body and visible in the anterior extremity. We also describe a fourth-stage female larva. Oligoryzomys nigripes is a new host record of L. esslingeri; this enlarges the host record to eight species highlighting the low specificity of this species.

  12. A new Syphacia species (Nematoda: Oxyuridae) collected from Bunomys spp. (Rodentia: Muridae) in central Sulawesi, Indonesia.

    PubMed

    Dewi, Kartika; Hasegawa, Hideo

    2010-02-01

    Syphacia (Syphacia) rifaii sp. n. (Nematoda: Oxyuridae) is described from endemic Bunomys chrysocomus and Bunomys prolatus (Rodentia: Muridae) on Sulawesi Island, Indonesia. The new species is closest morphologically to Syphacia (Syphacia) sulawesiensis , parasitic in Rattus xanthurus from Sulawesi Island, by having large vesicular lateral alae in males, but is readily distinguished by having a smaller body, a round cephalic plate in both sexes, the absence of lateral alae in females, a longer relative distance between excretory pore and vulva, and smaller eggs. Syphacia (S.) rifaii is surmised to be a specific parasite of Bunomys spp. and has evolved from a common ancestor with S. (S.) sulawesiensis on Sulawesi Island.

  13. Identification of lymphocytic choriomeningitis mammarenavirus in house mouse (Mus musculus, Rodentia) in French Guiana.

    PubMed

    Lavergne, Anne; de Thoisy, Benoît; Tirera, Sourakhata; Donato, Damien; Bouchier, Christiane; Catzeflis, François; Lacoste, Vincent

    2016-01-01

    Thirty-seven house mice (Mus musculus, Rodentia) caught in different localities in French Guiana were screened to investigate the presence of lymphocytic choriomeningitis mammarenavirus (LCMV). Two animals trapped in an urban area were found positive, hosting a new strain of LCMV, that we tentatively named LCMV "Comou". The complete sequence was determined using a metagenomic approach. Phylogenetic analyses revealed that this strain is related to genetic lineage I composed of strains inducing severe disease in humans. These results emphasize the need for active surveillance in humans as well as in house mouse populations, which is a rather common rodent in French Guianese cities and settlements.

  14. The evolution of ecomorphological traits within the Abrothrichini (Rodentia: Sigmodontinae): a Bayesian phylogenetics approach.

    PubMed

    Rodríguez-Serrano, Enrique; Palma, R Eduardo; Hernández, Cristián E

    2008-08-01

    The generally accepted hypothesis regarding the origin of fossorial mammals proposes adaptive convergence from open environments towards the use of subterranean environments. We evaluated this hypothesis for South American mole-mice using conventional and Bayesian frameworks, with independent evidence. By using a molecular approach based on Cytochrome b and IRBP sequences, we evaluated phylogenetic relationships, time of origin, the ancestral trait of fossoriality, and ancestral distributions of species belonging to the Andean Clade (Rodentia: Sigmodontinae). Our results indicate that the Andean Clade is highly sustained; with one clade grouping all fossorial forms and another grouping all cursorial species. We hypothesized that fossoriality originated in the Miocene/Pliocene transition, in the Temperate Forests of southern South America. We conclude that the origin of fossorial ecomorphological traits did not necessarily occur under a general model of open environments, the origin of these traits depends on the ecological-historical relationship of the taxon with the environment.

  15. A new species of Reithrodontomys, subgenus Aporodon (Cricetidae: Neotominae), from the highlands of Costa Rica, with comments on Costa Rican and Panamanian Reithrodontomys

    USGS Publications Warehouse

    Gardner, Alfred L.; Carleton, Michael D.

    2009-01-01

    A new species of the rodent genus Reithrodontomys (Cricetidae: Neotominae) is described from Cerro Asuncion in the western Cordillera de Talamanca, Costa Rica. The long tail, elongate rostrum, bulbous braincase, and complex molars of the new species associate it with members of the subgenus Aporodon, tenuirostris species group. In its diminutive size and aspects of cranial shape, the new species (Reithrodontomys musseri, sp. nov.) most closely resembles R. microdon, a form known from highlands in Guatemala and Chiapas, Mexico. In the course of differentially diagnosing the new species, we necessarily reviewed the Costa Rican and Panamanian subspecies of R. mexicanus based on morphological comparisons, study of paratypes and vouchers used in recent molecular studies, and morphometric analyses. We recognize Reithrodontomys cherrii (Allen, 1891) and R. garichensis finders and Pearson, 1940, as valid species, and allocate R. mexicanus potrerograndei Goodwin, 1945, as a subjective synonym of R. brevirostris Goodwin, 1943. Critical review of museum specimens collected subsequent to Hooper's (1952) revision is needed and would do much to improve understanding of Reithrodontomys taxonomy and distribution in Middle America.

  16. Two new species of Litomosoides (Nemata:Onchocercidae) from Ctenomys opimus (Rodentia:Ctenomyidae) on the altiplano of Bolivia.

    PubMed

    Brant, S V; Gardner, S L

    1997-08-01

    Two filarioid nematodes, Litomosoides andersoni n. sp. and Litomosoides ctenomyos n. sp. (Nemata: Onchocercidae), are described from the mesenteries of the subterranean rodent Ctenomys opimus (Rodentia: Hystrichognathi) collected on the altiplano of Bolivia. Specimens collected near Rancho Huancaroma (Oruro Dept.) in 1984 and 1986 can be recognized as undescribed by the structures of the spicules and stoma and the shape of the ovijector. This record represents the first time members of the genus Litomosoides have been recovered from rodents of the family Ctenomyidae; this also represents the first published report of these nematodes from mammals in Bolivia.

  17. A new genus and species of Heligmonellidae (Nematoda: Trichostrongylina) parasitic in Delomys dorsalis (Rodentia: Sigmodontinae) from Misiones, Argentina.

    PubMed

    Digiani, María Celina; Kinsella, John M

    2014-10-01

    Alippistrongylus bicaudatus gen. et sp. n. (Nematoda: Heligmonellidae) is described from the striped Atlantic forest rat, Delomys dorsalis (Hensel) (Rodentia: Sigmodontinae), from the province of Misiones in Argentina. The new genus and species is characterised by a synlophe of 21 unequal ridges in both sexes without a gradient in size, with two ridges weakly sclerotised and oriented perpendicularly in the dorsal left quadrant; males with a highly dissymmetrical bursa with a hypertrophied right lobe, and females with a dorsal conical appendage just posterior to the vulva, conferring a two-tailed appearance to the female worms.

  18. Molecular systematics of dormice (Rodentia: Gliridae) and the radiation of Graphiurus in Africa.

    PubMed Central

    Montgelard, Claudine; Matthee, Conrad A; Robinson, Terence J

    2003-01-01

    The phylogenetic relationships among the Gliridae (order Rodentia) were assessed using 3430 nucleotides derived from three nuclear fragments (beta-spectrin non-erythrocytic 1, thyrotropin and lecithin cholesterol acyl transferase) and one mitochondrial gene (12S rRNA). We included 14 glirid species, representative of seven genera of the three recognized subfamilies (Graphiurinae, Glirinae and Leithiinae) in our analysis. The molecular data identified three evolutionary lineages that broadly correspond to the three extant subfamilies. However, the data suggest that the genus Muscardinus, previously regarded as falling within the Glirinae, should be included in the Leithiinae. Molecular dating using local molecular clocks and partitioned datasets allowed an estimate of the timing of cladogenesis within the glirids. Graphiurus probably diverged early in the group's evolution (40-50 Myr ago) and the three subfamilies diverged contemporaneously, probably in Europe. The radiation within Graphiurus is more recent, with the colonization of Africa by this lineage estimated at ca. 8-10 Myr ago. PMID:14561309

  19. Ecomorphological diversification among South American spiny rats (Rodentia; Echimyidae): a phylogenetic and chronological approach.

    PubMed

    Galewski, Thomas; Mauffrey, Jean-François; Leite, Yuri L R; Patton, James L; Douzery, Emmanuel J P

    2005-03-01

    The phylogeny of South American spiny rats (Rodentia; Echimyidae) was studied using the exon 28 of the von Willebrand Factor nuclear gene (vWF). Sequences were analysed separately and in combination with a mitochondrial dataset (cyt b, 12S and 16S rRNAs) used in previous publications. The basal polytomy of echimyids was partially resolved and unexpected intergeneric clades were recovered. Thus, the intimate nested position of Myocastor within echimyids is evidenced. A well-supported clade is identified, including all the arboreal genera, and a group formed by Myocastor, Thrichomys, and Proechimys+Hoplomys. The clustering of Euryzygomatomys+Clyomys with Trinomys is also suggested. On the opposite, the phylogenetic position of Capromys as well as the relationships among arboreal genera remain unclear. Molecular divergence times were estimated using a Bayesian relaxed molecular clock and suggest a Middle Miocene origin for most of modern genera. The ecomorphological diversification of echimyids is discussed in the light of these new results and past environmental modifications in South America.

  20. Helminth fauna of the Siberian chipmunk, Tamias sibiricus Laxmann (Rodentia, Sciuridae) introduced in suburban French forests.

    PubMed

    Pisanu, Benoît; Jerusalem, Christelle; Huchery, Cindy; Marmet, Julie; Chapuis, Jean-Louis

    2007-05-01

    The spread of an immigrant host species can be influenced both by its specific helminth parasites that come along with it and by newly acquired infections from native fauna. The Siberian chipmunk, Tamias sibiricus Laxmann (Rodentia, Sciuridae), a northeastern Eurasiatic ground nesting Sciurid, has been introduced in France for less than three decades. Thirty individuals were collected from three suburban forests in the Ile-de-France Region between 2002 and 2006. Two intestinal nematode species dominated the helminth fauna: Brevistriata skrjabini [Prevalence, P, 99% C.I., 87% (64-97%); mean intensity, M.I., 99% C.I., 43 (28-78)] and Aonchotheca annulosa [P, 47% (25-69%); M.I., 35 (3-157)]. B. skrjabini is a direct life cycle nematode species of North Eurasiatic origin, with a restricted spectrum of phylogenetically related suitable hosts. This result indicates that B. skrjabini successfully settled and spread with founder pet chipmunks maintained in captivity and released in natura. Chipmunks acquired A. annulosa, a nematode species with a large spectrum of phylogenetically unrelated suitable host species, from local Muroid rodent species with similar behavior, life-history traits and habitats. Quantitative studies are needed to evaluate the potential for both B. skrjabini and A. annulosa to impede the spread of Tamias and for B. skrjabini to favor chipmunk colonization through detrimental effects upon native co-inhabiting host species.

  1. The complete mitochondrial genome of Microtus fortis calamorum (Arvicolinae, Rodentia) and its phylogenetic analysis.

    PubMed

    Jiang, Xianhuan; Gao, Jun; Ni, Liju; Hu, Jianhua; Li, Kai; Sun, Fengping; Xie, Jianyun; Bo, Xiong; Gao, Chen; Xiao, Junhua; Zhou, Yuxun

    2012-05-01

    Microtus fortis is a special resource of rodent in China. It is a promising experimental animal model for the study on the mechanism of Schistosome japonicum resistance. The first complete mitochondrial genome sequence for Microtus fortis calamorum, a subspecies of M. fortis (Arvicolinae, Rodentia), was reported in this study. The mitochondrial genome sequence of M. f. calamorum (Genbank: JF261175) showed a typical vertebrate pattern with 13 protein coding genes, 2 ribosomal RNAs, 22 transfer RNAs and one major noncoding region (CR region).The extended termination associated sequences (ETAS-1 and ETAS-2) and conserved sequence block 1 (CSB-1) were found in the CR region. The putative origin of replication for the light strand (O(L)) of M. f. calamorum was 35bp long and showed high conservation in stem and adjacent sequences, but the difference existed in the loop region among three species of genus Microtus. In order to investigate the phylogenetic position of M. f. calamorum, the phylogenetic trees (Maximum likelihood and Bayesian methods) were constructed based on 12 protein-coding genes (except for ND6 gene) on H strand from 16 rodent species. M. f. calamorum was classified into genus Microtus, Arvcicolinae for the highly phylogenetic relationship with Microtus kikuchii (Taiwan vole). Further phylogenetic analysis results based on the cytochrome b gene ranged from M. f. calamorum to one of the subspecies of M. fortis, which formed a sister group of Microtus middendorfii in the genus Microtus.

  2. Codivergence in heteromyid rodents (Rodentia: heteromyidae) and their sucking lice of the genus Fahrenholzia (Phthiraptera: anoplura).

    PubMed

    Light, Jessica E; Hafner, Mark S

    2008-06-01

    Although most studies of codivergence rely primarily on topological comparisons of host and parasite phylogenies, temporal assessments are necessary to determine if divergence events in host and parasite trees occurred contemporaneously. A combination of cophylogenetic analyses and comparisons of branch lengths are used in this study to understand the host-parasite association between heteromyid rodents (Rodentia: Heteromyidae) and their sucking lice of the genus Fahrenholzia (Phthiraptera: Anoplura). Cophylogenetic comparisons based on nucleotide substitutions in the mitochondrial COI gene reveal a significant, but not perfect, pattern of cophylogeny between heteromyids and their sucking lice. Regression analyses show a significant functional relationship between the lengths of analogous branches in the host and parasite trees, indicating that divergence events in hosts and parasites were approximately contemporaneous. Thus, the topological similarity observed between heteromyids and their lice is the result of codivergence. These analyses also show that the COI gene in lice is evolving two to three times faster than the same gene in their hosts (similar to the results of studies of other lice and their vertebrate hosts) and that divergence events in lice occurred shortly after host divergence. We recommend that future studies of codivergence include temporal comparisons and, when possible, use the same molecular marker(s) in hosts and parasites to achieve the greatest insight into the history of the host-parasite relationship.

  3. DNA extraction from bristles and quills of Chaetomys subspinosus (Rodentia: Erethizontidae) using a novel protocol.

    PubMed

    Oliveira, C G; Martinez, R A; Gaiotto, F A

    2007-01-01

    DNA extraction protocols are as varied as DNA sources. When it comes to endangered species, it is especially important to pay attention to all details that ensure the completion of the study goals and effectiveness in attaining useful data for conservation. Chaetomys subspinosus (Rodentia: Erethizontidae) is a secretive arboreal porcupine endemic to certain ecosystems of the Brazilian Atlantic Forest. A multidisciplinary study (including genetic data) was performed to create a management plan for the conservation of this species. Individuals from natural populations of the states of Bahia, Espírito Santo and Sergipe were sampled. To obtain a reliable and abundant amount of starting material, non-destructive methods were tested, extracting DNA from the bristles and quills that comprise most of this animal's hide. This method has also been innovative in adapting a DNA extraction protocol traditionally used for plants. Digestion using proteinase K was followed by protein precipitation with CTAB, a chloroform-isoamyl alcohol cleaning and DNA precipitation with isopropyl alcohol. This protocol supplies good-quality DNA for genetic analysis with molecular markers based on PCR. PMID:18050086

  4. A new species of porcupine, genus Coendou (Rodentia: Erethizontidae) from the Atlantic forest of northeastern Brazil.

    PubMed

    Pontes, Antonio Rossano Mendes; Gadelha, José Ramon; Melo, Éverton R A; de Sá, Fabrício Bezerra; Loss, Ana Carolina; Caldara Junior, Vilacio; Costa, Leonora Pires; Leite, Yuri L R

    2013-01-01

    We report the discovery of a new species of Coendou (Rodentia, Erethizontidae), here designated Coendou speratus sp. nov. This small porcupine, locally known as coandumirim, is found in the Pernambuco Endemism Centre in the Atlantic coast of northeastern Brazil north of the São Francisco river, one of the most important known biodiversity hotspots. The geographic range of C. speratus overlaps with that of the larger, widespread C. prehensilis, but not with that of C. insidiosus from the southeastern Atlantic forest, nor with that of C. nycthemera, an eastern Amazonian species. Coendou speratus is a small-bodied, long-tailed species that appears to be completely spiny because it lacks long dorsal fur. The dorsal quills have conspicuously brownish red tips that contrast with the blackish dorsal background color. The new species is overall similar to C. nycthemera, but the dorsal body quills are typically tricolored in the former and bicolored in the latter. The new species is externally very distinct from C. insidiosus, especially because the latter has bicolored dorsal quills that are almost completely hidden beneath longer and homogeneous pale or dark hairs. PMID:26042302

  5. A new species of porcupine, genus Coendou (Rodentia: Erethizontidae) from the Atlantic forest of northeastern Brazil.

    PubMed

    Pontes, Antonio Rossano Mendes; Gadelha, José Ramon; Melo, Éverton R A; de Sá, Fabrício Bezerra; Loss, Ana Carolina; Caldara Junior, Vilacio; Costa, Leonora Pires; Leite, Yuri L R

    2013-01-01

    We report the discovery of a new species of Coendou (Rodentia, Erethizontidae), here designated Coendou speratus sp. nov. This small porcupine, locally known as coandumirim, is found in the Pernambuco Endemism Centre in the Atlantic coast of northeastern Brazil north of the São Francisco river, one of the most important known biodiversity hotspots. The geographic range of C. speratus overlaps with that of the larger, widespread C. prehensilis, but not with that of C. insidiosus from the southeastern Atlantic forest, nor with that of C. nycthemera, an eastern Amazonian species. Coendou speratus is a small-bodied, long-tailed species that appears to be completely spiny because it lacks long dorsal fur. The dorsal quills have conspicuously brownish red tips that contrast with the blackish dorsal background color. The new species is overall similar to C. nycthemera, but the dorsal body quills are typically tricolored in the former and bicolored in the latter. The new species is externally very distinct from C. insidiosus, especially because the latter has bicolored dorsal quills that are almost completely hidden beneath longer and homogeneous pale or dark hairs.

  6. Broadening diversity in the Arostrilepis horrida complex: Arostrilepis kontrimavichusi n. sp. (Cyclophyllidea: Hymenolepididae) in the western red-backed vole Myodes californicus (Merriam) (Cricetidae: Arvicolinae) from temperate latitudes of the Pacific Northwest, North America.

    PubMed

    Makarikov, Arseny A; Hoberg, Eric P

    2016-06-01

    Specimens originally identified provisionally as Hymenolepis horrida (Linstow, 1901) [later Arostrilepis horrida (Linstow, 1901)] in Myodes californicus (Merriam) from near the Pacific coastal zone of southern Oregon are revised. Specimens in western red-backed voles represent an undescribed species of Arostrilepis Mas Coma & Tenora, 1997, contributing to recognition and resolution of a broadening complex encompassing cryptic diversity for these hymenolepidid tapeworms distributed across the Holarctic region. Consistent with recent studies defining diversity in the genus, the form, dimensions, and spination (pattern, shape and size) of the cirrus are diagnostic. Among 12 nominal congeners, specimens of A. kontrimavichusi n. sp. are further distinguished by the relative position and length of the cirrus-sac, arrangement of the testes and relative size of the external seminal vesicle and seminal receptacle. Specimens from Oregon voles represent the fifth endemic hymenolepidid in this genus from the Nearctic. Host range for the North American assemblage of species includes Cricetidae (Arvicolinae and Neotominae), Heteromyidae, Geomyidae, and rarely Sciuridae.

  7. Postnatal ontogeny of limb proportions and functional indices in the subterranean rodent Ctenomys talarum (Rodentia: Ctenomyidae).

    PubMed

    Echeverría, Alejandra Isabel; Becerra, Federico; Vassallo, Aldo Iván

    2014-08-01

    Burrow construction in the subterranean Ctenomys talarum (Rodentia: Ctenomyidae) primarily occurs by scratch-digging. In this study, we compared the limbs of an ontogenetic series of C. talarum to identify variation in bony elements related to fossorial habits using a morphometrical and biomechanical approach. Diameters and functional lengths of long bones were measured and 10 functional indices were constructed. We found that limb proportions of C. talarum undergo significant changes throughout postnatal ontogeny, and no significant differences between sexes were observed. Five of six forelimb indices and two of four hindlimb indices showed differences between ages. According to discriminant analysis, the indices that contributed most to discrimination among age groups were robustness of the humerus and ulna, relative epicondylar width, crural and brachial indices, and index of fossorial ability (IFA). Particularly, pups could be differentiated from juveniles and adults by more robust humeri and ulnae, wider epicondyles, longer middle limb elements, and a proportionally shorter olecranon. Greater robustness indicated a possible compensation for lower bone stiffness while wider epicondyles may be associated to improved effective forces in those muscles that originate onto them, compensating the lower muscular development. The gradual increase in the IFA suggested a gradual enhancement in the scratch-digging performance due to an improvement in the mechanical advantage of forearm extensors. Middle limb indices were higher in pups than in juveniles-adults, reflecting relatively more gracile limbs in their middle segments, which is in accordance with their incipient fossorial ability. In sum, our results show that in C. talarum some scratch-digging adaptations are already present during early postnatal ontogeny, which suggests that they are prenatally shaped, and other traits develop progressively. The role of early digging behavior as a factor influencing on

  8. First description of the nymph and larva of Dermacentor compactus Neumann, 1901 (Acari: Ixodidae), parasites of squirrels (Rodentia: Sciuridae) in southeast Asia.

    PubMed

    Apanaskevich, Dmitry A

    2016-05-01

    Recent reexamination of collection lots stored in the United States National Tick Collection revealed adult specimens of Dermacentor compactus Neumann, 1901 (Acari: Ixodidae) reared from field-collected nymphs, which allowed us to associate field-collected unidentified nymphs and larvae with this species. Nymphs of D. compactus can be easily distinguished from those of other congeneric species by the shape of the scutum and spiracular plate, the hypostome dentition, and the size of the spurs on the coxae. Larvae of this species can be distinguished by the shape and sculpture of the scutum, the shape of basis capituli, the absence of auriculae, and the size of the spurs on coxae II and III. Both nymphs and larvae feed mostly on various species of squirrels (Rodentia: Sciuridae). Considerably fewer nymphs and larvae were found on murid rodents (Rodentia: Muridae), domestic dogs (Carnivora: Canidae), and a snake (Squamata: Colubridae). PMID:27095664

  9. Squamasnema amazonica n. gen. n. sp. (Heligmonellinae): A new parasite of Proechimys roberti (Rodentia: Echimyidae) in the Brazilian Amazon.

    PubMed

    Cordeiro, Helrik da Costa; Melo, Francisco Tiago de Vasconcelos; Furtado, Adriano Penha; Giese, Elane Guerreiro; Maldonado, Arnaldo; dos Santos, Jeannie Nascimento

    2015-08-01

    A new species of nematode, Squamasnema amazonica n. gen. n. sp., is described based on specimens found parasitizing the small intestine of Proechimys roberti (Rodentia: Echimyidae) collected during a survey of the fauna of Tapirapé-Aquirí National Forest (Brazil, Eastern Brazilian Amazon). The nematodes were fixed and processed for light microscopy and scanning electron microscopy (SEM). These nematodes were classified under the family Heligmonellidae and the subfamily Heligmonellinae. Although several species in the family Heligmonellidae exhibit discontinuous ridges, Squamasnema n. gen. and Trichotravassosia are the only genera with columns of scales along their entire body, as an apomorphy of the synlophe. Squamasnema n. gen. has columns of cuticular cells along its body, except for on the left flank, and exhibits a synlophe with no size gradient or inclination and does not present chitinized structures supporting the synlophe. Therefore, due to these morphological differences of Squamasnema n. gen., the creation of a new genus was necessary.

  10. Broadening diversity in the Arostrilepis horrida complex: Arostrilepis kontrimavichusi n. sp. (Cyclophyllidea: Hymenolepididae) in the western red-backed vole Myodes californicus (Merriam) (Cricetidae: Arvicolinae) from temperate latitudes of the Pacific Northwest, North America.

    PubMed

    Makarikov, Arseny A; Hoberg, Eric P

    2016-06-01

    Specimens originally identified provisionally as Hymenolepis horrida (Linstow, 1901) [later Arostrilepis horrida (Linstow, 1901)] in Myodes californicus (Merriam) from near the Pacific coastal zone of southern Oregon are revised. Specimens in western red-backed voles represent an undescribed species of Arostrilepis Mas Coma & Tenora, 1997, contributing to recognition and resolution of a broadening complex encompassing cryptic diversity for these hymenolepidid tapeworms distributed across the Holarctic region. Consistent with recent studies defining diversity in the genus, the form, dimensions, and spination (pattern, shape and size) of the cirrus are diagnostic. Among 12 nominal congeners, specimens of A. kontrimavichusi n. sp. are further distinguished by the relative position and length of the cirrus-sac, arrangement of the testes and relative size of the external seminal vesicle and seminal receptacle. Specimens from Oregon voles represent the fifth endemic hymenolepidid in this genus from the Nearctic. Host range for the North American assemblage of species includes Cricetidae (Arvicolinae and Neotominae), Heteromyidae, Geomyidae, and rarely Sciuridae. PMID:27221000

  11. A new genus and two new species of chigger mites (Acari: Trombiculidae) from the Laotian rock-rat Laonastes aenigmamus Jenkins, Kilpatrick, Robinson & Timmins (Rodentia: Diatomyidae).

    PubMed

    Stekolnikov, Alexandr A

    2014-01-01

    A new chigger mite genus Laotrombicula n. g. and two new species, Laotrombicula khunboromi n. sp. (type-species) and L. fangumi n. sp., are described from the Laotian rock-rat Laonastes aenigmamus Jenkins, Kilpatrick, Robinson & Timmins (Rodentia: Diatomyidae). The new genus is most similar to Trombiculindus Radford, 1948 and Leptotrombidium Nagayo, Miyagawa, Mitamura & Imamura, 1916 and differs from these genera by having the scutum of subhexagonal or semicircular shape vs widely rectangular; pinnatifid dorsocentral idiosomal setae vs foliaceous in Trombiculindus and unexpanded in Leptotrombidium; and by the presence of serrated longitudinal crests in the middle part of scutum.

  12. Virtual endocasts of Eocene Paramys (Paramyinae): oldest endocranial record for Rodentia and early brain evolution in Euarchontoglires.

    PubMed

    Bertrand, Ornella C; Amador-Mughal, Farrah; Silcox, Mary T

    2016-01-27

    Understanding the pattern of brain evolution in early rodents is central to reconstructing the ancestral condition for Glires, and for other members of Euarchontoglires including Primates. We describe the oldest virtual endocasts known for fossil rodents, which pertain to Paramys copei (Early Eocene) and Paramys delicatus (Middle Eocene). Both specimens of Paramys have larger olfactory bulbs and smaller paraflocculi relative to total endocranial volume than later occurring rodents, which may be primitive traits for Rodentia. The encephalization quotients (EQs) of Pa. copei and Pa. delicatus are higher than that of later occurring (Oligocene) Ischyromys typus, which contradicts the hypothesis that EQ increases through time in all mammalian orders. However, both species of Paramys have a lower relative neocortical surface area than later rodents, suggesting neocorticalization occurred through time in this Order, although to a lesser degree than in Primates. Paramys has a higher EQ but a lower neocortical ratio than any stem primate. This result contrasts with the idea that primates were always exceptional in their degree of overall encephalization and shows that relative brain size and neocortical surface area do not necessarily covary through time. As such, these data contradict assumptions made about the pattern of brain evolution in Euarchontoglires.

  13. A phylogeographic study of the endemic rodent Eliurus carletoni (Rodentia: Nesomyinae) in an ecological transition zone of Northern Madagascar.

    PubMed

    Rakotoarisoa, Jean-Eric; Raheriarisena, Martin; Goodman, Steven M

    2013-01-01

    We conducted a mitochondrial phylogeographic study of the endemic dry forest rodent Eliurus carletoni (Rodentia: Nesomyinae) in an ecological transition zone of northern Madagascar (Loky-Manambato) and 2 surrounding regions (Ankarana and Analamerana). The main goal was to assess the evolutionary consequences on this taxon of the complex landscape features and Quaternary ecological vicissitudes. Three haplogroups were identified from the 215 specimens obtained from 15 populations. High levels of genetic diversity and significant genetic differentiation among populations were observed. The different geographical subdivisions of the study area by regions, by river catchment zones, and the physical distance between populations are not correlated with genetic patterns. In contrast, population structure is mostly explained by the geographic distribution of the samples among existing forest blocks. E. carletoni experienced a genetic bottleneck between 18 750 and 7500 years BP, which correlates with periods when moister climates existed on the island. Overall, our data suggest that the complex genetic patterns of E. carletoni can be explained by Quaternary climatic vicissitudes that resulted in habitat fluctuations between dry and humid forests, as well as subsequent human-induced fragmentation of forest habitat.

  14. Virtual endocasts of Eocene Paramys (Paramyinae): oldest endocranial record for Rodentia and early brain evolution in Euarchontoglires.

    PubMed

    Bertrand, Ornella C; Amador-Mughal, Farrah; Silcox, Mary T

    2016-01-27

    Understanding the pattern of brain evolution in early rodents is central to reconstructing the ancestral condition for Glires, and for other members of Euarchontoglires including Primates. We describe the oldest virtual endocasts known for fossil rodents, which pertain to Paramys copei (Early Eocene) and Paramys delicatus (Middle Eocene). Both specimens of Paramys have larger olfactory bulbs and smaller paraflocculi relative to total endocranial volume than later occurring rodents, which may be primitive traits for Rodentia. The encephalization quotients (EQs) of Pa. copei and Pa. delicatus are higher than that of later occurring (Oligocene) Ischyromys typus, which contradicts the hypothesis that EQ increases through time in all mammalian orders. However, both species of Paramys have a lower relative neocortical surface area than later rodents, suggesting neocorticalization occurred through time in this Order, although to a lesser degree than in Primates. Paramys has a higher EQ but a lower neocortical ratio than any stem primate. This result contrasts with the idea that primates were always exceptional in their degree of overall encephalization and shows that relative brain size and neocortical surface area do not necessarily covary through time. As such, these data contradict assumptions made about the pattern of brain evolution in Euarchontoglires. PMID:26817776

  15. Trypanosoma (Megatrypanum) lainsoni n. sp. from Mesomys hispidus (Rodentia: Echimyidae) in Brazil: trypomastigotes described from experimentally infected laboratory mice.

    PubMed

    Naiff, Roberto Daibes; Barrett, Toby Vincent

    2013-01-01

    We report the detection, isolation and description of Trypanosoma (Megatrypanum) lainsoni n. sp. from a caviomorph rodent, Mesomys hispidus (Rodentia: Echimyidae), obtained in the Rio Negro region of the state of Amazonas, in northern Brazil. Laboratory-bred white mice (Mus musculus) and rats (Rattus rattus) were inoculated with large numbers of culture forms by intraperitoneal route, and trypomastigotes appeared in their blood 3-8 days post-inoculation. One single epimastigote was also found in Mus musculus. Similar attempts to infect Rattus norvegicus, hamsters (Mesocricetus auratus), the opossum Didelphis marsupialis, the anteater Tamandua tetradactyla and triatomine bugs were unsuccessful, following six months of observations and microscopic examinations of blood films and blood cultures. As we have found no previous record of a Trypanosoma (Megatrypanum) species naturally infecting a member of the family Echimyidae, or any other caviomorph rodent, we conclude that this is the first time such an infection has been reported. The new species is unusual in the subgenus for its infectivity to laboratory mice. PMID:24309069

  16. Trypanosoma (Megatrypanum) lainsoni n. sp. from Mesomys hispidus (Rodentia: Echimyidae) in Brazil: trypomastigotes described from experimentally infected laboratory mice

    PubMed Central

    2013-01-01

    We report the detection, isolation and description of Trypanosoma (Megatrypanum) lainsoni n. sp. from a caviomorph rodent, Mesomys hispidus (Rodentia: Echimyidae), obtained in the Rio Negro region of the state of Amazonas, in northern Brazil. Laboratory-bred white mice (Mus musculus) and rats (Rattus rattus) were inoculated with large numbers of culture forms by intraperitoneal route, and trypomastigotes appeared in their blood 3–8 days post-inoculation. One single epimastigote was also found in Mus musculus. Similar attempts to infect Rattus norvegicus, hamsters (Mesocricetus auratus), the opossum Didelphis marsupialis, the anteater Tamandua tetradactyla and triatomine bugs were unsuccessful, following six months of observations and microscopic examinations of blood films and blood cultures. As we have found no previous record of a Trypanosoma (Megatrypanum) species naturally infecting a member of the family Echimyidae, or any other caviomorph rodent, we conclude that this is the first time such an infection has been reported. The new species is unusual in the subgenus for its infectivity to laboratory mice. PMID:24309069

  17. Catalog of type specimens of recent mammals: Rodentia (Sciuromorpha and Castorimorpha) in the National Museum of Natural History, Smithsonian Institution

    USGS Publications Warehouse

    Fisher, Robert D.; Ludwig, Craig A.

    2012-01-01

    The type collection of Recent mammals in the Division of Mammals, National Museum of Natural History, Smithsonian Institution, contains 843 specimens bearing names of 820 species group taxa of Rodentia (Sciuromorpha and Castorimorpha) as of July 2011. This catalog presents a list of these holdings, which comprise 798 holotypes, 14 lectotypes, seven syntypes (30 specimens), and one neotype. In addition, we include three holotypes and 10 specimens that are part of syntype series that should be in the collection but cannot be found and three syntypes that were originally in this collection but are now known to be in other collections. One specimen that no longer has name-bearing status is included for the record. Forty-one of the names are new since the last type catalog. One new lectotype is designated. Suborders and families are listed as in Wilson and Reeder. Within families, currently recognized genera are arranged alphabetically. Within each currently recognized genus, accounts are arranged alphabetically by original published name. Information in each account includes original name and abbreviated citation thereto, current name if other than original, citation for first use of current name combination for the taxon (or new name combination if used herein for the first time), type designation, U.S. National Museum catalog number(s), preparation, age and sex, type locality, date of collection and name of collector, collector’s original number, and comments or additional information as appropriate. Digital photographs of each specimen serve as a condition report and will be linked to each electronic specimen record.

  18. Body shape and life style of the extinct Balearic dormouse Hypnomys (Rodentia, Gliridae): new evidence from the study of associated skeletons.

    PubMed

    Bover, Pere; Alcover, Josep A; Michaux, Jacques J; Hautier, Lionel; Hutterer, Rainer

    2010-12-31

    Hypnomys is a genus of Gliridae (Rodentia) that occurred in the Balearic Islands until Late Holocene. Recent finding of a complete skeleton of the chronospecies H. morpheus (Late Pleistocene-Early Holocene) and two articulated skeletons of H. cf. onicensis (Late Pliocene) allowed the inference of body size and the calculation of several postcranial indexes. We also performed a Factorial Discriminant Analysis (FDA) in order to evaluate locomotory behaviour and body shape of the taxa. Using allometric models based on skull and tooth measurements, we calculated a body weight between 173 and 284 g for H. morpheus, and direct measurements of articulated skeletons yielded a Head and Body Length (HBL) of 179 mm and a Total Body Length of 295 mm for this species. In addition to the generally higher robustness of postcranial bones already recorded by previous authors, H. morpheus, similar to Canariomys tamarani, another extinct island species, displayed elongated zygopodium bones of the limbs and a wider distal humerus and femur than in an extant related taxon, Eliomys quercinus. Indexes indicated that Hypnomys was more terrestrial and had greater fossorial abilities than E. quercinus. This was also corroborated by a Discriminant Analysis, although no clear additional inference of locomotory abilities could be calculated.

  19. Catalog of type specimens of recent mammals: orders Didelphimorpha through Chiroptera (Excluding Rodentia) in the National Museum of Natural History, Smithsonian Institution

    USGS Publications Warehouse

    Fisher, Robert D.; Ludwig, Craig A.

    2015-01-01

    The type collection of Recent Mammals in the Division of Mammals, National Museum of Natural History, Smithsonian Institution, contains 820 specimens bearing names of 809 species-group taxa of Didelphimorphia through Chiroptera, excluding Rodentia, as of June 2014. This catalog presents an annotated list of these holdings comprised of 788 holotypes, 26 lectotypes, 11 syntypes (22 specimens), and 4 neotypes. Included are several specimens that should be in the collection but cannot be found or are now known to be in other collections. One hundred and twenty-seven of the names are new since the last type catalog covering these orders, Poole and Schantz (1942). Five specimens reported in Poole and Schantz (1942) were subsequently sent to the Vertebrate Paleontology collection and are not included here. Orders and families are ordered as in Wilson and Reeder (2005); within families, currently recognized genera are arranged alphabetically; within each currently recognized genus, accounts are arranged alphabetically by original published name. Information in each account includes original name and abbreviated citation thereto, current name if other than original, citation for first use of current name combination for the taxon (or new name combination if used herein for the first time), type designation, U.S. National Museum catalog number(s), preparation, age and sex, date of collection and collector, original collector number, type locality, and remarks as appropriate. Digital photographs of each specimen will serve as a condition report and will be attached to each electronic specimen record.

  20. Catalog of type specimens of recent mammals: Rodentia (Myomorpha, Anomaluromorpha, and Hystricomorpha) in the National Museum of Natural History, Smithsonian Institution

    USGS Publications Warehouse

    Fisher, Robert D.; Ludwig, Craig A.

    2014-01-01

    The type collection of Recent mammals in the Division of Mammals, National Museum of Natural History, Smithsonian Institution, contains 945 specimens bearing names of 931 species-group taxa of Rodentia (Myomorpha, Anomaluromorpha, and Hystricomorpha) as of August 2013. This catalog presents an annotated list of these holdings comprised of 905 holotypes, 16 lectotypes, 8 syntypes (48 specimens), and 2 neotypes. In addition, we include 44 specimens that are part of syntype series that should be in the collection but cannot be found or are now known to be in other collections. One hundred and ten of the names are new since the last type catalog covering these suborders A lectotype for Mus peruvianus Peale, 1848, is newly designated herein. Nine specimens previously reported were subsequently sent to the vertebrate paleontology collection and are not included here. Suborders and families are ordered as in Carleton and Musser; within families, currently recognized genera are arranged alphabetically; within each currently recognized genus, accounts are arranged alphabetically by original published name. Information in each account includes original name and abbreviated citation thereto, current name if other than original, citation for first use of current name combination for the taxon (or new name combination if used herein for the first time), type designation, U.S. National Museum catalog number(s), preparation, age and sex, date of collection and collector, original collector number, type locality, and remarks as appropriate. Digital photographs of each specimen will serve as a condition report and will be attached to each electronic specimen record.

  1. Body Shape and Life Style of the Extinct Balearic Dormouse Hypnomys (Rodentia, Gliridae): New Evidence from the Study of Associated Skeletons

    PubMed Central

    Bover, Pere; Alcover, Josep A.; Michaux, Jacques J.; Hautier, Lionel; Hutterer, Rainer

    2010-01-01

    Hypnomys is a genus of Gliridae (Rodentia) that occurred in the Balearic Islands until Late Holocene. Recent finding of a complete skeleton of the chronospecies H. morpheus (Late Pleistocene-Early Holocene) and two articulated skeletons of H. cf. onicensis (Late Pliocene) allowed the inference of body size and the calculation of several postcranial indexes. We also performed a Factorial Discriminant Analysis (FDA) in order to evaluate locomotory behaviour and body shape of the taxa. Using allometric models based on skull and tooth measurements, we calculated a body weight between 173 and 284 g for H. morpheus, and direct measurements of articulated skeletons yielded a Head and Body Length (HBL) of 179 mm and a Total Body Length of 295 mm for this species. In addition to the generally higher robustness of postcranial bones already recorded by previous authors, H. morpheus, similar to Canariomys tamarani, another extinct island species, displayed elongated zygopodium bones of the limbs and a wider distal humerus and femur than in an extant related taxon, Eliomys quercinus. Indexes indicated that Hypnomys was more terrestrial and had greater fossorial abilities than E. quercinus. This was also corroborated by a Discriminant Analysis, although no clear additional inference of locomotory abilities could be calculated. PMID:21209820

  2. Rodentia and lagomorpha

    USGS Publications Warehouse

    Sheffield, S.R.; Sawicka-Kapusta, K.; Cohen, J.B.; Rattner, B.A.; Shore, Richard F.; Rattner, Barnett A.

    2001-01-01

    This comprehensive review examines the extensive literature on wild rodents and lagomorphs as biomonitors of environmental contamination. This chapter covers studies dealing with exposure and effects of environmental contaminants on rodent and lagomorph species, including pesticides (organochlorines, organophosphorus and carbamate compounds, herbicides, plant growth regulators, fungicides, and rodenticides), other organic chemicals, metals, radionuclides, and other miscellaneous contaminants. Many research needs become evident when reviewing ecotoxicological data for rodents and lagomorphs, the most striking being the paucity of information on rodent families other than Muridae (mice and rats). While our ability to qualitatively extrapolate effects observed in laboratory studies to field situations is good for a variety of contaminants, quantitative predictions of dose-response relationships are poor because inter-specific variation and differences in exposure patterns between laboratory and wild species to toxicants are for the most part unknown. More sophisticated comparative toxicity studies need to be undertaken that build on previous work in order to develop a database of information, to account for and model differences in exposure pathways, to document interactions among multiple stressors, to generate data establishing thresholds, critical concentrations, and diagnostic guidelines, and even to develop physiologically-based toxicokinetic models. Such efforts may enhance our ability to predict effects on wild populations, including threatened and endangered species.

  3. Functional differentiation of trailing and leading forelimbs during locomotion on the ground and on a horizontal branch in the European red squirrel (Sciurus vulgaris, Rodentia).

    PubMed

    Schmidt, André

    2011-06-01

    Mammalian locomotion is characterized by the frequent use of in-phase gaits in which the footfalls of the left and right fore- or hindlimbs are unevenly spaced in time. Although previous studies have identified a functional differentiation between the first limb (trailing limb) and the second limb (leading limb) to touch the ground during terrestrial locomotion, the influence of a horizontal branch on limb function has never been explored. To determine the functional differences between trailing and leading forelimbs during locomotion on the ground and on a horizontal branch, X-ray motion analysis and force measurements were carried out in two European red squirrels (Sciurus vulgaris, Rodentia). The differences observed between trailing and leading forelimbs were minimal during terrestrial locomotion, where both limbs fulfill two functions and go through a shock-absorbing phase followed by a generating phase. During locomotion on a horizontal branch, European red squirrels reduce speed and all substrate reaction forces transmitted may be due to the reduction of vertical oscillation of the center of mass. Further adjustments during locomotion on a horizontal branch differ significantly between trailing and leading forelimbs and include limb flexion, lead intervals, limb protraction and vertical displacement of the scapular pivot. Consequently, trailing and leading forelimbs perform different functions. Trailing forelimbs function primarily as shock-absorbing elements, whereas leading forelimbs are characterized by a high level of stiffness. This functional differentiation indicates that European red squirrels 'test' the substrate for stability with the trailing forelimb, while the leading forelimb responds to or counteracts swinging or snapping branches.

  4. A Golgi study of the sixth layer of the cerebral cortex. I. The lissencephalic brain of Rodentia, Lagomorpha, Insectivora and Chiroptera.

    PubMed Central

    Ferrer, I; Fabregues, I; Condom, E

    1986-01-01

    A study of the morphological characteristics of the neurons in layer VI of the cerebral cortex was carried out using the rapid Golgi method in several lissencephalic species including Rodentia (rat, mouse, vole (Microtus agrestis) and hamster), Lagomorpha (rabbit), Insectivora (hedgehog) and in the Chiroptera the dwarf bat (Pipistrellus pipistrellus). There was a basic uniformity in the structure of the sixth layer. Main neuronal types in lamina VIa were large pyramidal neurons, triangular or atypical pyramidal cells, multiapical pyramidal neurons, inverted pyramids, fusiform neurons, Martinotti cells and bi-tufted cells. Main neuronal types in lamina VIb were medium sized, flattened pyramids, large and small horizontal neurons, horizontal pyramidal cells, fan shaped neurons and multipolar spinous neurons with long descending axons. Sparsely spinous and spine-free multipolar neurons with short axons were present in the two laminae of layer VI, but sparsely spinous neurons with axons similar to those found in basket cells of other layers of the cortex were observed mainly in lamina VIa. Neuronal subsystems were tentatively classified on the basis of the course of the axons. Pyramidal neurons, fusiform neurons, multiapical pyramidal cells, inverted pyramidal cells, fan shaped neurons and multipolar neurons with large descending axons were interpreted as being the main source of long projection and association connections. Large horizontal neurons were interpreted as possible ipsilateral association neurons because the horizontal course of the axons over long distances followed the boundary of the deeper region of the sixth layer. Three intracortical (association) subsystems were included. Axons of Martinotti cells and collateral ascending axons of pyramidal neurons (including multiapical pyramidal neurons) formed the ascending interlaminar fibrillary subsystem. Axons of small horizontal cells and horizontal collaterals of pyramidal neurons formed the horizontal

  5. Capture of syncytin-Mar1, a Fusogenic Endogenous Retroviral Envelope Gene Involved in Placentation in the Rodentia Squirrel-Related Clade

    PubMed Central

    Redelsperger, François; Cornelis, Guillaume; Vernochet, Cécile; Tennant, Bud C.; Catzeflis, François; Mulot, Baptiste; Heidmann, Odile; Dupressoir, Anne

    2014-01-01

    ABSTRACT Syncytin genes are fusogenic envelope protein (env) genes of retroviral origin that have been captured for a function in placentation. Within rodents, two such genes have previously been identified in the mouse-related clade, allowing a demonstration of their essential role via knockout mice. Here, we searched for similar genes in a second major clade of the Rodentia order, the squirrel-related clade, taking advantage of the complete sequencing of the ground squirrel Ictidomys tridecemlineatus genome. In silico search for env genes with full coding capacity identified several candidate genes with one displaying placenta-specific expression, as revealed by quantitative reverse transcription-PCR analysis of a large panel of tissues. This gene belongs to a degenerate endogenous retroviral element, with recognizable hallmarks of an integrated provirus. Cloning of the gene in an expression vector for ex vivo cell-cell fusion and pseudotype assays demonstrated fusogenicity on a large panel of mammalian cells. In situ hybridization on placenta sections showed specific expression in domains where trophoblast cells fuse into a syncytiotrophoblast at the fetomaternal interface, consistent with a role in syncytium formation. Finally, we show that the gene is conserved among the tribe Marmotini, thus dating its capture back to about at least 25 million years ago, with evidence for purifying selection and conservation of fusogenic activity. This gene that we named syncytin-Mar1 is distinct from all seven Syncytin genes identified to date in eutherian mammals and is likely to be a major effector of placentation in its related clade. IMPORTANCE Syncytin genes are fusogenic envelope genes of retroviral origin, ancestrally captured for a function in placentation. Within rodents, two such genes had been previously identified in the mouse-related clade. Here, in the squirrel-related rodent clade, we identified the envelope gene of an endogenous retrovirus with all the

  6. Capture of syncytin-Mar1, a fusogenic endogenous retroviral envelope gene involved in placentation in the Rodentia squirrel-related clade.

    PubMed

    Redelsperger, François; Cornelis, Guillaume; Vernochet, Cécile; Tennant, Bud C; Catzeflis, François; Mulot, Baptiste; Heidmann, Odile; Heidmann, Thierry; Dupressoir, Anne

    2014-07-01

    Syncytin genes are fusogenic envelope protein (env) genes of retroviral origin that have been captured for a function in placentation. Within rodents, two such genes have previously been identified in the mouse-related clade, allowing a demonstration of their essential role via knockout mice. Here, we searched for similar genes in a second major clade of the Rodentia order, the squirrel-related clade, taking advantage of the complete sequencing of the ground squirrel Ictidomys tridecemlineatus genome. In silico search for env genes with full coding capacity identified several candidate genes with one displaying placenta-specific expression, as revealed by quantitative reverse transcription-PCR analysis of a large panel of tissues. This gene belongs to a degenerate endogenous retroviral element, with recognizable hallmarks of an integrated provirus. Cloning of the gene in an expression vector for ex vivo cell-cell fusion and pseudotype assays demonstrated fusogenicity on a large panel of mammalian cells. In situ hybridization on placenta sections showed specific expression in domains where trophoblast cells fuse into a syncytiotrophoblast at the fetomaternal interface, consistent with a role in syncytium formation. Finally, we show that the gene is conserved among the tribe Marmotini, thus dating its capture back to about at least 25 million years ago, with evidence for purifying selection and conservation of fusogenic activity. This gene that we named syncytin-Mar1 is distinct from all seven Syncytin genes identified to date in eutherian mammals and is likely to be a major effector of placentation in its related clade. Importance: Syncytin genes are fusogenic envelope genes of retroviral origin, ancestrally captured for a function in placentation. Within rodents, two such genes had been previously identified in the mouse-related clade. Here, in the squirrel-related rodent clade, we identified the envelope gene of an endogenous retrovirus with all the features of a

  7. New species and records of mites of the superfamily Sarcoptoidea (Acariformes: Psoroptidia) from mammals in Brazil.

    PubMed

    Bochkov, Andre V; Valim, Michel P

    2016-01-01

    Sixteen species of the superfamily Sarcoptoidea (Acariformes: Psoroptidia) belonging to 10 genera of the families Atopomelidae, Listrophoridae, Chirodiscidae, and Listropsoralgidae are recorded in Brazil. Among them, three species, Prolistrophorus hylaeamys sp. nov. from Hylaeamys laticeps (Lund, 1840) (Cricetidae: Sigmodontinae) from Minas Gerais, Lynxacarus serrafreirei sp. nov. from Galictis cuja (Molina, 1782) (Carnivora: Mustelidae) from Rio de Janeiro (Listrophoridae), and Didelphoecius micoureus sp. nov. (Atopomelidae) from Micoureus paraguayanus (Tate, 1931) (Didelphimorphia: Didelphidae) from Minas Gerais are described as new for science. Three species of the family Listrophoridae, Prolistrophorus bidentatus Fain et Lukoschus, 1984 from Akodon cursor (Winge, 1887) (Rodentia: Cricetidae) (new host), Prolistrophorus ctenomys Fain, 1970 from Ctenomys torquatus Lichtenstein, 1830 (Rodentia: Ctenomyidae) (new host), and Leporacarus sylvilagi Fain, Whitaker et Lukoschus, 1981 from Sylvilagus brasiliensis (Linnaeus, 1758) (Lagomorpha: Leporidae) (new host) -from Minas Gerais and Rio Grande do Sul, and one species of the family Chirodiscidae, Parakosa tadarida McDaniel and Lawrence, 1962 from Molossus molossus (Pallas, 1766) (Chiroptera: Molossidae) are recorded for the first time in Brazil. The previously unknown female of Didelphoecius validus Fain, Zanatta-Coutinho et Fonseca, 1996 (Atopomelidae) from Metachirus nudicaudatus (Geoffroy, 1803) (Didelphimorphia: Didelphidae) from Minas Gerais is described. All data on host-parasite associations of sarcoptoids in Brazil are summarized. Totally, 61 sarcoptoid species of 8 families are recorded in Brazil.

  8. New species and records of mites of the superfamily Sarcoptoidea (Acariformes: Psoroptidia) from mammals in Brazil.

    PubMed

    Bochkov, Andre V; Valim, Michel P

    2016-01-01

    Sixteen species of the superfamily Sarcoptoidea (Acariformes: Psoroptidia) belonging to 10 genera of the families Atopomelidae, Listrophoridae, Chirodiscidae, and Listropsoralgidae are recorded in Brazil. Among them, three species, Prolistrophorus hylaeamys sp. nov. from Hylaeamys laticeps (Lund, 1840) (Cricetidae: Sigmodontinae) from Minas Gerais, Lynxacarus serrafreirei sp. nov. from Galictis cuja (Molina, 1782) (Carnivora: Mustelidae) from Rio de Janeiro (Listrophoridae), and Didelphoecius micoureus sp. nov. (Atopomelidae) from Micoureus paraguayanus (Tate, 1931) (Didelphimorphia: Didelphidae) from Minas Gerais are described as new for science. Three species of the family Listrophoridae, Prolistrophorus bidentatus Fain et Lukoschus, 1984 from Akodon cursor (Winge, 1887) (Rodentia: Cricetidae) (new host), Prolistrophorus ctenomys Fain, 1970 from Ctenomys torquatus Lichtenstein, 1830 (Rodentia: Ctenomyidae) (new host), and Leporacarus sylvilagi Fain, Whitaker et Lukoschus, 1981 from Sylvilagus brasiliensis (Linnaeus, 1758) (Lagomorpha: Leporidae) (new host) -from Minas Gerais and Rio Grande do Sul, and one species of the family Chirodiscidae, Parakosa tadarida McDaniel and Lawrence, 1962 from Molossus molossus (Pallas, 1766) (Chiroptera: Molossidae) are recorded for the first time in Brazil. The previously unknown female of Didelphoecius validus Fain, Zanatta-Coutinho et Fonseca, 1996 (Atopomelidae) from Metachirus nudicaudatus (Geoffroy, 1803) (Didelphimorphia: Didelphidae) from Minas Gerais is described. All data on host-parasite associations of sarcoptoids in Brazil are summarized. Totally, 61 sarcoptoid species of 8 families are recorded in Brazil. PMID:26751869

  9. Ocular comparative anatomy of the family Rodentia.

    PubMed

    Rodriguez-Ramos Fernandez, Julia; Dubielzig, Richard R

    2013-07-01

    There is little information regarding ocular anatomy and histology in many of the rodent species. Histological analyses for morphologic features were performed in 31 globes from 18 rodent species submitted to and archived at the Comparative Ocular Pathology Laboratory of Wisconsin. The following measurements were taken: thickness of the cornea, corneal epithelium, corneal stroma, Descemet's membrane, and retina. H&E sections were evaluated for the following anatomical features: presence of pigmented epithelial cells in the peripheral cornea, presence and location of Schlemm's canal, presence of iridal sphincter and dilator and ciliary body muscles, presence of pars plicata and plana, presence of retinal vessels, presence of lamina cribrosa, and presence of tapetum lucidum. The springhaas was the only rodent in our collection that presented a well-developed tapetum lucidum fibrosum. The presence of retinal vessels was variable: vessels were observed in all of the members of the mouse-related clade, except the springhaas and the beaver, in all of the squirrel-related clade members, and in none of the Ctenohystrica. In the flying squirrels, blood vessels extended to the outer limiting membrane in the photoreceptor layer. Beavers, chinchillas, capybara, and guinea pigs lacked vessels within the retina; however, they had vessels within the optic nerve head. Ground squirrels have an optic nerve head, which is linear in the horizontal plane and an asymmetric retina. The tree-dwelling squirrels have a rounded but still elongated optic nerve, and the flying squirrel has a round optic nerve head like all the other rodents.

  10. Ocular comparative anatomy of the family Rodentia.

    PubMed

    Rodriguez-Ramos Fernandez, Julia; Dubielzig, Richard R

    2013-07-01

    There is little information regarding ocular anatomy and histology in many of the rodent species. Histological analyses for morphologic features were performed in 31 globes from 18 rodent species submitted to and archived at the Comparative Ocular Pathology Laboratory of Wisconsin. The following measurements were taken: thickness of the cornea, corneal epithelium, corneal stroma, Descemet's membrane, and retina. H&E sections were evaluated for the following anatomical features: presence of pigmented epithelial cells in the peripheral cornea, presence and location of Schlemm's canal, presence of iridal sphincter and dilator and ciliary body muscles, presence of pars plicata and plana, presence of retinal vessels, presence of lamina cribrosa, and presence of tapetum lucidum. The springhaas was the only rodent in our collection that presented a well-developed tapetum lucidum fibrosum. The presence of retinal vessels was variable: vessels were observed in all of the members of the mouse-related clade, except the springhaas and the beaver, in all of the squirrel-related clade members, and in none of the Ctenohystrica. In the flying squirrels, blood vessels extended to the outer limiting membrane in the photoreceptor layer. Beavers, chinchillas, capybara, and guinea pigs lacked vessels within the retina; however, they had vessels within the optic nerve head. Ground squirrels have an optic nerve head, which is linear in the horizontal plane and an asymmetric retina. The tree-dwelling squirrels have a rounded but still elongated optic nerve, and the flying squirrel has a round optic nerve head like all the other rodents. PMID:23734597

  11. A novel satellite DNA sequence in the Peromyscus genome (PMSat): Evolution via copy number fluctuation.

    PubMed

    Louzada, Sandra; Vieira-da-Silva, Ana; Mendes-da-Silva, Ana; Kubickova, Svatava; Rubes, Jiri; Adega, Filomena; Chaves, Raquel

    2015-11-01

    Satellite DNAs (satDNA) are tandemly arrayed repeated sequences largely present in eukaryotic genomes, which play important roles in genome evolution and function, and therefore, their analysis is vital. Here, we describe the isolation of a novel satellite DNA family (PMSat) from the rodent Peromyscus eremicus (Cricetidae, Rodentia), which is located in pericentromeric regions and exhibits a typical satellite DNA genome organization. Orthologous PMSat sequences were isolated and characterized from three species belonging to Cricetidae: Cricetus cricetus, Phodopus sungorus and Microtus arvalis. In these species, PMSat is highly conserved, with the absence of fixed species-specific mutations. Strikingly, different numbers of copies of this sequence were found among the species, suggesting evolution by copy number fluctuation. Repeat units of PMSat were also found in the Peromyscus maniculatus bairdii BioProject, but our results suggest that these repeat units are from genome regions outside the pericentromere. The remarkably high evolutionary sequence conservation along with the preservation of a few numbers of copies of this sequence in the analyzed genomes may suggest functional significance but a different sequence nature/organization. Our data highlight that repeats are difficult to analyze due to the limited tools available to dissect genomes and the fact that assemblies do not cover regions of constitutive heterochromatin.

  12. Colonization process of the Brazilian common vesper mouse, Calomys expulsus (Cricetidae, Sigmodontinae): a biogeographic hypothesis.

    PubMed

    Nascimento, Fabrícia Ferreira do; Pereira, Luciana G; Geise, Lena; Bezerra, Alexandra M R; D'Andrea, Paulo S; Bonvicino, Cibele R

    2011-01-01

    Riverine barriers have been associated to genetic diversification and speciation of several taxa. The Rio São Francisco is one of the largest rivers in South America, representing the third largest river basin in Brazil and operating as a geographic barrier to gene flow of different taxa. To evaluate the influence of the Rio São Francisco in the speciation of small rodents, we investigated the genetic structure of Calomys expulsus with phylogenetic and network analyses of cytochrome b DNA. Our results suggested that C. expulsus can be divided into 3 subpopulations, 2 on the left and another one on the right bank of this river. The time of divergence of these subpopulations, using a Bayesian framework, suggested colonization from the south to the north/northeast. Spatial analysis using a clustering method and the Monmonier's algorithm suggested that the Rio São Francisco is a biogeographic barrier to gene flow and indicated that this river may play a role in the incipient speciation process of these subpopulations. PMID:21441460

  13. Seasonal energy requirements and thermoregulation of growing pouched mice, Saccostomus campestris (Cricetidae)

    NASA Astrophysics Data System (ADS)

    Ellison, G. T. H.; Skinner, J. D.

    1991-06-01

    Pouched mice ( Saccostomus campestris) were born in captivity during January and March and subsequently maintained under long photoperiod (14 h light: 10 h dark) at 25°C. During their first winter (July) and the following summer (January) the pouched mice were exposed to natural photoperiod in an unheated laboratory for 3 weeks prior to measurement. The pouched mice continued to grow during the study, and were significantly heavier after summer exposure than after winter exposure 6 months earlier. Although this increase in body mass would result in a decline in their surface area to volume ratio there was no significant decline in minimal thermal conductance ( C m) and winter-exposed pouched mice had a relatively lower C m than expected. Meanwhile the smaller, winter-exposed animals displayed a significantly higher capacity for non-shivering thermogenesis, together with higher levels of basal metabolism than summer individuals. These differences were not solely attributable to the contrasting body mass of each group and it is therefore clear that S. campestris can increase thermoregulatory heat production, and modify heat loss following exposure to short photoperiod and cold during their first winter. Despite the significant increase in metabolism, the overall energy requirements of small, winter-exposed animals were significantly lower than those for heavier pouched mice following exposure to summer conditions. These results suggest that growing pouched mice can effectively adapt to lower temperature conditions during their first winter, yet accrue considerable overall savings in total energy requirements as a result of their smaller body mass.

  14. Molecular diversification of Trichuris spp. from Sigmodontinae (Cricetidae) rodents from Argentina based on mitochondrial DNA sequences.

    PubMed

    Callejón, Rocío; Robles, María Del Rosario; Panei, Carlos Javier; Cutillas, Cristina

    2016-08-01

    A molecular phylogenetic hypothesis is presented for the genus Trichuris based on sequence data from mitochondrial cytochrome c oxidase 1 (cox1) and cytochrome b (cob). The taxa consisted of nine populations of whipworm from five species of Sigmodontinae rodents from Argentina. Bayesian Inference, Maximum Parsimony, and Maximum Likelihood methods were used to infer phylogenies for each gene separately but also for the combined mitochondrial data and the combined mitochondrial and nuclear dataset. Phylogenetic results based on cox1 and cob mitochondrial DNA (mtDNA) revealed three clades strongly resolved corresponding to three different species (Trichuris navonae, Trichuris bainae, and Trichuris pardinasi) showing phylogeographic variation, but relationships among Trichuris species were poorly resolved. Phylogenetic reconstruction based on concatenated sequences had greater phylogenetic resolution for delimiting species and populations intra-specific of Trichuris than those based on partitioned genes. Thus, populations of T. bainae and T. pardinasi could be affected by geographical factors and co-divergence parasite-host. PMID:27083190

  15. Colonization process of the Brazilian common vesper mouse, Calomys expulsus (Cricetidae, Sigmodontinae): a biogeographic hypothesis.

    PubMed

    Nascimento, Fabrícia Ferreira do; Pereira, Luciana G; Geise, Lena; Bezerra, Alexandra M R; D'Andrea, Paulo S; Bonvicino, Cibele R

    2011-01-01

    Riverine barriers have been associated to genetic diversification and speciation of several taxa. The Rio São Francisco is one of the largest rivers in South America, representing the third largest river basin in Brazil and operating as a geographic barrier to gene flow of different taxa. To evaluate the influence of the Rio São Francisco in the speciation of small rodents, we investigated the genetic structure of Calomys expulsus with phylogenetic and network analyses of cytochrome b DNA. Our results suggested that C. expulsus can be divided into 3 subpopulations, 2 on the left and another one on the right bank of this river. The time of divergence of these subpopulations, using a Bayesian framework, suggested colonization from the south to the north/northeast. Spatial analysis using a clustering method and the Monmonier's algorithm suggested that the Rio São Francisco is a biogeographic barrier to gene flow and indicated that this river may play a role in the incipient speciation process of these subpopulations.

  16. [The rodent. Akodon arviculoides, Wagner, 1842 (Cricetidae)--importance in plague foci in Brazil].

    PubMed

    de Almeida, C R; de Almeida, A M; Brasil, D P; Dantas Sobrinho, J; Leal, M A

    1986-01-01

    The occurrence of the rodent Akodon arviculoides Wagner, 1842 in the plague focus of the "Agreste" region of the State of Pernambuco and a report on its ability for survival, reproduction and development in captivity, its susceptibility to Yersinia pestis infection and the role of this rodent species in Brazilian plague foci are reported. PMID:3302594

  17. Diversity and Karyotypic Evolution in the Genus Neacomys (Rodentia, Sigmodontinae).

    PubMed

    da Silva, Willam O; Pieczarka, Julio C; Rossi, Rogério V; Schneider, Horacio; Sampaio, Iracilda; Miranda, Cleuton L; da Silva, Cláudia R; Cardoso, Elizandra M; Nagamachi, Cleusa Y

    2015-01-01

    Neacomys (Sigmodontinae) comprises 8 species mainly found in the Amazonian region. We describe 5 new karyotypes from Brazilian Amazonia: 2 cytotypes for N. paracou (2n = 56/FNa = 62-66), 1 for N. dubosti (2n = 64/FNa = 68), and 2 for Neacomys sp. (2n = 58/FNa = 64-70), with differences in the 18S rDNA. Telomeric probes did not show ITS. We provide a phylogeny using Cytb, and the analysis suggests that 2n = 56 with a high FNa is ancestral for the genus, as found in N. paracou, being retained by the ancestral forms of the other species, with an increase in 2n occurring independently in N. spinosus and N. dubosti. Alternatively, an increase in 2n may have occurred in the ancestral taxon of the other species, followed by independent 2n-reduction events in Neacomys sp. and in the ancestral species of N. tenuipes, N. guianae, N. musseri, and N. minutus. Finally, a drastic reduction event in the diploid number occurred in the ancestral species of N. musseri and N. minutus which exhibit the lowest 2n of the genus. The karyotypic variations found in both intra- and interspecific samples, associated with the molecular phylogeny, suggest a chromosomal evolution with amplification/deletion of constitutive heterochromatin and rearrangements including fusions, fissions, and pericentric inversions.

  18. Children's Attitudes towards Animals: Evidence from the RODENTIA Project

    ERIC Educational Resources Information Center

    Fonseca, Maria Joao; Franco, Nuno H.; Brosseron, Francis; Tavares, Fernando; Olsson, I. Anna S.; Borlido-Santos, Julio

    2011-01-01

    The instructional use of animals is a popular strategy to engage students with science, enhance their motivation, and promote values such as respect, tolerance, and empathy for all living beings. Although these beneficial outcomes are widely acknowledged, research has not provided reliable indicators of their efficiency. Therefore, it is essential…

  19. Dietary ecology of Murinae (Muridae, Rodentia): a geometric morphometric approach.

    PubMed

    Gómez Cano, Ana Rosa; Hernández Fernández, Manuel; Alvarez-Sierra, M Ángeles

    2013-01-01

    Murine rodents represent a highly diverse group, which displays great ecological versatility. In the present paper we analyse the relationship between dental morphology, on one hand, using geometric morphometrics based upon the outline of first upper molar and the dietary preference of extant murine genera, on the other. This ecomorphological study of extant murine rodents demonstrates that dietary groups can be distinguished with the use of a quantitative geometric morphometric approach based on first upper molar outline. A discriminant analysis of the geometric morphometric variables of the first upper molars enables us to infer the dietary preferences of extinct murine genera from the Iberian Peninsula. Most of the extinct genera were omnivore; only Stephanomys showed a pattern of dental morphology alike that of the herbivore genera. PMID:24236090

  20. Dietary Ecology of Murinae (Muridae, Rodentia): A Geometric Morphometric Approach

    PubMed Central

    Gómez Cano, Ana Rosa; Hernández Fernández, Manuel; Álvarez-Sierra, M. Ángeles

    2013-01-01

    Murine rodents represent a highly diverse group, which displays great ecological versatility. In the present paper we analyse the relationship between dental morphology, on one hand, using geometric morphometrics based upon the outline of first upper molar and the dietary preference of extant murine genera, on the other. This ecomorphological study of extant murine rodents demonstrates that dietary groups can be distinguished with the use of a quantitative geometric morphometric approach based on first upper molar outline. A discriminant analysis of the geometric morphometric variables of the first upper molars enables us to infer the dietary preferences of extinct murine genera from the Iberian Peninsula. Most of the extinct genera were omnivore; only Stephanomys showed a pattern of dental morphology alike that of the herbivore genera. PMID:24236090

  1. Systematics and evolution of the subfamily Gerbillinae (Mammalia, Rodentia, Muridae).

    PubMed

    Chevret, Pascale; Dobigny, Gauthier

    2005-06-01

    Although they represent a quarter of the mammalian species, the evolutionary relationships among as well as within, the main murid lineages are still controversial. The subfamily Gerbillinae is no exception as previous studies based on morphological, karyotypical, and allozyme characters are highly incongruent. Here, we present the first molecular phylogeny for gerbils based on cytochrome b and 12S rRNA mitochondrial genes. Results are largely congruent between the two genes as well as with the concatenated data set with most of the nodes being well-supported. Based on the topologies retrieved here, we (1) propose the identification of three main clades, (2) support the split of Tatera genus into an Asian and an African group, the latter including Gerbillurus species, and (3) provide some evidence towards the inaccuracy of subgeneric divisions within both Gerbillus and Meriones. In addition, the sharp contrast between the genetic characters and morphological data sets suggest high levels of convergence, probably as a result of strong environmental constraints imposed on these rodents adapted to arid and semi-arid regions. Finally, molecular datings for the various cladogenetic events are in good agreement with the known gerbilline fossil record and support an African origin with subsequent migrations to Asia.

  2. Late Pleistocene voles (Arvicolinae, Rodentia) from the Baranica Cave (Serbia)

    NASA Astrophysics Data System (ADS)

    Bogićević, Katarina; Nenadić, Draženko; Mihailović, Dušan

    2012-02-01

    Baranica is a cave system situated in the south-eastern part of Serbia, four kilometers south to Knjaževac, on the right bank of the Trgovi\\vski Timok. The investigations in Baranica were conducted from 1994 to 1997 by the Faculty of Philosophy from Belgrade and the National Museum of Knjaževac. Four geological layers of Quaternary age were recovered. The abundance of remains of both large and small mammals was noticed in the early phase of the research. In this paper, the remains of eight vole species are described: Arvicola terrestris (Linnaeus, 1758), Chionomys nivalis (Martins, 1842), Microtus (Microtus) arvalis (Pallas, 1778) and Microtus (Microtus) agrestis (Linnaeus, 1761), Microtus (Stenocranius) gregalis (Pallas, 1779), Microtus (Terricola) subterraneus (de Sélys-Longchamps, 1836), Clethrionomys glareolus (Schreber, 1780) and Lagurus lagurus (Pallas, 1773). Among them, steppe and open area inhabitants prevail. Based on the evolutionary level and dimensions of the Arvicola terrestris molars, as well as the overall characteristics of the fauna, it was concluded that the deposits were formed in the last glacial period of the Late Pleistocene. These conclusions are rather consistent with the absolute dating of large mammal bones (23.520 ± 110 B.P. for Layer 2 and 35.780 ± 320 B.P. for Layer 4).

  3. Chromosome Polymorphism in Microtus (Alexandromys) mujanensis (Arvicolinae, Rodentia).

    PubMed

    Lemskaya, Natalya A; Kartavtseva, Irina V; Rubtsova, Nadezhda V; Golenishchev, Fedor N; Sheremetyeva, Irina N; Graphodatsky, Alexander S

    2015-01-01

    The Muya Valley vole (Microtus mujanensis) has a constant diploid chromosome number of 2n = 38, but an unstable karyotype with polymorphic chromosome pairs. Here, we describe 4 karyotypic variants involving 2 polymorphic chromosome pairs, MMUJ8 and MMUJ14, in 6 animals from Buryatia using a combination of GTG-banding and chromosome painting with M. agrestis probes. We suggest that the polymorphic pairs MMUJ8 and MMUJ14 were formed through pericentric inversions that played a major role during karyotype evolution of the species. We also propose that the stable diploid number with some ongoing polymorphism in the number of chromosome arms indicates that this evolutionarily young endemic species of Russian Far East is on the way to karyotype and likely species stabilization.

  4. Complete mitochondrial genome of Lasiopodomys mandarinus mandarinus (Arvicolinae, Rodentia).

    PubMed

    Li, Yangwei; Lu, Jiqi; Wang, Zhenlong

    2016-01-01

    Mandarin voles (Lasiopodomys mandarinus) is a subterranean rodent species that are often used as a model for studying subterranean hypoxic stress in mammals. Its subspecies L. m. mandarinus span in cropland in most area of north China and is regarded as an agricultural pest. In this paper, the complete mitochondrial genome of L. m. mandarinus has been determined. Our results showed that the mitochondrial genome of L. m. mandarinus is a circular molecule of 16,367 bp, which contents 13 protein-coding, 22 tRNAs and 2 rRNAs genes. The overall base composition of the heavy strand is 32.47% A, 27.04% T, 27.01% C, and 13.47% G. with an AT content of 59.51%.

  5. [Structural characteristics of certain Rodents spines (Rodentia: Myomorpha, Hystricomorpha)].

    PubMed

    Chernova, O F; Kuznetsov, G V

    2001-01-01

    The architectonics of spines and hair was studied in Neacomys spinosus, Arvicanthis somalicus, Leopoldamys sabanus, L. edwardsi, Maxomys moi, M. surifer, Niviventer fulvescens, N. confucianus, N. cremoriventer, Acomys cahirinus, A. somalica, Hystrix indica, H. cristata, Atherurus macrourus, Erethizon dorsatum, Proechimys steerei, and Lonchotrix emiliae. The presence of a dorsal longitudinal furrow covered by a modified cuticle is a common structural feature of spines in all studied species except E. dorsatum, H. indica, and the frontal surface of the mosaic (scales located side by side) and terrace cuticle (steps between scales) varies in different species from smooth to rib-folded. A terminology has been proposed to describe the main structures of spine and hair. The adaptive significance of the spine architectonics in rodents is discussed.

  6. Late Pleistocene echimyid rodents (Rodentia, Hystricognathi) from northern Brazil.

    PubMed

    Ferreira, Thais M F; Olivares, Adriana Itati; Kerber, Leonardo; Dutra, Rodrigo P; Avilla, Leonardo S

    2016-06-01

    Echimyidae (spiny rats, tree rats and the coypu) is the most diverse family of extant South American hystricognath rodents (caviomorphs). Today, they live in tropical forests (Amazonian, coastal and Andean forests), occasionally in more open xeric habitats in the Cerrado and Caatinga of northern South America, and open areas across the southern portion of the continent (Myocastor). The Quaternary fossil record of this family remains poorly studied. Here, we describe the fossil echimyids found in karst deposits from southern Tocantins, northern Brazil. The analyzed specimens are assigned to Thrichomys sp., Makalata cf. didelphoides and Proechimys sp. This is the first time that a fossil of Makalata is reported. The Pleistocene record of echimyids from this area is represented by fragmentary remains, which hinders their determination at specific levels. The data reported here contributes to the understanding of the ancient diversity of rodents of this region, evidenced until now in other groups, such as the artiodactyls, cingulates, carnivores, marsupials, and squamate reptiles.

  7. Phylogeographic Study of Apodemus ilex (Rodentia: Muridae) in Southwest China

    PubMed Central

    Kilpatrick, C. William; Liu, Shao-Ying; Yu, Fa-Hong; Jiang, Xue-Long

    2012-01-01

    Background The Mountains of southwest China have complex river systems and a profoundly complex topography and are among the most important biodiversity hotspots in the world. However, only a few studies have shed light on how the mountains and river valleys promote genetic diversity. Apodemus ilex is a fine model for investigating this subject. Methodology/Principal Findings To assess the genetic diversity and biogeographic patterns of Apodemus ilex, the complete cytochrome b gene sequences (1,140 bp) were determined from 203 samples of A. draco/ilex that were collected from southwest China. The results obtained suggested that A. ilex and A. draco are sistergroups and diverged from each other approximately 2.25 million years ago. A. ilex could be divided into Eastern and Western phylogroups, each containing two sub-groups and being widespread in different geographical regions of the southern Hengduan Mountains and the western Yunnan - Guizhou Plateau. The population expansions of A. ilex were roughly from 0.089 Mya to 0.023 Mya. Conclusions Our result suggested that A. ilex is a valid species rather than synonym of A. draco. As a middle-high elevation inhabitant, the phylogenetic pattern of A. ilex was strongly related to the complex geographical structures in southwest China, particularly the existence of deep river valley systems, such as the Mekong and Salween rivers. Also, it appears that the evolutionary history of A. ilex, such as lineage divergences and population expansions were strongly affected by climate fluctuation in the Late Pleistocene. PMID:22347481

  8. [Ovarian activity of Agouti paca (Rodentia: Agoutidae) under captivity].

    PubMed

    Montes Pérez, Rubén C; Cabrera Baz, Elsy A

    2006-09-01

    The ovarian activity of Agouti paca was characterized by hormonal profiles and ovarian structures. Samples of blood were taken from eight females (seven adults and one juvenile) at the breeding grounds of the Facultad de Medicina Veterinaria y Zootecnia in Yucatśn, Mexico. Sampling lasted approximately two months and was done every three and six days. Blood was collected from anesthetized animals, and the levels of progesterone (P4) and 17 beta estradiol (E2) were analized by radioimmunoassay technique. Macroscopic and microscopic analyses were carried out in ovaries of dead animals. The estrous cycle lasted 29+/-8.4 days, levels of 1.61+/-0.65 ng/ml for P4 and 39+/-24 pg/ml for E2 were observed for a follicular phase, 6.18+/-3.70 ng/ml and 29+/-16 pg/ml for P4 and E2 respectively in the luteal phase. Statistically significant differences were found between phases for P4 but not for E2. The presence of extragonadal steroids with levels of P4 of 1.9+/-0.77 ng/ml and E2 of 22+/-17 pg/ml were observed, which are not produced by the effects of managing stress. The changes in the levels of P4 during the cycle are indicators of luteal activity, with the intersticial tissue acting probably as active steroids-producing gland. Follicular growth was observed during the entire cycle.

  9. Dietary ecology of Murinae (Muridae, Rodentia): a geometric morphometric approach.

    PubMed

    Gómez Cano, Ana Rosa; Hernández Fernández, Manuel; Alvarez-Sierra, M Ángeles

    2013-01-01

    Murine rodents represent a highly diverse group, which displays great ecological versatility. In the present paper we analyse the relationship between dental morphology, on one hand, using geometric morphometrics based upon the outline of first upper molar and the dietary preference of extant murine genera, on the other. This ecomorphological study of extant murine rodents demonstrates that dietary groups can be distinguished with the use of a quantitative geometric morphometric approach based on first upper molar outline. A discriminant analysis of the geometric morphometric variables of the first upper molars enables us to infer the dietary preferences of extinct murine genera from the Iberian Peninsula. Most of the extinct genera were omnivore; only Stephanomys showed a pattern of dental morphology alike that of the herbivore genera.

  10. [Intestinal parasites of Agouti paca (Rodentia: Dasyproctidae) in Costa Rica].

    PubMed

    Matamoros, Y; Velázquez, J; Pashov, B

    1991-06-01

    In a sample of 23 breeding places of pacas (Agouti paca) in Costa Rica, the following parasites were found: Eimeria agoutii, Balantidium coli, Capillaria sp., Trichuris sp., Taenia sp., Strongyloides sp., and members of the superfamilies Strongyloidea and Ascaroidea. PMID:1844153

  11. Chromosome Polymorphism in Microtus (Alexandromys) mujanensis (Arvicolinae, Rodentia).

    PubMed

    Lemskaya, Natalya A; Kartavtseva, Irina V; Rubtsova, Nadezhda V; Golenishchev, Fedor N; Sheremetyeva, Irina N; Graphodatsky, Alexander S

    2015-01-01

    The Muya Valley vole (Microtus mujanensis) has a constant diploid chromosome number of 2n = 38, but an unstable karyotype with polymorphic chromosome pairs. Here, we describe 4 karyotypic variants involving 2 polymorphic chromosome pairs, MMUJ8 and MMUJ14, in 6 animals from Buryatia using a combination of GTG-banding and chromosome painting with M. agrestis probes. We suggest that the polymorphic pairs MMUJ8 and MMUJ14 were formed through pericentric inversions that played a major role during karyotype evolution of the species. We also propose that the stable diploid number with some ongoing polymorphism in the number of chromosome arms indicates that this evolutionarily young endemic species of Russian Far East is on the way to karyotype and likely species stabilization. PMID:26314555

  12. Complete mitochondrial genome of Lasiopodomys mandarinus mandarinus (Arvicolinae, Rodentia).

    PubMed

    Li, Yangwei; Lu, Jiqi; Wang, Zhenlong

    2016-01-01

    Mandarin voles (Lasiopodomys mandarinus) is a subterranean rodent species that are often used as a model for studying subterranean hypoxic stress in mammals. Its subspecies L. m. mandarinus span in cropland in most area of north China and is regarded as an agricultural pest. In this paper, the complete mitochondrial genome of L. m. mandarinus has been determined. Our results showed that the mitochondrial genome of L. m. mandarinus is a circular molecule of 16,367 bp, which contents 13 protein-coding, 22 tRNAs and 2 rRNAs genes. The overall base composition of the heavy strand is 32.47% A, 27.04% T, 27.01% C, and 13.47% G. with an AT content of 59.51%. PMID:26258511

  13. Mesoamerican tree squirrels evolution (Rodentia: Sciuridae): a molecular phylogenetic analysis.

    PubMed

    Villalobos, Federico; Gutierrez-Espeleta, Gustavo

    2014-06-01

    The tribe Sciurini comprehends the genera Sciurus, Syntheosiurus, Microsciurus, Tamiasciurus and Rheinthrosciurus. The phylogenetic relationships within Sciurus have been only partially done, and the relationship between Mesoamerican species remains unsolved. The phylogenetic relationships of the Mesoamerican tree squirrels were examined using molecular data. Sequence data publicly available (12S, 16S, CYTB mitochondrial genes and IRBP nuclear gene) and cytochrome B gene sequences of four previously not sampled Mesoamerican Sciurus species were analyzed under a Bayesian multispecies coalescence model. Phylogenetic analysis of the multilocus data set showed the neotropical tree squirrels as a monophyletic clade. The genus Sciurus was paraphyletic due to the inclusion of Microsciurus species (M. alfari and M. flaviventer). The South American species S. aestuans and S. stramineus showed a sister taxa relationship. Single locus analysis based on the most compact and complete data set (i.e. CYTB gene sequences), supported the monophyly of the South American species and recovered a Mesoamerican clade including S. aureogaster, S. granatensis and S. variegatoides. These results corroborated previous findings based on cladistic analysis of cranial and post-cranial characters. Our data support a close relationship between Mesoamerican Sciurus species and a sister relationship with South American species, and corroborates previous findings in relation to the polyphyly of Microsciurus and Syntheosciurus paraphyly.

  14. Late Pleistocene echimyid rodents (Rodentia, Hystricognathi) from northern Brazil.

    PubMed

    Ferreira, Thais M F; Olivares, Adriana Itati; Kerber, Leonardo; Dutra, Rodrigo P; Avilla, Leonardo S

    2016-06-01

    Echimyidae (spiny rats, tree rats and the coypu) is the most diverse family of extant South American hystricognath rodents (caviomorphs). Today, they live in tropical forests (Amazonian, coastal and Andean forests), occasionally in more open xeric habitats in the Cerrado and Caatinga of northern South America, and open areas across the southern portion of the continent (Myocastor). The Quaternary fossil record of this family remains poorly studied. Here, we describe the fossil echimyids found in karst deposits from southern Tocantins, northern Brazil. The analyzed specimens are assigned to Thrichomys sp., Makalata cf. didelphoides and Proechimys sp. This is the first time that a fossil of Makalata is reported. The Pleistocene record of echimyids from this area is represented by fragmentary remains, which hinders their determination at specific levels. The data reported here contributes to the understanding of the ancient diversity of rodents of this region, evidenced until now in other groups, such as the artiodactyls, cingulates, carnivores, marsupials, and squamate reptiles. PMID:27276377

  15. Spontaneous expression of magnetic compass orientation in an epigeic rodent: the bank vole, Clethrionomys glareolus.

    PubMed

    Oliveriusová, Ludmila; Němec, Pavel; Pavelková, Zuzana; Sedláček, František

    2014-07-01

    Magnetoreception has been convincingly demonstrated in only a few mammalian species. Among rodents, magnetic compass orientation has been documented in four species of subterranean mole rats and two epigeic (i.e. active above ground) species-the Siberian hamster and the C57BL/6J mouse. The mole rats use the magnetic field azimuth to determine compass heading; their directional preference is spontaneous and unimodal, and their magnetic compass is magnetite-mediated. By contrast, the primary component of orientation response is learned in the hamster and the mouse, but both species also exhibit a weak spontaneous bimodal preference in the natural magnetic field. To determine whether the magnetic compass of wild epigeic rodents features the same functional properties as that of laboratory rodents, we investigated magnetic compass orientation in the bank vole Clethrionomys glareolus (Cricetidae, Rodentia). The voles exhibited a robust spontaneous bimodal directional preference, i.e. built nests and slept preferentially along the north-south axis, and deflected their directional preference according to a shift in the direction of magnetic north, clearly indicating that they were deriving directional information from the magnetic field. Thus, bimodal, axially symmetrical directional choice seems to be a common feature shared by epigeic rodents. However, spontaneous directional preference in the bank vole appeared to be more pronounced than that reported in the hamster and the mouse. These findings suggest that bank voles are well suited for future studies investigating the adaptive significance and mechanisms of magnetic orientation in epigeic rodents. PMID:24913128

  16. Spontaneous expression of magnetic compass orientation in an epigeic rodent: the bank vole, Clethrionomys glareolus

    NASA Astrophysics Data System (ADS)

    Oliveriusová, Ludmila; Němec, Pavel; Pavelková, Zuzana; Sedláček, František

    2014-07-01

    Magnetoreception has been convincingly demonstrated in only a few mammalian species. Among rodents, magnetic compass orientation has been documented in four species of subterranean mole rats and two epigeic (i.e. active above ground) species—the Siberian hamster and the C57BL/6J mouse. The mole rats use the magnetic field azimuth to determine compass heading; their directional preference is spontaneous and unimodal, and their magnetic compass is magnetite-mediated. By contrast, the primary component of orientation response is learned in the hamster and the mouse, but both species also exhibit a weak spontaneous bimodal preference in the natural magnetic field. To determine whether the magnetic compass of wild epigeic rodents features the same functional properties as that of laboratory rodents, we investigated magnetic compass orientation in the bank vole Clethrionomys glareolus (Cricetidae, Rodentia). The voles exhibited a robust spontaneous bimodal directional preference, i.e. built nests and slept preferentially along the north-south axis, and deflected their directional preference according to a shift in the direction of magnetic north, clearly indicating that they were deriving directional information from the magnetic field. Thus, bimodal, axially symmetrical directional choice seems to be a common feature shared by epigeic rodents. However, spontaneous directional preference in the bank vole appeared to be more pronounced than that reported in the hamster and the mouse. These findings suggest that bank voles are well suited for future studies investigating the adaptive significance and mechanisms of magnetic orientation in epigeic rodents.

  17. Shared ancestry between a newfound mole-borne hantavirus and hantaviruses harbored by cricetid rodents.

    PubMed

    Kang, Hae Ji; Bennett, Shannon N; Hope, Andrew G; Cook, Joseph A; Yanagihara, Richard

    2011-08-01

    Discovery of genetically distinct hantaviruses in multiple species of shrews (order Soricomorpha, family Soricidae) and moles (family Talpidae) contests the conventional view that rodents (order Rodentia, families Muridae and Cricetidae) are the principal reservoir hosts and suggests that the evolutionary history of hantaviruses is far more complex than previously hypothesized. We now report on Rockport virus (RKPV), a hantavirus identified in archival tissues of the eastern mole (Scalopus aquaticus) collected in Rockport, TX, in 1986. Pairwise comparison of the full-length S, M, and L genomic segments indicated moderately low sequence similarity between RKPV and other soricomorph-borne hantaviruses. Phylogenetic analyses, using maximum-likelihood and Bayesian methods, showed that RKPV shared a most recent common ancestor with cricetid-rodent-borne hantaviruses. Distributed widely across the eastern United States, the fossorial eastern mole is sympatric and syntopic with cricetid rodents known to harbor hantaviruses, raising the possibility of host-switching events in the distant past. Our findings warrant more-detailed investigations on the dynamics of spillover and cross-species transmission of present-day hantaviruses within communities of rodents and moles.

  18. Revision of fleas of the genus Plocopsylla belonging to the 'angusticeps-lewisi' complex in the Andean biogeographic region, with the description of a new species.

    PubMed

    Sanchez, J; Beaucournu, J-C; Lareschi, M

    2015-06-01

    In Argentina, the Andean biogeographic region accommodates the most diverse population of fleas in the country. The Craneopsyllinae (Siphonaptera: Stephanocircidae) represent one of the most commonly found subfamilies in this region and show some endemism and high diversity. Plocopsylla is the most diverse genus of Craneopsyllinae; it includes 10 species mainly distributed in the Patagonian subregion, which parasitize sigmodontine rodents (Rodentia: Cricetidae). We describe and illustrate the morphology of the aedeagus in species of Plocopsylla that belong to the 'angusticeps-lewisi' complex. This character is of diagnostic value in differentiating among species. A new species of this complex, Plocopsylla (Plocopsylla) linardii sp. n., is described and identified by the shape and chaetotaxy of the distal arm of sternite IX, as well as by the shape of the median dorsal lobe of the aedeagus. New host associations for this complex and range extensions for most of its species are reported. Plocopsylla (P.) silewi is recorded for the first time in Argentina. The southern limits of the distributions of Plocopsylla (P.) lewisi and Plocopsylla (P.) wilesi are extended to Santa Cruz Province. The angusticeps-lewisi complex is found for the first time in San Juan Province. The information may be useful in epidemiological studies of flea-borne diseases. PMID:25726809

  19. Shared Ancestry between a Newfound Mole-Borne Hantavirus and Hantaviruses Harbored by Cricetid Rodents ▿†

    PubMed Central

    Kang, Hae Ji; Bennett, Shannon N.; Hope, Andrew G.; Cook, Joseph A.; Yanagihara, Richard

    2011-01-01

    Discovery of genetically distinct hantaviruses in multiple species of shrews (order Soricomorpha, family Soricidae) and moles (family Talpidae) contests the conventional view that rodents (order Rodentia, families Muridae and Cricetidae) are the principal reservoir hosts and suggests that the evolutionary history of hantaviruses is far more complex than previously hypothesized. We now report on Rockport virus (RKPV), a hantavirus identified in archival tissues of the eastern mole (Scalopus aquaticus) collected in Rockport, TX, in 1986. Pairwise comparison of the full-length S, M, and L genomic segments indicated moderately low sequence similarity between RKPV and other soricomorph-borne hantaviruses. Phylogenetic analyses, using maximum-likelihood and Bayesian methods, showed that RKPV shared a most recent common ancestor with cricetid-rodent-borne hantaviruses. Distributed widely across the eastern United States, the fossorial eastern mole is sympatric and syntopic with cricetid rodents known to harbor hantaviruses, raising the possibility of host-switching events in the distant past. Our findings warrant more-detailed investigations on the dynamics of spillover and cross-species transmission of present-day hantaviruses within communities of rodents and moles. PMID:21632770

  20. The first description of eggs in the male reproductive system of Physaloptera bispiculata (Nematoda: Spiruroidaea).

    PubMed

    Oliveira-Menezes, A; Lanfredi-Rangel, A; Lanfredi, R M

    2011-06-01

    Physaloptera bispiculata (Nematoda: Spiruroidaea) is a parasite of Nectomys squamipes (Rodentia: Cricetidae), a water rat that only occurs in Brazil. Naturally infected rodents were captured in the municipality of Rio Bonito, Rio de Janeiro, Brazil. Adult P. bispiculata worms were collected, prepared and analysed by light and scanning electron microscopy. Under scanning electron microscopy, several eggs were seen glued by cement to the cloacal aperture. Light microscopy revealed that some male worms had an uncountable number of embryonated eggs in the ejaculatory duct, cloaca and also in the posterior portion of the intestine. The probable explanation is that the eggs developing in the female uterus are pumped by the female or sucked by the male to the cloacal opening and from this point to the intestine and ejaculatory duct. The male probably does not have the ability to expel the eggs and for this reason a large number were found in these organs. On the other hand, this could be an important adaptation for the parasite, i.e. male worms expelled by the host can carry a large number of eggs and spread them to intermediate hosts when ingested by these hosts. As far as we know this is the first record of a physalopterid nematode harbouring eggs in the cloacal region, ejaculatory duct or intestine.

  1. Analysis of ectoparasites (chigger mites, gamasid mites, fleas and sucking lice) of the Yunnan red-backed vole (Eothenomys miletus) sampled throughout its range in southwest China.

    PubMed

    Peng, P-Y; Guo, X-G; Song, W-Y; Hou, P; Zou, Y-J; Fan, R; He, X-S

    2015-12-01

    The Yunnan red-backed vole Eothenomys miletus (Rodentia: Cricetidae) is an endemic rodent species and reservoir host of zoonoses in southwest China. Based on a large host sample (2463 voles collected from 39 localities between 2001 and 2013), a general analysis of four categories of ectoparasite (fleas, sucking lice, chigger mites and gamasid mites) on E. miletus across its entire range of distribution was made. This analysis identified a total of 71 895 ectoparasites belonging to 320 species (30 species of flea, 9 of sucking louse, 106 of gamasid mite and 175 of chigger mite) with a high prevalence (87%), mean abundance (29.19) and mean intensity (33.69). Of the 18 vector species of zoonoses found on E. miletus, the flea Ctenophthalmus quadratus (Siphonaptera: Hystrichopsyllidae) and chigger mite Leptotrombidium scutellare (Trombidiformes: Trombiculidae) were the dominant species; these are the main vectors of zoonoses in China. All of the dominant parasite species showed an aggregated distribution pattern. Male voles harboured more species of parasite than females. Chigger mites represented the most abundant species group on voles and their prevalence was positively correlated with mean abundance (r = 0.73; P < 0.05). As a single rodent species, E. miletus has a high potential to harbour abundant ectoparasites with high species diversity and high rates of infestation. The sex of the vole affects ectoparasite infestation. PMID:26345365

  2. Extensive Chromosomal Reorganization in the Evolution of New World Muroid Rodents (Cricetidae, Sigmodontinae): Searching for Ancestral Phylogenetic Traits.

    PubMed

    Pereira, Adenilson Leão; Malcher, Stella Miranda; Nagamachi, Cleusa Yoshiko; O'Brien, Patricia Caroline Mary; Ferguson-Smith, Malcolm Andrew; Mendes-Oliveira, Ana Cristina; Pieczarka, Julio Cesar

    2016-01-01

    Sigmodontinae rodents show great diversity and complexity in morphology and ecology. This diversity is accompanied by extensive chromosome variation challenging attempts to reconstruct their ancestral genome. The species Hylaeamys megacephalus--HME (Oryzomyini, 2n = 54), Necromys lasiurus--NLA (Akodontini, 2n = 34) and Akodon sp.--ASP (Akodontini, 2n = 10) have extreme diploid numbers that make it difficult to understand the rearrangements that are responsible for such differences. In this study we analyzed these changes using whole chromosome probes of HME in cross-species painting of NLA and ASP to construct chromosome homology maps that reveal the rearrangements between species. We include data from the literature for other Sigmodontinae previously studied with probes from HME and Mus musculus (MMU) probes. We also use the HME probes on MMU chromosomes for the comparative analysis of NLA with other species already mapped by MMU probes. Our results show that NLA and ASP have highly rearranged karyotypes when compared to HME. Eleven HME syntenic blocks are shared among the species studied here. Four syntenies may be ancestral to Akodontini (HME2/18, 3/25, 18/25 and 4/11/16) and eight to Sigmodontinae (HME26, 1/12, 6/21, 7/9, 5/17, 11/16, 20/13 and 19/14/19). Using MMU data we identified six associations shared among rodents from seven subfamilies, where MMU3/18 and MMU8/13 are phylogenetic signatures of Sigmodontinae. We suggest that the associations MMU2entire, MMU6proximal/12entire, MMU3/18, MMU8/13, MMU1/17, MMU10/17, MMU12/17, MMU5/16, MMU5/6 and MMU7/19 are part of the ancestral Sigmodontinae genome.

  3. Parasite diversity at the Holarctic nexus: species of Arostrilepis (Eucestoda: Hymenolepididae) in voles and lemmings (Cricetidae: Arvicolinae) from greater Beringia.

    PubMed

    Makarikov, Arseny A; Galbreath, Kurt E; Hoberg, Eric P

    2013-01-01

    Previously unrecognized species of hymenolepidid cestodes attributable to Arostrilepis Mas-Coma & Tenora, 1997 in arvicoline rodents from the greater Beringian region and western North America are described. Discovery and characterization of these tapeworms contributes to the recognition of a complex of cryptic species distributed across the Holarctic region. Three species are proposed: Arostrilepis gulyaevi sp. n. is named for cestodes in Myodes rufocanus from the Republic of Buryatia, southeastern Siberia and from the Khabarovskiy Kray, Chukotka Autonomous Okrug, and Magadanskaya Oblast', Russian Far East (western Beringia); A. cooki sp. n. is named for cestodes in Myodes gapperi from British Columbia, Canada and Montana, USA; and A. rauschorum sp. n. is named for cestodes in Microtus oeconomus, M. longicaudus, M. pennsylvanicus and M. xanthognathus from the Brooks Range, Seward Peninsula, north-central interior, and Arctic coastal plains of Alaska (eastern Beringia) and Montana, USA. Consistent with recent studies defining diversity in the genus, the form, size, and spination (pattern, shape and size) of the cirrus are diagnostic; species are further distinguished by the relative position and length of the cirrus sac, and arrangement of the testes. Assessment of genetic data from the cytochrome b gene of mitochondrial DNA complements differentiation of this complex based on morphological attributes and confirms known species diversity within the genus. New data for geographical distribution and host specificity of known Arostrilepis spp. indicate that 3 of 12 recognized species have Holarctic distributions extending across Beringia. These include Arostrilepis beringiensis (Kontrimavichus & Smirnova, 1991) in lemmings (species of Lemmus and Synaptomys), A. cf. janickii Makarikov & Kontrimavichus, 2011 in root voles (M. oeconomus) MAKARIKOV ET AL. 402 · Zootaxa 3608 (6) © 2013 Magnolia Press and A. macrocirrosa Makarikov, Gulyaev & Kontrimavichus, 2011 in red backed voles (species of Myodes) and less often other rodent host species.

  4. The valid generic name for red-backed voles (Muroidea: Cricetidae: Arvicolinae): restatement of the case for Myodes Pallas, 1811

    USGS Publications Warehouse

    Carleton, Michael D.; Gardner, Alfred L.; Pavlinov, Igor Ya.; Musser, Guy G.

    2014-01-01

    In view of contradictions in the recent literature, the valid genus-group name to be applied to northern red-backed voles—Myodes Pallas, 1811, or Clethrionomys Tilesius, 1850—is reviewed. To develop the thesis that Myodes (type species, Mus rutilus Pallas, 1779) is the correct name, our discussion explores the 19th-century taxonomic works that bear on the relevant taxa, the transition in zoological codes apropos the identification of type species, and past nomenclatural habits in cases where no type species was originally indicated. We conclude that Myodes is the senior name to use for the genus-group taxon that includes the Holarctic species rutilus and frame this conclusion within a synonymy of the genus.

  5. Extensive Chromosomal Reorganization in the Evolution of New World Muroid Rodents (Cricetidae, Sigmodontinae): Searching for Ancestral Phylogenetic Traits

    PubMed Central

    Pereira, Adenilson Leão; Malcher, Stella Miranda; Nagamachi, Cleusa Yoshiko; O’Brien, Patricia Caroline Mary; Ferguson-Smith, Malcolm Andrew; Mendes-Oliveira, Ana Cristina; Pieczarka, Julio Cesar

    2016-01-01

    Sigmodontinae rodents show great diversity and complexity in morphology and ecology. This diversity is accompanied by extensive chromosome variation challenging attempts to reconstruct their ancestral genome. The species Hylaeamys megacephalus–HME (Oryzomyini, 2n = 54), Necromys lasiurus—NLA (Akodontini, 2n = 34) and Akodon sp.–ASP (Akodontini, 2n = 10) have extreme diploid numbers that make it difficult to understand the rearrangements that are responsible for such differences. In this study we analyzed these changes using whole chromosome probes of HME in cross-species painting of NLA and ASP to construct chromosome homology maps that reveal the rearrangements between species. We include data from the literature for other Sigmodontinae previously studied with probes from HME and Mus musculus (MMU) probes. We also use the HME probes on MMU chromosomes for the comparative analysis of NLA with other species already mapped by MMU probes. Our results show that NLA and ASP have highly rearranged karyotypes when compared to HME. Eleven HME syntenic blocks are shared among the species studied here. Four syntenies may be ancestral to Akodontini (HME2/18, 3/25, 18/25 and 4/11/16) and eight to Sigmodontinae (HME26, 1/12, 6/21, 7/9, 5/17, 11/16, 20/13 and 19/14/19). Using MMU data we identified six associations shared among rodents from seven subfamilies, where MMU3/18 and MMU8/13 are phylogenetic signatures of Sigmodontinae. We suggest that the associations MMU2entire, MMU6proximal/12entire, MMU3/18, MMU8/13, MMU1/17, MMU10/17, MMU12/17, MMU5/16, MMU5/6 and MMU7/19 are part of the ancestral Sigmodontinae genome. PMID:26800516

  6. Diversity at the Holarctic nexus: species of Arostrilepis (Eucestoda: Hymenolepididae) in arvicoline rodents (Cricetidae: Arvicolinae) from greater Beringia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously unrecognized species of hymenolepidid cestodes attributable to Arostrilepis Mas-Coma & Tenora, 1997 in arvicoline rodents from the greater Beringian region and western North America are described. Discovery and characterization of these tapeworms contributes to the recognition of a compl...

  7. A Newly Emerged Cutaneous Leishmaniasis Focus in Northern Israel and Two New Reservoir Hosts of Leishmania major

    PubMed Central

    Faiman, Roy; Abbasi, Ibrahim; Jaffe, Charles; Motro, Yoav; Nasereddin, Abdelmagid; Schnur, Lionel F.; Torem, Moshe; Pratlong, Francine; Dedet, Jean-Pierre; Warburg, Alon

    2013-01-01

    In 2006/7, 18 cases of cutaneous leishmaniasis (CL) were reported for the first time from Sde Eliyahu (pop. 650), a village in the Beit She'an valley of Israel. Between 2007–2011, a further 88 CL cases were diagnosed bringing the total to 106 (16.3% of the population of Sde Eliyahu). The majority of cases resided in the south-western part of the village along the perimeter fence. The causative parasite was identified as Leishmania major Yakimoff & Schokhor, 1914 (Kinetoplastida: Trypanosomatidae). Phlebotomus papatasi (Scopoli), 1786 (Diptera: Psychodidae) was found to be the most abundant phlebotomine species comprising 97% of the sand flies trapped inside the village, and an average of 7.9% of the females were positive for Leishmania ITS1 DNA. Parasite isolates from CL cases and a sand fly were characterized using several methods and shown to be L. major. During a comprehensive survey of rodents 164 Levant voles Microtus guentheri Danford & Alston, 1880 (Rodentia: Cricetidae) were captured in alfalfa fields bordering the village. Of these 27 (16.5%) tested positive for Leishmania ITS1 DNA and shown to be L. major by reverse line blotting. A very high percentage (58.3% - 21/36) of Tristram's jirds Meriones tristrami Thomas, 1892 (Rodentia: Muridae), found further away from the village also tested positive for ITS1 by PCR. Isolates of L. major were successfully cultured from the ear of a wild jird found positive by ITS1 PCR. Although none of the wild PCR-positive voles exhibited external pathology, laboratory-reared voles that were infected by intradermal L. major inoculation, developed patent lesions and sand flies became infected by feeding on the ears of these laboratory-infected voles. This is the first report implicating M. guentheri and M. tristrami as reservoirs of Leishmania. The widespread co-distribution of M. guentheri and P. papatasi, suggests a significant threat from the spread of CL caused by L. major in the Middle East, central Asia and southern

  8. Evolution of spatially coexpressed families of type-2 vomeronasal receptors in rodents.

    PubMed

    Francia, Simona; Silvotti, Lucia; Ghirardi, Filippo; Catzeflis, François; Percudani, Riccardo; Tirindelli, Roberto

    2014-12-23

    The vomeronasal organ (VNO) is an olfactory structure for the detection of pheromones. VNO neurons express three groups of unrelated G-protein-coupled receptors. Type-2 vomeronasal receptors (V2Rs) are specifically localized in the basal neurons of the VNO and are believed to sense protein pheromones eliciting specific reproductive behaviors. In murine species, V2Rs are organized into four families. Family-ABD V2Rs are expressed monogenically and coexpress with family-C V2Rs of either subfamily C1 (V2RC1) or subfamily C2 (V2RC2), according to a coordinate temporal diagram. Neurons expressing the phylogenetically ancient V2RC1 coexpress family-BD V2Rs or a specific group of subfamily-A V2Rs (V2RA8-10), whereas a second neuronal subset (V2RC2-positive) coexpresses a recently expanded group of five subfamily-A V2Rs (V2RA1-5) along with vomeronasal-specific Major Histocompatibility Complex molecules (H2-Mv). Through database mining and Sanger sequencing, we have analyzed the onset, diversification, and expansion of the V2R-families throughout the phylogeny of Rodentia. Our results suggest that the separation of V2RC1 and V2RC2 occurred in a Cricetidae ancestor in coincidence with the evolution of the H2-Mv genes; this phylogenetic event did not correspond with the origin of the coexpressing V2RA1-5 genes, which dates back to an ancestral myomorphan lineage. Interestingly, the evolution of receptors within the V2RA1-5 group may be implicated in the origin and diversification of some of the V2R putative cognate ligands, the exocrine secreting peptides. The establishment of V2RC2, which probably reflects the complex expansion and diversification of family-A V2Rs, generated receptors that have probably acquired a more subtle functional specificity.

  9. Localized versus generalist phenotypes in a broadly distributed tropical mammal: how is intraspecific variation distributed across disparate environments?

    PubMed Central

    2013-01-01

    Background The extent of phenotypic differentiation in response to local environmental conditions is a key component of species adaptation and persistence. Understanding the structuring of phenotypic diversity in response to local environmental pressures can provide important insights into species evolutionary dynamics and responses to environmental change. This work examines the influence of steep environmental gradients on intraspecific phenotypic variation and tests two hypotheses about how the tropical soft grass mouse, Akodon mollis (Cricetidae, Rodentia), contends with the disparate environmental conditions encompassed by its broad distribution. Specifically, we test if the species expresses a geographically unstructured, or generalist, phenotype throughout its range or if it shows geographically localized morphological differentiation across disparate environments. Results Using geometric morphometric and ecomorphological analyses of skull shape variation we found that despite distinct environmental conditions, geographically structured morphological variation is limited, with the notable exception of a distinct morphological disjunction at the high-elevation forest-grassland transition in the southern portion of A. mollis distribution. Based on genetic analyses, geographic isolation alone does not explain this localized phenotype, given that similar levels of genetic differentiation were also observed among individuals inhabiting other ecosystems that are nonetheless not distinct morphologically. Conclusions Instead of phenotypic specialization across environments in these tropical mountains, there was limited differentiation of skull shape and size across the broad range of A. mollis, with the exception of individuals from the puna, the highest-elevation ecosystem. The high morphological variance among individuals, together with a weak association with local environmental conditions, not only highlights the flexibility of A. mollis’ skull, but also

  10. Mitochondrial phylogeny reveals cryptic genetic diversity in the genus Niviventer (Rodentia, Muroidea).

    PubMed

    He, Kai; Jiang, Xue-Long

    2015-02-01

    Niviventer is a muroid genus with 17 species widely distributed in East and Southeast Asia. These animals are important components of both extant and fossil small mammal communities, and they are among the most common infectious agents in humans. In this study, we employed partitioned Bayesian and relaxed clock divergence dating analyses and included the Niviventer mitochondrial cytochrome b genes of from GenBank (n = 223). Although the intra-generic relationships were not fully resolved, we recognized four major clades/subclades that could support further division of the genus. Paraphyletic and polyphyletic species were discovered, and 21 putative species were recognized through species delimitation analysis, which indicated an imperfect taxonomy and the existent of cryptic species. Molecular dating supported Niviventer origination in the late Miocene, and relatively higher diversification rates were observed in the late Pliocene and the Pleistocene, which might correlate with climate fluctuations.

  11. Fatal placental subinvolution in a captive capybara (Hydrochaeris hydrochaeris, Order Rodentia).

    PubMed

    Juan-Sallés, C; Martínez, L S; Garner, M M

    2005-07-01

    An adult, captive-born female capybara died of systemic thrombosis and hemoperitoneum associated with placental subinvolution. Grossly, the uterus was enlarged, segmentally thickened, and associated with a large blood clot in the abdominal cavity. There was hemometra and a large ovoid mass in each uterine horn weakly adhered to the endometrium, and the right uterine horn wall had a small perforation over the mass. The mesometrial veins were markedly dilated due to thrombosis and occasionally perforated. Histologically, the uterine masses consisted of partly necrotic placental and subplacental tissue. The uterine wall surrounding the masses had full-thickness coagulative necrosis of the myometrium and diffuse endometrial ulceration with abundant syncytiotrophoblast-like cells within capillaries. Vascular lesions in the uterus and mesometrium consisted of mural invasion by cytotrophoblast and syncytiotrophoblast-like cells, thrombosis, fibrinoid necrosis, and/or heterophilic vasculitis. This is the first report of placental subinvolution in capybaras or any rodent species, to the authors' knowledge.

  12. Predicting the potential distribution of Vexillata (Nematoda: Ornithostrongylidae) and its hosts (Mammalia: Rodentia) within America.

    PubMed

    Martínez-Salazar, E A; Escalante, T; Linaje, M; Falcón-Ordaz, J

    2013-12-01

    Species distribution modelling has been a powerful tool to explore the potential distribution of parasites in wildlife, being the basis of studies on biogeography. Vexillata spp. are intestinal nematodes found in several species of mammalian hosts, such as rodents (Geomyoidea) and hares (Leporidae) in the Nearctic and northern Neotropical regions. In the present study, we modelled the potential distribution of Vexillata spp. and their hosts, using exclusively species from the Geomyidae and Heteromyidae families, in order to identify their distributional patterns. Bioclimatic and topographic variables were used to identify and predict suitable habitats for Vexillata and its hosts. Using these models, we identified that temperature seasonality is a significant environmental factor that influences the distribution of the parasite genus and its host. In particular, the geographical distribution is estimated to be larger than that predicted for its hosts. This suggests that the nematode has the potential to extend its geographical range and also its spectrum of host species. Increasing sample size and geographical coverage will contribute to recommendations for conservation of this host-parasite system.

  13. Ecology of the interaction between Ixodes loricatus (Acari: Ixodidae) and Akodon azarae (Rodentia: Criceridae).

    PubMed

    Colombo, Valeria C; Nava, Santiago; Antoniazzi, Leandro R; Monje, Lucas D; Racca, Andrea L; Guglielmone, Alberto A; Beldomenico, Pablo M

    2015-10-01

    The present study explores associations of different factors (i.e. host parameters, presence of other ectoparasites and [mainly biotic] environmental factors) with burdens of Ixodes loricatus immature stages in one of its main hosts in Argentina, the rodent Akodon azarae. For 2 years, rodents were trapped and sampled monthly at 16 points located in four different sites in the Parana River Delta region. Data were analysed with generalized linear mixed models with a negative binomial response (counts of larvae or nymphs). The independent variables assessed were (a) environmental: trapping year, presence of cattle, type of vegetation, rodent abundance; (b) host parameters: body length, sex, body condition, blood cell counts, natural antibody titers and (c) co-infestation with other ectoparasites. Two-way interaction terms deemed a priori as relevant were also included in the analysis. Most of the associations investigated were found significant, but in general, the direction and magnitude of the associations were context-dependent. An exception was the presence of cattle, which was consistently negatively associated with both larvae and nymphs independently of all other variables considered and had the strongest effect on tick burdens. Mites, fleas and Amblyomma triste were also significantly associated (mostly positively) with larval and nymph burdens, and in many cases, they influenced associations with environmental or host factors. Our findings strongly support that raising cattle may have a substantial impact on the dynamics of I. loricatus and that interactions within the ectoparasite community may be an important-but generally ignored-driver of tick dynamics.

  14. The evolution of bipedalism in jerboas (rodentia: Dipodoidea): origin in humid and forested environments.

    PubMed

    Wu, Shaoyuan; Zhang, Fuchun; Edwards, Scott V; Wu, Wenyu; Ye, Jie; Bi, Shundong; Ni, Xijun; Quan, Cheng; Meng, Jin; Organ, Chris L

    2014-07-01

    Mammalian bipedalism has long been thought to have arisen in response to arid and open environments. Here, we tested whether bipedalism coevolved with environmental changes using molecular and paleontological data from the rodent superfamily Dipodoidea and statistical methods for reconstructing ancestral characteristics and past climates. Our results show that the post-Late Miocene aridification exerted selective pressures on tooth shape, but not on leg length of bipedal jerboas. Cheek tooth crown height has increased since the Late Miocene, but the hind limb/head-body length ratios remained stable and high despite the environmental change from humid and forested to arid and open conditions, rather than increasing from low to high as predicted by the arid-bipedalism hypothesis. The decoupling of locomotor and dental character evolution indicates that bipedalism evolved under selective pressure different from that of dental hypsodonty in jerboas. We reconstructed the habitats of early jerboas using floral and faunal data, and the results show that the environments in which bipedalism evolved were forested. Our results suggest that bipedalism evolved as an adaptation to humid woodlands or forests for vertical jumping. Running at high speeds is likely a by-product of selection for jumping, which became advantageous in open environments later on.

  15. Re-evaluation of Sinocastor (Rodentia: Castoridae) with implications on the origin of modern beavers.

    PubMed

    Rybczynski, Natalia; Ross, Elizabeth M; Samuels, Joshua X; Korth, William W

    2010-11-15

    The extant beaver, Castor, has played an important role shaping landscapes and ecosystems in Eurasia and North America, yet the origins and early evolution of this lineage remain poorly understood. Here we use a geometric morphometric approach to help re-evaluate the phylogenetic affinities of a fossil skull from the Late Miocene of China. This specimen was originally considered Sinocastor, and later transferred to Castor. The aim of this study was to determine whether this form is an early member of Castor, or if it represents a lineage outside of Castor. The specimen was compared to 38 specimens of modern Castor (both C. canadensis and C. fiber) as well as fossil specimens of C. fiber (Pleistocene), C. californicus (Pliocene) and the early castorids Steneofiber eseri (early Miocene). The results show that the specimen falls outside the Castor morphospace and that compared to Castor, Sinocastor possesses a: 1) narrower post-orbital constriction, 2) anteroposteriorly shortened basioccipital depression, 3) shortened incisive foramen, 4) more posteriorly located palatine foramen, 5) longer rostrum, and 6) longer braincase. Also the specimen shows a much shallower basiocciptal depression than what is seen in living Castor, as well as prominently rooted molars. We conclude that Sinocastor is a valid genus. Given the prevalence of apparently primitive traits, Sinocastor might be a near relative of the lineage that gave rise to Castor, implying a possible Asiatic origin for Castor.

  16. First Miocene rodent from Lebanon provides the 'missing link' between Asian and African gundis (Rodentia: Ctenodactylidae).

    PubMed

    López-Antoñanzas, Raquel; Knoll, Fabien; Maksoud, Sibelle; Azar, Dany

    2015-08-07

    Ctenodactylinae (gundis) is a clade of rodents that experienced, in Miocene time, their greatest diversification and widest distribution. They expanded from the Far East, their area of origin, to Africa, which they entered from what would become the Arabian Peninsula. Questions concerning the origin of African Ctenodactylinae persist essentially because of a poor fossil record from the Miocene of Afro-Arabia. However, recent excavations in the Late Miocene of Lebanon have yielded a key taxon for our understanding of these issues. Proafricanomys libanensis nov. gen. nov. sp. shares a variety of dental characters with both the most primitive and derived members of the subfamily. A cladistic analysis demonstrates that this species is the sister taxon to a clade encompassing all but one of the African ctenodactylines, plus a southern European species of obvious African extraction. As such, Proafricanomys provides the 'missing link' between the Asian and African gundis.

  17. Diversification and biogeography of the Neotropical caviomorph lineage Octodontoidea (Rodentia: Hystricognathi).

    PubMed

    Upham, Nathan S; Patterson, Bruce D

    2012-05-01

    The rodent superfamily Octodontoidea comprises 6 families, 38 genera, and 193 living species of spiny rats, tuco-tucos, degus, hutias, and their relatives. All are endemic to the Neotropical Region where they represent roughly three-quarters of extant caviomorphs. Although caviomorph monophyly is well established and phylogenetic hypotheses exist for several families, understanding of octodontoid relationships is clouded by sparse taxon sampling and single-gene analyses. We examined sequence variation in one mitochondrial (12S rRNA) and three nuclear genes (vWF, GHR, and RAG1) across all caviomorph families (including 47 octodontoid species), all phiomorph families, and the sole remaining hystricognath family, using the gundi (Ctenodactylus) and springhaas (Pedetes) as outgroups. Our analyses support the monophyly of Phiomorpha, Caviomorpha, and the caviomorph superfamilies Cavioidea (Dasyproctidae, Cuniculidae, and Caviidae, the latter including Hydrochoerus), Erethizontoidea, Chinchilloidea (including Dinomyidae), and Octodontoidea. Cavioids and erethizontoids are strongly supported as sisters, whereas chinchilloids appear to be sister to octodontoids. Among octodontoids, Abrocomidae is consistently recovered as the basal element, sister to a pair of strongly supported clades; one includes Octodontidae and Ctenomyidae as reciprocally monophyletic lineages, whereas the other includes taxa currently allocated to Echimyidae, Capromyidae and Myocastoridae. Capromys appears near the base of this clade, in keeping with current classification, but Myocastor is nested securely inside a clade of Echimyidae that also contains eumysopines, echimyines and dactylomyines. Another, more weakly supported clade of Echimyidae contains fossorial and scansorial taxa from the Chaco-Cerrado-Caatinga and the Atlantic Forest. Biogeographic analyses robustly recover the Patagonia-Southern Andes complex as ancestral for the Octodontoidea, with three component lineages emerging by the Oligocene-Miocene boundary (∼23Ma): (1) stem abrocomids in the Central and Southern Andes; (2) a lineage leading to octodontids plus ctenomyids in Patagonia, later dispersing into the Chaco-Cerrado-Caatinga; and (3) a lineage leading to echimyids, capromyids, and myocastorids that subsequently radiated in more mesic biomes, including Amazonia, Atlantic Forest, and the Antilles. This reconstruction refutes earlier ideas that the diverse, generalized, mainly lowland family Echimyidae, which appears early in the fossil record, gave rise to the Andean lineages of octodontoids-instead, the reverse derivation appears to be true. We recommend formal synonymy of Myocastoridae with Echimyidae but defer a similar treatment of Capromyidae until additional hutia taxa and sequences can be analyzed.

  18. A new subspecies of hutia (Plagiodontia, Capromyidae, Rodentia) from southern Hispaniola.

    PubMed

    Turvey, Samuel T; Hansford, James; Kennerley, Rosalind J; Nuñez-Miño, José M; Brocca, Jorge L; Young, Richard P

    2015-05-14

    Continued uncertainty persists over the taxonomic status of many threatened Caribbean mammal populations. Recent molecular analysis has identified three genetically isolated allopatric hutia populations on Hispaniola that diverged during the Middle Pleistocene, with observed levels of sequence divergence interpreted as representing subspecies-level differentiation through comparison with genetic data for other capromyids. Subsequent analysis of existing museum specimens has demonstrated biogeographically congruent morphometric differentiation for two of these three populations, Plagiodontia aedium aedium (southwestern population) and P. aedium hylaeum (northern population). We report the first craniodental material for the southeastern Hispaniolan hutia population, and demonstrate that this population can also be differentiated using quantitative morphometric analysis from other Hispaniolan hutia subspecies. The holotype skull of P. aedium aedium, of unknown geographic provenance within Hispaniola, clusters morphometrically with the southwestern population. The southeastern Hispaniolan subspecies is described as Plagiodontia aedium bondi subsp. nov., and is assessed as Endangered under Criterion B1a,biii,v on the IUCN Red List.

  19. Complete mitochondrial genome of the Gansu zokor, Eospalax cansus (Rodentia, Spalacidae).

    PubMed

    Su, Junhu; Wang, Jing; Hua, Limin; Gleeson, Dianne; Ji, Weihong

    2013-12-01

    Mysopalacinae (zokors) is a group of fossorial rodents for which the taxonomy has yet to reach consensus. Furthermore, due to their fossorial lifestyle, little is known about their ecology. Molecular data are important to elucidate such aspects. In this paper, the complete mitochondrial DNA genome of Gansu zokor (Eospalax cansus) of the type found in Lintan, China was determined. The genome is 16,354 bp in length and consists of 13 protein-coding genes, 22 tRNA genes, two ribosomal RNA genes, and two main non-coding regions (the control region and the origin of the light strand replication), the gene composition and order of which are similar to most other mammals. The overall base composition is T 30.0%, C 24.2%, A 33.5%, and G 12.3%, with an A + T bias of 63.5%. These mitogenome sequence data are potentially important for evolutionary, population genetic, and ecological studies of the Mysopalacinae.

  20. Early evolutionary differentiation of morphological variation in the mandible of South American caviomorph rodents (Rodentia, Caviomorpha).

    PubMed

    Alvarez, A; Perez, S I; Verzi, D H

    2011-12-01

    Caviomorphs are a clade of South American rodents recorded at least since the early Oligocene (> 31.5 Ma) that exhibit ample eco-morphological variation. It has been proposed that phylogenetic structure is more important than ecological factors for understanding mandibular shape variation in this clade. This was interpreted as a result of the long-standing evolutionary history of caviomorphs and the early divergence of major lineages. In this work, we test this hypothesis through the analysis of morphological variation in the mandible of living and extinct species and compare this information with that obtained through comparative phylogenetic analyses. Our results support the hypothesis of early origin of mandibular variation; moreover, they suggest the conservation of early differentiated morphologies, which could indicate the existence of constrained evolutionary diversification.

  1. Another one bites the dust: bite force and ecology in three caviomorph rodents (Rodentia, Hystricognathi).

    PubMed

    Becerra, Federico; Echeverría, Alejandra Isabel; Casinos, Adrià; Vassallo, Aldo Iván

    2014-04-01

    Mammals have developed sophisticated strategies adapting to particular locomotor modes, feeding habits, and social interactions. Many rodent species have acquired a fossorial, semi-fossorial, or even subterranean life-style, converging on morphological, anatomical, and ecological features but diverging in the final arrangement. These ecological variations partially depend on the functional morphology of their digging tools. Muscular and mechanical features (e.g., lever arms relationship) of the bite force were analyzed in three caviomorph rodents with similar body size but different habits and ecological demands of the jaws. In vivo forces were measured at incisors' tip using a strain gauge load cell force transducer whereas theoretical maximal performance values, mechanical advantages, and particular contribution of each adductor muscle were estimated from dissections in specimens of Ctenomys australis (subterranean, solitary), Octodon degus (semi-fossorial, social), and Chinchilla laniger (ground-dweller, colonial). Our results showed that C. australis bites stronger than expected given its small size and C. laniger exhibited the opposite outcome, while O. degus is close to the expected value based on mammalian bite force versus body mass regressions; what might be associated to the chisel-tooth digging behavior and social interactions. Our key finding was that no matter how diverse these rodents' skulls were, no difference was found in the mechanical advantage of the main adductor muscles. Therefore, interspecific differences in the bite force might be primarily due to differences in the muscular development and force, as shown for the subterranean, solitary and territorial C. australis versus the more gracile, ground-dweller, and colonial C. laniger.

  2. Cryptic speciation and chromosomal repatterning in the South African climbing mice Dendromus (Rodentia, Nesomyidae).

    PubMed

    Solano, Emanuela; Taylor, Peter J; Rautenbach, Anita; Ropiquet, Anne; Castiglia, Riccardo

    2014-01-01

    We evaluate the intra- and interspecific diversity in the four South African rodent species of the genus Dendromus. The molecular phylogenetic analysis on twenty-three individuals have been conducted on a combined dataset of nuclear and mitochondrial markers. Moreover, the extent and processes underlying chromosomal variation, have been investigated on three species by mean of G-, C-bands, NORs and Zoo-FISH analysis. The molecular analysis shows the presence of six monophyletic lineages corresponding to D. mesomelas, D. mystacalis and four lineages within D. cfr. melanotis with high divergence values (ranges: 10.6% - 18.3%) that raises the question of the possible presence of cryptic species. The first description of the karyotype for D. mesomelas and D. mystacalis and C- and G- banding for one lineage of D. cfr. melanotis are reported highlighting an extended karyotype reorganization in the genus. Furthermore, the G-banding and Zoo-FISH evidenced an autosome-sex chromosome translocation characterizing all the species and our timing estimates this mutation date back 7.4 mya (Late Miocene). Finally, the molecular clock suggests that cladogenesis took place since the end of Miocene to Plio-Pleistocene, probably due to ecological factors, isolation in refugia followed by differential adaptation to the mesic or dry habitat.

  3. Bony labyrinth morphometry indicates locomotor adaptations in the squirrel-related clade (Rodentia, Mammalia).

    PubMed

    Pfaff, Cathrin; Martin, Thomas; Ruf, Irina

    2015-06-22

    The semicircular canals (SCs) of the inner ear detect angular acceleration and are located in the bony labyrinth of the petrosal bone. Based on high-resolution computed tomography, we created a size-independent database of the bony labyrinth of 50 mammalian species especially rodents of the squirrel-related clade comprising taxa with fossorial, arboreal and gliding adaptations. Our sampling also includes gliding marsupials, actively flying bats, the arboreal tree shrew and subterranean species. The morphometric anatomy of the SCs was correlated to the locomotion mode. Even if the phylogenetic signal cannot entirely be excluded, the main significance for functional morphological studies has been found in the diameter of the SCs, whereas the radius of curvature is of minor interest. Additionally, we found clear differences in the bias angle of the canals between subterranean and gliding taxa, but also between sciurids and glirids. The sensitivity of the inner ear correlates with the locomotion mode, with a higher sensitivity of the SCs in fossorial species than in flying taxa. We conclude that the inner ear of flying and gliding mammals is less sensitive due to the large information flow into this sense organ during locomotion.

  4. Gaudeamus lavocati sp. nov. (Rodentia, Hystricognathi) from the early Oligocene of Zallah, Libya: first African caviomorph?

    PubMed

    Coster, Pauline; Benammi, Mouloud; Lazzari, Vincent; Billet, Guillaume; Martin, Thomas; Salem, Mustafa; Bilal, Awad Abolhassan; Chaimanee, Yaowalak; Schuster, Mathieu; Valentin, Xavier; Brunet, Michel; Jaeger, Jean-Jacques

    2010-08-01

    A new African species of hystricognathous rodent, Gaudeamus lavocati sp. nov., is described herein from the early Oligocene deposits of Zallah locality (Sirt basin, Central Libya). The dental morphology of this species is very close to that of some earliest South American caviomorphs. It allows a reinterpretation of molar crest homologies among earliest caviomorphs, pentalophodonty being confirmed as the plesiomorphic molar condition in Caviomorpha. This morphological resemblance argues for close affinities between Gaudeamus and earliest South American hystricognaths. Cladistic analysis supports Gaudeamus lavocati sp. nov. as the first known African representative of Caviomorpha, implying that its ancestors were part of the African phiomyid group that crossed the South Atlantic by a direct immigration route. Alternatively, the series of derived dental features of Gaudeamus could also be interpreted as evolutionary synchronous convergences of an African hystricognath lineage towards the specialized pattern of some caviomorphs. However, the high level of similarities concerning teeth morphology and enamel microstructure and the similar age of fossiliferous strata on both continents make this interpretation less probable. The phylogenetic position of this taxon is of considerable importance because it represents an enigmatic component of the phiomorph-caviomorph radiation in Africa and appears as a new clue toward the understanding of caviomorph origins.

  5. Scaling and adaptations of incisors and cheek teeth in caviomorph rodents (Rodentia, Hystricognathi).

    PubMed

    Becerra, Federico; Vassallo, Aldo I; Echeverría, Alejandra I; Casinos, Adrià

    2012-10-01

    The South American hystricognath rodents are one of the most diverse mammalian clades considering their occupied habitats, locomotor modes and body sizes. This might have been partly evolved by diversification of their masticatory apparatus' structure and its ecological commitment, for example, chisel-tooth digging. In this phylogeny-based comparative study, we test the relationship between ecological behavior and mechanical features of their incisors and molariforms. In 33 species of nine families of caviomorph rodents, we analyze incisor attributes related to structural stress resistance and molar features related with grinding capacity, for example, second moment of inertia and enamel index (EI) (enamel band length/occlusal surface area), respectively. Most of these variables scaled isometrically to body mass, with a strong phylogenetic effect. A principal component analysis discrimination on the EI clustered the species according to their geographic distribution. We presume that selective pressures in Andean-Patagonian regions, on particular feeding habits and chisel-tooth digging behaviors, have modeled the morphological characteristics of the teeth. Subterranean/burrower ctenomyids, coruros, and plains viscachas showed the highest bending/torsion strength and anchorage values for incisors; a simplified enamel pattern in molariforms would be associated with a better grinding of the more abrasive vegetation present in more open and drier biomes.

  6. Phylogenetic relationships of extant zokors (Myospalacinae) (Rodentia, Spalacidae) inferred from mitochondrial DNA sequences.

    PubMed

    Su, Junhu; Ji, Weihong; Wang, Jing; Gleeson, Dianne M; Zhou, Janwei; Hua, Limin; Wei, Yanming

    2014-04-01

    In this study, we use three mitochondrial markers, cytochrome b gene (Cyt b), NADH dehydrogenase subunit 4 (ND4) and control region (D-loop) to investigate the phylogenetic relationships of extant zokor species in Mysopalacinae. The phylogenetic tree constructed based on Cyt b strongly supports the monophyly genera Eospalax and Myospalax with E. fontanierii being the most ancient species in Eospalax. Further phylogenetic analyses of four species of Eospalax based on ND4 and D-loop sequences revealed two clades that correspond to two geographical distributions. The basal clade includes E. cansus which is mainly found on Loess Plateau (LP) and another clade including E. baileyi, E. smithii and E. rufescens that inhabits areas above 2000 m on Qinghai-Tibetan Plateau (QTP) and Qinling Mountains. Geographical events of QTP and LP may have played a major role in the diversification and evolution of Mysopalacinae.

  7. Western gray squirrel (Rodentia: Sciuridae): a primary reservoir host of Borrelia burgdorferi in Californian oak woodlands?

    PubMed

    Lane, Robert S; Mun, Jeomhee; Eisen, Rebecca J; Eisen, Lars

    2005-05-01

    In California, dense woodlands have been recognized as important biotopes where humans are exposed to the nymphal stage of the western blacklegged tick, Ixodes pacificus Cooley & Kohls, the primary vector of the Lyme disease spirochete Borrelia burgdorferi sensu stricto (s.s.), in the far-western United States. To identify the principal reservoir host(s) of this spirochete, and of closely related spirochetes in the B. burgdorferi sensu lato (s.l.) complex, in dense woodlands in Mendocino County, California, approximately 50 species of birds and mammals, including wood rats and kangaroo rats, were evaluated as potential hosts for vector ticks and borreliae in 2002 and 2003. Although polymerase chain reaction (PCR) and sequencing analyses revealed that many vertebrate species had been exposed to one or more members of the B. burgdorferi s.l. spirochetal complex, only the western gray squirrel, Sciurus griseus, fulfilled the major criteria for a reservoir host of B. burgdorferi s.s. Ear-punch biopsies from eight of 10 squirrels collected from five separate woodlands were PCR-positive for B. burgdorferi s.s., 47% of I. pacificus larvae (n = 64) and 31% of nymphs (n = 49) removed from squirrels contained B. burgdorferi s.l., and the engorgement status of I. pacificus larvae was associated positively with acquisition of spirochetes. Overall, 83 and 100% of the amplicons sequenced from PCR-positive I. pacificus larvae and nymphs, respectively, were identified as B. burgdorferi s.s, Among the five remaining positive I. pacificus larvae, three contained B. bissettii and two had uncharacterized B. burgdorferi s.l. Borrelia burgdorferi s.s. was detected in one of five larvae and zero of two nymphs of the Pacific Coast tick, Dermacentor occidentalis Marx, that likewise had been removed from squirrels. The rickettsial agent of human anaplasmosis, Anaplasma phagocytophilum, was detected in the blood or ear biopsies of two squirrels and in one (1.6%) of 64 I. pacificus larvae and two (4.1%) of 49 nymphs obtained from squirrels. The one rickettsial-positive larva was coinfected with B. burgdorferi s.s. The apparently high reservoir potential of S. griseus for B. burgdorferi s.s., plus the fact that the geographic distribution of this squirrel coincides well with that of most reported human cases of Lyme disease in this region, indicated that it may be essential for maintaining foci of B. burgdorferi s.s. in certain types of woodlands. The findings with respect to A. phagocytophilum, although of less certain significance, suggest that S. griseus could serve as a secondary host of this rickettsia. PMID:15962792

  8. Characterization of the complete mitochondrial genome of the Hainan giant flying squirrel Petaurista hainana (Rodentia: Sciuridae).

    PubMed

    Kong, Lingming; Wang, Yanlu; Cong, Haiyan; Wang, Wenquan; Li, Yuchun

    2015-01-01

    The complete mitochondrial genome of Petaurista hainana from Hainan Island of China is 16,502 bp in length. Similar to most other mammals, it contains 13 protein-coding genes, 2 rRNAs, 22 tRNAs and 2 non-coding regions. The overall base composition of the H-strand is 31.77% A, 26.31% C, 13.31% G and 28.61% T. The base composition clearly showed the A-T skew. The mitochondrial genome of P. hainana presented in this report will be useful for species designation, conservation and phylogenetic study in Sciuridae. PMID:24409919

  9. Mandible shape and dwarfism in squirrels (Mammalia, Rodentia): interaction of allometry and adaptation.

    PubMed

    Hautier, Lionel; Fabre, Pierre-Henri; Michaux, Jacques

    2009-06-01

    Squirrels include several independent lineages of dwarf forms distributed into two ecological groups: the dwarf tree and flying squirrels. The mandible of dwarf tree squirrels share a highly reduced coronoid process and a condylar process drawn backwards. Dwarf flying squirrels on the other hand, have an elongated coronoid process and a well-differentiated condylar process. To interpret such a difference, Elliptic Fourier Transform was used to evaluate how mandible shape varies with dwarfism in sciurids. The results obtained show that this clear-cut difference cannot be explained by a simple allometric relationship in relation with size decrease. We concluded that the retention of anteriorly positioned eye sockets, in relation with distance estimation, allowed the conservation of a well-differentiated coronoid process in all flying species, despite the trend towards its reduction observed among sciurids as their size decreases. PMID:19288073

  10. Phylogenetic Relationships among Asian species of Petaurista (Rodentia, Sciuridae), Inferred from Mitochondrial Cytochrome b Gene Sequences.

    PubMed

    Oshida, T; Lin, L K; Masuda, R; Yoshida, M C

    2000-01-01

    To elucidate the phylogenetic relationships among four species belonging to the genus Petaurista (P. alborufus castaneus, P. alborufus lena, P. leucogenys leucogenys, P. leucogenys nikkonis, P. petaurista melanotus, and P. philippensis grandis), we investigated the partial sequences (1,068 bp) of the mitochondrial cytochrome b gene for these giant flying squirrels. Phylogenetic trees (NJ, MP, and ML trees) constructed from cytochrome b sequences indicated that P. leucogenys was grouped independently with other species, and that P. philippensis was most closely related to P. petaurista with 99-100% bootstrap values. In addition, two subspecies of P. alborufus did not form a single clade: P. alborufus castaneus from China was most distantly related to the other species, whereas P. alborufus lena from Taiwan was closely related to P. petaurista and P. philippensis with 82-90% bootstrap values. This result suggests that it is reasonable to regard P. alborufus lena as a distinct species from P. alborufus castaneus. PMID:18494567

  11. Bony labyrinth morphometry indicates locomotor adaptations in the squirrel-related clade (Rodentia, Mammalia).

    PubMed

    Pfaff, Cathrin; Martin, Thomas; Ruf, Irina

    2015-06-22

    The semicircular canals (SCs) of the inner ear detect angular acceleration and are located in the bony labyrinth of the petrosal bone. Based on high-resolution computed tomography, we created a size-independent database of the bony labyrinth of 50 mammalian species especially rodents of the squirrel-related clade comprising taxa with fossorial, arboreal and gliding adaptations. Our sampling also includes gliding marsupials, actively flying bats, the arboreal tree shrew and subterranean species. The morphometric anatomy of the SCs was correlated to the locomotion mode. Even if the phylogenetic signal cannot entirely be excluded, the main significance for functional morphological studies has been found in the diameter of the SCs, whereas the radius of curvature is of minor interest. Additionally, we found clear differences in the bias angle of the canals between subterranean and gliding taxa, but also between sciurids and glirids. The sensitivity of the inner ear correlates with the locomotion mode, with a higher sensitivity of the SCs in fossorial species than in flying taxa. We conclude that the inner ear of flying and gliding mammals is less sensitive due to the large information flow into this sense organ during locomotion. PMID:26019162

  12. Innervation of propatagial musculature in a flying squirrel, Glaucomys volans (Rodentia, Sciuridae).

    PubMed

    Chickering, J G; Sokoloff, A J

    1996-01-01

    The propatagium of gliding and flying mammals is of both functional and phylogenetic interest. The innervation of the propatagial muscle, platysma II, was studied with the axonal tracer wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) in a flying squirrel, Glaucomys volans. Injections of WGA-HRP into the proximal third of platysma II labeled motoneurons in the lateral part of the medial subdivision of the ipsilateral facial nucleus and in the ipsilateral ventral horn of the brachial enlargement. Injections into distal regions of platysma II labeled motoneurons in the ipsilateral ventral horn of spinal segments C5-C8 but not in the facial nucleus. Injections along the whole length of the muscle labeled afferent axons in the ipsilateral dorsal horn of spinal segments C4-T1. These results demonstrate a mixed facial and spinal motor innervation of propatagial musculature in the flying squirrel and indicate that this pattern of mixed innervation is more widespread among flying and gliding mammals than previously reported. Mixed facial and cervical propatagial innervation, independently derived in different flying and gliding mammals, may represent a common solution in the design of the propatagium. These findings complicate the use of propatagial muscle innervation patterns for the establishment of phylogenetic relationships among flying and gliding mammals. PMID:8834780

  13. Cranial morphometric study of four giant flying squirrels (Petaurista) (Rodentia: Sciuridae) from China.

    PubMed

    Li, Song; Yu, Fa-Hong; Lv, Xue-Fei

    2012-04-01

    The present study revisited the controversial taxonomic status of Petaurista yunanensis, P. philippensis, P. hainana, and P. petaurista by using a considerably extended set of morphometrical characters (26 cranial variables from 60 adult specimen skulls). The results revealed no sexual dimorphism in any of the four species but confirmed significant craniometric differences among the four species in both the principal components analysis (PCA) and discriminant function analysis (DFA), with the greatest distinction observed between P. petaurista and other Petaurista species. Both univariate and multivariate analysis indicated that the morphological differences between P. yunanensis and P. philippensis were less than that between P. philippensis and P. hainana. The morphometric results were concordant in geographic patterns with mtDNA data from previous studies and indicated that P. petaurista, P. hainana, P. philippensis, and P. yunanensis could be recognized as valid species. PMID:22467385

  14. Development and morphological changes in the vaginal closure membrane throughout gestation in Galea spixii (Rodentia: Caviidae).

    PubMed

    dos Santos, Amilton Cesar; Oliveira, Gleidson Benevides; Viana, Diego Carvalho; Oliveira, Franceliusa Delys; Silva, Renata dos Santos; Rici, Rose Eli Grassi; de Oliveira, Moacir Franco; de Assis-Neto, Antônio Chaves

    2016-05-01

    Present research was carried out in order to perform the monitoring of development, recognizes the type of tissue and describes histological and cellular changes of the vaginal closure membrane (VCM) throughout pregnancy in Galea spixii. The results showed that at 20 days of gestation (DG), the VCM occludes completely the external vaginal ostium. Microscopically, the VCM presented juxtaposed cells, derived from the stratum germinative of the stratified epithelium of vaginal mucosa at 20 DG and areas with cell clusters with the presence of intercellular spaces in the final stages of pregnancy (40-50 DG). At 0 DG, the stratified epithelium of vaginal mucosa presented all strata but at 20 DG presented stratified epithelium without the stratum corneum and stratum granular and showed communicant junctions by desmosomes and interdigitations in the cell membrane compound the VCM. Gradually from 40 to 50 DG the stratum germinative became barely perceptible. Many cells showed apoptotic nuclei and emerged many intercellular spacing. So, the interdigitations and desmosomes were not observed. Here, it was demonstrated for the first time that the VCM is formed after the extinction of the stratum granular and corneum of the vaginal mucosa epithelium, with the proliferation of the cells of stratum germinative and communication and junction through desmosomes and interdigitations of these cells. At the end of pregnancy, cellular apoptosis; the spread of stratum germinative; and, absence of cellular communication and junction may be responsible for the weakening of the VCM and may assist the process of rupture of this membrane.

  15. Glaciation Effects on the Phylogeographic Structure of Oligoryzomys longicaudatus (Rodentia: Sigmodontinae) in the Southern Andes

    PubMed Central

    Palma, R. Eduardo; Boric-Bargetto, Dusan; Torres-Pérez, Fernando; Hernández, Cristián E.; Yates, Terry L.

    2012-01-01

    The long-tailed pygmy rice rat Oligoryzomys longicaudatus (Sigmodontinae), the major reservoir of Hantavirus in Chile and Patagonian Argentina, is widely distributed in the Mediterranean, Temperate and Patagonian Forests of Chile, as well as in adjacent areas in southern Argentina. We used molecular data to evaluate the effects of the last glacial event on the phylogeographic structure of this species. We examined if historical Pleistocene events had affected genetic variation and spatial distribution of this species along its distributional range. We sampled 223 individuals representing 47 localities along the species range, and sequenced the hypervariable domain I of the mtDNA control region. Aligned sequences were analyzed using haplotype network, Bayesian population structure and demographic analyses. Analysis of population structure and the haplotype network inferred three genetic clusters along the distribution of O. longicaudatus that mostly agreed with the three major ecogeographic regions in Chile: Mediterranean, Temperate Forests and Patagonian Forests. Bayesian Skyline Plots showed constant population sizes through time in all three clusters followed by an increase after and during the Last Glacial Maximum (LGM; between 26,000–13,000 years ago). Neutrality tests and the “g” parameter also suggest that populations of O. longicaudatus experienced demographic expansion across the species entire range. Past climate shifts have influenced population structure and lineage variation of O. longicaudatus. This species remained in refugia areas during Pleistocene times in southern Temperate Forests (and adjacent areas in Patagonia). From these refugia, O. longicaudatus experienced demographic expansions into Patagonian Forests and central Mediterranean Chile using glacial retreats. PMID:22396751

  16. Homomorphic sex chromosomes and the intriguing Y chromosome of Ctenomys rodent species (Rodentia, Ctenomyidae).

    PubMed

    Suárez-Villota, Elkin Y; Pansonato-Alves, José C; Foresti, Fausto; Gallardo, Milton H

    2014-01-01

    Unlike the X chromosome, the mammalian Y chromosome undergoes evolutionary decay resulting in small size. This sex chromosomal heteromorphism, observed in most species of the fossorial rodent Ctenomys, contrasts with the medium-sized, homomorphic acrocentric sex chromosomes of closely related C. maulinus and C. sp. To characterize the sequence composition of these chromosomes, fluorescent banding, self-genomic in situ hybridization, and fluorescent in situ hybridization with an X painting probe were performed on mitotic and meiotic plates. High molecular homology between the sex chromosomes was detected on mitotic material as well as on meiotic plates immunodetected with anti-SYCP3 and anti-γH2AX. The Y chromosome is euchromatic, poor in repetitive sequences and differs from the X by the loss of a block of pericentromeric chromatin. Inferred from the G-banding pattern, an inversion and the concomitant prevention of recombination in a large asynaptic region seems to be crucial for meiotic X chromosome inactivation. These peculiar findings together with the homomorphism of Ctenomys sex chromosomes are discussed in the light of the regular purge that counteracts Muller's ratchet and the probable mechanisms accounting for their origin and molecular homology.

  17. Sequence and phylogenetic analysis of the complete mitochondrial genome of Lasiopodomys mandarinus mandarinus (Arvicolinae, Rodentia).

    PubMed

    Li, Yangwei; Shi, Yuhua; Lu, Jiqi; Ji, Weihong; Wang, Zhenlong

    2016-11-30

    Mandarin vole (Lasiopodomys mandarinus) is a subterranean rodent that is often used as a model for studying subterranean hypoxic stress in mammals. However the taxonomy of this species is still in dispute. Mitochondrial DNA (mtDNA) has long been used for phylogenetic reconstruction and, in this study, the complete mitochondrial genome of L. mandarinus mandarinus was sequenced. Our results showed that the mitochondrial genome of L. m. mandarinus is a circular molecule of 16,367bp, which contains 13 protein-coding genes, 22 tRNA and 2 rRNA genes. Except for the 8 tRNA and ND6 genes, all other mitochondrial genes are encoded on the heavy strand. We also analyzed the phylogenetic position of L. mandarinus in respect to the tribe Arvicolini using the sequence of complete Cytb gene, 2rRNA genes and 12 protein-coding genes, and maximum likelihood and Bayesian methods. Our results gave further support to the species status of L. mandarinus and the generic status of Lasiopodomys. PMID:27562081

  18. [Aberrations of the alarm call of the steppe marmot, Marmota bobak (Rodentia, Sciuridae)].

    PubMed

    Nikol'skiĭ, A A

    2008-01-01

    Aberrations, or deviations from the normal type of alarm call have been studied in the steppe marmot. One regular and several rare aberrations have been identified. The regular aberration manifests itself in all six populations studied, from the Kharkov Region in the west to the eastern border of the Orenburg Region in the east, with its frequency in the populations varying in different years from 10 to 66%. Rare aberrations occur sporadically and not in all populations.

  19. Phylogenetic and environmental components of morphological variation: skull, mandible, and molar shape in marmots (Marmota, Rodentia).

    PubMed

    Caumul, Radhekshmi; Polly, P David

    2005-11-01

    The phenotype is a product of its phylogenetic history and its recent adaptation to local environments, but the relative importance of the two factors is controversial. We assessed the effects of diet, habitat, elevation, temperature, precipitation, body size, and mtDNA genetic divergence on shape variation in skulls, mandibles, and molars, structures that differ in their genetic and functional control. We asked whether these structures have adapted to environment to the same extent and whether they retain the same amount of phylogenetic signal. We studied these traits in intra- and interspecific populations of Eurasian marmots whose last common ancestor lived 2-5 million years ago. Path Analysis revealed that body size explained 10% of variation in skulls, 7% in mandibles, and 15% in molars. Local vegetation explained 7% of variation in skulls, 11% in mandibles, and 12% in molars. Dietary category explained 25% of variation in skulls, 11% in mandibles, and 9% in molars. Cyt b mtDNA divergence (phylogeny) explained 15% of variation in skulls, 7% in mandibles, and 5% in molars. Despite the percentages of phylogenetic variance, maximum-likelihood trees based on molar and skull shape recovered most phylogenetic groupings correctly, but mandible shape did not. The good performance of molars and skulls was probably due to different factors. Skulls are genetically and functionally more complicated than teeth, and they had more mathematically independent components of variation (5-6-in skulls compared to 3-in molars). The high proportion of diet-related variance was not enough to mask the phylogenetic signal. Molars had fewer independent components, but they also have less ecophenotypic variation and evolve more slowly, giving each component a proportionally stronger phylogenetic signal. Molars require larger samples for each operational taxonomic unit than the other structures because the proportion of within-taxon to between-taxon variation was higher. Good phylogenetic signal in quantitative skeletal morphology is likely to be found only when the taxa have a common ancestry no older than hundreds of thousands or millions of years (1% to 10% mtDNA divergence)--under these conditions skulls and molars provide stronger signal than mandibles.

  20. The geometry of the marmot (rodentia: sciuridae) mandible: phylogeny and patterns of morphological evolution.

    PubMed

    Cardini, Andrea

    2003-04-01

    Marmots have a prominent role in the study of mammalian social evolution, but only recently has their systematics received the attention it deserves if sociobiological studies are to be placed in a phylogenetic context. Sciurid morphology can be used as model to test the congruence between morphological change and phylogeny because sciurid skeletal characters are considered to be inclined to convergence. However, no morphological study involving all marmot species has ever been undertaken. Geometric morphometric techniques were applied in a comparative study of the marmot mandible. The adults of all 14 living marmot species were compared, and mean mandible shape were used to investigate morphological evolution in the genus Marmota. Three major trends were observed. First, the phylogenetic signal in the variation of landmark geometry, which describes mandible morphology, seems to account for the shape differences at intermediate taxonomic levels. The subgenera Marmota and Petromarmota, recently proposed on the basis of mitochondrial cytochrome b sequence, receive support from mandible morphology. When other sciurid genera were included in the analysis, the monophyly of the genus Marmota and that of the tribe Marmotini (i.e., marmots, prairie dogs, and ground squirrels) was strengthened by the morphological data. Second, the marmotine mandible may have evolved as a mosaic of characters and does not show convergence determined by size similarities. Third, allopatric speciation in peripheral isolates may have acted as a powerful force for modeling shape. This hypothesis is strongly supported by the peculiar mandible of M. vancouverensis and, to a lesser degree, by that of M. olympus, both thought to have originated as isolated populations in Pleistocene ice-free refugia.

  1. [The influence of amplitude modulation on the structure of call spectrum in marmots (Marmota, rodentia, sciuridae)].

    PubMed

    Nikol'skiĭ, A A

    2007-01-01

    A relationship was established between the amplitude modulation and the structure of call spectrum in animals by the example of alarm call in three marmots (Marmota sibirica, M. menzbieri, and M. caudata). In the case of amplitude modulation, side frequencies are produced higher and lower than the carrier frequencies. In the absence of amplitude modulation, no side frequencies are produced.

  2. Rattus norvegicus (Rodentia: Muridae) Infected by Leishmania (Leishmania) infantum (syn. Le. chagasi) in Brazil.

    PubMed

    Lara-Silva, Fabiana de Oliveira; Barata, Ricardo Andrade; Michalsky, Erika Monteiro; Ferreira, Eduardo de Castro; Lopes, Maria Olímpia Garcia; Pinheiro, Aimara da Costa; Fortes-Dias, Consuelo Latorre; Dias, Edelberto Santos

    2014-01-01

    In the present study we surveyed the fauna of phlebotomine sand flies and small mammals in peridomestic areas from a Brazilian municipality where the American cutaneous leishmaniasis (ACL) is endemic. A total of 608 female phlebotomine sand flies were captured during nine months in 2009 and 2010. Seven different species were represented with 60% of them being Lutzomyia intermedia and Lu. whitmani, both incriminated vectors of ACL. Lu. longipalpis, a proven vector of visceral leishmaniasis (VL) was also captured at high proportion (12.8%). Genomic DNA analysis of 136 species-specific pools of female sand flies followed by molecular genotyping showed the presence of Leishmania infantum DNA in two pools of Lu. longipalpis. The same Leishmania species was found in one blood sample from Rattus norvegicus among 119 blood and tissue samples analysed. This is the first report of Le. infantum in R. norvegicus in the Americas and suggests a possible role for this rodent species in the zoonotic cycle of VL. Our study coincided with the reemergence of VL in Governador Valadares.

  3. Field evaluation of some bait additives against Indian crested porcupine (Hystrix indica) (Rodentia: Hystricidae).

    PubMed

    Mushtaq, Muhammad; Hussain, Iftikhar; Mian, Afsar; Munir, Shahid; Ahmed, Irfan; Khan, Abdul Aziz

    2013-09-01

    This research study evaluated the effect of different additives on the bait consumption by Indian crested porcupine, a serious forest and agricultural pest, under field conditions. Different additives (saccharin, common salt, bone meal, fish meal, peanut butter, egg yolk, egg shell powder, yeast powder, mineral oil and coconut oil) at 2 and 5% each were tested for their relative preference, using groundnut-maize (1:1) as basic bait. All the additives were tested under a no-choice test pattern. For control tests, no additive was mixed with the basic bait. Saccharin at 5% concentration significantly enhanced the consumption of bait over the basic bait, while 2% saccharin supplemented bait resulted in a non-significant bait consumption. All other additives did not enhance the consumption of the bait material; rather, these worked as repellents. However, the repellency was lowest with the common salt, followed by egg yolk, egg shell powder, bone meal, peanut butter, mineral oil, fish meal and yeast powder, while coconut remained the most repellent compound. The present study suggested that groundnut-maize (1:1) supplemented with 5% saccharin was the preferred bait combination, and can be used with different rodenticides for the management of Indian crested porcupine. PMID:24020467

  4. On the Indian crested porcupine, Hystrix indica (Kerr, 1792) in Turkey (Mammalia: Rodentia).

    PubMed

    Arslan, Atilla

    2008-01-15

    This study presents some data about ecological, biological and taxonomical characteristics of Hystrix indica (Kerr, 1792) from Turkey. For this purpose characteristics of burrow, skull, tooth and measurements of external and cranial characters of two female H. indica from Turkey were investigated. It was concluded that our specimens are between the Middle East and Indian sub-region specimens in terms of morphometrical. It was also determined that there were roots in stomach contents of specimens. PMID:18817213

  5. Two new species of fossil Leggadina (Rodentia: Muridae) from Northwestern Queensland

    PubMed Central

    Godthelp, Henk

    2015-01-01

    Only three species of fossil murine have been described to date in Australia even though they are often found in fossil deposits and can be highly useful in understanding environmental change over time. Until now the genus Leggadina, a group of short-tailed mice that is particularly well adapted to an arid environment, was only known from two extant species: L. forresti and L. lakedownensis. Here two new fossil species of the genus are described from sites in northwestern Queensland. Leggadina gregoriensis sp. nov. comes from the Early Pleistocene Rackham’s Roost Site in the Riversleigh World Heritage Area and Leggadina macrodonta sp. nov. is from the Plio-Pleistocene Site 5C at Floraville Station. The evolution of the genus Leggadina and the lineage’s response to palaeoecological factors is considered. Taphonomy of the two fossil deposits is examined and shows marked differences in both faunal composition of the assemblages and preservation. Description of L. gregoriensis and L. macrodonta extends the known temporal range of the Leggadina lineage by over 2 million years. PMID:26207193

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

    PubMed

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

    2009-04-01

    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.

  7. Taxonomic hypotheses regarding the genus Gerbillus (Rodentia, Muridae, Gerbillinae) based on molecular analyses of museum specimens

    PubMed Central

    Ndiaye, Arame; Tatard, Caroline; Stanley, William; Granjon, Laurent

    2016-01-01

    Abstract Methodological improvements now allow routine analyses of highly degraded DNA samples as found in museum specimens. Using these methods could be useful in studying such groups as rodents of the genus Gerbillus for which i) the taxonomy is still highly debated, ii) collection of fresh specimens may prove difficult. Here we address precise taxonomic questions using a small portion of the cytochrome b gene obtained from 45 dry skin/skull museum samples (from 1913 to 1974) originating from two African and three Asian countries. The specimens were labelled Gerbillus gerbillus, Gerbillus andersoni, Gerbillus nanus, Gerbillus amoenus, Gerbillus perpallidus and Gerbillus pyramidum, and molecular results mostly confirmed these assignations. The close relationship between Gerbillus nanus (Asian origin) and Gerbillus amoenus (African origin) confirmed that they represent vicariant sibling species which differentiated in allopatry on either side of the Red Sea. In the closely related Gerbillus perpallidus and Gerbillus pyramidum, specimens considered as belonging to one Gerbillus pyramidum subspecies (Gerbillus pyramidum floweri) appeared closer to Gerbillus perpallidus suggesting that they (Gerbillus pyramidum floweri and Gerbillus perpallidus) may represent a unique species, distributed on both sides of the Nile River, for which the correct name should be Gerbillus floweri. Furthermore, the three other Gerbillus pyramidum subspecies grouped together with no apparent genetic structure suggesting that they may not yet represent genetically differentiated lineages. This study confirms the importance of using these methods on museum samples, which can open new perspectives in this particular group as well as in other groups of interest. PMID:27047247

  8. Digital dissection of the masticatory muscles of the naked mole-rat, Heterocephalus glaber (Mammalia, Rodentia)

    PubMed Central

    Faulkes, Chris G.

    2014-01-01

    The naked mole-rat, Heterocephalus glaber, of the family Bathyergidae is a subterranean rodent that feeds on underground roots and tubers and digs extensive tunnel systems with its incisors. It is a highly unusual mammal with regard to its social structure, longevity, pain insensitivity and cancer resistance, all of which have made it the subject of a great deal of research in recent years. Yet, much of the basic anatomy of this species remains undocumented. In this paper, we describe the morphology of the jaw-closing musculature of the naked mole-rat, as revealed by contrast-enhanced micro-computed tomography. This technique uses an iodine stain to enable the imaging of soft tissues with microCT. The iodine-enhanced scans were used to create 3D reconstructions of the naked mole-rat masticatory muscles from which muscle masses were calculated. The jaw-closing musculature of Heterocephalus glaber is relatively very large compared to other rodents and is dominated by the superficial masseter, the deep masseter and the temporalis. The temporalis in particular is large for a rodent, covering the entirety of the braincase and much of the rear part of the orbit. The morphology of the masseter complex described here differs from two other published descriptions of bathyergid masticatory muscles, but is more similar to the arrangement seen in other rodent families. The zygomaticomandibularis (ZM) muscle does not protrude through the infraorbital foramen on to the rostrum and thus the naked mole-rat should be considered protrogomorphous rather than hystricomorphous, and the morphology is consistent with secondarily lost hystricomorphy as has been previously suggested for Bathyergidae. Overall, the morphology of the masticatory musculature indicates a species with a high bite force and a wide gape–both important adaptations for a life dominated by digging with the incisors. PMID:25024917

  9. [Ectoparasites of the zokor Myospalax myospalax (Rodentia) in northern Altaĭ].

    PubMed

    Litvinov, Iu N; Sapegina, V F

    2003-01-01

    Following ectoparasites have been recorded on the zokor in the Northern Altay: specific fleas--Ctenophthalmus dilatatus, Rhadinopsylla ioffi, Brachyctenonotus myospalacis; a flea distributed on various rodents; ixodid ticks--Ixodes crenulatus, I. persulcatus; gamasid mites--Hirstionyssus myosplalacis. The C. dilatatus carried hypopi of acaroid mites.

  10. The comparative gastrointestinal morphology of Jaculus jaculus (Rodentia) and Paraechinus aethiopicus (Erinaceomorpha).

    PubMed

    Pereira, Daniella L; Walters, Jacklynn; Bennett, Nigel C; Alagaili, Abdulaziz N; Mohammed, Osama B; Kotzé, Sanet H

    2016-05-01

    Jaculus jaculus (Lesser Egyptian jerboa) and Paraechinus aethiopicus (Desert hedgehog) are small mammals which thrive in desert conditions and are found, among others, in the Arabian Peninsula. Jaculus jaculus is omnivorous while P. aethiopicus is described as being insectivorous. The study aims to describe the gastrointestinal tract (GIT) morphology of these animals which differ in diet and phylogeny. The GITs of J. jaculus (n = 8) and P. aethiopicus (n = 7) were weighed, photographed, and the length, basal surface areas, and luminal surface areas of each of the anatomically distinct gastrointestinal segments were determined. The internal aspects of each area were examined and photographed while representative histological sections of each area were processed to wax and stained using haematoxylin and eosin. Both species had a simple unilocular stomach which was confirmed as wholly glandular on histology sections. Paraechinus aethiopicus had a relatively simple GIT which lacked a caecum. The caecum of J. jaculus was elongated, terminating in a narrow cecal appendix which contained lymphoid tissue on histological examination. The internal aspect of the proximal colon of J. jaculus revealed distinct V-shaped folds. Stomach content analysis of J. jaculus revealed mostly plant and seed material and some insects, whereas P. aethiopicus samples showed plant material in addition to insects, indicating omnivorous feeding tendencies in areas where insects may be scarce.

  11. First Miocene rodent from Lebanon provides the 'missing link' between Asian and African gundis (Rodentia: Ctenodactylidae)

    PubMed Central

    López-Antoñanzas, Raquel; Knoll, Fabien; Maksoud, Sibelle; Azar, Dany

    2015-01-01

    Ctenodactylinae (gundis) is a clade of rodents that experienced, in Miocene time, their greatest diversification and widest distribution. They expanded from the Far East, their area of origin, to Africa, which they entered from what would become the Arabian Peninsula. Questions concerning the origin of African Ctenodactylinae persist essentially because of a poor fossil record from the Miocene of Afro-Arabia. However, recent excavations in the Late Miocene of Lebanon have yielded a key taxon for our understanding of these issues. Proafricanomys libanensis nov. gen. nov. sp. shares a variety of dental characters with both the most primitive and derived members of the subfamily. A cladistic analysis demonstrates that this species is the sister taxon to a clade encompassing all but one of the African ctenodactylines, plus a southern European species of obvious African extraction. As such, Proafricanomys provides the 'missing link' between the Asian and African gundis. PMID:26250050

  12. Microsatellites indicate a high frequency of multiple paternity in Apodemus (Rodentia).

    PubMed

    Baker, R J; Makova, K D; Chesser, R K

    1999-01-01

    Microsatellites were employed to estimate frequency of multiple paternity litters of two species of mice (genus Apodemus): striped field mouse (A. agrarius), and wood mouse (A. sylvaticus). Ten pregnant females of A. agrarius and six of A. sylvaticus were collected from natural populations in the northern Ukraine and analysed with 11 and nine microsatellite loci, respectively. Multiple paternity was indicated in eight of 10 litters in A. agrarius and in three of six litters in A. sylvaticus. Multiple paternity was documented at several loci (ranging from two to 10). In two cases (A. agrarius), three males were estimated to have fathered the litter. PMID:12187947

  13. Mandible shape and dwarfism in squirrels (Mammalia, Rodentia): interaction of allometry and adaptation

    NASA Astrophysics Data System (ADS)

    Hautier, Lionel; Fabre, Pierre-Henri; Michaux, Jacques

    2009-06-01

    Squirrels include several independent lineages of dwarf forms distributed into two ecological groups: the dwarf tree and flying squirrels. The mandible of dwarf tree squirrels share a highly reduced coronoid process and a condylar process drawn backwards. Dwarf flying squirrels on the other hand, have an elongated coronoid process and a well-differentiated condylar process. To interpret such a difference, Elliptic Fourier Transform was used to evaluate how mandible shape varies with dwarfism in sciurids. The results obtained show that this clear-cut difference cannot be explained by a simple allometric relationship in relation with size decrease. We concluded that the retention of anteriorly positioned eye sockets, in relation with distance estimation, allowed the conservation of a well-differentiated coronoid process in all flying species, despite the trend towards its reduction observed among sciurids as their size decreases.

  14. Distinct Leishmania Species Infecting Wild Caviomorph Rodents (Rodentia: Hystricognathi) from Brazil

    PubMed Central

    Cássia-Pires, Renata; Boité, Mariana C.; D'Andrea, Paulo S.; Herrera, Heitor M.; Cupolillo, Elisa; Jansen, Ana Maria; Roque, André Luiz R.

    2014-01-01

    Background Caviomorph rodents, some of the oldest Leishmania spp. hosts, are widely dispersed in Brazil. Despite both experimental and field studies having suggested that these rodents are potential reservoirs of Leishmania parasites, not more than 88 specimens were analyzed in the few studies of natural infection. Our hypothesis was that caviomorph rodents are inserted in the transmission cycles of Leishmania in different regions, more so than is currently recognized. Methodology We investigated the Leishmania infection in spleen fragments of 373 caviomorph rodents from 20 different species collected in five Brazilian biomes in a period of 13 years. PCR reactions targeting kDNA of Leishmania sp. were used to diagnose infection, while Leishmania species identification was performed by DNA sequencing of the amplified products obtained in the HSP70 (234) targeting. Serology by IFAT was performed on the available serum of these rodents. Principal findings In 13 caviomorph rodents, DNA sequencing analyses allowed the identification of 4 species of the subgenus L. (Viannia): L. shawi, L. guyanensis, L. naiffi, and L. braziliensis; and 1 species of the subgenus L. (Leishmania): L. infantum. These include the description of parasite species in areas not previously included in their known distribution: L. shawi in Thrichomys inermis from Northeastern Brazil and L. naiffi in T. fosteri from Western Brazil. From the four other positive rodents, two were positive for HSP70 (234) targeting but did not generate sequences that enabled the species identification, and another two were positive only in kDNA targeting. Conclusions/Significance The infection rate demonstrated by the serology (51.3%) points out that the natural Leishmania infection in caviomorph rodents is much higher than that observed in the molecular diagnosis (4.6%), highlighting that, in terms of the host species responsible for maintaining Leishmania species in the wild, our current knowledge represents only the “tip of the iceberg.” PMID:25503973

  15. Bony labyrinth morphometry indicates locomotor adaptations in the squirrel-related clade (Rodentia, Mammalia)

    PubMed Central

    Pfaff, Cathrin; Martin, Thomas; Ruf, Irina

    2015-01-01

    The semicircular canals (SCs) of the inner ear detect angular acceleration and are located in the bony labyrinth of the petrosal bone. Based on high-resolution computed tomography, we created a size-independent database of the bony labyrinth of 50 mammalian species especially rodents of the squirrel-related clade comprising taxa with fossorial, arboreal and gliding adaptations. Our sampling also includes gliding marsupials, actively flying bats, the arboreal tree shrew and subterranean species. The morphometric anatomy of the SCs was correlated to the locomotion mode. Even if the phylogenetic signal cannot entirely be excluded, the main significance for functional morphological studies has been found in the diameter of the SCs, whereas the radius of curvature is of minor interest. Additionally, we found clear differences in the bias angle of the canals between subterranean and gliding taxa, but also between sciurids and glirids. The sensitivity of the inner ear correlates with the locomotion mode, with a higher sensitivity of the SCs in fossorial species than in flying taxa. We conclude that the inner ear of flying and gliding mammals is less sensitive due to the large information flow into this sense organ during locomotion. PMID:26019162

  16. Sequencing and analysis of complete mitochondrial genome of Apodemus draco (Rodentia: Arvicolinae).

    PubMed

    Wei, Haixue; Jia, Qiang; Li, Fengjun; Liu, Yongcheng; Chen, Shunde; Yong, Bin

    2016-07-01

    The genus Apodemus are the most common small rodents in fields. They are also one of the best species for biogeographic study and understanding the environmental changes. In this study, the complete mitochondrial genome sequence of Apodemus draco is determined. The mitogenome is 16 220 bp in length and contains 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a control region, with a base composition of 35.1% A, 29.0% T, 23.8% C and 12.1% G. The nucleotide sequence data of 12 heavy-strand protein-coding genes of Apodemus draco and other 23 rodents were used for mitochondrial genome phylogenetic analyses. The monophyly of the genus Apodemus was well supported with sister to the genus Mus. Bayesian analysis also suggested that Apodemus draco was a sister to Apodemus latronum. The present study may facilitate further investigation of the molecular evolution and biogeographic study of the genus Apodemus.

  17. [Meiosis in gray voles of the subgenus microtus (rodentia, arvicolinae) and in their hybrids].

    PubMed

    Safronova, L D; Golenishchev, F N; Cherepanova, E V; Baskevich, M I

    2011-07-01

    The results of light and electron microscopic (EM) studies of meiosis in Microtus arvalis males of the karyoform "arvalis" (2n = 46, NFa = 80), in hybrids between the chromosomal forms arvalis and obscurus (2n = 46, NFa = 68), in M. rossiaemeridionalis voles (2n = 54, NFa = 54), and in a hybrid between the species M. rossiaemeridionalis and M. kermanensis (2n = 54, NFa = 54) are presented. SC (synaptonemal complex) karyotypes of the parental forms and the hybrids were constructed on the basis of measurements of the length ofautosomal SCs revealed by the EM analysis in spermatocytes at the stage of middle pachytene. The SC karyotypes of M. arvalis and the hybrids female obscurus x male arvalis consist of 22 synaptonemal complexes of autosomal bivalents and the axial elements of the synaptonemal complexes of the sex chromosomes X and Y. The SC karyotypes of M. rossiaemeridionalis and the hybrid M. rossiaemeridionalis x M. kermanensis consist of 26 synaptonemal complexes of autosomal bivalents and a sex bivalent; they differ only in the length of the Y chromosome axis (Y chromosome in the hybrid was inherited from M. kermanensis). Asynaptic configurations of the autosomal SCs were not observed in the hybrids. The SC axial elements of the X and Y chromosomes in the parental forms and in the hybrids were located close to each other throughout pachytene, but they did not form a synaptic region. The normal synapsis in sterile hybrids (M. rossiaemeridionalis x M. kermanensis) and the behavior of the sex chromosomes in meiosis in fertile and sterile hybrids are discussed in the context of specific features of meiosis and reproductive isolation.

  18. Complete mitochondrial genome of the Père David's Vole, Eothenomys melanogaster (Rodentia: Arvicolinae).

    PubMed

    Chen, Shunde; Chen, Guiying; Wei, Haixue; Wang, Qiong

    2016-07-01

    The Père David's Vole, Eothenomys melanogaster belongs to subfamily Arvicolinae. It is widespread in south China, and ranges into northern Southeast Asia. In this study, the complete mitochondrial genome sequence of Eothenomys melanogaster was determined. The mitogenome is 16,331 base pairs in length. The nucleotide sequence data of 12 heavy-strand protein-coding genes of E. melanogaster and other 17 rodents were used for phylogenetic analyses. Tree constructed using Bayesian phylogenetic methods demonstrated that E. melanogaster as a sister to E. chinensis, was clustered in subfamily Arvicolinae. The monophyly of the genus Eothenomys was supported as well with Eothenomys sister to the genus Myodes.

  19. Multilocus systematics and non-punctuated evolution of Holarctic Myodini (Rodentia: Arvicolinae).

    PubMed

    Kohli, Brooks A; Speer, Kelly A; Kilpatrick, C William; Batsaikhan, Nyamsuren; Damdinbazar, Darmaa; Damdinbaza, Darmaa; Cook, Joseph A

    2014-07-01

    The tribe Myodini consists of five genera of forest and alpine voles (Alticola, Caryomys, Eothenomys, Hyperacrius and Myodes) distributed throughout the Holarctic. Because mitochondrial evidence has revealed paraphyly and polyphyly among genera, we apply the first multilocus tests to clarify taxonomy and phylogenetic relationships. Our analyses of 28 of 36 species within Myodini, including three not previously sequenced (A. montosa, A. albicaudus, and H. fertilis), identify four distinct clades and provide the first molecular evidence that Hyperacrius may not belong in Myodini. Myodes is paraphyletic, while polyphyly of Alticola reflects apparent ancient mitochondrial introgression. Diversification in this tribe was hypothesized to be tightly linked to Late Cenozoic climatic events, however, lineage through time analysis indicates diversification over the last 4 My was gradual and not strongly punctuated.

  20. Phylogeny of Oriental voles (Rodentia: Muridae: Arvicolinae): molecular and morphological evidence.

    PubMed

    Liu, Shaoying; Liu, Yang; Guo, Peng; Sun, Zhiyu; Murphy, Robert W; Fan, Zhenxin; Fu, Jianrong; Zhang, Yaping

    2012-09-01

    The systematics of Oriental voles remains controversial despite numerous previous studies. In this study, we explore the systematics of all species of Oriental voles, except Eothenomys wardi, using a combination of DNA sequences and morphological data. Our molecular phylogeny, based on two mitochondrial genes (COI and cyt b), resolves the Oriental voles as a monophyletic group with strong support. Four distinct lineages are resolved: Eothenomys, Anteliomys, Caryomys, and the new subgenus Ermites. Based on morphology, we consider Caryomys and Eothenomys to be valid genera. Eothenomys, Anteliomys, and Ermites are subgenera of Eothenomys. The molecular phylogeny resolves subgenera Anteliomys and Ermites as sister taxa. Subgenus Eothenomys is sister to the clade Anteliomys + Ermites. Caryomys is the sister group to genus Eothenomys. Further, the subspecies E. custos hintoni and E. chinensis tarquinius do not cluster with E. custos custos and E. chinensis chinensis, respectively, and the former two taxa are elevated to species level and assigned to the new subgenus Ermites.

  1. The complete mitochondrial genome of the bank vole Clethrionomys glareolus (Rodentia: Arvicolinae).

    PubMed

    Bendová, Karolína; Marková, Silvia; Searle, Jeremy B; Kotlík, Petr

    2016-01-01

    We present the first complete sequence of the bank vole (Clethrionomys glareolus) mitochondrial genome (GenBank accession no. KF918859). The bank vole mitogenome is 16,353 base pairs long and shows the gene content, genome architecture and gene strand asymmetry typical for mammals. The sequence provides an important new genomic resource for the bank vole, which is a popular study species in ecological and evolutionary research.

  2. Complete mitochondrial genome of the Chinese oriental vole Eothenomys chinensis (Rodentia: Arvicolinae).

    PubMed

    Yang, Chengzhong; Hao, Haibang; Liu, Shaoying; Liu, Yang; Yue, Bisong; Zhang, Xiuyue

    2012-04-01

    The Chinese oriental vole (Eothenomys chinensis) belongs to subfamily Arvicolinae, which is endemic to the mountains in southwest China. E. chinensis and other Arvicoline species display a number of features that make them ideal for evolutionary studies of speciation and the role of Quaternary glacial cycles on diversification. In this study, the complete mitochondrial genome of E. chinensis was sequenced. It was determined to be 16,362 bases. The nucleotide sequence data of 12 heavy-strand protein-coding genes of E. chinensis and other 19 rodents were used for phylogenetic analyses. Trees constructed using three different phylogenetic methods (Bayesian, maximum parsimony, and maximum likelihood) showed a similar topology demonstrating that E. chinensis was clustered in subfamily arvicolinae--formed a solid monophyletic group being sister to the subfamily Cricetinae. And the trees also suggested that E. chinensis is a sister to the genus Microtus and Proedromys.

  3. Clues on Syntenic Relationship among Some Species of Oryzomyini and Akodontini Tribes (Rodentia: Sigmodontinae)

    PubMed Central

    Suárez, Pablo; Nagamachi, Cleusa Yoshiko; Lanzone, Cecilia; Malleret, Matias Maximiliano; O’Brien, Patricia Caroline Mary; Ferguson-Smith, Malcolm Andrew; Pieczarka, Julio Cesar

    2015-01-01

    Sigmodontinae rodents represent one of the most diverse and complex components of the mammalian fauna of South America. Among them most species belongs to Oryzomyini and Akodontini tribes. The highly specific diversification observed in both tribes is characterized by diploid complements, which vary from 2n = 10 to 86. Given this diversity, a consistent hypothesis about the origin and evolution of chromosomes depends on the correct establishment of synteny analyzed in a suitable phylogenetic framework. The chromosome painting technique has been particularly useful for identifying chromosomal synteny. In order to extend our knowledge of the homeological relationships between Akodontini and Oryzomyini species, we analyzed the species Akodon montensis (2n = 24) and Thaptomys nigrita (2n = 52) both from the tribe Akodontini, with chromosome probes of Hylaeamys megacephalus (2n = 54) of the tribe Oryzomyini. The results indicate that at least 12 of the 26 autosomes of H. megacephalus show conserved synteny in A. montensis and 14 in T. nigrita. The karyotype of Akodon montensis, as well as some species of the Akodon cursor species group, results from many chromosomal fusions and therefore the syntenic associations observed probably represent synapomorphies. Our finding of a set of such associations revealed by H. megacephalus chromosome probes (6/21; 3/25; 11/16/17; and, 14/19) provides phylogenetic information for both tribes. An extension of these observations to other members of Akodontini and Oryzomyini tribes should improve our knowledge about chromosome evolution in both these groups. PMID:26642204

  4. Sequence and phylogenetic analysis of the complete mitochondrial genome of Lasiopodomys mandarinus mandarinus (Arvicolinae, Rodentia).

    PubMed

    Li, Yangwei; Shi, Yuhua; Lu, Jiqi; Ji, Weihong; Wang, Zhenlong

    2016-11-30

    Mandarin vole (Lasiopodomys mandarinus) is a subterranean rodent that is often used as a model for studying subterranean hypoxic stress in mammals. However the taxonomy of this species is still in dispute. Mitochondrial DNA (mtDNA) has long been used for phylogenetic reconstruction and, in this study, the complete mitochondrial genome of L. mandarinus mandarinus was sequenced. Our results showed that the mitochondrial genome of L. m. mandarinus is a circular molecule of 16,367bp, which contains 13 protein-coding genes, 22 tRNA and 2 rRNA genes. Except for the 8 tRNA and ND6 genes, all other mitochondrial genes are encoded on the heavy strand. We also analyzed the phylogenetic position of L. mandarinus in respect to the tribe Arvicolini using the sequence of complete Cytb gene, 2rRNA genes and 12 protein-coding genes, and maximum likelihood and Bayesian methods. Our results gave further support to the species status of L. mandarinus and the generic status of Lasiopodomys.

  5. Scaling and adaptations of incisors and cheek teeth in caviomorph rodents (Rodentia, Hystricognathi).

    PubMed

    Becerra, Federico; Vassallo, Aldo I; Echeverría, Alejandra I; Casinos, Adrià

    2012-10-01

    The South American hystricognath rodents are one of the most diverse mammalian clades considering their occupied habitats, locomotor modes and body sizes. This might have been partly evolved by diversification of their masticatory apparatus' structure and its ecological commitment, for example, chisel-tooth digging. In this phylogeny-based comparative study, we test the relationship between ecological behavior and mechanical features of their incisors and molariforms. In 33 species of nine families of caviomorph rodents, we analyze incisor attributes related to structural stress resistance and molar features related with grinding capacity, for example, second moment of inertia and enamel index (EI) (enamel band length/occlusal surface area), respectively. Most of these variables scaled isometrically to body mass, with a strong phylogenetic effect. A principal component analysis discrimination on the EI clustered the species according to their geographic distribution. We presume that selective pressures in Andean-Patagonian regions, on particular feeding habits and chisel-tooth digging behaviors, have modeled the morphological characteristics of the teeth. Subterranean/burrower ctenomyids, coruros, and plains viscachas showed the highest bending/torsion strength and anchorage values for incisors; a simplified enamel pattern in molariforms would be associated with a better grinding of the more abrasive vegetation present in more open and drier biomes. PMID:22730038

  6. Development of yolk sac inversion in Galea spixii and Cavia porcellus (Rodentia, Caviidae).

    PubMed

    de Oliveira, M F; do Vale, A M; Favaron, P O; Vasconcelos, B G; de Oliveira, G B; Miglino, M A; Mess, A

    2012-10-01

    Caviomorph development includes an inverted yolk sac. Since principle processes are not understood, we investigated its differentiation in Galea and re-examined material from the guinea pig. Galea showed the typical caviomorph conditions in blastocyst development and the nature of the definitive yolk sac, formed of the visceral layer that became villous, proliferative, vascularized and attached to the uterus and placenta. In contrast to what was known before, in both species parts of the parietal yolk sac and a yolk sac cavity were temporarily present. Data suggest that early yolk sac development in caviomorphs is more complex than thought before.

  7. Field evaluation of some bait additives against Indian crested porcupine (Hystrix indica) (Rodentia: Hystricidae).

    PubMed

    Mushtaq, Muhammad; Hussain, Iftikhar; Mian, Afsar; Munir, Shahid; Ahmed, Irfan; Khan, Abdul Aziz

    2013-09-01

    This research study evaluated the effect of different additives on the bait consumption by Indian crested porcupine, a serious forest and agricultural pest, under field conditions. Different additives (saccharin, common salt, bone meal, fish meal, peanut butter, egg yolk, egg shell powder, yeast powder, mineral oil and coconut oil) at 2 and 5% each were tested for their relative preference, using groundnut-maize (1:1) as basic bait. All the additives were tested under a no-choice test pattern. For control tests, no additive was mixed with the basic bait. Saccharin at 5% concentration significantly enhanced the consumption of bait over the basic bait, while 2% saccharin supplemented bait resulted in a non-significant bait consumption. All other additives did not enhance the consumption of the bait material; rather, these worked as repellents. However, the repellency was lowest with the common salt, followed by egg yolk, egg shell powder, bone meal, peanut butter, mineral oil, fish meal and yeast powder, while coconut remained the most repellent compound. The present study suggested that groundnut-maize (1:1) supplemented with 5% saccharin was the preferred bait combination, and can be used with different rodenticides for the management of Indian crested porcupine.

  8. Functional anatomy of the limbs of erethizontidae (Rodentia, Caviomorpha): Indicators of locomotor behavior in Miocene porcupines.

    PubMed

    Candela, Adriana M; Picasso, Mariana B J

    2008-05-01

    Functional analysis of the limb bones of the erethizontid Steiromys duplicatus, one of the most abundant Miocene porcupines from Patagonia, provides evidence to infer their locomotor behavior. Remains of the giant Neosteiromys pattoni (Late Miocene of Northeast Argentina) are also analyzed. Osteological and myological features of extant porcupines were evaluated and used as a model to interpret the functional significance of Miocene species' limbs. Several features in erethizontids are compatible with the ability to climb: the low humeral tuberosities indicate a mobile gleno-humeral joint; the prominent and distally extended deltopectoral crest indicates a powerful pectoral muscle, which is particularly active when climbing; the humero-ulnar and humero-radial joints are indicative of pronation-supination movements; the well-developed lateral epicondylar ridge and the medially protruding entepicondyle are in agreement with an important development of the brachioradialis, supinator, flexor digitorum profundus, and pronator teres muscles, acting in climbing and grasping functions; the mechanical advantage of the biceps brachii would be emphasized because of its distal attachment on the bicipital tuberosity. As with extant porcupines, in Miocene species, the large femoral head would have permitted a broad range of abduction of the femur, and the medially protruding lesser trochanter would have emphasized the abduction and outward rotation of the femur by the action of the ilio-psoas complex. In S. duplicatus, the shape of the hip, knee, and cruro-astragalar, calcaneo-astragalar, and astragalo-navicular joints would have allowed lateral and rotational movements, although probably to a lesser degree than in extant porcupines. Foot features of S. duplicatus (e.g., great medial sesamoid bone, medial astragalar head, complete hallux) indicate that this species would have had grasping ability, but would not have achieved the high degree of specialization of Coendou. Steiromys duplicatus would have been a semiarboreal dweller, resembling Erethizon dorsatum.

  9. Genetic diversity and population structure of the Guinea pig (Cavia porcellus, Rodentia, Caviidae) in Colombia

    PubMed Central

    Burgos-Paz, William; Cerón-Muñoz, Mario; Solarte-Portilla, Carlos

    2011-01-01

    The aim was to establish the genetic diversity and population structure of three guinea pig lines, from seven production zones located in Nariño, southwest Colombia. A total of 384 individuals were genotyped with six microsatellite markers. The measurement of intrapopulation diversity revealed allelic richness ranging from 3.0 to 6.56, and observed heterozygosity (Ho) from 0.33 to 0.60, with a deficit in heterozygous individuals. Although statistically significant (p < 0.05), genetic differentiation between population pairs was found to be low. Genetic distance, as well as clustering of guinea-pig lines and populations, coincided with the historical and geographical distribution of the populations. Likewise, high genetic identity between improved and native lines was established. An analysis of group probabilistic assignment revealed that each line should not be considered as a genetically homogeneous group. The findings corroborate the absorption of native genetic material into the improved line introduced into Colombia from Peru. It is necessary to establish conservation programs for native-line individuals in Nariño, and control genealogical and production records in order to reduce the inbreeding values in the populations. PMID:22215979

  10. Mitochondrial phylogeny of African wood mice, genus Hylomyscus (Rodentia, Muridae): implications for their taxonomy and biogeography.

    PubMed

    Nicolas, V; Quérouil, S; Verheyen, E; Verheyen, W; Mboumba, J F; Dillen, M; Colyn, M

    2006-03-01

    This paper investigates the usefulness of two mitochondrial genes (16S rRNA and cytochrome b) to solve taxonomical difficulties within the genus Hylomyscus and to infer its evolutionary history. Both genes proved to be suitable molecular markers for diagnosis of Hylomyscus species. Nevertheless the resolving powers of these two genes differ, and with both markers (either analyzed singly or in combination), some nodes remain unresolved. This is probably related to the fact that the species emerged during a rapid diversification event that occurred 2-6 Myr ago (4-5 Myr ago for most divergence events). Our molecular data support the recognition of an "aeta" group, while the "alleni" and "parvus" groups are not fully supported. Based on tree topology and genetic divergence, two taxa generally recognized as subspecies should be elevated at the species level (H. simus and H. cf kaimosae). H. stella populations exhibit ancient haplotype segregation that may represent currently unrecognized allopatric species. The existence of cryptic species within H. parvus is questioned. Finally, three potentially new species may occur in West Central Africa. The Congo and Oubangui Rivers, as well as the Volta and Niger Rivers and/or the Dahomey gap could have formed effective barriers to Hylomyscus species dispersal, favoring their speciation in allopatry. The pronounced shifts in African climate during the late Pliocene and Miocene, which resulted in major changes in the distribution and composition of the vegetation, could have promoted speciation within the genus (refuge theory). Future reports should focus on the geographic distribution of Hylomyscus species in order to get a better understanding of the evolutionary history of the genus. PMID:16414288

  11. Records of Coendou ichillus (Rodentia, Erethizontidae) from the Lower Urubamba Region of Peru

    PubMed Central

    Gregory, Tremaine; Lunde, Darrin; Zamora-Meza, Hugo Tomás; Carrasco-Rueda, Farah

    2015-01-01

    Abstract Coendou ichillus was first described in 2001 by Voss and da Silva, with a range from Amazonian Ecuador to Iquitos, Peru. Here, we describe an adult female Coendou ichillus specimen collected in a Tomahawk trap in the forest canopy of the Lower Urubamba Region of Peru in October 2013. We also describe pathologies and behaviors observed through 379 camera trapping photo events (2,196 photos) gathered in natural canopy bridges over the course of a year (7,198 trap nights), including information on activity period over the course of the day and over the course of the lunar cycle. We conservatively estimate that 17 individuals were photographed, including one juvenile. Being 900 km away from Iquitos, Peru (the site of the closest record), discovery of this species in the Lower Urubamba constitutes a significant range extension. PMID:26175605

  12. Ectoparasites of the critically endangered insular cavy, Cavia intermedia (Rodentia: Caviidae), southern Brazil

    PubMed Central

    Regolin, André Luis; Furnari, Nina; de Castro Jacinavicius, Fernando; Linardi, Pedro Marcos; de Carvalho-Pinto, Carlos José

    2015-01-01

    Cavia intermedia is a rodent species critically endangered and is found only on a 10 hectare island off the southern Brazilian coast. To identify the ectoparasites of C. intermedia, 27 specimens (14 males and 13 females), representing approximately 65% of the estimated total population, were captured and examined. A total of 1336 chewing lice of two species were collected: Gliricola lindolphoi (Amblycera: Gyropidae) and Trimenopon hispidum (Amblycera: Trimenoponidae). In addition, chiggers Arisocerus hertigi (Acari: Trombiculidae) and Eutrombicula sp. (Acari: Trombiculidae) were collected from the ears of all captured animals. This low species richness compared to those for other Cavia species is expected for island mammals. Although the results presented here are not conclusive about the relationship between C. intermedia and ectoparasites, this low species richness found might be reflected in a low level of investment by the hosts in the basal immune defense, since investments in white blood cell production by mammals are influenced by the diversity of parasites in the environment. Additionally, considering that it might result in host vulnerability to other parasites that might be introduced through exotic or migratory host species, the monitoring of C. intermedia, including parasitological and immunological assessments, is recommended as a key component of conservation efforts. PMID:25830106

  13. Nucleolus organizer regions and B-chromosomes of wood mice (mammalia, rodentia, Apodemus)

    SciTech Connect

    Boeskorov, G.G.; Kartavtseva, I.V.; Zagorodnyuk, I.V.; Belyanin, A.N.; Lyapunova, E.A.

    1995-02-01

    Distribution of nucleolus organizer regions (NORs) in karyotypes was studied in 10 species of wood mice, including Apodemus flavicollis, A. sylvaticus, A. uralensis (=A. microps), A. fulvipectus (=A. falzfeini), A. ponticus, A. hyrcanicus, A. mystacinus, A. agrarius, A. peninsulae, and A. speciosus. Peculiarities of NOR location in karyotypes can be used in interspecific diagnostics of wood mice. Intraspecific polymorphism of A. sylvaticus, A. agrarius, and A. peninsulae in terms of the number of NORs and their localization in chromosomes can serve as evidence for karyological differentiation in certain populations of these species. The minimum number of active NORs in mice of the genus Apodemus is two to four. Two A. flavicollis wood mice with karyotypes containing one small acrocentric B-chromosome (2n = 49) were identified among animals captured in Estonia. In A. peninsulae, B-chromosomes were found among animals captured in the following regions: the vicinity of Kyzyl (one mouse with 17 microchromosomes, 2n = 65); the vicinity of Birakan (two mice with one metacentric chromosome each, 2n = 49); and in the Ussuri Nature Reserve (one mouse with five B-chromosomes, including three metacentric and two dotlike chromosomes; 2n = 53). In the latter animal, the presence of NORs on two metacentric B-chromosomes was revealed; this is the first case of identification of active NORs on extra chromosomes of mammals. 29 refs., 4 figs., 1 tab.

  14. Taxonomic hypotheses regarding the genus Gerbillus (Rodentia, Muridae, Gerbillinae) based on molecular analyses of museum specimens.

    PubMed

    Ndiaye, Arame; Tatard, Caroline; Stanley, William; Granjon, Laurent

    2016-01-01

    Methodological improvements now allow routine analyses of highly degraded DNA samples as found in museum specimens. Using these methods could be useful in studying such groups as rodents of the genus Gerbillus for which i) the taxonomy is still highly debated, ii) collection of fresh specimens may prove difficult. Here we address precise taxonomic questions using a small portion of the cytochrome b gene obtained from 45 dry skin/skull museum samples (from 1913 to 1974) originating from two African and three Asian countries. The specimens were labelled Gerbillus gerbillus, Gerbillus andersoni, Gerbillus nanus, Gerbillus amoenus, Gerbillus perpallidus and Gerbillus pyramidum, and molecular results mostly confirmed these assignations. The close relationship between Gerbillus nanus (Asian origin) and Gerbillus amoenus (African origin) confirmed that they represent vicariant sibling species which differentiated in allopatry on either side of the Red Sea. In the closely related Gerbillus perpallidus and Gerbillus pyramidum, specimens considered as belonging to one Gerbillus pyramidum subspecies (Gerbillus pyramidum floweri) appeared closer to Gerbillus perpallidus suggesting that they (Gerbillus pyramidum floweri and Gerbillus perpallidus) may represent a unique species, distributed on both sides of the Nile River, for which the correct name should be Gerbillus floweri. Furthermore, the three other Gerbillus pyramidum subspecies grouped together with no apparent genetic structure suggesting that they may not yet represent genetically differentiated lineages. This study confirms the importance of using these methods on museum samples, which can open new perspectives in this particular group as well as in other groups of interest. PMID:27047247

  15. Mitochondrial phylogeny of African wood mice, genus Hylomyscus (Rodentia, Muridae): implications for their taxonomy and biogeography.

    PubMed

    Nicolas, V; Quérouil, S; Verheyen, E; Verheyen, W; Mboumba, J F; Dillen, M; Colyn, M

    2006-03-01

    This paper investigates the usefulness of two mitochondrial genes (16S rRNA and cytochrome b) to solve taxonomical difficulties within the genus Hylomyscus and to infer its evolutionary history. Both genes proved to be suitable molecular markers for diagnosis of Hylomyscus species. Nevertheless the resolving powers of these two genes differ, and with both markers (either analyzed singly or in combination), some nodes remain unresolved. This is probably related to the fact that the species emerged during a rapid diversification event that occurred 2-6 Myr ago (4-5 Myr ago for most divergence events). Our molecular data support the recognition of an "aeta" group, while the "alleni" and "parvus" groups are not fully supported. Based on tree topology and genetic divergence, two taxa generally recognized as subspecies should be elevated at the species level (H. simus and H. cf kaimosae). H. stella populations exhibit ancient haplotype segregation that may represent currently unrecognized allopatric species. The existence of cryptic species within H. parvus is questioned. Finally, three potentially new species may occur in West Central Africa. The Congo and Oubangui Rivers, as well as the Volta and Niger Rivers and/or the Dahomey gap could have formed effective barriers to Hylomyscus species dispersal, favoring their speciation in allopatry. The pronounced shifts in African climate during the late Pliocene and Miocene, which resulted in major changes in the distribution and composition of the vegetation, could have promoted speciation within the genus (refuge theory). Future reports should focus on the geographic distribution of Hylomyscus species in order to get a better understanding of the evolutionary history of the genus.

  16. Re-Evaluation of Sinocastor (Rodentia: Castoridae) with Implications on the Origin of Modern Beavers

    PubMed Central

    Rybczynski, Natalia; Ross, Elizabeth M.; Samuels, Joshua X.; Korth, William W.

    2010-01-01

    The extant beaver, Castor, has played an important role shaping landscapes and ecosystems in Eurasia and North America, yet the origins and early evolution of this lineage remain poorly understood. Here we use a geometric morphometric approach to help re-evaluate the phylogenetic affinities of a fossil skull from the Late Miocene of China. This specimen was originally considered Sinocastor, and later transferred to Castor. The aim of this study was to determine whether this form is an early member of Castor, or if it represents a lineage outside of Castor. The specimen was compared to 38 specimens of modern Castor (both C. canadensis and C. fiber) as well as fossil specimens of C. fiber (Pleistocene), C. californicus (Pliocene) and the early castorids Steneofiber eseri (early Miocene). The results show that the specimen falls outside the Castor morphospace and that compared to Castor, Sinocastor possesses a: 1) narrower post-orbital constriction, 2) anteroposteriorly shortened basioccipital depression, 3) shortened incisive foramen, 4) more posteriorly located palatine foramen, 5) longer rostrum, and 6) longer braincase. Also the specimen shows a much shallower basiocciptal depression than what is seen in living Castor, as well as prominently rooted molars. We conclude that Sinocastor is a valid genus. Given the prevalence of apparently primitive traits, Sinocastor might be a near relative of the lineage that gave rise to Castor, implying a possible Asiatic origin for Castor. PMID:21085579

  17. Late cenozoic history of the genus Micromys (mammalia, rodentia) in Central Europe.

    PubMed

    Horáček, Ivan; Knitlová, Markéta; Wagner, Jan; Kordos, László; Nadachowski, Adam

    2013-01-01

    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.

  18. Evaluation of squirrels (Rodentia: Sciuridae) as ecologically significant hosts for Anaplasma phagocytophilum in California.

    PubMed

    Nieto, Nathan C; Foley, Janet E

    2008-07-01

    Granulocytic anaplasmosis (GA), caused by Anaplasma phagocytophilum, is a potentially fatal, emerging rickettsial disease of humans, domestic animals, and wildlife. The purpose of this study was to determine whether sciurids from multiple areas of northern California were infested with ticks or exposed to or infected with A. phagocytophilum using polymerase chain reaction (PCR) and indirect-fluorescent antibody (IFA) serology. Sciurids of nine different tree- and ground-dwelling species were assessed: arboreal squirrels (western and eastern gray squirrels, Sciurus griseus and S. carolinensis, and Douglas squirrels, Tamiasciurus douglasii) but not northern flying squirrels (Glaucomys sabrinus) had greater evidence of exposure and current infection than did semiarboreal or ground dwelling sciurids (California ground squirrels, Spermophilus beecheyi, and chipmunks, Tamias spp.). Western gray squirrels had the most extensive exposure (70.7% seroprevalence and 12.1% PCR prevalence). Positive squirrels were identified in all regions where squirrels were collected. A logistic regression identified being a western gray squirrel (OR = 20.5, P = 2.95 X 10(-8)) and from the north coastal region of California (OR = 9.052, P = 1.41 X 10(-6)) as having the highest risk of exposure to A. phagocytophilum. Five of nine sciurid species had evidence of infestation with Ixodes pacificus or I. spinipalpis that could vector A. phagocytophilum. Extensive exposure from multiple areas suggests sciurids may be important in the maintenance of GA in California and indicates that studies of reservoir competence of these species are warranted. PMID:18714881

  19. Accelerated molecular evolution in Microtus (Rodentia) as assessed via complete mitochondrial genome sequences.

    PubMed

    Triant, Deborah A; Dewoody, J Andrew

    2006-01-01

    Microtus is one of the most taxonomically diverse mammalian genera, including over 60 extant species. These rodents have evolved rapidly, as the genus originated less than 2 million years ago. If these numbers are taken at face value, then an average of 30 microtine speciation events have occurred every million years. One explanation for the rapid rate of cladogenesis in Microtus could be the karyotypic differentiation exhibited across the genus: diploid numbers range from 17 to 64. Despite the striking chromosomal variability within Microtus, phenotypic variation is unremarkable. To determine whether nucleotide substitution rates are also elevated in voles, we sequenced the entire mitochondrial DNA (mtDNA) genome of the Eurasian sibling vole (Microtus rossiaemeridionalis). We compared this genome to another previously sequenced vole mtDNA genome (Microtus kikuchii) and performed pairwise sequence comparisons with the mtDNA genomes of ten additional mammalian genera. We found that microtine mtDNA genomes are evolving more rapidly than any other mammalian lineage we sampled, as gauged by the rate of nucleotide substitution across the entire mtDNA genome as well as at each individual protein-coding gene. Additionally, we compared substitution rates within the cytochrome b gene to seven other rodent genera and found that Microtus mtDNA is evolving fastest. The root cause of accelerated evolution in Microtus remains uncertain, but merits further investigation.

  20. Species groups in Proechimys (Rodentia: Echimyidae) as indicated by karyology and bullar morphology

    USGS Publications Warehouse

    Gardner, A.L.; Emmons, L.H.

    1984-01-01

    The genus Proechimys is divisible into four groups of species on the basis of bullar septal patterns. Each of the four groups can be further characterized by distinctive distributions and karyotypes. The subgenus Trinomys and the guatrae species group each are comprised of phylogenetically closely-related species. The semispinosus- and brevicauda-groups, although generally distinctive on the basis of bullar septa, are not phylogenetically equivalent to the first two groups. The brevicauda-group, for example, consists of at least three separate species complexes. The taxonomy used in this report reflects several nomenclatural changes from that used in the recent literature. In addition, previously unreported karyotypes are described for P. quadruplicatus, P. gularis, P. decumanus, P. oris, P. oconnelli, and P. mincae.

  1. A new species of sucking louse (Insecta, Anoplura) parasitic on Auliscomys (Mammalia, Rodentia) in Argentina.

    PubMed

    Castro, D D; Gonzalez, A; Dreon, M

    2001-04-01

    Hoplopleura auliscomydis n. sp. is described based on specimens collected from Auliscomys micropus (Waterhouse 1837), from Collń Curá, Neuquén Province, Argentina. Descriptions are provided for the holotype male, female, first nymphal instar, external architecture of eggs (by scanning electron microscopy), and sites of oviposition, providing differences from its close relative Hoplopleura neotomydis Castro, González, and Cicchino, 1995. The geographical ranges of these 2 species are restricted to the Neuquén Province in Argentina. A key to the 9 species of the Hoplopleura travassosi species-group recorded in Argentina is also given.

  2. Parasitism underground: lice (Insecta: Phthiraptera) from Ctenomys talarum (Rodentia: Ctenomyidae) along its coastal distribution in Argentina.

    PubMed

    Martino, Natalia S; Romero, Mariano D; Malizia, Ana I

    2014-03-01

    Species of South American subterranean rodents belonging to the genus Ctenomys (commonly called tuco-tucos) are widely distributed across the southern Neotropical region. Despite their relatively well-studied biology and reproductive physiology, current knowledge of their ectoparasite fauna is limited to a few ambiguous studies, based on scattered samples from a small number of host individuals. Ctenomys talarum is the most widely distributed species in the genus. Lice (Phthiraptera) were collected from these tuco-tucos throughout their entire coastal range. Two species, one chewing louse (Gyropus parvus), and one sucking louse (Eulinognathus americanus) were collected. The distribution ranges for both louse species were extended with new locality records. No lice were found in two host populations. Furthermore, co-occurrence of both ectoparasites was not detected.

  3. Functional anatomy of the limbs of erethizontidae (Rodentia, Caviomorpha): Indicators of locomotor behavior in Miocene porcupines.

    PubMed

    Candela, Adriana M; Picasso, Mariana B J

    2008-05-01

    Functional analysis of the limb bones of the erethizontid Steiromys duplicatus, one of the most abundant Miocene porcupines from Patagonia, provides evidence to infer their locomotor behavior. Remains of the giant Neosteiromys pattoni (Late Miocene of Northeast Argentina) are also analyzed. Osteological and myological features of extant porcupines were evaluated and used as a model to interpret the functional significance of Miocene species' limbs. Several features in erethizontids are compatible with the ability to climb: the low humeral tuberosities indicate a mobile gleno-humeral joint; the prominent and distally extended deltopectoral crest indicates a powerful pectoral muscle, which is particularly active when climbing; the humero-ulnar and humero-radial joints are indicative of pronation-supination movements; the well-developed lateral epicondylar ridge and the medially protruding entepicondyle are in agreement with an important development of the brachioradialis, supinator, flexor digitorum profundus, and pronator teres muscles, acting in climbing and grasping functions; the mechanical advantage of the biceps brachii would be emphasized because of its distal attachment on the bicipital tuberosity. As with extant porcupines, in Miocene species, the large femoral head would have permitted a broad range of abduction of the femur, and the medially protruding lesser trochanter would have emphasized the abduction and outward rotation of the femur by the action of the ilio-psoas complex. In S. duplicatus, the shape of the hip, knee, and cruro-astragalar, calcaneo-astragalar, and astragalo-navicular joints would have allowed lateral and rotational movements, although probably to a lesser degree than in extant porcupines. Foot features of S. duplicatus (e.g., great medial sesamoid bone, medial astragalar head, complete hallux) indicate that this species would have had grasping ability, but would not have achieved the high degree of specialization of Coendou. Steiromys duplicatus would have been a semiarboreal dweller, resembling Erethizon dorsatum. PMID:18157864

  4. Records of Coendouichillus (Rodentia, Erethizontidae) from the Lower Urubamba Region of Peru.

    PubMed

    Gregory, Tremaine; Lunde, Darrin; Zamora-Meza, Hugo Tomás; Carrasco-Rueda, Farah

    2015-01-01

    Coendouichillus was first described in 2001 by Voss and da Silva, with a range from Amazonian Ecuador to Iquitos, Peru. Here, we describe an adult female Coendouichillus specimen collected in a Tomahawk trap in the forest canopy of the Lower Urubamba Region of Peru in October 2013. We also describe pathologies and behaviors observed through 379 camera trapping photo events (2,196 photos) gathered in natural canopy bridges over the course of a year (7,198 trap nights), including information on activity period over the course of the day and over the course of the lunar cycle. We conservatively estimate that 17 individuals were photographed, including one juvenile. Being 900 km away from Iquitos, Peru (the site of the closest record), discovery of this species in the Lower Urubamba constitutes a significant range extension. PMID:26175605

  5. [Phylogeny of the order Rodentia inferred from structural analysis of short retrotransposon B1].

    PubMed

    Veniaminova, N A; Vasetskiĭ, N S; Lavrechenko, L A; Popov, S V; Kramerov, D A

    2007-07-01

    A large-scale study of short retroposon (SINE) B1 has been conducted in the genome of rodents from most of the known families of this mammalian order. The B1 nucleotide sequences of rodents from different families exhibited a number of characteristic features including substitutions, deletions, and tandem duplications. Comparing the distribution of these features among the rodent families, the currently discussed phylogenetic relationships were tested. The results of analysis indicated (1) an early divergence of Sciuridae and related families (Aplodontidae and Gliridae) from the other rodents; (2) a possible subsequent divergence of beavers (Castoridae); (3) a monophyletic origin of the group Hystricognathi, which includes several families, such as porcupines (Hystricidae) and guinea pigs (Caviidae); (4) a possible monophyletic origin of the group formed by the remaining families, including six families of mouselike rodents (Myodonta). Various approaches to the use of short retroposons for phylogenetic studies are discussed. PMID:17899810

  6. Late Cenozoic History of the Genus Micromys (Mammalia, Rodentia) in Central Europe

    PubMed Central

    Horáček, Ivan; Knitlová, Markéta; Wagner, Jan; Kordos, László; Nadachowski, Adam

    2013-01-01

    Molecular phylogeography suggests that Micromys minutus, the sole extant species of the genus, colonized its extensive range quite recently, during the Late Pleistocene-Holocene period. Rich Pliocene and Pleistocene fossil records both from Europe and China suggest rather continuous and gradual in situ phenotype rearrangements from the Pliocene to the Recent periods. To elucidate the discrepancy we reexamined a considerable part of the European fossil record of the genus (14 sites from MN15 to Q3, 0.4–4.2 Ma, including the type series of M. preaminutus from MN15 Csarnóta 2), analyzed them with the aid of detailed morphometric comparisons, and concluded that: (a) The European Pliocene form, M. praeminutus, differs significantly from the extant species; (b) it exhibits a broad phenotypic variation covering the presumptive diagnostic characters of MN16 M. caesaris; (c) despite having smaller dimensions, the Early and Middle Pleistocene forms (MN17-Q3, 2.6–0.4 Ma) seem to be closer to M. praeminutus than to the extant species; (d) the extinction of M. praeminutus during Q3 and the re-occupation of its niche by the recent expansion of M. minutus from E-European – C Asiatic sources (suggested by phylogeographic hypotheses) cannot be excluded. Discussing interpretations of the phylogenetic past of the genus we emphasize the distinct history of the West Palearctic clade (Late Miocene-Early Pleistocene) terminating with M. praeminutus and the East Asiatic clade (chalceus, tedfordi, minutus), and the possible identity of the Western clade with the Late Miocene genus Parapodemus. PMID:23671605

  7. Bots (Diptera: Oestridae) infesting a neotropical forest rodent, Proechimys semispinosus (Rodentia: Echimyidae), in Panama.

    PubMed

    Adler, Gregory H; Davis, Shannon L; Carvajal, Alejandra

    2003-08-01

    Botfly larvae (Cuterebra sp.) infesting spiny rats (Proechimys semispinosus) in 8 small islands in the Panama Canal were studied. Rats were live trapped monthly on each island from January 1991 through February 2000 and visually examined for the presence of bots. Overall, bot prevalence was 4.6% and differed statistically among island rat populations. Rats were simultaneously infested by as many as 4 bots. Overall bot intensity was 1.3 bots per infested rat and did not differ among islands. Mean bot density across all islands was 0.0111 and was greater during the dry seasons than during the rainy seasons, but it did not differ among islands. Bots were found during all the 12 calendar months, suggesting a multivoltine reproductive schedule. Although bot activity varied seasonally, there was little synchrony of bot activity among islands. Bot density was related negatively to rainfall but was not related to host density, suggesting that drier ambient conditions may promote reproduction by adult bot flies in this system. PMID:14533675

  8. Fleas (Siphonaptera) in the Nests of Dormice (Gliridae: Rodentia) in Lithuania.

    PubMed

    Lipatova, I; Stanko, M; Paulauskas, A; Spakovaite, S; Gedminas, V

    2015-05-01

    Negative effects of flea (Siphonaptera) parasitism on the host may be expressed in different ways. The aim of this study was to assess distribution of the flea fauna in nests of dormice in Lithuania. Nests of Glis glis (L.), Dryomys nitedula (Pallas), and Muscardinus avellanarius (L.) were collected from nest boxes in 2012 and 2013. Fleas were collected from nests in the laboratory and put into plastic tubes with 70% ethanol. Flea species were identified using morphological keys. From 400 nest boxes, 112 nests of dormice were collected from eight sites from mixed forests of central Lithuania. Twenty-three nests of G. glis were collected from nest boxes, with 16 of them containing 286 fleas belonging to four species: Ceratophyllus sciurorum (Schrank) (259), C. gallinae (Schrank) (23), Hystrichopsylla talpae (Curtis) (3), and Megabothris turbidus (Rothschild) (1). Fourteen nests of M. avellanarius were collected from nest boxes, 4 of which contained 224 fleas belonging to two species: C. sciurorum (221) and C. gallinae (3). Twenty-four nests of D. nitedula were collected from nest boxes, including 17 containing 207 fleas belonging to two species: C. sciurorum (205) and C. gallinae (2). Fifty-one nests of undetermined dormice species also were collected from nest boxes, 12 of them contained 395 fleas belonging to three species: C. sciurorum (374), Ctenophthalmus agyrtes (Heller) (19), and Ctenophthalmus assimilis (Taschenberg) (2). C. sciurorum was a predominant species in the nests of dormice. The occurrence of C. gallinae was documented in Lithuania for the first time.

  9. Molecular cytogenetics and allotetraploidy in the red vizcacha rat, Tympanoctomys barrerae (Rodentia, Octodontidae).

    PubMed

    Gallardo, M H; González, C A; Cebrián, I

    2006-08-01

    The theoretical impossibility of polyploidy in mammals was overturned by the discovery of tetraploidy in the red vizcacha rat, Tympanoctomys barrerae (2n = 102). As a consequence of genome duplication, remarkably increased cell dimensions are observed in the spermatozoa and in different somatic cell lines of this species. Locus duplication had been previously demonstrated by in situ PCR and Southern blot analysis of single-copy genes. Here, we corroborate duplication of loci in multiple-copy (major rDNAs) and single-copy (Hoxc8) genes by fluorescence in situ hybridization. We also demonstrate that nucleolar dominance, a large-scale epigenetic silencing phenomenon characteristic of allopolyploids, explains the presence of only one Ag-NOR chromosome pair in T. barrerae. Nucleolar dominance, together with the chromosomal heteromorphism detected in the G-banding pattern and synaptonemal complexes of the species' diploid-like meiosis, consistently indicates allotetraploidy. Allotetraploidization can coherently explain the peculiarities of gene silencing, cell dimensions, and karyotypic features of T. barrerae that remain unexplained by assuming diploidy and a large genome size attained by the dispersion of repetitive sequences. PMID:16580173

  10. DNA Profiling of B Chromosomes from the Yellow-necked Mouse Apodemus flavicollis (Rodentia, Mammalia)

    PubMed Central

    Tanić, Nikola; Dedović, Nasta; Vujos̆ević, Mladen; Dimitrijević, Bogomir

    2000-01-01

    Using AP-PCR-based DNA profiling we examined some structural features of B chromosomes from yellow-necked mice Apodemus flavicollis. Mice harboring one, two, or three or lacking B chromosomes were examined. Chromosomal structure was scanned for variant bands by using a series of arbitrary primers and from these, informative bands were selected. The selection criteria used were the ability to differentiate between individuals of the species, to detect markers common for both A and B chromosomes, and, importantly, to differentiate between A- and B-chromosome sets. In addition to primers, profiling conditions were found to be critical for meeting the selection criteria. Primers and analysis conditions that demonstrated structural characteristics unique to the B-chromosome set are described. These characteristics included variant bands as qualitative parameters and altered electrophoretic band intensities as quantitative distinctions estimated by integration of densitometric profiles of electrophoretograms. B chromosome-specific molecular markers are easy to detect by AP-PCR-based DNA profiling in the presence of a full set of A chromosomes. Models for the origin of yellow-necked mouse B chromosomes are discussed in the context of presented data. PMID:10645950

  11. Complete mitochondrial genome of the Père David's Vole, Eothenomys melanogaster (Rodentia: Arvicolinae).

    PubMed

    Chen, Shunde; Chen, Guiying; Wei, Haixue; Wang, Qiong

    2016-07-01

    The Père David's Vole, Eothenomys melanogaster belongs to subfamily Arvicolinae. It is widespread in south China, and ranges into northern Southeast Asia. In this study, the complete mitochondrial genome sequence of Eothenomys melanogaster was determined. The mitogenome is 16,331 base pairs in length. The nucleotide sequence data of 12 heavy-strand protein-coding genes of E. melanogaster and other 17 rodents were used for phylogenetic analyses. Tree constructed using Bayesian phylogenetic methods demonstrated that E. melanogaster as a sister to E. chinensis, was clustered in subfamily Arvicolinae. The monophyly of the genus Eothenomys was supported as well with Eothenomys sister to the genus Myodes. PMID:26024146

  12. Ecology of the interaction between Ixodes loricatus (Acari: Ixodidae) and Akodon azarae (Rodentia: Criceridae).

    PubMed

    Colombo, Valeria C; Nava, Santiago; Antoniazzi, Leandro R; Monje, Lucas D; Racca, Andrea L; Guglielmone, Alberto A; Beldomenico, Pablo M

    2015-10-01

    The present study explores associations of different factors (i.e. host parameters, presence of other ectoparasites and [mainly biotic] environmental factors) with burdens of Ixodes loricatus immature stages in one of its main hosts in Argentina, the rodent Akodon azarae. For 2 years, rodents were trapped and sampled monthly at 16 points located in four different sites in the Parana River Delta region. Data were analysed with generalized linear mixed models with a negative binomial response (counts of larvae or nymphs). The independent variables assessed were (a) environmental: trapping year, presence of cattle, type of vegetation, rodent abundance; (b) host parameters: body length, sex, body condition, blood cell counts, natural antibody titers and (c) co-infestation with other ectoparasites. Two-way interaction terms deemed a priori as relevant were also included in the analysis. Most of the associations investigated were found significant, but in general, the direction and magnitude of the associations were context-dependent. An exception was the presence of cattle, which was consistently negatively associated with both larvae and nymphs independently of all other variables considered and had the strongest effect on tick burdens. Mites, fleas and Amblyomma triste were also significantly associated (mostly positively) with larval and nymph burdens, and in many cases, they influenced associations with environmental or host factors. Our findings strongly support that raising cattle may have a substantial impact on the dynamics of I. loricatus and that interactions within the ectoparasite community may be an important-but generally ignored-driver of tick dynamics. PMID:26122994

  13. Unique Regulation of the Melatonin Synthetic Pathway in the Retina of Diurnal Female Arvicanthis ansorgei (Rodentia).

    PubMed

    Gianesini, Coralie; Clesse, Daniel; Tosini, Gianluca; Hicks, David; Laurent, Virginie

    2015-09-01

    Knowledge about melatonin synthesis and its potential roles within the retina remains fragmented, especially in mammals where studies have focused on the penultimate enzyme of melatonin synthesis arylalkylamine N-acetyltransferase (AA-NAT), whereas the final enzyme necessary for melatonin production is hydroxyindole-O-methytransferase (HIOMT). We explored multiple parameters of the melatonin synthetic pathway in the cone-rich retina of a diurnal rodent, Arvicanthis ansorgei, cones being previously implicated as probable reservoirs of melatonin production. We analyzed the temporal and spatial expression of Aa-nat mRNA and AA-NAT protein and enzymatic activity of AA-NAT, HIOMT, as well as the melatonin receptor type 1 and melatonin itself. We report that Aa-nat mRNA was localized principally to cones and ganglion cells (retinal ganglion cell [RGC]) with opposing cyclic expression, being maximal in cones during the night, and maximal in RGC in the daytime. AA-NAT protein was also immunolocalized to these same populations, and was present and active throughout the 24-hour period. HIOMT immunolocalization mirrored that of AA-NAT, but expression levels and activity were extremely low and remained uniform throughout the 24-hour period. MT1 showed a complementary expression pattern to the synthetic enzymes, present in rod photoreceptors, some inner retinal neurons and RGC. Surprisingly, melatonin levels were consistently low throughout the day/night cycle, in accordance with the low activity levels of HIOMT. These data demonstrate that the melatonin synthetic pathway in a diurnal rodent differs from that described for other tissues and species (nocturnal and diurnal), the contrasting phase expression in photoreceptors and RGC, suggesting distinct roles in these populations.

  14. [Reproduction of European bank vole (Myodes glareolus, Rodentia) under conditions of natural geochemical anomalies].

    PubMed

    Baĭtimirova, E A; Mamina, V P; Zhigal'skiĭ, O A

    2010-01-01

    Estimates of abundance, morpho-functional state of ovaries, potential and actual fecundity of European bank vole, Myodes glareolus, inhabiting the territories of natural geochemical anomalies that are situated over ultra-basic rock and have an excess content of chrome, nickel, and cobaltare obtained. The population adaptive response to extreme geochemical conditions that facilitates the species survival under unfavorable environmental conditions and is manifested through an increase in potential and actual fecundity, decline of pre-implantation mortality, and decrease in proportion of females with pre-implantation losses is revealed. It is shown that in anomalous areas the intensity of folliculogenesis in mature voles is independent of the population cycle phase. As for immature animals residing within geochemical anomalies, an increase in size and numbers of follicles in ovaries is observed which is indicative of maturation fastening. An increase in potential and actual fecundity, as well as changes in morpho-functional state of ovaries, can be interpreted as means of birth rate accelerating which is supposed to compensate high postnatal mortality and maintain population abundance.

  15. Are ribosomal DNA clusters rearrangement hotspots? A case study in the genus Mus (Rodentia, Muridae)

    PubMed Central

    2011-01-01

    Background Recent advances in comparative genomics have considerably improved our knowledge of the evolution of mammalian karyotype architecture. One of the breakthroughs was the preferential localization of evolutionary breakpoints in regions enriched in repetitive sequences (segmental duplications, telomeres and centromeres). In this context, we investigated the contribution of ribosomal genes to genome reshuffling since they are generally located in pericentromeric or subtelomeric regions, and form repeat clusters on different chromosomes. The target model was the genus Mus which exhibits a high rate of karyotypic change, a large fraction of which involves centromeres. Results The chromosomal distribution of rDNA clusters was determined by in situ hybridization of mouse probes in 19 species. Using a molecular-based reference tree, the phylogenetic distribution of clusters within the genus was reconstructed, and the temporal association between rDNA clusters, breakpoints and centromeres was tested by maximum likelihood analyses. Our results highlighted the following features of rDNA cluster dynamics in the genus Mus: i) rDNA clusters showed extensive diversity in number between species and an almost exclusive pericentromeric location, ii) a strong association between rDNA sites and centromeres was retrieved which may be related to their shared constraint of concerted evolution, iii) 24% of the observed breakpoints mapped near an rDNA cluster, and iv) a substantial rate of rDNA cluster change (insertion, deletion) also occurred in the absence of chromosomal rearrangements. Conclusions This study on the dynamics of rDNA clusters within the genus Mus has revealed a strong evolutionary relationship between rDNA clusters and centromeres. Both of these genomic structures coincide with breakpoints in the genus Mus, suggesting that the accumulation of a large number of repeats in the centromeric region may contribute to the high level of chromosome repatterning observed in this group. However, the elevated rate of rDNA change observed in the chromosomally invariant clade indicates that the presence of these sequences is insufficient to lead to genome instability. In agreement with recent studies, these results suggest that additional factors such as modifications of the epigenetic state of DNA may be required to trigger evolutionary plasticity. PMID:21569527

  16. Sequencing and analysis of complete mitochondrial genome of Apodemus draco (Rodentia: Arvicolinae).

    PubMed

    Wei, Haixue; Jia, Qiang; Li, Fengjun; Liu, Yongcheng; Chen, Shunde; Yong, Bin

    2016-07-01

    The genus Apodemus are the most common small rodents in fields. They are also one of the best species for biogeographic study and understanding the environmental changes. In this study, the complete mitochondrial genome sequence of Apodemus draco is determined. The mitogenome is 16 220 bp in length and contains 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a control region, with a base composition of 35.1% A, 29.0% T, 23.8% C and 12.1% G. The nucleotide sequence data of 12 heavy-strand protein-coding genes of Apodemus draco and other 23 rodents were used for mitochondrial genome phylogenetic analyses. The monophyly of the genus Apodemus was well supported with sister to the genus Mus. Bayesian analysis also suggested that Apodemus draco was a sister to Apodemus latronum. The present study may facilitate further investigation of the molecular evolution and biogeographic study of the genus Apodemus. PMID:27158789

  17. Rattus norvegicus (Rodentia: Muridae) Infected by Leishmania (Leishmania) infantum (syn. Le. chagasi) in Brazil

    PubMed Central

    Lara-Silva, Fabiana de Oliveira; Michalsky, Érika Monteiro; Ferreira, Eduardo de Castro; Lopes, Maria Olímpia Garcia; Pinheiro, Aimara da Costa; Fortes-Dias, Consuelo Latorre; Dias, Edelberto Santos

    2014-01-01

    In the present study we surveyed the fauna of phlebotomine sand flies and small mammals in peridomestic areas from a Brazilian municipality where the American cutaneous leishmaniasis (ACL) is endemic. A total of 608 female phlebotomine sand flies were captured during nine months in 2009 and 2010. Seven different species were represented with 60% of them being Lutzomyia intermedia and Lu. whitmani, both incriminated vectors of ACL. Lu. longipalpis, a proven vector of visceral leishmaniasis (VL) was also captured at high proportion (12.8%). Genomic DNA analysis of 136 species-specific pools of female sand flies followed by molecular genotyping showed the presence of Leishmania infantum DNA in two pools of Lu. longipalpis. The same Leishmania species was found in one blood sample from Rattus norvegicus among 119 blood and tissue samples analysed. This is the first report of Le. infantum in R. norvegicus in the Americas and suggests a possible role for this rodent species in the zoonotic cycle of VL. Our study coincided with the reemergence of VL in Governador Valadares. PMID:24707492

  18. [Molecular genetic relationships among east Palearctic ground squirrels of the genus Spermophilus (Sciuridae, Rodentia)].

    PubMed

    Tsvirka, M V; Spiridonova, L N; Korablev, V P

    2008-08-01

    Genetic diversity in the four east Palearctic ground squirrel species of the genus Spermophilus--S. undulatus, S. parryi (subgenus Urocitellus), S. dauricus, and S. relictus (subgenus Citellus)--- was investigated using RAPD PCR with ten random primers. Siberian chipmunk, Tamias sibiricus, was used as an outgroup. Molecular markers for different taxonomic ranks were identified, including those for the genera Spermophilus and Tamias, subgenera Urocitellus and Citellus, as well as for each of the four species, S. undulatus, S. parryi, S. dauricus, and S. relictus. For the ground squirrel species and subgenera, genetic differentiation indices (H(t), H(s), D(st), G(st), Nm, and D) were calculated. In addition, for these groups the NJ phylogenetic reconstructions and UPGMA dendrograms of genetic similarity of the individuals and combined populations were constructed. Comparative molecular genetic analysis revealed a high genetic differentiation between S. undulates, S. dauricus, S. relicts, and S. parryi (G(st) = 0.58 to 0.82; D = 0.53 to 1.06), along with a low level of genetic differentiation of the subgenera Citellus and Urocitellus (G(st) = 0.33; D = 0.27), distinguished in accordance with the existing taxonomic systems of the genus Spermophilus.

  19. The comparative gastrointestinal morphology of Jaculus jaculus (Rodentia) and Paraechinus aethiopicus (Erinaceomorpha).

    PubMed

    Pereira, Daniella L; Walters, Jacklynn; Bennett, Nigel C; Alagaili, Abdulaziz N; Mohammed, Osama B; Kotzé, Sanet H

    2016-05-01

    Jaculus jaculus (Lesser Egyptian jerboa) and Paraechinus aethiopicus (Desert hedgehog) are small mammals which thrive in desert conditions and are found, among others, in the Arabian Peninsula. Jaculus jaculus is omnivorous while P. aethiopicus is described as being insectivorous. The study aims to describe the gastrointestinal tract (GIT) morphology of these animals which differ in diet and phylogeny. The GITs of J. jaculus (n = 8) and P. aethiopicus (n = 7) were weighed, photographed, and the length, basal surface areas, and luminal surface areas of each of the anatomically distinct gastrointestinal segments were determined. The internal aspects of each area were examined and photographed while representative histological sections of each area were processed to wax and stained using haematoxylin and eosin. Both species had a simple unilocular stomach which was confirmed as wholly glandular on histology sections. Paraechinus aethiopicus had a relatively simple GIT which lacked a caecum. The caecum of J. jaculus was elongated, terminating in a narrow cecal appendix which contained lymphoid tissue on histological examination. The internal aspect of the proximal colon of J. jaculus revealed distinct V-shaped folds. Stomach content analysis of J. jaculus revealed mostly plant and seed material and some insects, whereas P. aethiopicus samples showed plant material in addition to insects, indicating omnivorous feeding tendencies in areas where insects may be scarce. PMID:26968578

  20. Ultrasonic vocalization and body temperature maintenance in infant voles of three species (Rodentia: Arvicolidae).

    PubMed

    Blake, B H

    1992-12-01

    Infant voles thermoregulate poorly and produce ultrasonic vocalizations when cooled. Vocalizing and the ability to maintain body temperature in isolated pups cold-challenged at 5 degrees C or 22 degrees C were studied in nestling Clethrionomys glareolus, Microtus agrestis, and Arvicola terrestris. The tendency to vocalize varied with age, since pups vocalized more in their 2nd week than in their 1st or 3rd weeks. Rate of vocalizing was correlated with sound pressure level of vocalizations. Their was no apparent relation between vocalizing rate and deep body temperature. M. agrestis pups vocalized most and A. terrestris pups least, and all three species vocalized more at the lower temperature. Maximal vocalizing occurred in mid aged M. agrestis (at 5 degrees C) with mean of 1291 vocalizations/20 min and mean SPL of 80 dB (decibels re: 20 microN/m2). It is suggested that the vocalizing response is an adaptation related to risk from hypothermia in infant voles. PMID:1487083

  1. Phylogeography of a post-glacial colonizer: Microtus longicaudus (Rodentia: muridae).

    PubMed

    Conroy, C J; Cook, J A

    2000-02-01

    The molecular phylogeography of Microtus longicaudus was investigated with DNA sequences of the mitochondrial cytochrome b gene. We used phylogenetic and pairwise distance methods to reconstruct the history of the species with particular emphasis on the Pacific Northwest. Genetic variation across the species was consistent with vicariant events during the Pleistocene and subsequent northern postglacial expansion following the receding Laurentide and Cordilleran ice sheets. The largest break (> 6% uncorrected sequence divergence) was found to exist between populations found southeast of the Colorado River (eastern Arizona, Colorado, Wyoming and New Mexico) and all other western populations. Other well-supported subclades were composed of samples from: (i) the islands and north coast of southeast Alaska; (ii) eastern Alaska, British Columbia, Washington and Oregon; and (iii) northern California, Idaho and Montana. Within subclades, divergence was low. Our results suggest that the close relationships among haplotypes within northern subclades are a result of recent colonization, whereas higher among-subclade divergence is caused by genetic differentiation during prolonged periods of isolation, possibly as a result of mid-Pleistocene climatic events. PMID:10672160

  2. A widespread distribution for Arostrilepis tenuicirrosa (Eucestoda: Hymenolepididae) in Myodes voles (Cricetidae: Arvicolinae) from the Palearctic based on molecular and morphological evidence: historical and biogeographic implications.

    PubMed

    Galbreath, Kurt E; Ragaliauskaite, Kristina; Kontrimavichus, Leonas; Makarikov, Arseny A; Hoberg, Eric P

    2013-12-01

    Hymenolepidid cestodes in Myodes glareolus from Lithuania and additional specimens originally attributed to Arostrilepis horrida from the Republic of Belarus are now referred to A. tenuicirrosa. Our study includes the first records of A. tenuicirrosa from the European (western) region of the Palearctic, and contributes to the recognition of A. horrida (sensu lato) as a complex of cryptic species distributed broadly across the Holarctic. Specimens of A. tenuicirrosa from Lithuania were compared to cestodes representing apparently disjunct populations in the eastern Palearctic based on structural characters of adult parasites and molecular sequence data from nuclear (ITS2) and mitochondrial (cytochrome b) genes. Morphological and molecular data revealed low levels of divergence between eastern and western populations. Phylogeographic relationships among populations and host biogeographic history suggests that limited intraspecific diversity within A. tenuicirrosa may reflect a Late Pleistocene transcontinental range expansion from an East Asian point of origin.

  3. A review of Gongylonema spp. (Nematoda: Gongylonematidae) in North American rodents with description of a new species from the cotton rat, Sigmodon hispidus (Mammalia: Cricetidae).

    PubMed

    Kinsella, John M; Robles, Maria Del Rosario; Preisser, Whitney C

    2016-01-01

    Gongylonema archboldi n. sp. (Nematoda: Gongylonematidae) is described from tunnels in the gastric mucosa of the stomach of the cotton rat (Sigmodon hispidus) from Highlands County, Florida, U.S.A. Measurements are also given for specimens from cotton mice (Peromyscus gossypinus), oldfield mice (Peromyscus polionotus), Florida mice (Podomys floridanus), and golden mice (Ochrotomys nuttalli) from the same locality. Additional specimens were collected from the cotton rat and the rice rat (Oryzomys palustris) from Berry Island, San Patricio County, Texas. The new species is differentiated from congeners by a combination of the following characters: length of the left spicule, length and shape of the gubernaculum, distribution of cuticular bosses, length of esophagus, and distance of the vulva from the posterior end. The status of the genus Gongylonema in North American rodents is reviewed. PMID:27394819

  4. A widespread distribution for Arostrilepis tenuicirrosa (Eucestoda: Hymenolepididae) among arvicoline rodent hosts (Cricetidae) from the Palearctic based on molecular and morphological criteria: Historical and biogeographic

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hymenolepidid cestodes in Myodes glareolus from Lithuania and additional specimens originally attributed to Arostrilepis horrida from the Republic of Belarus are now referred to A. tenuicirrosa. Our study includes the first records of A. tenuicirrosa from the European (western) region of the Palearc...

  5. Sarcocystis clethrionomyelaphis Matuschka, 1986 (Apicomplexa: Sarcocystidae) infecting the large oriental vole Eothenomys miletus (Thomas) (Cricetidae: Microtinae) and its phylogenetic relationships with other species of Sarcocystis Lankester, 1882.

    PubMed

    Hu, Jun-Jie; Liu, Ting-Ting; Liu, Qiong; Esch, G W; Chen, Jin-Qing

    2015-07-01

    Sarcocystis clethrionomyelaphis Matuschka, 1986 was first identified in skeletal muscles of 47 (75.8%) of 62 large oriental voles Eothenomys miletus (Thomas) captured between March 2012 and May 2014 in Anning Prefecture of Yunnan Province (China). Sarcocyst walls were thick and possessed villous protrusions measuring 3.5-5.5 μm in length. Beauty rat snakes Elaphe taeniura (Cope) fed sarcocysts of the species shed sporulated oöcysts measuring 13-18×9-13 (16×12) μm with a prepatent period of 16 to 17 days. Phylogenetic analysis based on 18S rRNA gene sequences revealed a close relationship between S. clethrionomyelaphis and other colubrid-transmitted species of Sarcocystis Lankester, 1882. This is the first report identifying S. clethrionomyelaphis from its natural intermediate host. PMID:26063304

  6. A new flea of the genus Ctenidiosomus (Siphonaptera, Pygiopsyllidae) from Salta Province, Argentina

    PubMed Central

    López-Berrizbeitia, M. Fernanda; Hastriter, Michael W.; Barquez, Rubén M.; Díaz, M. Mónica

    2015-01-01

    Abstract A new species of flea of the genus Ctenidiosomus Jordan, 1931 (Siphonaptera: Pygiopsyllidae) is described from Phyllotis osilae J. A. Allen, 1901, from Salta Province, Argentina. This is the first time that Ctenidiosomus has been recorded in Argentina. A key to species of males of Ctenidiosomus is presented. PMID:26257563

  7. Evolution of Spatially Coexpressed Families of Type-2 Vomeronasal Receptors in Rodents

    PubMed Central

    Francia, Simona; Silvotti, Lucia; Ghirardi, Filippo; Catzeflis, François; Percudani, Riccardo; Tirindelli, Roberto

    2015-01-01

    The vomeronasal organ (VNO) is an olfactory structure for the detection of pheromones. VNO neurons express three groups of unrelated G-protein-coupled receptors. Type-2 vomeronasal receptors (V2Rs) are specifically localized in the basal neurons of the VNO and are believed to sense protein pheromones eliciting specific reproductive behaviors. In murine species, V2Rs are organized into four families. Family-ABD V2Rs are expressed monogenically and coexpress with family-C V2Rs of either subfamily C1 (V2RC1) or subfamily C2 (V2RC2), according to a coordinate temporal diagram. Neurons expressing the phylogenetically ancient V2RC1 coexpress family-BD V2Rs or a specific group of subfamily-A V2Rs (V2RA8-10), whereas a second neuronal subset (V2RC2-positive) coexpresses a recently expanded group of five subfamily-A V2Rs (V2RA1-5) along with vomeronasal-specific Major Histocompatibility Complex molecules (H2-Mv). Through database mining and Sanger sequencing, we have analyzed the onset, diversification, and expansion of the V2R-families throughout the phylogeny of Rodentia. Our results suggest that the separation of V2RC1 and V2RC2 occurred in a Cricetidae ancestor in coincidence with the evolution of the H2-Mv genes; this phylogenetic event did not correspond with the origin of the coexpressing V2RA1-5 genes, which dates back to an ancestral myomorphan lineage. Interestingly, the evolution of receptors within the V2RA1-5 group may be implicated in the origin and diversification of some of the V2R putative cognate ligands, the exocrine secreting peptides. The establishment of V2RC2, which probably reflects the complex expansion and diversification of family-A V2Rs, generated receptors that have probably acquired a more subtle functional specificity. PMID:25539725

  8. Effects of mitochondria-targeted plastoquinone derivative antioxidant (SkQ1) on demography of free-breeding Campbell dwarf hamsters (Phodopus campbelli) kept in outdoor conditions. reproduction and lifespan: explanation in the framework of ultimate loads.

    PubMed

    Rogovin, K A; Khrushcheva, A M; Shekarova, O N; Ushakova, M V; Manskikh, V N; Sokolova, O V; Vasilieva, N Yu

    2014-10-01

    We studied demographic effects of the mitochondria-targeted antioxidant SkQ1 on free-breeding Campbell dwarf hamsters (Phodopus campbelli, Thomas, 1905, Rodentia, Cricetidae) in an outdoor vivarium with seasonally varying day length and temperatures. The animals were kept in pairs from their young age. We removed litters from parental cages at their age of 25 days. Experimental hamsters received daily 50 nmol/kg SkQ1 with water by oral dosing, whereas control animals received water. SkQ1 had no effect on the lifespan of either males or females in reproductive pairs. Mortality among females was higher than among males irrespective of SkQ1 treatment, this being related to higher costs of reproduction in females. However, SkQ1 accelerated breeding in pairs in the first half of the reproductive period of a year. Although there were no statistical differences in body mass of males and females between experimental and control animals during most of their life, SkQ1-receiving males had higher body mass at the end of their life. The opposite tendency was characteristic for old females. One-year-old males and females of the experimental and control groups showed no difference in intensity of immune response to sheep red blood cells. The dermal hypersensitivity response to phytohemagglutinin (test for T-cell immunity) was significantly higher in SkQ1-treated 1- and 1.5-year-old males. This was not true for females. There was a tendency toward increased density of the neutrophil population in blood in 1-year-old SkQ1-treated males. However, experimental males showed no difference from control males in the activity of the "peroxidase-endogenous hydrogen peroxide system" of neutrophils. The background level of stress estimated by the concentration of cortisol in blood serum was significantly lower in the SkQ1-treated males during autumn adaptive adjustment of the organism. A similar trend was also observed during the January frosts, when the background level of stress was

  9. Ectoparasitic chigger mites on large oriental vole (Eothenomys miletus) across southwest, China.

    PubMed

    Peng, Pei-Ying; Guo, Xian-Guo; Song, Wen-Yu; Hou, Peng; Zou, Yun-Ji; Fan, Rong

    2016-02-01

    An investigation of chigger mites on the large oriental vole, Eothenomys miletus (Rodentia: Cricetidae), was conducted between 2001 and 2013 at 39 localities across southwest China, and 2463 individuals of the vole hosts were captured and examined, which is a big host sample size. From the body surface of E. miletus, 49,850 individuals of chigger mites were collected, and they were identified as comprising 175 species, 13 genera, and 3 subfamilies in 2 families (Trombiculidae and Leeuwenhoekiidae). The 175 species of chigger mites from such a single rodent species (E. miletus) within a certain region (southwest China) extremely exceeded all the species of chigger mites previously recorded from multiple species of hosts in a wide region or a whole country in some other countries, and this suggests that E. miletus has a great potential to harbor abundant species of chigger mites on its body surface. Of 175 mite species, Leptotrombidium scutellare was the most dominant species, which has been proved as one of the main vectors of scrub typhus and the potential vector of haemorrhagic fever with renal syndrome (HFRS) in China. The patchiness index (m*/m) was used to measure the spatial patterns of the dominant chigger mite species, and all the three dominant mite species (L. scutellare, Leptotrombidium sinicum, and Helenicula simena) showed aggregated distributions among the different host individuals. The coefficient of association (V) was adopted to measure the interspecies interaction between the dominant mite species and a slightly positive association existed between L. scutellare and L. sinicum (V = 0.28, P < 0.01), which implies that these two mite species can co-exist on the same species of the host, E. miletus. The tendency curve of species abundance showed that the number of chigger mite species gradually decreased with the increase of mite individuals, and this revealed that most chigger mite species were rare with very few individuals, but few

  10. Evolution of spatially coexpressed families of type-2 vomeronasal receptors in rodents.

    PubMed

    Francia, Simona; Silvotti, Lucia; Ghirardi, Filippo; Catzeflis, François; Percudani, Riccardo; Tirindelli, Roberto

    2015-01-01

    The vomeronasal organ (VNO) is an olfactory structure for the detection of pheromones. VNO neurons express three groups of unrelated G-protein-coupled receptors. Type-2 vomeronasal receptors (V2Rs) are specifically localized in the basal neurons of the VNO and are believed to sense protein pheromones eliciting specific reproductive behaviors. In murine species, V2Rs are organized into four families. Family-ABD V2Rs are expressed monogenically and coexpress with family-C V2Rs of either subfamily C1 (V2RC1) or subfamily C2 (V2RC2), according to a coordinate temporal diagram. Neurons expressing the phylogenetically ancient V2RC1 coexpress family-BD V2Rs or a specific group of subfamily-A V2Rs (V2RA8-10), whereas a second neuronal subset (V2RC2-positive) coexpresses a recently expanded group of five subfamily-A V2Rs (V2RA1-5) along with vomeronasal-specific Major Histocompatibility Complex molecules (H2-Mv). Through database mining and Sanger sequencing, we have analyzed the onset, diversification, and expansion of the V2R-families throughout the phylogeny of Rodentia. Our results suggest that the separation of V2RC1 and V2RC2 occurred in a Cricetidae ancestor in coincidence with the evolution of the H2-Mv genes; this phylogenetic event did not correspond with the origin of the coexpressing V2RA1-5 genes, which dates back to an ancestral myomorphan lineage. Interestingly, the evolution of receptors within the V2RA1-5 group may be implicated in the origin and diversification of some of the V2R putative cognate ligands, the exocrine secreting peptides. The establishment of V2RC2, which probably reflects the complex expansion and diversification of family-A V2Rs, generated receptors that have probably acquired a more subtle functional specificity. PMID:25539725

  11. Effects of mitochondria-targeted plastoquinone derivative antioxidant (SkQ1) on demography of free-breeding Campbell dwarf hamsters (Phodopus campbelli) kept in outdoor conditions. reproduction and lifespan: explanation in the framework of ultimate loads.

    PubMed

    Rogovin, K A; Khrushcheva, A M; Shekarova, O N; Ushakova, M V; Manskikh, V N; Sokolova, O V; Vasilieva, N Yu

    2014-10-01

    We studied demographic effects of the mitochondria-targeted antioxidant SkQ1 on free-breeding Campbell dwarf hamsters (Phodopus campbelli, Thomas, 1905, Rodentia, Cricetidae) in an outdoor vivarium with seasonally varying day length and temperatures. The animals were kept in pairs from their young age. We removed litters from parental cages at their age of 25 days. Experimental hamsters received daily 50 nmol/kg SkQ1 with water by oral dosing, whereas control animals received water. SkQ1 had no effect on the lifespan of either males or females in reproductive pairs. Mortality among females was higher than among males irrespective of SkQ1 treatment, this being related to higher costs of reproduction in females. However, SkQ1 accelerated breeding in pairs in the first half of the reproductive period of a year. Although there were no statistical differences in body mass of males and females between experimental and control animals during most of their life, SkQ1-receiving males had higher body mass at the end of their life. The opposite tendency was characteristic for old females. One-year-old males and females of the experimental and control groups showed no difference in intensity of immune response to sheep red blood cells. The dermal hypersensitivity response to phytohemagglutinin (test for T-cell immunity) was significantly higher in SkQ1-treated 1- and 1.5-year-old males. This was not true for females. There was a tendency toward increased density of the neutrophil population in blood in 1-year-old SkQ1-treated males. However, experimental males showed no difference from control males in the activity of the "peroxidase-endogenous hydrogen peroxide system" of neutrophils. The background level of stress estimated by the concentration of cortisol in blood serum was significantly lower in the SkQ1-treated males during autumn adaptive adjustment of the organism. A similar trend was also observed during the January frosts, when the background level of stress was

  12. Ectoparasitic chigger mites on large oriental vole (Eothenomys miletus) across southwest, China.

    PubMed

    Peng, Pei-Ying; Guo, Xian-Guo; Song, Wen-Yu; Hou, Peng; Zou, Yun-Ji; Fan, Rong

    2016-02-01

    An investigation of chigger mites on the large oriental vole, Eothenomys miletus (Rodentia: Cricetidae), was conducted between 2001 and 2013 at 39 localities across southwest China, and 2463 individuals of the vole hosts were captured and examined, which is a big host sample size. From the body surface of E. miletus, 49,850 individuals of chigger mites were collected, and they were identified as comprising 175 species, 13 genera, and 3 subfamilies in 2 families (Trombiculidae and Leeuwenhoekiidae). The 175 species of chigger mites from such a single rodent species (E. miletus) within a certain region (southwest China) extremely exceeded all the species of chigger mites previously recorded from multiple species of hosts in a wide region or a whole country in some other countries, and this suggests that E. miletus has a great potential to harbor abundant species of chigger mites on its body surface. Of 175 mite species, Leptotrombidium scutellare was the most dominant species, which has been proved as one of the main vectors of scrub typhus and the potential vector of haemorrhagic fever with renal syndrome (HFRS) in China. The patchiness index (m*/m) was used to measure the spatial patterns of the dominant chigger mite species, and all the three dominant mite species (L. scutellare, Leptotrombidium sinicum, and Helenicula simena) showed aggregated distributions among the different host individuals. The coefficient of association (V) was adopted to measure the interspecies interaction between the dominant mite species and a slightly positive association existed between L. scutellare and L. sinicum (V = 0.28, P < 0.01), which implies that these two mite species can co-exist on the same species of the host, E. miletus. The tendency curve of species abundance showed that the number of chigger mite species gradually decreased with the increase of mite individuals, and this revealed that most chigger mite species were rare with very few individuals, but few

  13. Into Tibet: An Early Pliocene Dispersal of Fossil Zokor (Rodentia: Spalacidae) from Mongolian Plateau to the Hinterland of Tibetan Plateau.

    PubMed

    Li, Qiang; Wang, Xiaoming

    2015-01-01

    This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan Plateau within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian Plateau, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan Plateau during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an "out of Tibet" hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan Plateau or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an "into Tibet" scenario--earlier and more primitive taxa originated from outside of the Tibetan Plateau and the later the lineage became extinct in southwestern Tibet. PMID:26658457

  14. Demodex castoris sp. nov. (Acari: Demodecidae) parasitizing Castor fiber (Rodentia), and other parasitic arthropods associated with Castor spp.

    PubMed

    Izdebska, Joanna N; Fryderyk, Sławomira; Rolbiecki, Leszek

    2016-02-11

    A new species of demodecid mite, Demodex castoris sp. nov. (Acari: Prostigmata: Demodecidae), is described based on adult stages from the skin of the nasal region of the Eurasian beaver Castor fiber Linnaeus, 1758, collected in Poland. This is the first detection of a representative demodecid mite in rodents of the suborder Castorimorpha and also represents the first detection of a skin mite in Eurasian beavers. The new species is a small skin mite (average 173 µm in length) characterized by sexual dimorphism related to body proportions. D. castoris sp. nov. was observed in 4 out of 6 beavers examined (66.6%), with a mean intensity of 10.8 and an intensity range of 2-23 ind. host(-1). This paper also contains a checklist of parasitic arthropods known from Castor spp.

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

    PubMed

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

    2012-08-01

    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.

  16. Chromosome synapsis and recombination in simple and complex chromosomal heterozygotes of tuco-tuco (Ctenomys talarum: Rodentia: Ctenomyidae).

    PubMed

    Basheva, Ekaterina A; Torgasheva, Anna A; Gomez Fernandez, Maria Jimena; Boston, Emma; Mirol, Patricia; Borodin, Pavel M

    2014-09-01

    The chromosomal speciation hypothesis suggests that irregularities in synapsis, recombination, and segregation in heterozygotes for chromosome rearrangements may restrict gene flow between karyotypically distinct populations and promote speciation. Ctenomys talarum is a South American subterranean rodent inhabiting the coastal regions of Argentina, whose populations polymorphic for Robertsonian and tandem translocations seem to have a very restricted gene flow. To test if chromosomal differences are involved in isolation among its populations, we examined chromosome pairing, recombination, and meiotic silencing of unsynapsed chromatin in male meiosis of simple and complex translocation heterozygotes using immunolocalization of the MLH1 marking mature recombination nodules and phosphorylated histone γH2A.X marking unrepaired double-strand breaks. We observed small asynaptic areas labeled by γH2A.X in pericentromeric regions of the chromosomes involved in the trivalents and quadrivalents. We also observed a decrease of recombination frequency and a distalization of the crossover distribution in the heterozygotes and metacentric homozygotes compared to acrocentric homozygotes. We suggest that the asynapsis of the pericentromeric regions are unlikely to induce germ cell death and decrease fertility of the heterozygotes; however, suppressed recombination in pericentromeric areas of the multivalents may reduce gene flow between chromosomally different populations of the Talas tuco-tuco.

  17. [Diet of the capybara Hydrochaeris hydrochaeris (Rodentia: Hydrocharidae) in Caño Limón, Arauca, Colombia].

    PubMed

    Forero-Montaña, Jimena; Betancur, Julio; Cavelier, Jaime

    2003-06-01

    We studied the composition and seasonal variation of the diet of the capybara (Hydrochaeris hydrochaeris) in the flooded savannas of Caño Limón, Colombia. This was achieved by direct observation of the consumption patterns of these animals. The capybaras only consumed plants, and their diet included 89 species of 22 families. Sixty three percent of these plant species had not been reported before. The most commonly consumed plants (94% of the diet), belonged to the Poaceae, Cyperaceae, Leguminosae and Pontederiaceae. Only seven species represented 60% of the total diet: the grasses Hymenachne amplexicaulis (16.9%), Digitaria bicornis (4.5%) and Panicum maximum (4.4%) and the Cyperaceae Rynchospora corymbosa (4.4%). There was seasonal variation in the diet composition of capybaras.

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

    PubMed

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

    2012-01-01

    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.

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

    PubMed

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

    2013-01-01

    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.

  20. Diversity of tuco-tucos (Ctenomys, Rodentia) in the Northeastern wetlands from Argentina: mitochondrial phylogeny and chromosomal evolution.

    PubMed

    Caraballo, Diego A; Abruzzese, Giselle A; Rossi, María Susana

    2012-06-01

    Tuco-tucos (small subterranean rodents of the genus Ctenomys) that inhabit sandy soils of the area under the influence of the second largest wetland of South America, in Northeastern Argentina (Corrientes province), are a complex of species and forms whose taxonomic status were not defined, nor are the evolutionary relationships among them. The tuco-tuco populations of this area exhibit one of the most ample grades of chromosomal variability within the genus. In order to analyze evolutionary relationships within the Corrientes group and its chromosomal variability, we completed the missing karyotypic information and performed a phylogenetic analysis. We obtained partial sequences of three mitochondrial markers: D-loop, cytochrome b and cytochrome oxidase I. The Corrientes group was monophyletic and split into three main clades that grouped related karyomorphs. The phylogeny suggested an ancestral condition of the karyomorph with diploid number (2n) 70 and fundamental number (FN) 84 that has evolved mainly via reductions of the FN although amplifications occurred in certain lineages. We discuss the relationship between patterns of chromosomal variability and species and groups boundaries. From the three main clades the one named iberá exhibited a remarkable karyotypic homogeneity, and could be considered as an independent and cohesive evolutionary lineage. On the contrary, the former recognized species C. dorbignyi is a polyphyletic lineage and hence its systematic classification should be reviewed.

  1. High levels of polymorphism found through cross-amplification of microsatellite loci in a Ctenomys pearsoni (Rodentia, Ctenomyidae) population.

    PubMed

    Mannise, N; González, S; Maldonado, J E; Izquierdo, G; Francescoli, G; Cosse, M

    2013-04-02

    Ctenomys pearsoni (Pearson's tuco-tuco) is a subterranean rodent native to Uruguay. We tested the amplification pattern of 12 microsatellite loci, designed for C. sociabilis and C. haigi in a C. pearsoni population. DNA extractions were made from hair samples, and PCR amplification products were run on an ABI 3100 microcapillary gel. Eight loci were selected to form a highly polymorphic panel that could be used to efficiently screen populations of this species. In DNA from 35 tuco-tucos, the mean polymorphic information content value was 0.6536 and the mean expected heterozygosity was 0.7166. Paternity non-exclusion probabilities for seven independent loci were NE-1P = 0.0766 and NE-2P = 0.0108, and combined non-exclusion P(ID) was 6.2 x 10(-7). This panel of microsatellite loci has sufficient power to make inferences regarding group structure, mating strategies and evolutionary relationships among populations.

  2. Redescription of Echinocoleus hydrochoeri (Travassos, 1916) (Nematoda: Trichuridae) from Hydrochoeris hydrochaeris Linnaeus, 1766 (Rodentia: Caviidae) from Argentina.

    PubMed

    Robles, María del Rosario; Eberhardt, María Ayelen Teresita; Bain, Odile; Beldomenico, Pablo Martín

    2013-08-01

    Twenty-eight Capillariinae species have been recorded in rodents; 1 of these species was reported from a caviomorph rodent, Hydrochoeris hydrochaeris (capybara), and placed in the genus Echinocoleus by Moravec (1982). However, both original description and subsequent contributions of Echinocoleus hydrochoeri are poor and incomplete. In this paper, this species is redescribed, and a new geographical distribution is reported. The redescription is based on morphologic and morphometrical features; intestine ends in a cloaca beside ejaculatory duct, caudal bursa composed of 2 large ventrolateral lobes with a fleshy internal part and a membranous external part (they are not united dorsally with a membrane), 1 pair of caudal papillae, terminal part of cylindrical cirrus ornamented with thin and thick spines (and particular pattern distribution), sclerotized spicule in male, and vulvar appendage in female, and 3 bacillary bands (1 ventral and 2 lateral). Generic and specific analyses were performed to establish new standards for future studies on the systematic position of Capillariinae species. This study presents new morphological information and a new record of a capillariid species from Argentina.

  3. First record of Mylagaulid rodents (Rodentia, Mammalia) from the Miocene of Eastern Siberia (Olkhon Island, Baikal Lake, Irkutsk Region, Russia).

    PubMed

    Tesakov, A S; Lopatin, A V

    2015-01-01

    A new genus and species of rodent, Lamugaulus olkhonensis, belonging to the subfamily Promylagaulinae of the family Mylagaulidae, is described on the basis of isolated teeth from the Khalagay Formation of the Lower Miocene Tagay locality (Olkhon island, Lake Baikal, Irkutsk Region). This is the first record of mylagaulids in Eastern Siberia, significantly expanding the data on the distribution of this mainly North American group of rodents in Asia and showing its presence outside the Central Asian arid zone.

  4. On the Origin and Evolution of the Extant System of B Chromosomes in Oryzomyini Radiation (Rodentia, Sigmodontinae).

    PubMed

    Ventura, Karen; O'Brien, Patricia Caroline Mary; do Nascimento Moreira, Camila; Yonenaga-Yassuda, Yatiyo; Ferguson-Smith, Malcolm Andrew

    2015-01-01

    Heterogeneous supernumerary chromosomes (Bs) are recognized in the oryzomyines Holochilus brasiliensis, Nectomys rattus, N. squamipes, Oligoryzomys flavescens and Sooretamys angouya, representing about 10% of all known B-containing rodent species. They provide an outstanding model for understanding the origin, evolution and diversity of Bs in a phylogenetic context. Therefore, whole chromosome-specific probes were generated from flow-sorted Holochilus brasiliensis (HBR) autosomes 11 and 25+26 and chromosomes X, Y and Bs. Hybridizations were performed on male metaphases of 15 Oryzomyini species of which 3 are B-containing species. The results reveal that among the species sampled, 12 of them, belonging to a monophyletic Oryzomiyini subclade, are positive for an anonymous Oryzomyini shared heterochromatic region (OSHR) on both sex chromosomes. The OSHR is also present on Bs of Holochilus brasiliensis, Nectomys rattus and N. squamipes but not on Bs of O. flavescens and S. angouya. Two distinct additional OSHR/autosome associations are observed on S. angouya. The three species that are OSHR negative belong to an outgroup. Molecular dating suggests that the OSHR originated between 7.8 and 3 Mya on ancestral sex chromosomes. A tentative explanation for the OSHR-positive nature of B regions in three species could be that transposable elements (TEs) from this specific sex chromosome region may have invaded existing B chromosomes. The presence of the OSHR on entire Xp and Yp adjacent to interstitial telomeric sequences at pericentromeric positions, as observed in Drymoreomys albimaculatus, show a similar organization as on B chromosomes in Nectomys squamipes. The diversity of the Oryzomyini Bs in number, size, morphology and genetic content may be explained by the independent origin of B chromosomes in different subgroups of species, with Bs in Holochilus brasiliensis, Nectomys squamipes and N. rattus sharing the OSHR with sex chromosomes, and those in Oligoryzomys flavescens and Sooretamys angouya lacking OSHR in Bs. The species-specific pattern of Bs is probably a consequence of their independent evolutionary origin.

  5. Penial morphology in three species of Brazilian tuco-tucos, Ctenomys torquatus, C. minutus, and C. flamarioni (Rodentia: Ctenomyidae).

    PubMed

    Rocha-Barbosa, O; Bernardo, J S L; Loguercio, M F C; Freitas, T R O; Santos-Mallet, J R; Bidau, C J

    2013-02-01

    The present study analyses the glans penis and baculum morphology of three Brazilian tuco-tucos, Ctenomys torquatus Lichtenstein, 1830, Ctenomys minutus Nehring, 1887 and Ctenomys flamarioni Travi, 1981, in order to identify possible variations and understand some more about this taxonomically complex group. We used fixed penis from 15 previously listed adult specimens. For a more detailed baculum analysis, the penis underwent dissection and diaphanisation, whereas to analyse the glans penis surface we used Scanning Electron Microscopy (SEM). Results showed striking differences in baculum morphology among the three species. While C. minutus have a particular V-shaped proximal baculum tip, C. flamarioni baculum is thin throughout the shaft with rounded proximal and distal tips. Ctenomys torquatus have a shorter and larger baculum, similar to what has previously been described for the species. Glans penis surface microstructure analyses also revealed inter-specific differences, with penial spines varying in shape, size and, especially density. Although C. torquatus has a relatively small penis, it has the largest penial spine density, which suggests a more complex penial ornamentation in this species.

  6. Molecular phylogeny and biogeography of woolly flying squirrel (Rodentia: Sciuridae), inferred from mitochondrial cytochrome b gene sequences.

    PubMed

    Yu, Fahong; Yu, Farong; McGuire, Peter M; Kilpatrick, C William; Pang, Junfeng; Wang, Yingxiang; Lu, Shunqing; Woods, Charles A

    2004-12-01

    To investigate the genetic diversity between the populations of woolly flying squirrels (Eupetaurus) from the eastern and western extremes of the Himalayas, partial mitochondrial cytochrome b gene sequences (390-810 bp) that were determined from the museum specimens were analyzed using maximum parsimony (MP) and maximum likelihood (ML) methods. The molecular data reveal that the two specimens that were collected in northwestern Yunnan (China) are members of the genus Eupetaurus. Reconstructed phylogenetic relationships show that the populations of Eupetaurus in the eastern and western extremes of the Himalayas are two distinct species with significant genetic differences (12%) and diverged about 10.8 million years ago. Eupetaurus is significantly different from Petaurista and Pteromys. The level of estimated pairwise-sequence divergence observed between Eupetaurus and Petaurista or Pteromys is greater than that observed between Eupetaurus and Trogopterus, Belomys, Glaucomys, or Hylopetes. Considering the divergence time of the two Eupetaurus groups, the glaciations and the uplift of the Himalayas and Qinghai-Tibet plateau during the Pliocene-Pleistocene period might be the major factors affecting the present distribution of Eupetaurus along the Himalayas. PMID:15522800

  7. Nuclear DNA phylogeny of the squirrels (Mammalia: Rodentia) and the evolution of arboreality from c-myc and RAG1.

    PubMed

    Steppan, Scott J; Storz, Brian L; Hoffmann, Robert S

    2004-03-01

    Although the family Sciuridae is large and well known, phylogenetic analyses are scarce. We report on a comprehensive molecular phylogeny for the family. Two nuclear genes (c-myc and RAG1) comprising approximately 4500 bp of data (most in exons) are applied for the first time to rodent phylogenetics. Parsimony, likelihood, and Bayesian analyses of the separate gene regions and combined data reveal five major lineages and refute the conventional elevation of the flying squirrels (Pteromyinae) to subfamily status. Instead, flying squirrels are derived from one of the tree squirrel lineages. C-myc indels corroborate the sequence-based topologies. The common ancestor of extant squirrels appears to have been arboreal, confirming the fossil evidence. The results also reveal an unexpected clade of mostly terrestrial squirrels with African and Holarctic centers of diversity. We present a revised classification of squirrels. Our results demonstrate the phylogenetic utility of relatively slowly evolving nuclear exonic data even for relatively recent clades. PMID:15012949

  8. Rediscovery of Biswamoyopterus (Mammalia: Rodentia: Sciuridae: Pteromyini) in Asia, with the description of a new species from Lao PDR.

    PubMed

    Sanamxay, Daosavanh; Douangboubpha, Bounsavane; Bumrungsri, Sara; Xayavong, Sysouphanh; Xayaphet, Vilakhan; Satasook, Chutamas; Bates, Paul J J

    2013-01-01

    A new species of the flying squirrel genus Biswamoyopterus is described from Lao PDR. It is based on a single specimen collected from a local food market at Ban Thongnami, Pak Kading District, Bolikhamxai Province. The new taxon shows close affinities to Biswamoyopterus biswasi, which is only known from the holotype collected in 1981, 1250 km from the current locality, in Arunachal Pradesh, Northeast India. However, it differs substantially in pelage colour, most particularly on the ventral surfaces of the body, patagia, tail membrane, and tail. The single specimen was found in an area of central Lao PDR, which is characterised by its extensive limestone karst formations and which is home to other rare endemic rodents, including the Khanyou (Laonastes aenigmamus) nd the Lao limestone rat (Saxatilomyspaulinae). PMID:26473234

  9. Phylogeny and biogeography of the Petaurista philippensis complex (Rodentia: Sciuridae), inter- and intraspecific relationships inferred from molecular and morphometric analysis.

    PubMed

    Yu, Farong; Yu, Fahong; Pang, Junfeng; Kilpatrick, C William; McGuire, Peter M; Wang, Yingxiang; Lu, Shunqing; Woods, Charles A

    2006-03-01

    With modified DNA extraction and purification protocols, the complete cytochrome b gene sequences (1140 bp) were determined from degraded museum specimens. Molecular analysis and morphological examination of cranial characteristics of the giant flying squirrels of Petaurista philippensis complex (P. grandis, P. hainana, and P. yunanensis) and other Petaurista species yielded new insights into long-standing controversies in the Petaurista systematics. Patterns of genetic variations and morphological differences observed in this study indicate that P. hainana, P. albiventer, and P. yunanensis can be recognized as distinct species, and P. grandis and P. petaurista are conspecific populations. Phylogenetic relationships reconstructed by using parsimony, likelihood, and Bayesian methods reveal that, with P. leucogenys as the basal branch, all Petaurista groups formed two distinct clades. Petaurista philippensis, P. hainana, P. yunanensis, and P. albiventer are clustered in the same clade, while P. grandis shows a close relationship to P. petaurista. Deduced divergence times based on Bayesian analysis and the transversional substitution at the third codon suggest that the retreating of glaciers and upheavals or movements of tectonic plates in the Pliocene-Pleistocene were the major factors responsible for the present geographical distributions of Petaurista groups. PMID:16414285

  10. A new species of Trichuris Roederer, 1761 (Nematoda: Trichuridae) from Heteromys gaumeri Allen & Chapman (Rodentia: Heteromyidae) in Yucatan, Mexico.

    PubMed

    Panti-May, Jesús Alonso; Robles, María Del Rosario

    2016-09-01

    In Mexico, four species of Trichuris Roederer, 1761 have been recorded in wild rodents belonging to the family Heteromyidae. In the present paper, we describe a new species based on specimens collected from Heteromys gaumeri Allen & Chapman (Heteromyidae: Heteromyinae) in the tropical forests of the Yucatan Peninsula, Mexico. Trichuris silviae n. sp. can be differentiated from the congeners described in North and South American rodents by morphological and morphometric features, such as the possession of a wide spicular tube, a thicker proximal cloacal tube, a shorter distal cloacal tube and a cylindrical spicular sheath. This is the first description of a Trichuris spp. from heteromyid rodents in Mexico and the fourth in North America. Despite the broad distribution of Heteromys spp., few cases of Trichuris infection have been reported. Further studies are necessary to verify if the new species is present in other heteromyid rodents in order to increase our knowledge about its geographical and host distribution. PMID:27522370

  11. Convergent evolution of aquatic foraging in a new genus and species (Rodentia: Muridae) from Sulawesi Island, Indonesia.

    PubMed

    Rowe, Kevin C; Achmadi, Anang S; Esselstyn, Jacob A

    2014-01-01

    The island of Sulawesi, in Indonesia, lies at the crossroads of the Indo-Australian Archipelago and has remained isolated from the Asian (Sunda) and Australian (Sahul) continental shelves for at least the last 10 million years. Of the 50 native species of rodents on Sulawesi, all are endemic and represent the evolution of a variety of ecological and morphological forms within the Muridae and Sciuridae. Carnivorous rodents have evolved, perhaps independently, in Muridae from the Philippines, Sulawesi, and Sahul, but semi-aquatic murids are only known from Sahul. Here we describe a new genus and species of insectivorous water rat from Sulawesi. Phylogenetic analyses demonstrate that it is related to the shrew rats of Sulawesi and represents an origin of aquatic carnivory that is independent from the evolution of water rats on Sahul. Many areas of Sulawesi have not been surveyed systematically and current lists of mammal species are likely to dramatically underestimate actual diversity. PMID:24943633

  12. Genetic Pool Information Reflects Highly Suitable Areas: The Case of Two Parapatric Endangered Species of Tuco-tucos (Rodentia: Ctenomiydae)

    PubMed Central

    Galiano, Daniel; Bernardo-Silva, Jorge; de Freitas, Thales R. O.

    2014-01-01

    Conservation of small mammals requires knowledge of the genetically and ecologically meaningful spatial scales at which species respond to habitat modifications. Conservation strategies can be improved through the use of ecological niche models and genetic data to classify areas of high environmental suitability. In this study, we applied a Maxent model integrated with genetic information (nucleotide diversity, haplotype diversity and Fu's Fs neutrality tests) to evaluate potential genetic pool populations with highly suitable areas for two parapatric endangered species of tuco-tucos (Ctenomys minutus and C. lami). Our results demonstrated that both species were largely influenced by vegetation and soil variables at a landscape scale and inhabit a highly specific niche. Ctenomys minutus was also influenced by the variable altitude; the species was associated with low altitudes (sea level). Our model of genetic data associated with environmental suitability indicate that the genetic pool data were associated with highly suitable areas for C. minutus. This pattern was not evident for C. lami, but this outcome could be a consequence of the restricted range of the species. The preservation of species requires not only detailed knowledge of their natural history and genetic structure but also information on the availability of suitable areas where species can survive, and such knowledge can aid significantly in conservation planning. This finding reinforces the use of these two techniques for planning conservation actions. PMID:24819251

  13. Distribution and habitat of the Laotian Rock Rat Laonastesaenigmamus Jenkins, Kilpatrick, Robinson & Timmins, 2005 (Rodentia: Diatomyidae) in Vietnam.

    PubMed

    Nguyen, Dang Xuan; Nguyen, Nghia Xuan; Nguyen, Duy Dinh; Dinh, Tri Huy; Le, Dinh Thuc; Dinh, Duong Hai

    2014-01-01

    The Laotian Rock Rat Laonastesaenigmamus Jenkins, Kilpatrick, Robinson & Timmins, 2005 was originally discovered in Lao People's Democratic Republic in 2005. This species has been recognized as the sole surviving member of the otherwise extinct rodent family Diatomyidae. Laonastesaenigmamus was initially reported only in limestone forests of Khammouane Province, Central Lao. A second population was recently discovered in Phong Nha Ke Bang National Park (PNKB NP), Quang Binh Province, Central Vietnam in 2011. The confirmed distribution range of L.aenigmamus in Vietnam is very small, approximately 150 km(2), covering low karst mountains in five communes of Minh Hoa District, Quang Binh Province, at elevations between 250 and 400 m asl. The Laotian Rock Rat inhabits the lower part of steep karst towers with many rock boulders and crevices under tall limestone evergreen forest. They use small rock crevices for their dens. The natural habitat of this species in PNKB NP has been affected by selected timber harvesting, however, a complex 3-4 layer forest structure is retained. The Laotian Rock Rat is omnivorous, feeding on parts (leaves, buds, fruits and roots) of 18 plant species and also some insects (cicada, mantis, grasshopper). The population of this species in PNKB NP is seriously threatened with extinction due to its very restricted distribution, high hunting pressure, and habitat disturbance. Laonastesaenigmamus is listed in the IUCN Red List as endangered and in the Wildlife and Aquatic Red List of Lao, however, this species has not been listed in the Red Data Book or any conservation legislative documents of Vietnam. PMID:25589873

  14. [Morphological diversity in the postnatal skull development in representatives of two families of rodents (Spalacidae, Castoridae, Rodentia)].

    PubMed

    Puzachenko, A Iu; Korablev, N P

    2014-01-01

    This is the first study to describe the results of measurement of three information parameters of morphological diversity (entropy, the measure of organization, and the Kullback-Leibler divergence) in the course of postnatal development of the skull in the populations of two rodent species (greater mole rat (Spalax microphthalmus Guld.) and Eurasian beaver (Castor fiber (L.)). The terms "morphosystem" and "morphological space" and its structure are introduced. Within the framework of the developed approach, "morphological diversity" is considered as a variable associated with the morphological space structure. Testing the hypothesis of the dominance of self-organization processes and an increase in the organization of the morphological diversity of the skull in the course ofontogeny showed its inconsistency. The morphosystem of the skull of the studied species undergoes transitions between more organized and less organized states, periodically approaching and departing from the "steady state." Such dynamics characterizes the morphosystem of the skull as a dynamic and nonlinear system.

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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.

  16. New data on occurrence of Demodex flagellurus (Acari, Demodecidae) - rarely recorded parasite from the house mouse Mus musculus (Rodentia, Muridae).

    PubMed

    Izdebska, Joanna N; Rolbiecki, Leszek

    2015-01-01

    Demodex flagellurus Bukva, 1985 is one of two known demodecid mites of the house mouse Mus musculus Linnaeus, 1758, in which it is observed in genital area. Skin fragments of 30 house mice from various regions of Poland (residential buildings in Gdynia and Gdańsk, rural region in Wielkopolska-Kujawska Lowland) were examined. The mites were noted in 25.0% of the mice, with mean intensity of 48.0 and intensity range of 2-103. D. flagellurus demonstrated the differentiated occurrence in host populations. PMID:25911036

  17. Demodex castoris sp. nov. (Acari: Demodecidae) parasitizing Castor fiber (Rodentia), and other parasitic arthropods associated with Castor spp.

    PubMed

    Izdebska, Joanna N; Fryderyk, Sławomira; Rolbiecki, Leszek

    2016-02-11

    A new species of demodecid mite, Demodex castoris sp. nov. (Acari: Prostigmata: Demodecidae), is described based on adult stages from the skin of the nasal region of the Eurasian beaver Castor fiber Linnaeus, 1758, collected in Poland. This is the first detection of a representative demodecid mite in rodents of the suborder Castorimorpha and also represents the first detection of a skin mite in Eurasian beavers. The new species is a small skin mite (average 173 µm in length) characterized by sexual dimorphism related to body proportions. D. castoris sp. nov. was observed in 4 out of 6 beavers examined (66.6%), with a mean intensity of 10.8 and an intensity range of 2-23 ind. host(-1). This paper also contains a checklist of parasitic arthropods known from Castor spp. PMID:26865230

  18. Evolutionary acceleration in the most endangered mammal of Canada: speciation and divergence in the Vancouver Island marmot (Rodentia, Sciuridae).

    PubMed

    Cardini, A; Thorington, R W; Polly, P D

    2007-09-01

    The Vancouver Island marmot is the most endangered mammal of Canada. Factors which have brought this population to the verge of extinction have not yet been fully elucidated, but the effects of deforestation and habitat fragmentation on survival rates, as well as those of variation in rainfall, temperature, snowpack depth and snowmelt strongly suggest that marmots on the island are struggling to keep pace with environmental changes. Genetic analyses, however, seem to indicate that the Vancouver Island marmot may merely represent a melanistic population of its parental species on the mainland. Were it not for its black pelage colour, it is unlikely that it would have attracted much attention as a conservation priority. Our study uses three-dimensional coordinates of cranial landmarks to further assess phenotypic differentiation of the Vancouver Island marmot. A pattern of strong interspecific divergence and low intraspecific variation was found which is consistent with aspects of drift-driven models of speciation. However, the magnitude of shape differences relative to the putatively neutral substitutions in synonymous sites of cytochrome b is too large for being compatible with a simple neutral model. A combination of bottlenecks and selective pressures due to natural and human-induced changes in the environment may offer a parsimonious explanation for the large phenotypic differentiation observed in the species. Our study exemplifies the usefulness of a multidisciplinary approach to the study of biological diversity for a better understanding of evolutionary models and to discover aspects of diversity that may be undetected by using only a few genetic markers to characterize population divergence and uniqueness.

  19. Comparison of climate space and phylogeny of Marmota (Mammalia: Rodentia) indicates a connection between evolutionary history and climate preference.

    PubMed

    Davis, Edward Byrd

    2005-03-01

    Palaeobiologists have investigated the evolutionary responses to extinct organisms to climate change, and have also used extinct organisms to reconstruct palaeoclimates. There is evidence of a disconnection between climate change and evolution that suggest that organism may not be accurate paleoclimate indicators. Here, marmots (Marmota sp.) are used as a case study to examine whether similarity of climate preferences is correlated with evolutionary relatedness of species. This study tests for a relationship between phylogenetic distance and 'climate distance' of species with a clade. There should be a significant congruence between maximus likelihood distance and standardized Euclidian distance between climates if daughter species tend to say in environments similar to parent species. Marmots make a good test case because there are many extant species, their phylogenetics are well established and individual survival is linked to climatic factors. A Mantel test indicates a significant correlation between climate and phylogenetic distance matrices, but this relationship explains only a small fraction of the variance (regression R(2) = 0.114). These results that (i) closely related species of marmots tend to stay in similar environments; (ii) marmots may be more susceptible than may mammals to global climate change; and (iii) because of the considerable noise in this system, the correlation cannot be used for detailed palaeoclimate reconstruction.

  20. Comparison of climate space and phylogeny of Marmota (Mammalia: Rodentia) indicates a connection between evolutionary history and climate preference

    PubMed Central

    Davis, Edward Byrd

    2005-01-01

    Palaeobiologists have investigated the evolutionary responses of extinct organisms to climate change, and have also used extinct organisms to reconstruct palaeoclimates. There is evidence of a disconnection between climate change and evolution that suggests that organisms may not be accurate palaeoclimate indicators. Here, marmots (Marmota sp.) are used as a case study to examine whether similarity of climate preferences is correlated with evolutionary relatedness of species. This study tests for a relationship between phylogenetic distance and `climate distance' of species within a clade. There should be a significant congruence between maximum likelihood distance and standardized Euclidian distance between climates if daughter species tend to stay in environments similar to parent species. Marmots make a good test case because there are many extant species, their phylogenies are well established and individual survival is linked to climatic factors. A Mantel test indicates a significant correlation between climate and phylogenetic distance matrices, but this relationship explains only a small fraction of the variance (regression R2=0.114). These results suggest that (i) closely related species of marmots tend to stay in similar environments; (ii) marmots may be more susceptible than many mammals to global climate change; and (iii) because of the considerable noise in this system, the correlation cannot be used for detailed palaeoclimate reconstruction. PMID:15799948

  1. Molecular characterization and mitochondrial sequence variation in two sympatric species of Proechimys (Rodentia: Echimyidae) in French Guiana.

    PubMed

    Steiner; Sourrouille; Catzeflis

    2000-12-01

    Variations in mitochondrial DNA characters were used to characterize two morphologically similar and sympatric species of Neotropical terrestrial rodents of the genus Proechimys (Mammalia: Echimyidae). We sequenced both cytochrome b (1140pb) and part of the control region (445pb) from four individuals of P. cuvieri and five of P. cayennensis from French Guiana, which allowed us to depict intra- and inter-specific patterns of variation. The phylogenetic relationships between the nine sequences evidence the monophyly of each species, and illustrate that more polymorphism might exist within P. cuvieri than within P. cayennensis. By developing species-specific primers to amplify a fragment of the cytochrome b gene, we were able to identify 50 individuals of Proechimys spp. caught in two localities of French Guiana. In both sites of primary rainforests, we showed that the two species live in syntopy, and this observation emphasizes the need to document ecological differences which should exist in order to diminish inter-specific competition.

  2. On the Origin and Evolution of the Extant System of B Chromosomes in Oryzomyini Radiation (Rodentia, Sigmodontinae).

    PubMed

    Ventura, Karen; O'Brien, Patricia Caroline Mary; do Nascimento Moreira, Camila; Yonenaga-Yassuda, Yatiyo; Ferguson-Smith, Malcolm Andrew

    2015-01-01

    Heterogeneous supernumerary chromosomes (Bs) are recognized in the oryzomyines Holochilus brasiliensis, Nectomys rattus, N. squamipes, Oligoryzomys flavescens and Sooretamys angouya, representing about 10% of all known B-containing rodent species. They provide an outstanding model for understanding the origin, evolution and diversity of Bs in a phylogenetic context. Therefore, whole chromosome-specific probes were generated from flow-sorted Holochilus brasiliensis (HBR) autosomes 11 and 25+26 and chromosomes X, Y and Bs. Hybridizations were performed on male metaphases of 15 Oryzomyini species of which 3 are B-containing species. The results reveal that among the species sampled, 12 of them, belonging to a monophyletic Oryzomiyini subclade, are positive for an anonymous Oryzomyini shared heterochromatic region (OSHR) on both sex chromosomes. The OSHR is also present on Bs of Holochilus brasiliensis, Nectomys rattus and N. squamipes but not on Bs of O. flavescens and S. angouya. Two distinct additional OSHR/autosome associations are observed on S. angouya. The three species that are OSHR negative belong to an outgroup. Molecular dating suggests that the OSHR originated between 7.8 and 3 Mya on ancestral sex chromosomes. A tentative explanation for the OSHR-positive nature of B regions in three species could be that transposable elements (TEs) from this specific sex chromosome region may have invaded existing B chromosomes. The presence of the OSHR on entire Xp and Yp adjacent to interstitial telomeric sequences at pericentromeric positions, as observed in Drymoreomys albimaculatus, show a similar organization as on B chromosomes in Nectomys squamipes. The diversity of the Oryzomyini Bs in number, size, morphology and genetic content may be explained by the independent origin of B chromosomes in different subgroups of species, with Bs in Holochilus brasiliensis, Nectomys squamipes and N. rattus sharing the OSHR with sex chromosomes, and those in Oligoryzomys flavescens and Sooretamys angouya lacking OSHR in Bs. The species-specific pattern of Bs is probably a consequence of their independent evolutionary origin. PMID:26305702

  3. Into Tibet: An Early Pliocene Dispersal of Fossil Zokor (Rodentia: Spalacidae) from Mongolian Plateau to the Hinterland of Tibetan Plateau.

    PubMed

    Li, Qiang; Wang, Xiaoming

    2015-01-01

    This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan Plateau within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian Plateau, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan Plateau during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an "out of Tibet" hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan Plateau or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an "into Tibet" scenario--earlier and more primitive taxa originated from outside of the Tibetan Plateau and the later the lineage became extinct in southwestern Tibet.

  4. Genetic assessment of the Atlantic Forest bristle porcupine, Chaetomys subspinosus (Rodentia: Erethizontidae), an endemic species threatened with extinction.

    PubMed

    Oliveira, C G; Martinez, R A; Giné, G A F; Faria, D M; Gaiotto, F A

    2011-01-01

    The bristle-spined porcupine, Chaetomys subspinosus, an endemic rodent from Atlantic Forest, was considered to be abundant in the recent past, but population reductions due to habitat loss and expansion of human activities caused this species to be included in the "vulnerable" category of the World Conservation Union Red List. We performed the first genetic assessment in natural populations of this focal species along its geographical distribution. Thirty-five non-invasive samples (hair) were collected from three natural populations in the Brazilian States of Sergipe, Bahia and Espírito Santo. Genetic similarity obtained by Jaccard's index, based on dominant RAPD and ISSR markers, varied between 25 and 100%. Four clusters, mainly coincident with the geographical distribution of the populations, were observed. Analysis of molecular variance based on 47 polymorphic loci showed that there was 15.99% genetic variability among populations and 84.01% within populations. The estimated genetic structure among populations (Φ(ST)) was 0.16. The populations may have formed a continuum along the past distribution of the Atlantic rainforest but historical events of human occupation resulted in recent divergence among sampled populations.

  5. Comparative gastrointestinal morphology of three small mammalian insectivores: Acomys spinosissimus (Rodentia), Crocidura cyanea (Eulipotyphla), and Amblysomus hottentotus (Afrosoricida).

    PubMed

    Boonzaier, Julia; Van der Merwe, Elizabeth L; Bennett, Nigel C; Kotzé, Sanet H

    2013-06-01

    The gastrointestinal morphology was investigated in three mammalian insectivorous species, namely Acomys spinosissimus, Crocidura cyanea, and Amblysomus hottentotus. The aim of the study was to provide a comprehensive morphological comparison between the different species and to explore whether anatomical gastrointestinal adaptations are associated with the insectivorous diet of these species. The shape, proportional length, and proportional surface areas of the different gastrointestinal regions were recorded and compared in the three insectivores. Hematoxylin and Eosin (H&E) and Alcian Blue/Periodic Acid Schiff (AB/PAS) were used for morphological assessment. In all three species, the stomach was simple and uncompartmentalized. The internal aspect of the stomach in A. spinosissimus was hemi-glandular, containing stratified squamous epithelium in the fundus, with glandular epithelium in the body and pyloric region. However, C. cyanea and A. hottentotus had wholly glandular stomachs. Paneth cells were not observed in the intestinal tracts of C. cyanea and A. hottentotus. Acomys spinosissimus was the only species studied that had a cecum. The proximal colonic region of A. spinosissimus had V-shaped mucosal folds. Histologically, C. cyanea had villi throughout the entire gastrointestinal tract (GIT), whereas for A. hottentotus villi were not present in the most distal gastrointestinal regions. In both C. cyanea and A. hottentotus, longitudinal mucosal folds were present in the distal part of the colon. The GITs of C. cyanea and A. hottentotus showed little morphological differentiation namely, a simple, glandular stomach and the lack of a cecum.

  6. Laoxyuris laonasti n. gen., n. sp. (Nematoda: Syphaciinae) parasite of Laonastes aenigmamus (Rodentia: Diatomyidae): morphology, biology, taxonomy, phylogeny.

    PubMed

    Hugot, Jean Pierre; Feliu, Carlos; Douangboupha, Bounneuang; Ribas, Alexis

    2013-06-01

    A new Oxyurid genus and species are described in a rodent recently discovered in Lao PDR: Laonastes aenigmamus which happens to be the single survivor of the Diatomyidae, a family considered to be extinct since the Miocene. The morphological characters of the new parasite species allow classifying it within the Syphaciinae Railliet, 1916, a subfamily whose members are exclusively parasites of Lagomorpha and Rodents. Male Syphaciinae have developed several types of ventral cuticular ornamentation used to firmly grip the female during mating. The ornamental characters observed in the new species include a finger like appendix, which, until now, has not been described in the subfamily. The originality of this apparatus justifies the creation of a new genus and a new species for the pinworm parasite of Laonastes. Using morphological characters, the new species is analyzed phylogenetically to describe its affinities with representatives of the main groups distinguished within the Syphaciinae. The phylogenetic study produces a cladogram similar to the phylogeny recently proposed for the hosts of the subfamily and in agreement with a close association of the Diatomyidae with the Ctenodactylidae. Such a phenomenon of cophylogeny is interpreted as the result of the existence of a strict specificity between the Syphaciinae and their respective hosts, due to the very close adaptation of their life cycle with the behaviors of their hosts. In Lagomorpha and Rodents, caecotrophy and grooming activities allow a direct transmission of the parasite eggs and favor successive self-infestations, increasing the chances for the parasite to maintain itself in the same host species but decreasing the probability of host switching. The resulting high host specificity allowed the Syphaciinae to out-compete other pinworms and maintain themselves in their specific host over millions of years. PMID:23357582

  7. On cognitive ecology and the environmental factors that promote Alzheimer disease: lessons from Octodon degus (Rodentia: Octodontidae).

    PubMed

    Rivera, Daniela S; Inestrosa, Nibaldo C; Bozinovic, Francisco

    2016-01-01

    Cognitive ecologist posits that the more efficiently an animal uses information from the biotic and abiotic environment, the more adaptive are its cognitive abilities. Nevertheless, this approach does not test for natural neurodegenerative processes under field or experimental conditions, which may recover animals information processing and decision making and may explain, mechanistically, maladaptive behaviors. Here, we call for integrative approaches to explain the relationship between ultimate and proximate mechanisms behind social behavior. We highlight the importance of using the endemic caviomorph rodent Octodon degus as a valuable natural model for mechanistic studies of social behavior and to explain how physical environments can shape social experiences that might influence impaired cognitive abilities and the onset and progression of neurodegenerative disorders such as Alzheimer disease. We consequently suggest neuroecological approaches to examine how key elements of the environment may affect neural and cognitive mechanisms associated with learning, memory processes and brain structures involved in social behavior. We propose the following three core objectives of a program comprising interdisciplinary research in O. degus, namely: (1) to determine whether diet types provided after weaning can lead to cognitive impairment associated with spatial memory, learning and predisposing to develop Alzheimer disease in younger ages; (2) to examine if early life social experience has long term effects on behavior and cognitive responses and risk for development Alzheimer disease in later life and (3) To determine if an increase of social interactions in adult degu reared in different degree of social stressful conditions alter their behavior and cognitive responses. PMID:26897365

  8. Into Tibet: An Early Pliocene Dispersal of Fossil Zokor (Rodentia: Spalacidae) from Mongolian Plateau to the Hinterland of Tibetan Plateau

    PubMed Central

    Li, Qiang; Wang, Xiaoming

    2015-01-01

    This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan Plateau within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian Plateau, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan Plateau during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an “out of Tibet” hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan Plateau or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an “into Tibet” scenario–earlier and more primitive taxa originated from outside of the Tibetan Plateau and the later the lineage became extinct in southwestern Tibet. PMID:26658457

  9. On the Origin and Evolution of the Extant System of B Chromosomes in Oryzomyini Radiation (Rodentia, Sigmodontinae)

    PubMed Central

    Ventura, Karen; O’Brien, Patricia Caroline Mary; do Nascimento Moreira, Camila; Yonenaga-Yassuda, Yatiyo; Ferguson-Smith, Malcolm Andrew

    2015-01-01

    Heterogeneous supernumerary chromosomes (Bs) are recognized in the oryzomyines Holochilus brasiliensis, Nectomys rattus, N. squamipes, Oligoryzomys flavescens and Sooretamys angouya, representing about 10% of all known B-containing rodent species. They provide an outstanding model for understanding the origin, evolution and diversity of Bs in a phylogenetic context. Therefore, whole chromosome-specific probes were generated from flow-sorted Holochilus brasiliensis (HBR) autosomes 11 and 25+26 and chromosomes X, Y and Bs. Hybridizations were performed on male metaphases of 15 Oryzomyini species of which 3 are B-containing species. The results reveal that among the species sampled, 12 of them, belonging to a monophyletic Oryzomiyini subclade, are positive for an anonymous Oryzomyini shared heterochromatic region (OSHR) on both sex chromosomes. The OSHR is also present on Bs of Holochilus brasiliensis, Nectomys rattus and N. squamipes but not on Bs of O. flavescens and S. angouya. Two distinct additional OSHR/autosome associations are observed on S. angouya. The three species that are OSHR negative belong to an outgroup. Molecular dating suggests that the OSHR originated between 7.8 and 3 Mya on ancestral sex chromosomes. A tentative explanation for the OSHR-positive nature of B regions in three species could be that transposable elements (TEs) from this specific sex chromosome region may have invaded existing B chromosomes. The presence of the OSHR on entire Xp and Yp adjacent to interstitial telomeric sequences at pericentromeric positions, as observed in Drymoreomys albimaculatus, show a similar organization as on B chromosomes in Nectomys squamipes. The diversity of the Oryzomyini Bs in number, size, morphology and genetic content may be explained by the independent origin of B chromosomes in different subgroups of species, with Bs in Holochilus brasiliensis, Nectomys squamipes and N. rattus sharing the OSHR with sex chromosomes, and those in Oligoryzomys flavescens and Sooretamys angouya lacking OSHR in Bs. The species-specific pattern of Bs is probably a consequence of their independent evolutionary origin. PMID:26305702

  10. Genetic pool information reflects highly suitable areas: the case of two parapatric endangered species of Tuco-tucos (Rodentia: Ctenomiydae).

    PubMed

    Galiano, Daniel; Bernardo-Silva, Jorge; Freitas, Thales R O de

    2014-01-01

    Conservation of small mammals requires knowledge of the genetically and ecologically meaningful spatial scales at which species respond to habitat modifications. Conservation strategies can be improved through the use of ecological niche models and genetic data to classify areas of high environmental suitability. In this study, we applied a Maxent model integrated with genetic information (nucleotide diversity, haplotype diversity and Fu's Fs neutrality tests) to evaluate potential genetic pool populations with highly suitable areas for two parapatric endangered species of tuco-tucos (Ctenomys minutus and C. lami). Our results demonstrated that both species were largely influenced by vegetation and soil variables at a landscape scale and inhabit a highly specific niche. Ctenomys minutus was also influenced by the variable altitude; the species was associated with low altitudes (sea level). Our model of genetic data associated with environmental suitability indicate that the genetic pool data were associated with highly suitable areas for C. minutus. This pattern was not evident for C. lami, but this outcome could be a consequence of the restricted range of the species. The preservation of species requires not only detailed knowledge of their natural history and genetic structure but also information on the availability of suitable areas where species can survive, and such knowledge can aid significantly in conservation planning. This finding reinforces the use of these two techniques for planning conservation actions.

  11. Pterygodermatites (Mesopectines) quentini (Nematoda, Rictulariidae), a parasite of Praomys rostratus (Rodentia, Muridae) in Mali: scanning electron and light microscopy

    PubMed Central

    2013-01-01

    Pterygodermatites (Mesopectines) quentini n. sp. (Nematoda, Rictulariidae) is described from the murine host Praomys rostratus in the south of the Republic of Mali. It differs from other species of the subgenus by the morphology of the head, which bears four simple cephalic papillae and a nearly axial oral opening, the number of caudal papillae, the number of precloacal cuticular formations, unequal spicules and the ratio of spicule lengths/body length. The use of scanning electron microscopy in combination with conventional light microscopy enabled us to give a detailed description of the morphological characters of this new species. PMID:24025692

  12. Geographic Variation in Skull Morphology of the Large Japanese Field Mice, Apodemus speciosus (Rodentia: Muridae) Revealed by Geometric Morphometric Analysis.

    PubMed

    Shintaku, Yuta; Motokawa, Masaharu

    2016-04-01

    We analyzed geographic variation in skull morphology of the large Japanese field mouse (Apodemus speciosus) and determined changes in skull morphology that occurred during the evolutionary history of A. speciosus in relation to the estimated distribution range in the last glacial maximum (LGM). We analyzed 1,416 specimens from 78 localities using geometric morphometric techniques applied to the dorsal side of the cranium and mandible. While large variations within and among the populations in Honshu, Shikoku, and Kyushu were observed, geographic patterns were not observed. Hokkaido and peripheral island populations showed shared differentiation from the Honshu, Shikoku, and Kyushu populations with a larger skull and distinct mandible shape. In addition, these two groups also differed from each other in accumulated random shape variation. Common characteristics found in Hokkaido and peripheral island populations were considered to be the ancestral states, which were retained by geographic isolation from the main islands. Random variations in Hokkaido and the peripheral island populations were formed through stochastic processes in relation to their isolation. Characteristic morphologies widely found in the populations of Honshu, Shikoku, and Kyushu were considered to be derived states that expanded after separation from the peripheral islands. Complex geomorphology and a shift in distribution range related to climate change and altitudinal distribution are suggested to have formed the complex geographic variation in this species. PMID:27032678

  13. New data on recently described rodent species Paulina's Limestone Rat Saxatilomys paulinae Musser, Smith, Robinson & Lunde, 2005 (Mammalia: Rodentia)

    PubMed Central

    Nguyen, Nghia Xuan; Ngo, Tuong Xuan; Nguyen, Duy Dinh

    2015-01-01

    Abstract Background Paulina's Limestone Rat Saxatilomys paulinae Musser et al., 2005 was first discovered by Musser et al. (2005) based on specimens from the Khammouane Limestone National Biodiversity Conservation Area (NBCA) in Khammouane Province in central Lao People's Democratic Republic (PDR). This tower karst landscape is part of the Central Indochina Limestone massif, which extends eastward into north-central Vietnam in Quang Binh and Quang Tri Provinces. New information In April 2014, we conducted a rodent survey and collected four (4) whole specimens of Saxatilomys paulinae in Quang Binh province. This is the first record of Saxatilomys paulinae in Vietnam. External and craniodental characteristics of all specimens clearly exhibit the characters of Saxatilomys paulinae as described in Musser et al. (2005)​. The rats are of medium size (HB: 160.3 ± 2.03 mm, T: 192.3 ± 6.69 mm) with some specific morpological characteristics. The external and craniodental measurement of the specimens from Vietnam tend to be larger than those of specimens from Lao. However, this needs to be verified by more studies in future. The habitat of Saxatilomys paulinae in Vietnam is characterized by complicated terrain comprising low karst towers (around 400 m) with steep slopes covered under limestone humid evergreen forest. The forest has been affected by selected timber logging in the past, but still has a complex 4-layer structure. The population of Saxatilomys paulinae in Vietnam is threatened by rodent trapping/snaring and habitat disturbance. More status surveys should be conducted to assess the species distributional range and its population status for undertaking relevant conservation measures. PMID:26023285

  14. Comparative chromosome banding of two South-American species of rice rats of the genus Oligoryzomys (Rodentia, Sigmodontinae).

    PubMed

    Aniskin, V M; Volobouev, V T

    1999-01-01

    Comparative analysis of G- and C-banding patterns in two species of pygmy rice rats, namely Oligoryzomys microtis from Peru (Ucayali and Loreto departments) and O. flavescens from Bolivia (Tarija department) established that the diploid number of the former species is 64 (NFa = 66), whereas, in the latter, it varies between 64 and 66 (NFa = 66-68) due to the presence of 0-2 heterochromatic supernumerary or B chromosomes. The G-banding pattern of the euchromatic part of their karyotypes is similar in spite of differences in morphology of the largest and smallest autosomal pairs caused by a centromeric shift and the presence of heterochromatic arms, respectively. In addition, the total quantity of C-heterochromatin is smaller in the karyotype of O. microtis than in that of O. flavescens, resulting in differences in the number and size of chromosome pairs (including sex chromosomes) bearing C-blocks. It follows from present and previous data that these karyotypic features are stable in each of these species and thus may be used as species-specific markers.

  15. Karyotype diversity suggests that Laonastes aenigmamus (Laotian rock rat) (Rodentia, Diatomyidae) is a multi-specific genus.

    PubMed

    Richard, Florence; Gerbault-Seureau, Michèle; Douangboupha, Bounneuang; Keovichit, Kham; Hugot, Jean-Pierre; Dutrillaux, Bernard

    2016-09-01

    Laonastes aenigmamus (Khanyou) is a recently described rodent species living in geographically separated limestone formations of the Khammuan Province in Lao PDR. Chromosomes of 21 specimens of L. aenigmamus were studied using chromosome banding as well as fluorescent in situ hybridization (FISH) techniques using human painting, telomere repeats, and 28S rDNA probes. Four different karyotypes were established. Study with human chromosome paints and FISH revealed that four large chromosomes were formed by multiple common tandem fusions, with persistence of some interstitial telomeres. The rearrangements separating the different karyotypes (I to IV) were also reconstructed. Various combinations of Robertsonian translocations or tandem fusions involving the same chromosomes differentiate these karyotypes. These rearrangements create a strong gametic barrier, which isolates specimens with karyotype II from the others. C-banding and FISH with telomere repeats also exhibit large and systematized differences between karyotype II and others. These data indicate an ancient reproductive separation and suggest that Laonastes is not a mono-specific genus.

  16. Brain structure volumes in the mole rat, Spalax ehrenbergi (Spalacidae, Rodentia) in comparison to the rat and subterrestrial insectivores.

    PubMed

    Frahm, H D; Rehkämper, G; Nevo, E

    1997-01-01

    Natural blindness and a subterranean, digging mode of life demand peculiar adaptations of the central nervous system in the mole rat Spalax ehrenbergi, which are the focus of this quantitative investigation. Volumes of 25 brain structures in Spalax were evaluated allometrically, using the least encephalized mammalian species, the Madagassian hedgehog-like tenrecs (Tenrecinae) as a reference base, and their sizes compared with those of the rat (as a more generalized representative of rodents) and of some subterranean Insectivora. The allometric approach reveals that Spalax has a larger brain than tenrecs and the rat. Within the brain, the neocortex and diencephalon are well developed, an observation also made in other mammalian species with a relatively high encephalization. An unique feature in Spalax is the enlargement of motor structures of the brain, such as the cerebellum (and cerebellar nuclei), and the striatum. Most conspicuous is the large size of the nucleus motorius nervi trigemini, reflecting the importance of masticatory muscles for the special digging technique, which demand an intense use of the teeth for loosening the soil.

  17. Redescription of Gyropus parvus (Ewing, 1924) (Insecta: Phthiraptera: Amblycera: Gyropidae) from tucos-tucos (Rodentia: Ctenomyidae: Ctenomys ) in Patagonia, Argentina.

    PubMed

    Martino, N S; Romero, M D; Castro, D C

    2010-02-01

    A detailed redescription of Gyropus parvus (Insecta: Phthiraptera: Amblycera: Gyropidae) is given based on specimens collected from the type host, Ctenomys colburni Allen 1903 , and the type locality, Estancia Huanuluán, Provincia de Rio Negro, Argentina. We expand and provide new chaetotaxy. New scanning electron microscopy images showing microstructural details of adults and eggs of G. parvus obtained from topotype specimens are included. Sexual dimorphism was mainly shown by differences in body size and abdominal chaetotaxy, with females being 17.5% larger than males and with more setae in each cluster. Significant differences between males and females were also observed in sternal plate measurements. Features described here show homogeneity within type host population. This information contributes to our knowledge of intra- and inter-specific variability for parasite populations. Our investigation constitutes the first collection of G. parvus from the type host and locality since it was described.

  18. Teasing apart socially-induced infertility in non-reproductive female Damaraland mole-rats, Fukomys damarensis (Rodentia: Bathyergidae).

    PubMed

    Bennett, Nigel C

    2011-12-01

    The Damaraland mole-rat is a subterranean mammal exhibiting extreme reproductive skew with a single reproductive female in each colony responsible for procreation. Non-reproductive female colony members are physiologically suppressed while in the colony, exhibiting reduced concentrations of plasma luteinizing hormone (LH) and a decreased response of the pituitary, as measured by the release of bioactive LH, to an exogenous dose of gonadotrophin releasing hormone (GnRH). Removal of the reproductive female from the colony results in an elevation of LH and an enhanced response of the pituitary to a GnRH challenge in non-reproductive females comparable to reproductive females, implying control of reproduction in these individuals by the reproductive female. The Damaraland mole-rat is an ideal model for investigating the physiological and behavioral mechanisms that regulate the hypothalamo-pituitary-gonadal axis. In contrast, we know less about the control of reproduction at the level of the hypothalamus. The immunohistochemistry of the GnRH system of both reproductive and non-reproductive female Damaraland mole-rats has revealed no significant differences with respect to morphology, distribution or numbers of immunoreactive GnRH perikarya. We examined whether the endogenous opioid peptide beta-endorphin was responsible for the inhibition of the release of the GnRH from the neurons indirectly by measuring LH concentrations in these non-reproductive females following single, hourly and 8 hourly injections of the opioid antagonist naloxone. The results imply that the endogenous opioid peptide, beta-endorphin, is not responsible for the inhibition of GnRH release from the perikarya in non-reproductive females. Preliminary data examining the circulating levels of cortisol also do not support a role for circulating glucocorticoids. The possible role of kisspeptin is discussed.

  19. Genetic assessment of the Atlantic Forest bristle porcupine, Chaetomys subspinosus (Rodentia: Erethizontidae), an endemic species threatened with extinction.

    PubMed

    Oliveira, C G; Martinez, R A; Giné, G A F; Faria, D M; Gaiotto, F A

    2011-01-01

    The bristle-spined porcupine, Chaetomys subspinosus, an endemic rodent from Atlantic Forest, was considered to be abundant in the recent past, but population reductions due to habitat loss and expansion of human activities caused this species to be included in the "vulnerable" category of the World Conservation Union Red List. We performed the first genetic assessment in natural populations of this focal species along its geographical distribution. Thirty-five non-invasive samples (hair) were collected from three natural populations in the Brazilian States of Sergipe, Bahia and Espírito Santo. Genetic similarity obtained by Jaccard's index, based on dominant RAPD and ISSR markers, varied between 25 and 100%. Four clusters, mainly coincident with the geographical distribution of the populations, were observed. Analysis of molecular variance based on 47 polymorphic loci showed that there was 15.99% genetic variability among populations and 84.01% within populations. The estimated genetic structure among populations (Φ(ST)) was 0.16. The populations may have formed a continuum along the past distribution of the Atlantic rainforest but historical events of human occupation resulted in recent divergence among sampled populations. PMID:21644209

  20. Histopathology associated with angiostrongylosis in Akodon species (Rodentia: Sigmodontinae) from Sierra de la Ventana, Buenos Aires, Argentina.

    PubMed

    Robles, María del Rosario; Perfumo, Carlos; Kinsella, John M; Navone, Graciela T

    2012-12-01

    Angiostrongylus is a metastrongylid nematode genus that includes species found in carnivores, rodents, and occasionally primates (including humans). About 100 species of wild sigmodontine rodents occur in Argentina, 16 of which are species of Akodon. The lungs of Akodon azarae and Akodon dolores from Sierra de la Ventana, Buenos Aires, Argentina, were examined, and 2 of 10 A. dolores specimens were positive for angiostrongylosis, showing macroscopic lesions of verminous pneumonia. Adults found were identified as Angiostrongylus morerai. Histopathology of the lungs revealed multiple nodules in the interstitium, alveoli, and vessels, resulting in interstitial fibrosis and the destruction of small capillaries and arterioles. Since extensive pathology in the lung was noted here from only 2 adults, it is probable that heavier infections may cause mortality in their hosts. This is the first record of this nematode species from A. dolores , expanding its geographic distribution to the southwest of Buenos Aires Province, and the first description of the histopathology of larval angiostrongylosis in a wild rodent from South America.

  1. Microcavia australis (Caviidae, Rodentia), a new highly competent host of Trypanosoma cruzi I in rural communities of northwestern Argentina.

    PubMed

    Cecere, M Carla; Cardinal, Marta V; Arrabal, Juan P; Moreno, Claudio; Gürtler, Ricardo E

    2015-02-01

    Rodents are well-known hosts of Trypanosoma cruzi but little is known on the role of some caviomorph rodents. We assessed the occurrence and prevalence of T. cruzi infection in Microcavia australis ("southern mountain, desert or small cavy") and its infectiousness to the vector Triatoma infestans in four rural communities of Tafí del Valle department, northwestern Argentina. Parasite detection was performed by xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR) from blood samples. A total of 51 cavies was captured in traps set up along cavy paths in peridomestic dry-shrub fences located between 25 and 85 m from the nearest domicile. We document the first record of M. australis naturally infected by T. cruzi. Cavies presented a very high prevalence of infection (46.3%; 95% confidence interval, CI=33.0-59.6%). Only one (4%) of 23 cavies negative by xenodiagnosis was found infected by kDNA-PCR. TcI was the only discrete typing unit identified in 12 cavies with a positive xenodiagnosis. The infectiousness to T. infestans of cavies positive by xenodiagnosis or kDNA-PCR was very high (mean, 55.8%; CI=48.4-63.1%) and exceeded 80% in 44% of the hosts. Cavies are highly-competent hosts of T. cruzi in peridomestic habitats near human dwellings in rural communities of Tucumán province in northwestern Argentina.

  2. Distribution and habitat of the Laotian Rock Rat Laonastesaenigmamus Jenkins, Kilpatrick, Robinson & Timmins, 2005 (Rodentia: Diatomyidae) in Vietnam.

    PubMed

    Nguyen, Dang Xuan; Nguyen, Nghia Xuan; Nguyen, Duy Dinh; Dinh, Tri Huy; Le, Dinh Thuc; Dinh, Duong Hai

    2014-01-01

    The Laotian Rock Rat Laonastesaenigmamus Jenkins, Kilpatrick, Robinson & Timmins, 2005 was originally discovered in Lao People's Democratic Republic in 2005. This species has been recognized as the sole surviving member of the otherwise extinct rodent family Diatomyidae. Laonastesaenigmamus was initially reported only in limestone forests of Khammouane Province, Central Lao. A second population was recently discovered in Phong Nha Ke Bang National Park (PNKB NP), Quang Binh Province, Central Vietnam in 2011. The confirmed distribution range of L.aenigmamus in Vietnam is very small, approximately 150 km(2), covering low karst mountains in five communes of Minh Hoa District, Quang Binh Province, at elevations between 250 and 400 m asl. The Laotian Rock Rat inhabits the lower part of steep karst towers with many rock boulders and crevices under tall limestone evergreen forest. They use small rock crevices for their dens. The natural habitat of this species in PNKB NP has been affected by selected timber harvesting, however, a complex 3-4 layer forest structure is retained. The Laotian Rock Rat is omnivorous, feeding on parts (leaves, buds, fruits and roots) of 18 plant species and also some insects (cicada, mantis, grasshopper). The population of this species in PNKB NP is seriously threatened with extinction due to its very restricted distribution, high hunting pressure, and habitat disturbance. Laonastesaenigmamus is listed in the IUCN Red List as endangered and in the Wildlife and Aquatic Red List of Lao, however, this species has not been listed in the Red Data Book or any conservation legislative documents of Vietnam.

  3. On cognitive ecology and the environmental factors that promote Alzheimer disease: lessons from Octodon degus (Rodentia: Octodontidae).

    PubMed

    Rivera, Daniela S; Inestrosa, Nibaldo C; Bozinovic, Francisco

    2016-02-20

    Cognitive ecologist posits that the more efficiently an animal uses information from the biotic and abiotic environment, the more adaptive are its cognitive abilities. Nevertheless, this approach does not test for natural neurodegenerative processes under field or experimental conditions, which may recover animals information processing and decision making and may explain, mechanistically, maladaptive behaviors. Here, we call for integrative approaches to explain the relationship between ultimate and proximate mechanisms behind social behavior. We highlight the importance of using the endemic caviomorph rodent Octodon degus as a valuable natural model for mechanistic studies of social behavior and to explain how physical environments can shape social experiences that might influence impaired cognitive abilities and the onset and progression of neurodegenerative disorders such as Alzheimer disease. We consequently suggest neuroecological approaches to examine how key elements of the environment may affect neural and cognitive mechanisms associated with learning, memory processes and brain structures involved in social behavior. We propose the following three core objectives of a program comprising interdisciplinary research in O. degus, namely: (1) to determine whether diet types provided after weaning can lead to cognitive impairment associated with spatial memory, learning and predisposing to develop Alzheimer disease in younger ages; (2) to examine if early life social experience has long term effects on behavior and cognitive responses and risk for development Alzheimer disease in later life and (3) To determine if an increase of social interactions in adult degu reared in different degree of social stressful conditions alter their behavior and cognitive responses.

  4. In the Wake of Invasion: Tracing the Historical Biogeography of the South American Cricetid Radiation (Rodentia, Sigmodontinae)

    PubMed Central

    Leite, Rafael N.; Kolokotronis, Sergios-Orestis; Almeida, Francisca C.; Werneck, Fernanda P.; Rogers, Duke S.; Weksler, Marcelo

    2014-01-01

    The Great American Biotic Interchange (GABI) was greatly influenced by the completion of the Isthmus of Panama and impacted the composition of modern faunal assemblages in the Americas. However, the contribution of preceding events has been comparatively less explored, even though early immigrants in the fossil records are evidence for waif dispersals. The cricetid rodents of the subfamily Sigmodontinae are a classic example of a species-rich South American radiation resulting from an early episode of North American invasion. Here, we provide a temporal and spatial framework to address key aspects of the historical biogeography and diversification of this diverse mammal group by using mitochondrial and nuclear DNA datasets coupled with methods of divergence time estimation, ancestral area reconstruction and comparative phylogenetics. Relaxed-clock time estimates indicate that divergence of the Sigmodontinae began in the middle–late Miocene (ca. 12–9 Ma). Dispersal-vicariance analyses point to the arrival of a single lineage of northern invaders with a widespread ancestral distribution and imply that the initial differentiation between Central and South America gave rise to the most basal groups within the subfamily. These two major clades diversified in the late Miocene followed by the radiation of main tribes until the early Pliocene. Within the Oryzomyalia, tribes diverged initially in eastern South America whereas multiple dispersals into the Andes promoted further diversification of the majority of modern genera. A comparatively uniform background tempo of diversification explains the species richness of sigmodontines across most nodes, except for two akodontine genera with recent increases in diversification rates. The bridging of the Central American seaway and episodes of low sea levels likely facilitated the invasion of South America long before the onset of the post-Isthmian phase of the GABI. PMID:24963664

  5. Population dynamics and bioenergetics of a fossorial herbivore, Thomomys talpoides (Rodentia: Geomyidae), in a spruce-fir sere

    USGS Publications Warehouse

    Andersen, Douglas C.; MacMahon, James A.

    1981-01-01

    Studies of the bioenergetics of the northern pocket gopher, Thomomys talpoides, are coupled with data on demography, activity budgets, and microclimates to model the energy requirements of individuals and populations in the Wasatch Mountains of Utah during 1976-1979. Metabolic rates during rest increased linearly with decreasing ambient temperature, but burrowing metabolic rates (16.3 mL O2 • h-1 • g-9.75) were independent of both temperature and physical properties of the soil. Radio-telemetry studies indicated that free-ranging gophers are active =50% of each day. Conservative estimates of true energy consumption were calculated using estimates of habitat-specific minimum daily burrowing requirements. Rates of burrowing measured in the laboratory were either ∞ 0.0 or ∞ 2.0 cm/min. The low burrowing rate was observed when the soil was frozen or saturated with water, as would occur in the field in early winter and in spring, respectively. Gophers burrowed through soil at the study site at an average rate of ∞ 1.5 cm/min. Belowground food energy densities at gopher foraging depth declined from 24.6 to 3.2 J/cm3 along a successional gradient (subalpine forb meadow to Engelmann spruce dominated forest). We conclude that individual gophers are food limited within the climax spruce seral stage. Further, daily energy costs associated with reproduction in females may exceed the belowground energy supply available in intermediate seral stages (aspen and subalpine fir). Reduction of burrowing rates for any reason will affect gophers in the late seral stages proportionately more than those resident in the meadow. The peak gopher densities recorded (from 62 individuals/ha in the meadow to 2 individuals/ha in spruce forest) support these inferences. Detailed demographic information was obtained only in the meadow seral stage. Adult survivorship was lower in winter than in summer and varied greatly between years (0.18-0.70 yr-1). Juvenile survivorship from weaning through the first year was comparable to adult annual rates. The fertility rate was 3.75 young • female-1 • yr-1. The energy supply and demand analyses indicate that the growth of Thomomys talpoides populations in the early seral stages is seldom directly limited by the amount of food present. From our demographic, environmental, and autecological studies we conclude that stochastic events associated with weather affect energy acquisition (burrowing) rates, and thus survivorship. In montane environments, such events may prevent populations from attaining sizes at which territorial behavior would hypothetically limit further increases. The energy flow through the meadow population at moderate to high )1976-1977) densities (at least 1100 MJ • ha-1 • yr-1) indicates that pocket gophers are proficient energy movers relative to non-fossorial small mammals. Subalpine T. talpoides populations appear commonly to attain such densities. More than 30% of the annual primary productivity allocated to belowground parts of meadow forbs may be consumed by gophers.

  6. Cryptic Species in Proechimys goeldii (Rodentia, Echimyidae)? A Case of Molecular and Chromosomal Differentiation in Allopatric Populations.

    PubMed

    Rodrigues da Costa, Marlyson J; Siqueira do Amaral, Paulo J; Pieczarka, Julio C; Sampaio, Maria I; Rossi, Rogério V; Mendes-Oliveira, Ana C; Rodrigues Noronha, Renata C; Nagamachi, Cleusa Y

    2016-01-01

    The spiny rats of the genus Proechimys have a wide distribution in the Amazon, covering all areas of endemism of this region. We analyzed the karyotype and cytochrome b (Cyt b) sequences in Proechimys goeldii from 6 localities representing 3 interfluves of the eastern Amazon. A clear separation of P. goeldii into 2 monophyletic clades was observed, both chromosomally and based on Cyt b sequences: cytotype A (2n = 26x2640;/27x2642;, NF = 42) for samples from the Tapajos-Xingu interfluve and cytotype B (2n = 24x2640;/25x2642;, NF = 42) for samples from the Xingu-Tocantins interfluve and east of the Tocantins River. The karyotypes differ in a pericentric inversion and a centric fusion/fission and an average nucleotide divergence of 6.1%, suggesting cryptic species. Meiotic analysis confirmed the presence of a XX/XY1Y2 multiple sex chromosome determination system for both karyotypes. The karyotypes also vary from the literature (2n = 24, NF = 42, XX/XY). The autosome translocated to the X chromosome is different both in size and morphology to P. cf. longicaudatus, which also has a multiple sex chromosome determination system (2n = 14x2640;/15x2640;x2642;/16x2640;/17x2642;, NF = 14). The Xingu River is a barrier that separates populations of P. goeldii, thus maintaining their allopatric nature and providing an explanation for the molecular and cytogenetic patterns observed for the Xingu River but not the Tocantins River. PMID:27255109

  7. Geographic Variation in Skull Morphology of the Large Japanese Field Mice, Apodemus speciosus (Rodentia: Muridae) Revealed by Geometric Morphometric Analysis.

    PubMed

    Shintaku, Yuta; Motokawa, Masaharu

    2016-04-01

    We analyzed geographic variation in skull morphology of the large Japanese field mouse (Apodemus speciosus) and determined changes in skull morphology that occurred during the evolutionary history of A. speciosus in relation to the estimated distribution range in the last glacial maximum (LGM). We analyzed 1,416 specimens from 78 localities using geometric morphometric techniques applied to the dorsal side of the cranium and mandible. While large variations within and among the populations in Honshu, Shikoku, and Kyushu were observed, geographic patterns were not observed. Hokkaido and peripheral island populations showed shared differentiation from the Honshu, Shikoku, and Kyushu populations with a larger skull and distinct mandible shape. In addition, these two groups also differed from each other in accumulated random shape variation. Common characteristics found in Hokkaido and peripheral island populations were considered to be the ancestral states, which were retained by geographic isolation from the main islands. Random variations in Hokkaido and the peripheral island populations were formed through stochastic processes in relation to their isolation. Characteristic morphologies widely found in the populations of Honshu, Shikoku, and Kyushu were considered to be derived states that expanded after separation from the peripheral islands. Complex geomorphology and a shift in distribution range related to climate change and altitudinal distribution are suggested to have formed the complex geographic variation in this species.

  8. Phylogenetic relationships in the Niviventer-Chiromyscus complex (Rodentia, Muridae) inferred from molecular data, with description of a new species

    PubMed Central

    Balakirev, Alexander E.; Abramov, Alexei V.; Rozhnov, Viatcheslav V.

    2014-01-01

    Abstract Based on molecular data for mitochondrial (Cyt b, COI) and nuclear (IRBP, GHR) genes, and morphological examinations of museum specimens, we examined diversity, species boundaries, and relationships within and between the murine genera Chiromyscus and Niviventer. Phylogenetic patterns recovered demonstrate that Niviventer sensu lato is not monophyletic but instead includes Chiromyscus chiropus, the only previously recognized species of Chiropus. To maintain the genera Niviventer and Chiropus as monophyletic lineages, the scope and definition of the genus Chiromyscus is revised to include at least three distinct species: Chiromyscus chiropus (the type species of Chiromyscus), Chiromyscus langbianis (previously regarded as a species of Niviventer), and a new species, described in this paper under the name Chiromyscus thomasi sp. n. PMID:25493050

  9. Comparative glycopattern analysis of mucins in the Brunner's glands of the guinea-pig and the house mouse (Rodentia).

    PubMed

    Scillitani, Giovanni; Mentino, Donatella

    2015-09-01

    The mucins secreted by the Brunner's glands and the duodenal goblet cells of the Guinea-pig and the house mouse were compared by conventional and FITC-conjugated lectin histochemistry. Methylation/saponification and sialidase digestion were performed prior to lectin binding to detect the residues subterminal to sulfated groups and sialic acid, respectively. In the Guinea-pig the Brunner's glands produce class-III stable sulfosialomucins. Sialic acid is mostly 2,6-linked to galactose or to N-acetylgalactosamine and is in part O-acetylated in C7, C8, and C9. Sulfated groups are probably linked to sialic acid and N-acetylgalactosamine. Terminal residuals of N-acetylglucosamine, galactose, N-acetylgalactosamine and fucose linked in α1,2, α1,3, and α1,4 are also present. Duodenal goblet cells of the Guinea-pig present a lower number of residuals in respect to the Brunner's glandular ones, with sialic acid and N-acetylgalactosamine subterminal to sulfated groups. In the house mouse the Brunner's glands produce class-III stable neutral mucins, binding to same lectins as in the Guinea-pig except for those specific to sialic acid. A diversity of fucosylated residuals higher than in the Guinea-pig is observed. The mouse duodenal goblet cells lack stable class-III mucins, have little sialic acid and present a lower number of residuals in respect to the correspondent Brunner's glands. Regulation of the acidic intestinal microenvironment, prevention of pathologies and hosting of microflora can explain the observed results and the differences observed between the two rodents.

  10. Chronology and causes of the extinction of the Lava Mouse, Malpaisomys insularis (Rodentia: Muridae) from the Canary Islands

    NASA Astrophysics Data System (ADS)

    Rando, Juan Carlos; Alcover, Josep Antoni; Navarro, Juan Francisco; García-Talavera, Francisco; Hutterer, Rainer; Michaux, Jacques

    2008-09-01

    Understanding late Holocene extinctions on islands requires accurate chronologies for all relevant events, including multiple colonisations by humans and the introduction of alien species. The most widely held hypothesis on the causes of Holocene island vertebrate extinctions incorporates human impacts, although climatic-related hypotheses cannot be excluded. Both hypotheses have been suggested to account for the extinction of the endemic Lava Mouse, Malpaisomys insularis from the Canary Islands. Here we present the first accelerator mass spectrometer (AMS) 14C ages from collagen of M. insularis bones from ancient owl pellets collected at Fuerteventura (Canary Islands, eastern Atlantic Ocean). These new dates contribute to an understanding of the extinction of this species. We are able to exclude climatic causes, predation by invasive species, and competition with the house mouse, Mus musculus. The arrival of Europeans in the Canary Islands correlates with the extinction of Malpaisomys. The introduction of rats, Rattus spp., together with their parasites and diseases, emerges as the most reasonable hypothesis explaining the extinction of M. insularis.

  11. Distribution and habitat of the Laotian Rock Rat Laonastes aenigmamus Jenkins, Kilpatrick, Robinson & Timmins, 2005 (Rodentia: Diatomyidae) in Vietnam

    PubMed Central

    Nguyen, Nghia Xuan; Nguyen, Duy Dinh; Dinh, Tri Huy; Le, Dinh Thuc; Dinh, Duong Hai

    2014-01-01

    Abstract The Laotian Rock Rat Laonastes aenigmamus Jenkins, Kilpatrick, Robinson & Timmins, 2005 was originally discovered in Lao People's Democratic Republic in 2005. This species has been recognized as the sole surviving member of the otherwise extinct rodent family Diatomyidae. Laonastes aenigmamus was initially reported only in limestone forests of Khammouane Province, Central Lao. A second population was recently discovered in Phong Nha Ke Bang National Park (PNKB NP), Quang Binh Province, Central Vietnam in 2011. The confirmed distribution range of L. aenigmamus in Vietnam is very small, approximately 150 km2, covering low karst mountains in five communes of Minh Hoa District, Quang Binh Province, at elevations between 250 and 400 m asl. The Laotian Rock Rat inhabits the lower part of steep karst towers with many rock boulders and crevices under tall limestone evergreen forest. They use small rock crevices for their dens. The natural habitat of this species in PNKB NP has been affected by selected timber harvesting, however, a complex 3-4 layer forest structure is retained. The Laotian Rock Rat is omnivorous, feeding on parts (leaves, buds, fruits and roots) of 18 plant species and also some insects (cicada, mantis, grasshopper). The population of this species in PNKB NP is seriously threatened with extinction due to its very restricted distribution, high hunting pressure, and habitat disturbance. Laonastes aenigmamus is listed in the IUCN Red List as endangered and in the Wildlife and Aquatic Red List of Lao, however, this species has not been listed in the Red Data Book or any conservation legislative documents of Vietnam. PMID:25589873

  12. Multivariate discrimination among cryptic mites of the genus Androlaelaps (Acari: Mesostigmata: Laelapidae) parasitic of sympatric akodontine rodents (Cricetidae: Sigmodontinae) in northeastern Argentina: possible evidence of host switch followed by speciation, with the description of two new species.

    PubMed

    Lareschi, Marcela; Galliari, Carlos

    2014-12-01

    Laelapids are among the most common ectoparasites of rodents. Currently, it is under discussion whether there is a single polixenous species that parasites a variety of hosts, or whether there are cryptic species highly host specific. Herein, multivariate morphometric analyses of cryptic sympatric laelapids of the genus Androlaelaps allowed us to identify different species. These species are specific of their akodontine hosts, Akodon montensis and Thaptomys nigrita, in localities situated in northeastern Argentina. In addition, we analyzed similar laelapids associated with the akodontines Deltamys kempi and Akodon cursor. Using principle component analyses we differentiated four laelapid species, each one host specific, independent of sympatry of the hosts, and without geographical variation. From these four species, we described two new species (Androlaelaps navonae n. sp. and Androlaelaps wingei n. sp.). We determined the four species based on a range of variations in several characters, mainly size. These four laelapid species belong to the Androlaelaps rotundus species group, specific to akodontines. These species are very similar among them but differ from the remainder species of the group by their small size, distance between j6 setae similar to the distance between the z5 setae, strong ventral setae, opisthogaster with 13 pairs of strong setae (one close to the distal margin of epigynal shield), and anal shield wider than long. Further studies will elucidate whether they constitute a new laelapid genus. Phylogenetic and ecological factors influencing host-specificity are discussed, and we propose that host colonization could have taken place by host switching of a single laelapid species among rodent species, followed by speciation. PMID:25039004

  13. Four new coccidia (Apicomplexa: Eimeriidae) from the Plateau zokor, Myospalax baileyi Thomas (Rodentia: Myospalacinae), a subterranean rodent from Haibei area, Qinghai Province, China.

    PubMed

    Cao, Yi-Fan; Nie, Xu-Heng; Zhang, Tong-Zuo; Du, Shou-Yang; Duszynski, Donald W; Bian, Jiang-Hui

    2014-02-01

    Thirty-eight faecal samples from the Plateau zokor, Myospalax baileyi Thomas, collected in the Haibei Area, Qinghai Province, China, were examined for the presence of coccidia (Apicomplexa: Eimeriidae). Seventeen of 38 faecal samples (44.7%) were found to contain coccidian oöcysts representing four new species of Eimeria Schneider, 1875, and four of 17 (23.5%) infected zokors were concurrently infected with two or three of these eimerian species. The sporulated oöcysts of Eimeria myospalacensis n. sp. are ovoidal, 9.5-17.0 × 8.0-13.0 (mean 13.0 × 10.4) μm; a polar granule is present, oöcyst residuum is absent; sporocysts are ovoidal, 4.5-7.5 × 3.0-5.0 (mean 6.3 × 4.2) μm and have both a Stieda body and residuum. Oöcysts of Eimeria fani n. sp. are ellipsoidal to cylindroidal, 12.5-16.0 × 8.0-11.0 (mean 14.6 × 9.9) μm; a polar granule is present, but micropyle and residuum are lacking; sporocysts are ovoidal, 4.5-7.5 × 3.0-5.3 (mean 6.7 × 4.4) μm; a residuum and a Steida body are present. Oöcysts of Eimeria baileyii n. sp. are ellipsoidal, 15.0-23.0 × 12.0-18.0 (mean 18.2 × 13.7) μm; a polar granule is present but oöcyst residuum is absent; sporocysts are ovoidal, 8.0-11.0 × 5.0-7.0 (mean 9.5 × 5.9) μm and have both a Stieda body and residuum. Oöcysts of Eimeria menyuanensis n. sp. are ovoidal, 12.5-21.0 × 11.0-18.0 (mean 17.1 × 14.6) μm, with a distinct micropyle c.2.5 μm wide; a polar granule is present but a residuum is absent; sporocysts are ovoidal, 8.0-12.0 × 5.0-7.0 (mean 10.2 × 6.4) μm, and have both a Stieda body and residuum.

  14. Variation in progesterone receptors and GnRH expression in the hypothalamus of the pregnant South American plains vizcacha, Lagostomus maximus (Mammalia, Rodentia).

    PubMed

    Dorfman, Verónica Berta; Saucedo, Lucía; Di Giorgio, Noelia Paula; Inserra, Pablo Ignacio Felipe; Fraunhoffer, Nicolás; Leopardo, Noelia Paola; Halperín, Julia; Lux-Lantos, Victoria; Vitullo, Alfredo Daniel

    2013-11-01

    In mammals, elevated levels of progesterone (P4) throughout gestation maintain a negative feedback over the hypothalamic-hypophyseal-gonadal (H-H-G) axis, avoiding preovulatory follicular growth and preventing ovulation. Recent studies showed that in the South American plains vizcacha (Lagostomus maximus) folliculogenesis progresses to preovulatory stages during gestation, and an ovulatory process seems to occur at midgestation. The aim of this work was to analyze hypothalamic gonadotropin-releasing hormone (GnRH) and P4 receptors (PR) expression and luteinizing hormone (LH) secretion and correlate these with the functional state of the ovary in nonovulating and ovulating females and gestating females with special emphasis in the supposedly ovulating females at midgestation. We investigated P4 and LH serum levels as well as the distribution, localization, and expression of PR and GnRH in the hypothalamus of L. maximus at different time points during gestation and in nongestating, ovulating and nonovulating, females. A significant increment in GnRH, P4, and LH was detected in midpregnant vizcachas with respect to early-pregnant and to ovulating females. PR was also significantly increased in midpregnant animals. PR was detected in neurons of the preoptic and hypothalamic areas. Coexistence of both PR and GnRH in neurons of medial preoptic area and supraoptic nucleus was detected. Midpregnant animals showed increased number of PR immunoreactive cells at median eminence, localized adjacently to GnRH immunoreactive fibers. High expression of hypothalamic GnRH and PR, despite an increased level of P4, was correlated with the presence of antral, preovulatory follicles, and luteinized unruptured follicles at midgestation that suggest a possible role of the H-H-G axis in the modulation of ovulation during gestation in L. maximus.

  15. The role of chromosomal rearrangements and geographical barriers in the divergence of lineages in a South American subterranean rodent (Rodentia: Ctenomyidae: Ctenomys minutus).

    PubMed

    Lopes, C M; Ximenes, S S F; Gava, A; de Freitas, T R O

    2013-10-01

    Identifying factors and the extent of their roles in the differentiation of populations is of great importance for understanding the evolutionary process in which a species is involved. Ctenomys minutus is a highly karyotype-polymorphic subterranean rodent, with diploid numbers ranging from 42 to 50 and autosomal arm numbers (ANs) ranging from 68 to 80, comprising a total of 45 karyotypes described so far. This species inhabits the southern Brazilian coastal plain, which has a complex geological history, with several potential geographical barriers acting on different time scales. We assessed the geographical genetic structure of C. minutus, examining 340 individuals over the entire distributional range and using information from chromosomal rearrangements, mitochondrial DNA (mtDNA) sequences and 14 microsatellite loci. The mtDNA results revealed seven main haplogroups, with the most recent common ancestors dating from the Pleistocene, whereas clustering methods defined 12 populations. Some boundaries of mtDNA haplogroups and population clusters can be associated with potential geographical barriers to gene flow. The isolation-by-distance pattern also has an important role in fine-scale genetic differentiation, which is strengthened by the narrowness of the coastal plain and by common features of subterranean rodents (that is, small fragmented populations and low dispersal rates), which limit gene flow among populations. A step-by-step mechanism of chromosomal evolution can be suggested for this species, mainly associated with the metapopulation structure, genetic drift and the geographical features of the southern Brazilian coastal plain. However, chromosomal variations have no or very little role in the diversification of C. minutus populations.

  16. [Patterns of morphological variability in reintroduced populations with two beaver subspecies Castor fiber orientoeuropaeus and Castor fiber belorussicus (Castoridae, Rodentia) as an example].

    PubMed

    Korablev, N P; Korablev, P N

    2012-01-01

    Taking as an example two beaver subspecies (Castor fiber orientoeuropaeus and Castor fiber belorussicus) with documented history of population formation, the patterns of morphological variability in translocated groups of mammals are studied. The variability of quantitative and qualitative traits in the formed populations is not characterized by a single direction. The main trend consists in increasing of adaptive norms diversity as related to body size. There observed a slight increase in the level of fluctuating asymmetry, reduction in polymorphism of nonmetric traits, and increase in fraction of rare aberrations. All these may be caused by inbreeding taking place during the period of prapopulations formation. The results of the study allow for considering the intraspecific differentiation as a consequence of adaptive variability (adaptatiogenesis) or subspecies hybridization. As for stochastic processes (genetic drift, founder effect), they seem to not influence the morphological variability significantly. The differences between discrete and dimensional traits are indicative of population groups' peculiarity.

  17. Bartonella jaculi sp. nov., Bartonella callosciuri sp. nov., Bartonella pachyuromydis sp. nov. and Bartonella acomydis sp. nov., isolated from wild Rodentia.

    PubMed

    Sato, Shingo; Kabeya, Hidenori; Fujinaga, Yuta; Inoue, Kai; Une, Yumi; Yoshikawa, Yasuhiro; Maruyama, Soichi

    2013-05-01

    Four novel strains of members of the genus Bartonella, OY2-1(T), BR11-1(T), FN15-2(T) and KS2-1(T), were isolated from the blood of wild-captured greater Egyptian jerboa (Jaculus orientalis), plantain squirrel (Callosciurus notatus), fat-tailed gerbil (Pachyuromys duprasi) and golden spiny mouse (Acomys russatus). All the animals were imported to Japan as pets from Egypt, Thailand and the Netherlands. The phenotypic characterization (growth conditions, incubation periods, biochemical properties and cell morphologies), DNA G+C contents (37.4 mol% for strain OY2-1(T), 35.5 mol% for strain BR11-1(T), 35.7 mol% for strain FN15-2(T) and 37.2 mol% for strain KS2-1(T)), and sequence analyses of the 16S rRNA genes indicated that those strains belong to the genus Bartonella. Sequence comparisons of gltA and rpoB genes suggested that all of the strains should be classified as novel species of the genus Bartonella. In phylogenetic trees based on the concatenated sequences of five loci, including the 16S rRNA, ftsZ, gltA and rpoB genes and the ITS region, and on the concatenated deduced amino acid sequences of three housekeeping genes (ftsZ, gltA and rpoB), all strains formed distinct clades and had unique mammalian hosts that could be discriminated from other known species of the genus Bartonella. These data strongly support the hypothesis that strains OY2-1(T), BR11-1(T), FN15-2(T) and KS2-1(T) should be classified as representing novel species of the genus Bartonella. The names Bartonella jaculi sp. nov., Bartonella callosciuri sp. nov., Bartonella pachyuromydis sp. nov. and Bartonella acomydis sp. nov. are proposed for these novel species. Type strains of Bartonella jaculi sp. nov., Bartonella callosciuri sp. nov., Bartonella pachyuromydis sp. nov. and Bartonella acomydis sp. nov. are OY2-1(T) ( = JCM 17712(T) = KCTC 23655(T)), BR11-1(T) ( = JCM 17709(T) = KCTC 23909(T)), FN15-2(T) ( = JCM 17714(T) = KCTC 23657(T)) and KS2-1(T) ( = JCM 17706(T) = KCTC 23907(T)), respectively.

  18. Parasitic protozoa of the blood of rodents. VI. Two new hemogregarines of the pygmy flying squirrel Idiurus macrotis (Rodentia: Theridomyomorpha: Anomaluridae) in West Africa.

    PubMed

    Killick-Kendrick, R

    1984-11-01

    Descriptions are given of two new species of Hepatozoon Miller, 1908 found in the pygmy squirrel, Idiurus macrotis, in the Ivory Coast. Gamonts of both are parasites of monocytes. The size and shape of the gamonts of one, H. normani n. sp., are similar to those of a number of gamonts of other species of rodent hemogregarines and the separate identity of the parasite is based on the host restriction of mammalian hemogregarines. The gamonts of the other species, H. dolichomorphon n. sp., are remarkably long and slender and are unlike those of any other known hemogregarine of mammals. Schizonts of this species were found in a smear prepared from heart blood. PMID:6096538

  19. Phylogenetic relationships among Japanese species of the family Sciuridae (Mammalia, Rodentia), inferred from nucleotide sequences of mitochondrial 12S ribosomal RNA genes.

    PubMed

    Oshida, T; Masuda, R; Yoshida, M C

    1996-08-01

    In order to investigate phylogenetic relationships of the family Sciuridae living in Japan, we sequenced partial regions (379 bases) of mitochondrial 12S rRNA genes in six species of Japanese and other Asian squirrels. Phylogenetic trees constructed by sequence data indicated that two genera of flying squirrels (Petaurista and Pteromys) were clustered in a group distinct from non-flying squirrels, suggesting a possible monophyletic relationships of these flying squirrels. The evolutionary distance between the Japanese squirrel (Sciurus lis) from Honshu island and the Eurasian red squirrel (Sciurus vulgaris) from Hokkaido island was comparable to intraspecific distances of the remaining species examined. PMID:8940915

  20. 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

    Elbel, Robert E; Bossard, Robert L

    2007-11-01

    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

  1. Characterization of the Kidney Transcriptome of the Long-Haired Mouse Abrothrix hirta (Rodentia, Sigmodontinae) and Comparison with That of the Olive Mouse A. olivacea

    PubMed Central

    Valdez, Lourdes; Giorello, Facundo; Feijoo, Matías; Opazo, Juan C.; Lessa, Enrique P.; Naya, Daniel E.; D’Elía, Guillermo

    2015-01-01

    To understand how small mammals cope with the challenge of water homeostasis is a matter of interest for ecologists and evolutionary biologists. Here we take a step towards the understanding of the transcriptomic functional response of kidney using as a model the long–haired mouse (Abrothrix hirta) a species that distributes across Patagonian steppes and Austral temperate rainforests in Argentina and Chile. Specifically, we i) characterize the renal transcriptome of A. hirta, and ii) compare it with that—already available—of the co-generic and co-distributed A. olivacea. Renal mRNA transcripts from 16 specimens of A. hirta from natural populations were analyzed. Over 500 million Illumina paired-end reads were assembled de novo under two approaches, an individual assembly for each specimen, and a single in-silico normalized joint assembly including all reads from all specimens. The total number of annotated genes was similar with both strategies: an average of 14,956 in individual assemblies and 14,410 in the joint assembly. Overall, 15,463 distinct genes express in the kidney of A. hirta. Transcriptomes of A. hirta and A. olivacea were similar in terms of gene abundance and composition: 95.6% of the genes of A. hirta were also found in A. olivacea making their functional profiles also similar. However, differences in the transcriptome of these two species were observed in the set of highly expressed genes, in terms of private genes for each species and the functional profiles of highly expressed genes. As part of the novel transcriptome characterization, we provide distinct gene lists with their functional annotation that would constitute the basis for further research on these or any other species of the subfamily Sigmodontinae, which includes about 400 living species distributed from Tierra del Fuego to southern United States. PMID:25860131

  2. Panic-like defensive behavior but not fear-induced antinociception is differently organized by dorsomedial and posterior hypothalamic nuclei of Rattus norvegicus (Rodentia, Muridae).

    PubMed

    Biagioni, A F; Silva, J A; Coimbra, N C

    2012-04-01

    The hypothalamus is a forebrain structure critically involved in the organization of defensive responses to aversive stimuli. Gamma-aminobutyric acid (GABA)ergic dysfunction in dorsomedial and posterior hypothalamic nuclei is implicated in the origin of panic-like defensive behavior, as well as in pain modulation. The present study was conducted to test the difference between these two hypothalamic nuclei regarding defensive and antinociceptive mechanisms. Thus, the GABA(A) antagonist bicuculline (40 ng/0.2 µL) or saline (0.9% NaCl) was microinjected into the dorsomedial or posterior hypothalamus in independent groups. Innate fear-induced responses characterized by defensive attention, defensive immobility and elaborate escape behavior were evoked by hypothalamic blockade of GABA(A) receptors. Fear-induced defensive behavior organized by the posterior hypothalamus was more intense than that organized by dorsomedial hypothalamic nuclei. Escape behavior elicited by GABA(A) receptor blockade in both the dorsomedial and posterior hypothalamus was followed by an increase in nociceptive threshold. Interestingly, there was no difference in the intensity or in the duration of fear-induced antinociception shown by each hypothalamic division presently investigated. The present study showed that GABAergic dysfunction in nuclei of both the dorsomedial and posterior hypothalamus elicit panic attack-like defensive responses followed by fear-induced antinociception, although the innate fear-induced behavior originates differently in the posterior hypothalamus in comparison to the activity of medial hypothalamic subdivisions. PMID:22437484

  3. Two New Species of Demodex (Acari: Demodecidae) with a Redescription of Demodex musculi and Data on Parasitism in Mus musculus (Rodentia: Muridae).

    PubMed

    Izdebska, Joanna N; Rolbiecki, Leszek

    2015-07-01

    This article describes two new skin mite species found on the house mouse Mus musculus L., 1758. Demodex marculus sp. nov. is a very small demodecid mite (adult stages, on average, 99 µm in length) found in mouse skin in the abdomen, back, limbs, and anal area. It is characterized by relatively large bossing hammer-shaped supracoxal spines, embedded in the trapezoidal gnathosoma. Demodex fusiformis sp. nov., in turn, is a little larger (adult stages on average 111 µm in length), with a small oval gnathosoma equipped with fine, knob-like supracoxal spines. It was found in the skin of abdomen, back, and limbs. Moreover, Demodex musculi (Oudemans, 1897) was redescribed, which is small demodecid mite (adult stages on average 142 µm in length) and characterized by relatively large morphological variation and considerable sexual dimorphism. The characteristic feature of this species is the strongly elongated and rectangular gnathosoma equipped with very large wedge-shaped supracoxal spines. D. musculi was found in the skin of various, haired regions of the mice body (head, neck, abdomen, back, limbs, genital-anal region, and tail). Moreover, one more demodecid mite was found in the skin of the examined mice, it was Demodex flagellurus Bukva, 1985, which was found only in the genital area. Overall infection of Mus musculus L. by all species of Demodex was with the prevalence of 100%, mean intensity of 24.0, and range of intensity of 1-109. Despite high infection levels, no symptoms of parasitosis were observed in the hosts. PMID:26335466

  4. A new species of the genus Demodex Owen, 1843 (Acari: Demodecidae) from the ear canals of the house mouse Mus musculus L. (Rodentia: Muridae).

    PubMed

    Izdebska, Joanna N; Rolbiecki, Leszek

    2015-06-01

    A new species Demodex conicus n. sp. is described based on adult and juvenile stages from the ear canals of the house mouse Mus musculus L. in Poland. The new species is most similar to D. auricularis Izdebska, Rolbiecki & Fryderyk, 2014 from the ear canals of the wood mouse Apodemus sylvaticus (L.), but differs in the following features: the gnathosoma is triangular, the supracoxal spines (setae elc.p) are conical, the spines on the terminal segment of palp are four, the striation on opisthosoma is fine but dense, the vulva is located at a distance of c.17 µm from posterior level of legs IV, and the male genital opening is located at the level of legs I. The differences also relate to body size and proportions, female D. conicus n. sp. being, on average slightly larger, and male significantly larger than D. auricularis. Males of the new species also have longer and more massive opisthosoma than males of D. auricularis. Demodex conicus n. sp. was found in 17.5% of the mice studied from different locations in Poland. PMID:25962464

  5. [Spatial distribution of Marmota baibacina and M. sibirica (Marmota, Sciuridae, Rodentia) in a zone of sympatry in Mongolian Altai: bioacoustic analysis].

    PubMed

    Brandler, O V; Nikol'skiĭ, A A; Kolesnikov, V V

    2010-01-01

    The spatial distribution of two marmot species Marmota baibacina and M. sibirica in a zone of coexistence was studied by using their alarm call as a diagnostic trait. It was found that M. baibacina prefers to inhabit bouldery screes, whereas M. sibirica inhabits all suitable biotopes. The difference in biotopic distribution of these species could be explained by M. sibirica forcing M. baibacina out of optimum habitats. Cases of coexistence of both species in one family group sites were registered, which might contribute to the appearance of hybrids.

  6. Causes and consequences of change rates in the habitat of the threatened tropical porcupine, Sphiggurus mexicanus (Rodentia: Erethizontidae) in Oaxaca, Mexico: implications for its conservation.

    PubMed

    Lorenzo, Consuelo; Sántiz, Eugenia C; Navarrete, Darío A; Bolaños, Jorge

    2014-12-01

    Land use changes by human activities have been the main causes of habitats and wildlife population degradation. In the Tehuantepec Isthmus in Oaxaca, the tropical habitat of the porcupine Sphiggurus mexicanus has been subject to vegetation and land use changes, causing its reduction and fragmentation. In this study, we estimated vegetation cover and land use (δn) change rates and assessed habitat availability and potential cor- ridors for possible porcupine movements to avoid its isolation. In the study area, the type of vegetation with the most change rate value was the savanna (δn = -2.9), transformed into induced grasslands. Additionally, we have observed the porcupine (since 2011) in semi-deciduous (δn = -0.87) and tropical dry (δn = -0.89) forests that have been transformed in temporal agriculture and mesquite and induced grasslands. The vegetation inhabited by the porcupine resulted in recording a total of 64 plant species (44 trees, nine vines, seven herbs, four shrubs), of which the vine Bunchosia lanceolata showed the highest importance value (41.85) followed by the trees Guazuma ulmifolia (22.71), Dalbergia glabra (18.05), and Enterolobium cyclocarpum (17.02). The habitat evaluation and potential corridor analysis showed that only 1 501.93ha could be considered as suitable habitats with optimum structural conditions (coverage, surface, and distances to transformed areas) to maintain viable populations of S. mexicanus, and 293.6 ha as corridors. An increasing destruction of the porcupines' habitat has been observed in the study area due to excessive logging, and actions for this species and its habitat conserva- tion and management have to be taken urgently.

  7. [A modular approach to studying of fluctuating asymmetry of complex morphological structures in rodents with the mandible of the bank vole (Clethrionomys glareolus, Arvicolinae, Rodentia) as an example].

    PubMed

    Ialkovskaia, L É; Borodin, A V; Fominykh, M A

    2014-01-01

    The expediency of a modular approach to estimating fluctuating asymmetry (FA) of complex morphological structures was shown using the mandible of the bank vole (Clethrionomys glareolus Schreber, 1780) as an example. FA of the shape of two mandibular regions (modules) defined developmentally and functionally, was assessed by means of geometric morphometrics. The differences between mandibular regions in the FA levels were found for both individual landmarks and integral indices of asymmetry. Regardless of age, gender or sampling year, FA estimates obtained for posterior region including part of the ramus and processes were higher than those for anterior region including the diastemal area. The results suggest that modularity of complex morphological structures should be taken into account when analyzing FA.

  8. A new species of swamp rat of the genus Scapteromys waterhouse, 1837 (Rodentia: Sigmodontinae) endemic to Araucaria angustifolia forest in Southern Brazil.

    PubMed

    Quintela, Fernando Marques; Gonçalves, Gislene Lopes; Althoff, Sérgio Luiz; Sbalqueiro, Ives Jose; Oliveira, Luiz Flamarion Barbosa; De Freitas, Thales Renato Ochotorena

    2014-01-01

    A new species of swamp rat of the genus Scapteromys from the Meridional Plateau of Southern Brazil is described. Morphological, molecular, and karyological analysis support the recognition of the new species, distinct from S. aquaticus and S. tumidus. Scapteromys sp. nov. is significantly smaller than the congeneric taxa considering most of the external and craniometric measurements and the pelage is conspicuously grayer and darker. It can be distinguished from S. tumidus by the laterally extended thenar pad of the manus and the parallel edges of the hamular process of the pterygoid, and from S. aquaticus by a grayer and darker pelage and smaller values of most external and craniometric measurements. Karyological analysis indicated a difference in chromosome numbers across the distributional range: 2n=34 and 2n=36. A total of 11 haplotypes were found along the range of the new species within the biogeographic province of Araucaria angustifolia Forest. Strongly supported substructure was found within the new taxon, resulting in two reciprocally monophyletic clades.

  9. Stress-associated radiation effects in pygmy wood mouse Apodemus uralensis (Muridae, Rodentia) populations from the East-Urals Radioactive Trace.

    PubMed

    Orekhova, Natal'ya A; Modorov, Makar V

    2016-09-01

    This work is based on the comparative analysis of data obtained in the course of monitoring pygmy wood mouse populations (Apodemus uralensis Pallas, 1811) in the East-Urals Radioactive Trace (EURT) area and background territories. The effect of population size and its interaction with the radioactivity on biochemical parameters in the spleen and adrenal glands was studied. The concentrations of total lipids, proteins, DNA and RNA, activity of glucose-6-phosphate isomerase and catalase as well as the level of lipid peroxidation (LPO) were evaluated. The functional-metabolic shifts seen with large population sizes were characterized by delipidisation of adrenocortical cells, increased LPO as the main mechanism for steroidogenesis, growth of the protein components of the adrenal glands to maintain their hyperfunction, as well as immunosuppression associated with the restriction of carbohydrates providing splenocytes, reduction of DNA synthesis, and the development of a pro-/antioxidant imbalance. Reactivity of the neuroendocrine and hematopoietic systems of animals experiencing a high population density was higher in the EURT zone compared with the reference group. This difference can be explained by the additional stress from the chronic radiation exposure. The level of LPO, catalase activity, and DNA/protein ratio in the spleen and the total protein content in the adrenal glands were the most sensitive to the interaction of population size and radiation exposure. The harmful effect (distress) of the interaction of non-radiation and radiation factors can manifest when there is a population abundance above 30 ind./100 trap-day and a radiation burden which exceeds the lower boundary of the Derived Consideration Reference Levels, which is above 0.1 mGy/day.

  10. The gastrointestinal helminths of Lorentzimys nouhuysi (Rodentia: Muridae) with descriptions of two new genera and three new species (Nematoda) from Papua New Guinea.

    PubMed

    Smales, L R

    2010-06-01

    Helminths, 3 cestode and 8 nematode species, including 2 new genera, 5 new species, and 1 putative new species, of nematode were collected from the digestive tracts of 23 Lorentzimys nouhuysi (Murinae; Hydromyini) from Papua New Guinea. Odilia wauensis n. sp. (Heligmonellidae) most closely resembles Odilia mallomyos Hasegawa and Syafruddin, 1994, but differs from this species in the detail of the synlophe ridges, the length and tip shape of the spicules, the absence of a gubernaculum, and the size of the eggs. Papuastrongylus kishinamiae n. gen., n. sp. differs from all other genera in the Herpetostrongylidae in the form of the synlophe and spicules, the lack of a gubernaculum, and in being monodelphic. Syphacia lorentzimyos n. sp. and Syphacia mamelonitenuis n. sp. (Oxyuridae) differ from all other species in having a circular cephalic plate and from each other in that S. mamelonitenuis lacks lateral alae. Lorentzicola woolleyae n. gen., n. sp. differs from all other genera in the Oxyuridae (Syphaciini) in having the peribuccal wall with denticles, a simple esophagus, and males with 3 mamelons of the Syphacia type. The helminth assemblage of L. nouhuysi did not resemble that of any other hydromyin rodent from the region studied thus far.

  11. Nematodes of Heligmonellidae (Strongylida) of Pogonomys championi Flannery and Pogonomys sylvestris Thomas (Rodentia: Muridae) from Papua New Guinea with descriptions of five new species.

    PubMed

    Smales, Lesley R

    2015-10-01

    Eight species of heligmonellid nematodes including five new species and a putative new species were identified from the digestive tracts of 12 Pogonomys championi Flannery and 27 P. sylvestris Thomas (Murinae: Hydromyini) from Papua Indonesia. Hasanuddinia pogonomyos Smales, 2014 had been previously described from P. loriae Thomas and P. macrourus (Milne-Edwards) and Odilia mackerrasae (Mawson, 1961) from several endemic rodent species. Bunomystrongylus ilami n. sp. can be distinguished from its congeners by the number of rounded ridges in the synlophe; Hasanuddinia hasegawai n. sp. by the number of ridges, three ventral being hypertrophied, in the synlophe; Montistrongylus kaindiensis n. sp. by the number of ridges in the synlophe and the length of the spicules; Odilia helgeni n. sp. in the characters of the synlophe ridges; Odilia whittingtoni n. sp. in the characters of the synlophe ridges and the length of the spicules. Species richness of the nematode assemblage of P. sylvestris, nine species and a juvenile heligmonellid, was comparable to those of P. loriae and P. macrourus but that of P. championi, five species, was considered depauperate. Species composition showed both commonalities between the host species as well as distinctive features. Three of five species in the assemblage were unique to P. championi and five of nine species to P. sylvestris.

  12. [Experimental hybridization of voies of the genus Microtus s.l. M. socialis with species of the group arvalis (Mammalia, Rodentia)].

    PubMed

    Koval'skaia, Iu M; Savinetskaia, L E; Aksenova, T G

    2014-01-01

    The results of interspecific crosses of the social vole Microtus socialis with the Altai vole M. obscurus, the East European vole M. rossiaemeridionalis, and the Transcaspian vole M. transcaspicus are presented. The role of the sperm head structure in the reproductive isolation of this species was studied. Hybrids were obtained in five of the six crossing combinations. It is established that significant differences in the sperm head shape in the social vole and in arvalis group species do not prevent fertilization. The sterility of hybrids indicates the existence of postcopulative mechanisms of reproductive isolation.

  13. Development of nine new microsatellite loci for the American beaver, Castor canadensis (Rodentia: Castoridae), and cross-species amplification in the European beaver, Castor fiber

    USGS Publications Warehouse

    Pelz-Serrano, K.; Munguia-Vega, A.; Piaggio, A.J.; Neubaum, M.; Munclinger, P.; PArtl, A.; van Riper, Charles; Culver, M.

    2009-01-01

    We developed nine new nuclear dinucleotide microsatellite loci for Castor canadensis. All loci were polymorphic, except for one. The number of alleles ranged from two to four and from five to 12 in populations from Arizona and Wisconsin, respectively. Average heterozygosity ranged from 0.13 to 0.86 per locus. Since cross-species amplification in Castor fiber was successful only in four loci, we tested also nine recently published C. canadensis loci in the Eurasian species. Eight of the published loci amplified; however, three were monomorphic. The number of alleles was lower in C. fiber than in C. canadensis at all loci tested. ?? 2009 Blackwell Publishing Ltd.

  14. Stress-associated radiation effects in pygmy wood mouse Apodemus uralensis (Muridae, Rodentia) populations from the East-Urals Radioactive Trace.

    PubMed

    Orekhova, Natal'ya A; Modorov, Makar V

    2016-09-01

    This work is based on the comparative analysis of data obtained in the course of monitoring pygmy wood mouse populations (Apodemus uralensis Pallas, 1811) in the East-Urals Radioactive Trace (EURT) area and background territories. The effect of population size and its interaction with the radioactivity on biochemical parameters in the spleen and adrenal glands was studied. The concentrations of total lipids, proteins, DNA and RNA, activity of glucose-6-phosphate isomerase and catalase as well as the level of lipid peroxidation (LPO) were evaluated. The functional-metabolic shifts seen with large population sizes were characterized by delipidisation of adrenocortical cells, increased LPO as the main mechanism for steroidogenesis, growth of the protein components of the adrenal glands to maintain their hyperfunction, as well as immunosuppression associated with the restriction of carbohydrates providing splenocytes, reduction of DNA synthesis, and the development of a pro-/antioxidant imbalance. Reactivity of the neuroendocrine and hematopoietic systems of animals experiencing a high population density was higher in the EURT zone compared with the reference group. This difference can be explained by the additional stress from the chronic radiation exposure. The level of LPO, catalase activity, and DNA/protein ratio in the spleen and the total protein content in the adrenal glands were the most sensitive to the interaction of population size and radiation exposure. The harmful effect (distress) of the interaction of non-radiation and radiation factors can manifest when there is a population abundance above 30 ind./100 trap-day and a radiation burden which exceeds the lower boundary of the Derived Consideration Reference Levels, which is above 0.1 mGy/day. PMID:27353005

  15. Population history of the Hispaniolan hutia Plagiodontia aedium (Rodentia: Capromyidae): testing the model of ancient differentiation on a geotectonically complex Caribbean island.

    PubMed

    Brace, Selina; Barnes, Ian; Powell, Adam; Pearson, Rebecca; Woolaver, Lance G; Thomas, Mark G; Turvey, Samuel T

    2012-05-01

    Hispaniola is a geotectonically complex island consisting of two palaeo-islands that docked c. 10 Ma, with a further geological boundary subdividing the southern palaeo-island into eastern and western regions. All three regions have been isolated by marine barriers during the late Cenozoic and possess biogeographically distinct terrestrial biotas. However, there is currently little evidence to indicate whether Hispaniolan mammals show distributional patterns reflecting this geotectonic history, as the island's endemic land mammal fauna is now almost entirely extinct. We obtained samples of Hispaniolan hutia (Plagiodontia aedium), one of the two surviving Hispaniolan land mammal species, through fieldwork and historical museum collections from seven localities distributed across all three of the island's biogeographic regions. Phylogenetic analysis using mitochondrial DNA (cytochrome b) reveals a pattern of historical allopatric lineage divergence in this species, with the spatial distribution of three distinct hutia lineages biogeographically consistent with the island's geotectonic history. Coalescent modelling, approximate Bayesian computation and approximate Bayes factor analyses support our phylogenetic inferences, indicating near-complete genetic isolation of these biogeographically separate populations and differing estimates of their effective population sizes. Spatial congruence of hutia lineage divergence is not however matched by temporal congruence with divergences in other Hispaniolan taxa or major events in Hispaniola's geotectonic history; divergence between northern and southern hutia lineages dates to c. 0.6 Ma, significantly later than the unification of the palaeo-islands. The three allopatric Plagiodontia populations should all be treated as distinct management units for conservation, with particular attention required for the northern population (low haplotype diversity) and the south-western population (high haplotype diversity but highly threatened). PMID:22404699

  16. Evidence for eight tandem and five centric fusions in the evolution of the karyotype of Aethomys namaquensis A. Smith (Rodentia: Muridae).

    PubMed

    Baker, R J; Qumsiyeh, M B; Rautenbach, I L

    1988-06-30

    G- and C-banded chromosomes of Aethomys namaquensis (2n = 24), A. chrysophilus (2n = 44), and Praomys coucha (2n = 36) are compared and contrasted with published material on Australian Muridae and North American Sigmodontidae. Direction and types of chromosomal rearrangements are established using cladistic methodology. An acrocentric morphology for chromosomes 5, 14, 15 and 20 (numbering system from Peromyscus) are proposed as primitive for the common ancestor of the Muridae and Sigmodontidae rodent lineages. Reduced diploid number of Aethomys namaquensis is derived by eight tandem and five centric fusions since divergence from the common ancestor with A. chrysophilus. The two species of Aethomys share one derived metacentric chromosome that distinguishes them from Praomys. Praomys has unique chromosomes which can be derived from the proposed primitive condition by five centric fusions and five pericentric inversions. It is concluded that karyotypic orthoselection for tandem and centric fusions is best explained by cellular or biochemical mechanisms rather than variation in population characteristics.

  17. Microtus oeconomus (Rodentia), a useful mammal for studying the induction of sex-chromosome nondisjunction and diploid gametes in male germ cells.

    PubMed Central

    Tates, A D

    1979-01-01

    Preliminary data indicate that chemicals can also increase the frequency of sex-chromosome nondisjunction. Positive results--which certainly need further confirmation--have been obtained for MMS, p-fluorophenylalanine, vincristine, procarbazine, carbendazim, and bleomycin. Nocodazole, benomyl, colcemic, 6-mercaptopurine, and halothane were all negative at the concentrations tested. For the induction of diploid spermatids positive results were only obtained for MMS and parafluorophenylalanine. In view of the results obtained, the Microtus system is considered a very useful tool for analyzing factors contributing to the high frequency of aneuploidy and triploidy among abortuses and of aneuploidy in liveborn infants of men. A method is described for the detection of sex-chromosome nondisjunction and diploid spermatids in male germ cells of the field vole Microtus oeconomus. The method is based on the unique distribution pattern of heterochromatin in Microtus cells, which makes it possible to identify X and Y chromosomes in early spermatids with a simple C-banding procedure. Slide preparation is easy. Scoring of early spermatids for extra sex-chromosomes is simple and 2000-4000 cells per hour can be examined. With the Microtus system it has now been demonstrated that radiation of spermatocyte stages with doses of 50, 100 and 200 R results in a higher frequency of sex chromosome nondisjunction and of diploid gametes. Both types of aberrant gametes can be produced during the first and second meiotic division. Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 4. PMID:387396

  18. Stratigraphic context and paleoenvironmental significance of minor taxa (Pisces, Reptilia, Aves, Rodentia) from the late Early Pleistocene paleoanthropological site of Buia (Eritrea).

    PubMed

    Rook, L; Ghinassi, M; Carnevale, G; Delfino, M; Pavia, M; Bondioli, L; Candilio, F; Coppa, A; Martínez-Navarro, B; Medin, T; Papini, M; Zanolli, C; Libsekal, Y

    2013-01-01

    The Buia Homo site, also known as Wadi Aalad, is an East African paleoanthropological site near the village of Buia that, due to its very rich yield from the late Early Pleistocene, has been intensively investigated since 1994. In this paper, which reports on the finds of the 2010-2011 excavations, we include new fossil evidence on previously identified taxa (i.e., reptiles), as well as the very first description of the small mammal, fish and bird remains discovered. In particular, this study documents the discovery of the first African fossil of the genus Burhinus (Aves, Charadriiformes) and of the first rodent from the site. This latter is identified as a thryonomyid rodent (cane rat), a relatively common taxon in African paleoanthropological faunal assemblages. On the whole, the new occurrences documented within the Buia vertebrate assemblage confirm the occurrence of taxa characterized by strong water dependence. The paleoenvironmental characteristics of the fauna are confirmed as fully compatible with the evidence obtained through sedimentology and facies analysis, documenting the sedimentary evolution of fluvio-deltaic and lacustrine systems. PMID:23159190

  19. Panic-like defensive behavior but not fear-induced antinociception is differently organized by dorsomedial and posterior hypothalamic nuclei of Rattus norvegicus (Rodentia, Muridae).

    PubMed

    Biagioni, A F; Silva, J A; Coimbra, N C

    2012-04-01

    The hypothalamus is a forebrain structure critically involved in the organization of defensive responses to aversive stimuli. Gamma-aminobutyric acid (GABA)ergic dysfunction in dorsomedial and posterior hypothalamic nuclei is implicated in the origin of panic-like defensive behavior, as well as in pain modulation. The present study was conducted to test the difference between these two hypothalamic nuclei regarding defensive and antinociceptive mechanisms. Thus, the GABA(A) antagonist bicuculline (40 ng/0.2 µL) or saline (0.9% NaCl) was microinjected into the dorsomedial or posterior hypothalamus in independent groups. Innate fear-induced responses characterized by defensive attention, defensive immobility and elaborate escape behavior were evoked by hypothalamic blockade of GABA(A) receptors. Fear-induced defensive behavior organized by the posterior hypothalamus was more intense than that organized by dorsomedial hypothalamic nuclei. Escape behavior elicited by GABA(A) receptor blockade in both the dorsomedial and posterior hypothalamus was followed by an increase in nociceptive threshold. Interestingly, there was no difference in the intensity or in the duration of fear-induced antinociception shown by each hypothalamic division presently investigated. The present study showed that GABAergic dysfunction in nuclei of both the dorsomedial and posterior hypothalamus elicit panic attack-like defensive responses followed by fear-induced antinociception, although the innate fear-induced behavior originates differently in the posterior hypothalamus in comparison to the activity of medial hypothalamic subdivisions.

  20. Panic-like defensive behavior but not fear-induced antinociception is differently organized by dorsomedial and posterior hypothalamic nuclei of Rattus norvegicus (Rodentia, Muridae)

    PubMed Central

    Biagioni, A.F.; Silva, J.A.; Coimbra, N.C.

    2012-01-01

    The hypothalamus is a forebrain structure critically involved in the organization of defensive responses to aversive stimuli. Gamma-aminobutyric acid (GABA)ergic dysfunction in dorsomedial and posterior hypothalamic nuclei is implicated in the origin of panic-like defensive behavior, as well as in pain modulation. The present study was conducted to test the difference between these two hypothalamic nuclei regarding defensive and antinociceptive mechanisms. Thus, the GABAA antagonist bicuculline (40 ng/0.2 µL) or saline (0.9% NaCl) was microinjected into the dorsomedial or posterior hypothalamus in independent groups. Innate fear-induced responses characterized by defensive attention, defensive immobility and elaborate escape behavior were evoked by hypothalamic blockade of GABAA receptors. Fear-induced defensive behavior organized by the posterior hypothalamus was more intense than that organized by dorsomedial hypothalamic nuclei. Escape behavior elicited by GABAA receptor blockade in both the dorsomedial and posterior hypothalamus was followed by an increase in nociceptive threshold. Interestingly, there was no difference in the intensity or in the duration of fear-induced antinociception shown by each hypothalamic division presently investigated. The present study showed that GABAergic dysfunction in nuclei of both the dorsomedial and posterior hypothalamus elicit panic attack-like defensive responses followed by fear-induced antinociception, although the innate fear-induced behavior originates differently in the posterior hypothalamus in comparison to the activity of medial hypothalamic subdivisions. PMID:22437484

  1. The ear in subterranean insectivora and rodentia in comparison with ground-dwelling representatives. I. Sound conducting system of the middle ear.

    PubMed

    Burda, H; Bruns, V; Hickman, G C

    1992-10-01

    Compared to acoustically unspecialized mammals (soricids and murids), the middle ear of subterranean insectivores and rodents (twelve species of six families examined) was clearly distinguished and characterized by many common features: rather round and relatively larger eardrum without a pars flaccida; reduced gonial; loose or no connection between the malleus and the tympanic bone; reduced and straightened transversal part of the malleus; enlarged incus; increased and rather flat incudo-mallear joint; rather parallel position of the mallear manubrium and incudal crus longum in some species (and their fusion in bathyergids); reduced or even missing middle ear muscles. Convergent occurrence of these structural features in taxa of different origin and their generally derived character suggest that they cannot be categorized as degenerative. The form of the stapes can be considered as a non-adaptive trait; it was taxon specific yet remarkably polymorphous in some species and exhibited no convergent features among subterranean mammals. Structural retrogression resulting in a columella-like stapes was observed in some species lacking the stapedial artery. The stapedial base was relatively larger than in unspecialized mammals. The subterranean mammals did not exhibit conspicuously enlarged eardrums as would be required for sensitive tuning to low frequencies. It is, however, argued that while selective pressures in the subterranean ecotope promoted hearing of low frequencies, hearing sensitivity did not have to be enhanced.

  2. Hepatic parasitosis in two wood mice, Apodemus sylvaticus (Rodentia: Muridae), due to Aonchotheca annulosa (Nematoda: Trichuridae), and Eucoleus bacillatus (Nematoda: Trichuridae). Erratic parasitism or post mortem migration?

    PubMed

    Debenedetti, Ángela L; Sáez-Durán, Sandra; Sainz-Elipe, Sandra; Galán-Puchades, Maria Teresa; Fuentes, Màrius V

    2014-10-01

    Aonchotheca annulosa and Eucoleus bacillatus are two capillariin nematodes parasitizing the intestinal and stomach mucosa, respectively, of various rodent species, and two, among others, component species of the helminth fauna of the wood mouse, Apodemus sylvaticus. A capillariin each was found in the liver parenchyma of two wood mice in a post-fire regeneration enclave in Serra Calderona Natural Park (Valencian Community, Spain). Due to their location, the preliminary identification of the helminths corresponded to Calodium hepaticum, a hepatic capillariin with rodents as its main host. So far, this species had never been found in Serra Calderona. To verify the preliminary identification, a comparative morphometric study between the specimens from Serra Calderona and a preserved individual of C. hepaticum from another enclave was carried out. Morphometric analysis revealed that the adult helminth as well as the eggs found in the liver of the first mouse belonged to A. annulosa, whereas the second one was identified as a male E. bacillatus. Moreover, the liver from both hosts showed a visible pathology, being the consequence of aberrant migration of the parasites. This is the first evidence that A. annulosa and E. bacillatus may migrate erratically and thus produce ectopic foci in other organs.

  3. Musserakis sulawesiensis gen. et sp. n. (Nematoda: Heterakidae) collected from Echiothrix centrosa (Rodentia: Muridae), an old endemic rat of Sulawesi, Indonesia.

    PubMed

    Hasegawa, Hideo; Dewi, Kartika; Asakawa, Mitsuhiko

    2014-11-04

    Musserakis sulawesiensis gen. et sp. n. (Nematoda: Heterakidae) is described from the large-bodied shrew rat, Echiothrix centrosa, one of the old endemic rats of Sulawesi, Indonesia. Musserakis is readily distinguished from other heterakid genera by having non-recurrent and non-anastomosing cephalic cordons, by lacking papillae between papillae groups around precloacal sucker and cloacal aperture and by lacking teeth in the pharyngeal portion. The spicules are equal but with marked dimorphism among individuals. Heterakids collected from other old endemic murids examined, i.e., Crunomys celebensis, Tateomys macrocercus and Tateomys rhinogradoides, and the new endemic rats of Sulawesi, were Heterakis spumosa Schneider, 1866, a cosmopolitan nematode of various murids. It is suggested that M. sulawesiensis is specific to Echiothrix.

  4. The sympatric occurrence of two genetically divergent lineages of sucking louse, Polyplax arvicanthis (Phthiraptera: Anoplura), on the four-striped mouse genus, Rhabdomys (Rodentia: Muridae).

    PubMed

    du Toit, Nina; Matthee, Sonja; Matthee, Conrad A

    2013-04-01

    Within southern Africa, the widely distributed four-striped mouse genus (Rhabdomys) is parasitized by, amongst others, the specific ectoparasitic sucking louse, Polyplax arvicanthis. Given the presence of significant geographically structured genetic divergence in Rhabdomys, and the propensity of parasites to harbour cryptic diversity, the molecular systematics of P. arvicanthis was investigated. Representatives of P. arvicanthis were sampled from Rhabdomys at 16 localities throughout southern Africa. Parsimony and Bayesian gene trees were constructed for the mitochondrial COI, 12S rRNA, 16S rRNA and nuclear CAD genes. Our findings support the existence of 2 genetic groups within P. arvicanthis separated by at least 25% COI sequence divergence, which is comparable to that observed among recognized Polyplax species. We therefore propose that these 2 genetic lineages probably represent distinct species and that the apparent absence of clear morphological differences may point to cryptic speciation. The 2 taxa have sympatric distributions throughout most of the sampled host range and also occasionally occur sympatrically on the same host individual. The co-occurrence of these genetically distinct lineages probably resulted from parasite duplication via host-associated allopatric divergence and subsequent reciprocal range expansions of the 2 parasite taxa throughout southern Africa.

  5. Causes and consequences of change rates in the habitat of the threatened tropical porcupine, Sphiggurus mexicanus (Rodentia: Erethizontidae) in Oaxaca, Mexico: implications for its conservation.

    PubMed

    Lorenzo, Consuelo; Sántiz, Eugenia C; Navarrete, Darío A; Bolaños, Jorge

    2014-12-01

    Land use changes by human activities have been the main causes of habitats and wildlife population degradation. In the Tehuantepec Isthmus in Oaxaca, the tropical habitat of the porcupine Sphiggurus mexicanus has been subject to vegetation and land use changes, causing its reduction and fragmentation. In this study, we estimated vegetation cover and land use (δn) change rates and assessed habitat availability and potential cor- ridors for possible porcupine movements to avoid its isolation. In the study area, the type of vegetation with the most change rate value was the savanna (δn = -2.9), transformed into induced grasslands. Additionally, we have observed the porcupine (since 2011) in semi-deciduous (δn = -0.87) and tropical dry (δn = -0.89) forests that have been transformed in temporal agriculture and mesquite and induced grasslands. The vegetation inhabited by the porcupine resulted in recording a total of 64 plant species (44 trees, nine vines, seven herbs, four shrubs), of which the vine Bunchosia lanceolata showed the highest importance value (41.85) followed by the trees Guazuma ulmifolia (22.71), Dalbergia glabra (18.05), and Enterolobium cyclocarpum (17.02). The habitat evaluation and potential corridor analysis showed that only 1 501.93ha could be considered as suitable habitats with optimum structural conditions (coverage, surface, and distances to transformed areas) to maintain viable populations of S. mexicanus, and 293.6 ha as corridors. An increasing destruction of the porcupines' habitat has been observed in the study area due to excessive logging, and actions for this species and its habitat conserva- tion and management have to be taken urgently. PMID:25720182

  6. Lineage-Specific Responses of Tooth Shape in Murine Rodents (Murinae, Rodentia) to Late Miocene Dietary Change in the Siwaliks of Pakistan

    PubMed Central

    Kimura, Yuri; Jacobs, Louis L.; Flynn, Lawrence J.

    2013-01-01

    Past ecological responses of mammals to climate change are recognized in the fossil record by adaptive significance of morphological variations. To understand the role of dietary behavior on functional adaptations of dental morphology in rodent evolution, we examine evolutionary change of tooth shape in late Miocene Siwalik murine rodents, which experienced a dietary shift toward C4 diets during late Miocene ecological change indicated by carbon isotopic evidence. Geometric morphometric analysis in the outline of upper first molars captures dichotomous lineages of Siwalik murines, in agreement with phylogenetic hypotheses of previous studies (two distinct clades: the Karnimata and Progonomys clades), and indicates lineage-specific functional responses to mechanical properties of their diets. Tooth shapes of the two clades are similar at their sympatric origin but deviate from each other with decreasing overlap through time. Shape change in the Karnimata clade is associated with greater efficiency of propalinal chewing for tough diets than in the Progonomys clade. Larger body mass in Karnimata may be related to exploitation of lower-quality food items, such as grasses, than in smaller-bodied Progonomys. The functional and ecophysiological aspects of Karnimata exploiting C4 grasses are concordant with their isotopic dietary preference relative to Progonomys. Lineage-specific selection was differentially greater in Karnimata, and a faster rate of shape change toward derived Karnimata facilitated inclusion of C4 grasses in the diet. Sympatric speciation in these clades is most plausibly explained by interspecific competition on resource utilization between the two, based on comparisons of our results with the carbon isotope data. Interspecific competition with Karnimata may have suppressed morphological innovation of the Progonomys clade. Pairwise analyses of morphological and carbon isotope data can uncover ecological causes of sympatric speciation and define functional adaptations of teeth to resources. PMID:24155885

  7. Lineage-specific responses of tooth shape in murine rodents (murinae, rodentia) to late Miocene dietary change in the Siwaliks of Pakistan.

    PubMed

    Kimura, Yuri; Jacobs, Louis L; Flynn, Lawrence J

    2013-01-01

    Past ecological responses of mammals to climate change are recognized in the fossil record by adaptive significance of morphological variations. To understand the role of dietary behavior on functional adaptations of dental morphology in rodent evolution, we examine evolutionary change of tooth shape in late Miocene Siwalik murine rodents, which experienced a dietary shift toward C4 diets during late Miocene ecological change indicated by carbon isotopic evidence. Geometric morphometric analysis in the outline of upper first molars captures dichotomous lineages of Siwalik murines, in agreement with phylogenetic hypotheses of previous studies (two distinct clades: the Karnimata and Progonomys clades), and indicates lineage-specific functional responses to mechanical properties of their diets. Tooth shapes of the two clades are similar at their sympatric origin but deviate from each other with decreasing overlap through time. Shape change in the Karnimata clade is associated with greater efficiency of propalinal chewing for tough diets than in the Progonomys clade. Larger body mass in Karnimata may be related to exploitation of lower-quality food items, such as grasses, than in smaller-bodied Progonomys. The functional and ecophysiological aspects of Karnimata exploiting C4 grasses are concordant with their isotopic dietary preference relative to Progonomys. Lineage-specific selection was differentially greater in Karnimata, and a faster rate of shape change toward derived Karnimata facilitated inclusion of C4 grasses in the diet. Sympatric speciation in these clades is most plausibly explained by interspecific competition on resource utilization between the two, based on comparisons of our results with the carbon isotope data. Interspecific competition with Karnimata may have suppressed morphological innovation of the Progonomys clade. Pairwise analyses of morphological and carbon isotope data can uncover ecological causes of sympatric speciation and define functional adaptations of teeth to resources.

  8. [Variability of Cytochrome b Gene and Adjacent Section of Gene tRNA-Thr of Mitochondrial DNA in the Northern Mole Vole Ellobius talpinus (Mammalia, Rodentia)].

    PubMed

    Bogdanov, A S; Lebedev, V S; Zykov, A E; Bakloushinskaya, I Yu

    2015-12-01

    The Northern mole vole E. talpinus, despite its wide distribution, is characterized by a stable karyotype (2n = NF = 54) and slight morphological polymorphism. We made a preliminary analysis of a mitochondrial DNA fragment to clarify the level of genetic variation and differentiation of E. talpinus. the complete cytochrome b gene (cyt b, 1143 bp) and a short part of its flanking gene tRNA-Thr (27 bp) were sequenced. We studied 16 specimens from eight localities, including Crimea, the Volga region, the Trans-Volga region, the Southern Urals, Western Siberia, and Eastern Turkmenistan. Mitotypes of E. talpinus were distributed on a ML dendrogram as four distinct clusters: the first (I) contains specimens from the Crimea, the second (II) combines individuals from the Volgograd region and the left bank of the Don River, the third (III) includes those from the Trans-Volga region, Southern Urals, the left bank of the Irtysh River, and Eastern Turkmenistan; the fourth (IV) are those from the right bank of the Irtysh River. These clusters were relatively distant from each other: the mean genetic distances (D) between them are 0.021-0.051. The Eastern mole vole E. tancrei differed from E. talpinus population groups 1.5-2 times more (D = 0.077-0.084) than the latter did among themselves. Such variations indirectly proved the unity of E. talpinus, despite its high intraspecific differentiation for the studied fragment of mitochondrial DNA. This differentiation apparently occurred because of the long isolation of E. talpinus population groups, which was due to geographic barriers, in particular, the large rivers that completely separate the species range meridionally (the Volga River, the Irtysh River). Sociality and underground lifestyle could accelerate the fixation of mutations in disjunct populations. The composition and distribution of intraspecific groups of E. talpinus, which were identified in analysis of the mitochondrial DNA fragment, do not coincide with the subspecies taxonomy. The subspecies E. t. talpinus is actually a complex taxon, including two or three genetically discrete forms (III, IV, and probably II). Moreover, one of the forms (III) occupies the territory where three subspecies, E. t. talpinus, E. t. rufescens, and E. t. transcaspiae, were described. PMID:27055303

  9. Characterization of the kidney transcriptome of the long-haired mouse Abrothrix hirta (Rodentia, Sigmodontinae) and comparison with that of the olive mouse A. olivacea.

    PubMed

    Valdez, Lourdes; Giorello, Facundo; Feijoo, Matías; Opazo, Juan C; Lessa, Enrique P; Naya, Daniel E; D'Elía, Guillermo

    2015-01-01

    To understand how small mammals cope with the challenge of water homeostasis is a matter of interest for ecologists and evolutionary biologists. Here we take a step towards the understanding of the transcriptomic functional response of kidney using as a model the long-haired mouse (Abrothrix hirta) a species that distributes across Patagonian steppes and Austral temperate rainforests in Argentina and Chile. Specifically, we i) characterize the renal transcriptome of A. hirta, and ii) compare it with that-already available-of the co-generic and co-distributed A. olivacea. Renal mRNA transcripts from 16 specimens of A. hirta from natural populations were analyzed. Over 500 million Illumina paired-end reads were assembled de novo under two approaches, an individual assembly for each specimen, and a single in-silico normalized joint assembly including all reads from all specimens. The total number of annotated genes was similar with both strategies: an average of 14,956 in individual assemblies and 14,410 in the joint assembly. Overall, 15,463 distinct genes express in the kidney of A. hirta. Transcriptomes of A. hirta and A. olivacea were similar in terms of gene abundance and composition: 95.6% of the genes of A. hirta were also found in A. olivacea making their functional profiles also similar. However, differences in the transcriptome of these two species were observed in the set of highly expressed genes, in terms of private genes for each species and the functional profiles of highly expressed genes. As part of the novel transcriptome characterization, we provide distinct gene lists with their functional annotation that would constitute the basis for further research on these or any other species of the subfamily Sigmodontinae, which includes about 400 living species distributed from Tierra del Fuego to southern United States.

  10. MtDNA CytB Structure of Rhombomys opimus (Rodentia: Gerbellidae), the Main Reservoir of Cutaneous Leishmaniasis in the Borderline of Iran-Turkmenistan

    PubMed Central

    Bakhshi, Hasan; Oshaghi, Mohammad Ali; Abai, Mohammad Reza; Rassi, Yavar; Akhavan, Amir Ahmad; Mohebali, Mehdi; Hajaran, Homa; Mohtarami, Fatemeh; Mirzajani, Hossein; Maleki-Ravasan, Naseh

    2013-01-01

    Background: Great gerbils, Rhombomys opimus, are the main reservoir host of zoonootic cutaneous leishmaniasis (ZCL) in Iran and neighboring countries. Based on morphological traits two subspecies R. opimus sodalis and R. opimus sargadensis have reported in the country. However, variation in infection rate and signs to Leishmania parasites, phenotype, size, and sexual polymorphisms demand more details to elucidate clearly the role of great gerbils in ZCL epidemiology. Methods: PCR-RFLP and PCR-direct sequencing were used to analyze mitochondrial DNA cytochrome B (mtDNA-cytB) gene structure of R. opimus collected from Golestan and Khorasan-e-Razavi Provinces in 2011 that are neighbor to Turkmenistan Country where ZCL is endemic in both sides of the borderline. Results: All of the specimens (n= 61) were morphologically or genetically similar to the typical R. opimus sodalis. However, there were 9 (1.5%) DNA substitutions throughout the 583 bp of the Cyt b gene of the samples sequenced comprising six DNA haplotypes. Maximum likelihood or neighbor joining phylogenetic trees inferred from the sequences could resolve the populations according to their subspecies as well as geographical origins. Discussion: The DNA polymorphisms in the great gerbils may correspond to the signs and infection rate in the animal. However, further studies are needed to match these six haplotypes with different signs and parasite sustaining following infection with L. major in the great gerbils. PMID:24409443

  11. First detection of Leishmania killicki (Kinetoplastida, Trypanosomatidae) in Ctenodactylus gundi (Rodentia, Ctenodactylidae), a possible reservoir of human cutaneous leishmaniasis in Tunisia

    PubMed Central

    2011-01-01

    Background Leishmania killicki was originally described in 1980 in southeast Tunisia. It was also recently reported in Lybia and Algeria. Nevertheless, neither vector nor reservoirs of this parasite are known. The identification of the vector and the animal reservoir host of L. killicki is critical for the establishment of an efficient control strategy. Findings blood, popliteal lymph node, spleen, bone marrow, liver and skin were collected from 50 rodents in 2009 in south western Tunisia. Samples were smeared onto glass slides, cultured on NNN medium and tested by polymerase chain reaction for Leishmania detection. Parasites were detected by PCR from 10 Psammomys obesus and from two Ctenodactylus gundi. Parasite identification was performed simultaneously by internal transcribed spacer 1 PCR-RFLP and by PCR sequencing. Both Leishmania major and Leishmania killicki were identified from infected Psammomys and Ctenodactylus gundi respectively. Conclusion This is the first report of Leishmania killicki identified from Ctenodactylus gundi in Tunisia. This result supports the assumption that C. gundi is a potential reservoir for Leishmania killicki. PMID:21834996

  12. First Report on Isolation and Characterization of Leishmania major from Meriones hurrianae (Rodentia: Gerbillidae) of A Rural Cutaneous leishmaniasis Focus in South-Eastern Iran

    PubMed Central

    Kassiri, Hamid; Naddaf, Saied Reza; Javadian, Ezat–Aldin; Mohebali, Mehdi

    2013-01-01

    Background Zoonotic Cutaneous Leishmaniasis (ZCL) is an endemic health problem in many rural areas of Iran, with doubled number of incidences over the last decade. Different species of rodents serve as natural reservoir host for ZCL. The disease is considered as a major health problem in rural areas of Mirjaveh, Chabahar, and Konarak Counties of Sistan va Baluchistan Province. Objectives This study describes the identity of Leishmania species, isolated from Meriones hurrianae from Chabahar County using RAPD-PCR methodology. Materials and Methods Rodents were entrapped by live traps baited with roasted walnut, tomato, and cucumber during spring and summer. All rodents were identified based on external features including fur color, ears characteristics, tail length, hind feet, body measurements, and internal features of teeth and cranium. Giemsa-stained impressions from rodents’ ears were examined for amastigotes microscopically. The samples from infected rodents were cultured in NNN+LIT medium and then the harvested parasites at the stationary phase were subjected to DNA extraction followed by amplification with RAPD-PCR. Results All the 28 entrapped animals were identified as M. hurrianae. Five animals showed to harbor Leishmania parasite by microscopy. Leishmania DNA isolated from five M. hurrianae produced distinctive bands of L. major with four primers. However, the products that were amplified with primers AB1-07, 327, and 329 were stable and reproducible. This is the first report on the isolation and identification of L. major from M. hurrianae from Iran. Conclusions Regarding infection rate of 17.8%, M. hurrianae seems to play the major role in the maintenance and transmission of disease to humans in this area. PMID:24616787

  13. Expression of androgen receptor, estrogen receptors alpha and beta and aromatase in the fetal, perinatal, prepubertal and adult testes of the South American plains Vizcacha, Lagostomus maximus (Mammalia, Rodentia).

    PubMed

    González, Candela Rocío; Muscarsel Isla, María Laura; Leopardo, Noelia Paola; Willis, Miguel Alfredo; Dorfman, Verónica Berta; Vitullo, Alfredo Daniel

    2012-01-01

    Androgens and androgen receptor play a critical role in spermatogenesis and fertility in mammals, and estrogens and their receptors contribute to regulation of testicular function through initiation and maintenance of spermatogenesis and germ cell division and survival. However, results from different species are still far from establishing a clear understanding of these receptors in the different cell types from the testis. We analyzed the expression of androgen receptor, estrogen receptors α and β and aromatase protein by immunohistochemistry and real-time PCR, in relation to proliferation followed by the expression of proliferation cell nuclear antigen (PCNA) and germinal identity by VASA protein, in fetal, perinatal, prepubertal and adult testes of Lagostomus maximus, a rodent with sustained germ cell proliferation and an increasing number of OCT-4-expressing gonocytes in the developing ovary. AR expression was restricted to Leydig cells and peritubular cells before sexual maturity, at which point it also became expressed in Sertoli cells. ERα and ERβ were expressed in seminiferous tubules and the interstitium, respectively, in both fetal and prepubertal testes. In adult testes, both ERα and ERβ co-localized in Leydig and peritubular cells. The aromatase enzyme, which converts androgenic precursors into estrogens, was detectable in all developmental stages analyzed and was restricted to Leydig cells. PCNA remained high until sexual maturity. ERα nuclear detection in germ cells and AR in Leydig cells in PCNA-positive cells suggest the possibility of a stimulatory effect of estrogens on spermatogonia proliferation. This effect might explain the increase found in VASA-expressing cells in the adult testis.

  14. [Morphology and biometry of eggs and larvae of Strongyloides sp. Grassi, 1879 (Rhabditoidea: Strongyloididae), a gastrointestinal parasite of Hydrochaeris hydrochaeris (Linnaeus, 1766) (Rodentia: Hydrochaeridae), in the municipality of Juiz de Fora, Minas Gerais, Brazil].

    PubMed

    Vieira, Fabiano M; Lima, Sueli de S; Bessa, Elisabeth Cristina de A

    2006-01-01

    An important method to diagnose and study the helminthofauna of wild animals is to examine the host's feces to find eggs and larvae, seeking to identify the parasites and study their morphobiology. The objective of the present work is to provide morphological and biometric data on the eggs and larvae of Strongyloides sp., a capybara gastrointestinal parasite. Using the technique of Gordon and Whitlock, simple flotation and the modified Baermann examination, capybara fecal samples were selected based on a criterion of the highest proportion of eggs and larvae in the initial development stages, for morphometric description of eggs, L1, L2 and L3 of Strongyloides sp. From past reports of parasitism in Hydrochaeris hydrochaeris, we suspect that the eggs and larvae in this study are of Strongyloides chapini Sandground, 1925, which constitutes the first description of these stages for this species of nematode. Nevertheless, the morphology and biometry data of these stages demonstrate that they are similar to those of other species of the Strongyloides genus.

  15. About rats and jackfruit trees: modeling the carrying capacity of a Brazilian Atlantic Forest spiny-rat Trinomys dimidiatus (Günther, 1877) - Rodentia, Echimyidae - population with varying jackfruit tree (Artocarpus heterophyllus L.) abundances.

    PubMed

    Mello, J H F; Moulton, T P; Raíces, D S L; Bergallo, H G

    2015-01-01

    We carried out a six-year study aimed at evaluating if and how a Brazilian Atlantic Forest small mammal community responded to the presence of the invasive exotic species Artocarpus heterophyllus, the jackfruit tree. In the surroundings of Vila Dois Rios, Ilha Grande, RJ, 18 grids were established, 10 where the jackfruit tree was present and eight were it was absent. Previous results indicated that the composition and abundance of this small mammal community were altered by the presence and density of A. heterophyllus. One observed effect was the increased population size of the spiny-rat Trinomys dimidiatus within the grids where the jackfruit trees were present. Therefore we decided to create a mathematical model for this species, based on the Verhulst-Pearl logistic equation. Our objectives were i) to calculate the carrying capacity K based on real data of the involved species and the environment; ii) propose and evaluate a mathematical model to estimate the population size of T. dimidiatus based on the monthly seed production of jackfruit tree, Artocarpus heterophyllus and iii) determinate the minimum jackfruit tree seed production to maintain at least two T. dimidiatus individuals in one study grid. Our results indicated that the predicted values by the model for the carrying capacity K were significantly correlated with real data. The best fit was found considering 20~35% energy transfer efficiency between trophic levels. Within the scope of assumed premises, our model showed itself to be an adequate simulator for Trinomys dimidiatus populations where the invasive jackfruit tree is present.

  16. The gastrointestinal helminths of Rattus niobe (Rodentia: Muridae) with descriptions of two new genera and three new species (Nematoda) from Papua New Guinea and Papua Indonesia.

    PubMed

    Smales, L R

    2016-05-31

    Cestodes, to be identified elsewhere, the acanthocephalan Moniliformis moniliformis and 15 species of nematode including 2 new genera, a new species and 2 putative new species from the families Heligmonellidae and Oxyuridae, as well as juveniles and a putative heligmonellid that could not be fully identified, were collected from the digestive tracts of 34 Rattus niobe (Muridae: Murinae: Rattini) from Papua, Indonesia and Papua New Guinea. The ascaridid, Toxocara mackerrasae, the chabertiid Cyclodontostomum purvisi, the heterakid Heterakis sp., the spirurids Protospirura kaindiensis and P. muricola the subulurid Subulura andersoni and the trichurids Eucoleus sp. and Trichuris muris have been reported previously from endemic Rattus spp. Syphacia (Syphacia) niobe n. sp. was distinguished from its congeners by a combination of characters including a round cephalic plate, the lack of cervical and lateral alae, a longer male tail and an attenuated female tail. Nugininema titokis n. gen., n. sp. differs from all other genera in the Heligmonellidae in the characters of the synlophe, 10-17 ridges orientated subfrontally at mid body and 2 right ventral ridges hypertrophied anteriorly. Rodentanema aenigma n. gen., n. sp. differs from all other genera in the Heligmonellidae in the characters of the synlophe 6-7 ridges at mid body not symmetrical in relation to frontal axis. Species richness of the nematode assemblage was similar to that reported for Rattus leucopus in Papua New Guinea, with about 90% of possible species found as indicated by bootstrap analysis. Species composition included 6 species unique to R. niobe and 7 species reported from at least one other species of Rattus indigenous to New Guinea, as well as juvenile worms, probably ascaridids.

  17. Gastrointestinal helminths (Cestoda, Chabertiidae and Heligmonellidae) of Pogonomys loriae and Pogonomys macrourus (Rodentia: Muridae) from Papua Indonesia and Papua New Guinea with the description of a new genus and two new species.

    PubMed

    Smales, L R

    2014-11-28

    Pieces of cestode, not indentified further, and 12 species of nematode including 1 new genus, 3 new species and 7 putative new species from the Families Chabertiidae and Heligmonellidae were collected from the digestive tracts of 16 Pogonomys loriae and 19 P. macrurous (Murinae: Hydromyini) from Papua, Indonesia and Papua New Guinea. The chabertiid Cyclodontostomum purvisi and the heligmonellid Odilia mackerrasae have been described previously from endemic murids. Hasanuddinia pogonomyos n. sp. can be distinguished from its congeners by the number of ridges in the synlophe, length of spicules and having a vagina with a dorsal diverticulum. Odilia dividua n. sp. is larger than its congeners, has a longer oesophagus, relatively shorter spicules and larger eggs. Pogonomystrongylus domaensis n. gen., n. sp. differs from all other genera in the Heligmonellidae in the characters of the synlophe, 7-10 ridges oriented sub frontally with a single left ventral ridge hypertrophied. Species richness of the nematode assemblages of P. loriae and P. macrourus are comparable to those of Abeomelomys sevia, Chiruromys vates and Coccymys rummleri when numbers of hosts examined are considered. Species composition was distinctive with 12, including the 7 putative species, of 14 species presently known only from species of Pogonomys. Similarities between the nematode fauna of endemic rodent hosts from Indonesia and Papua New Guinea were noted.

  18. [Genetic variation and phylogeography of the bank vole (Clethrionomys glareolus, Arvicolinae, Rodentia) in Russia with special reference to the introgression of the mtDNA of a closely related species, red-backed vole (C. rutilus)].

    PubMed

    Abramson, N I; Rodchenkova, E N; Kostygov, A Iu

    2009-05-01

    Totally, 294 bank voles (Clethrionomys glareolus) and 18 red-backed voles (C. rutilus) from 62 sites of European Russia were studied. Incomplete sequences (967 bp) of the mitochondrial cytochrome b gene were determined for 93 C. glareolus individuals from 56 sites and 18 C. rutilus individuals from the same habitats. Analysis of the cytochrome b gene variation has demonstrated that practically the entire European part of Russia, Ural, and a considerable part of Western Europe are inhabited by bank voles of the same phylogroup, displaying an extremely low genetic differentiation. Our data suggest that C. glareolus very rapidly colonized over the presently occupied territory in the post-Pleistocene period from no more than two (central European and western European) refugia for ancestral populations with a small efficient size. PCR typing of the mitochondrial cytochrome b gene allowed us to assess the scale of mtDNA introgression from a closely related species, C. rutilus, and to outline the geographical zone of this introgression. Comparison with the red-backed vole haplotypes in the habitats shared by both species favors the hypothesis of an ancient hybridization event (mid-Holocene) and a subsequent introgression. These results suggest that the hybridization took place in the southern and middle Pre-Ural region. PMID:19534420

  19. The gastrointestinal helminths of Rattus niobe (Rodentia: Muridae) with descriptions of two new genera and three new species (Nematoda) from Papua New Guinea and Papua Indonesia.

    PubMed

    Smales, L R

    2016-01-01

    Cestodes, to be identified elsewhere, the acanthocephalan Moniliformis moniliformis and 15 species of nematode including 2 new genera, a new species and 2 putative new species from the families Heligmonellidae and Oxyuridae, as well as juveniles and a putative heligmonellid that could not be fully identified, were collected from the digestive tracts of 34 Rattus niobe (Muridae: Murinae: Rattini) from Papua, Indonesia and Papua New Guinea. The ascaridid, Toxocara mackerrasae, the chabertiid Cyclodontostomum purvisi, the heterakid Heterakis sp., the spirurids Protospirura kaindiensis and P. muricola the subulurid Subulura andersoni and the trichurids Eucoleus sp. and Trichuris muris have been reported previously from endemic Rattus spp. Syphacia (Syphacia) niobe n. sp. was distinguished from its congeners by a combination of characters including a round cephalic plate, the lack of cervical and lateral alae, a longer male tail and an attenuated female tail. Nugininema titokis n. gen., n. sp. differs from all other genera in the Heligmonellidae in the characters of the synlophe, 10-17 ridges orientated subfrontally at mid body and 2 right ventral ridges hypertrophied anteriorly. Rodentanema aenigma n. gen., n. sp. differs from all other genera in the Heligmonellidae in the characters of the synlophe 6-7 ridges at mid body not symmetrical in relation to frontal axis. Species richness of the nematode assemblage was similar to that reported for Rattus leucopus in Papua New Guinea, with about 90% of possible species found as indicated by bootstrap analysis. Species composition included 6 species unique to R. niobe and 7 species reported from at least one other species of Rattus indigenous to New Guinea, as well as juvenile worms, probably ascaridids. PMID:27395168

  20. Involvement of pre- and post-synaptic serotonergic receptors of dorsal raphe nucleus neural network in the control of the sweet-substance-induced analgesia in adult Rattus norvegicus (Rodentia, Muridae).

    PubMed

    Miyase, Cátia Isumi; Kishi, Renato; de Freitas, Renato Leonardo; Paz, Denise Amorim; Coimbra, Norberto Cysne

    2005-05-13

    In order to investigate the effects of monoaminergic mechanisms of the dorsal raphe nucleus on the elaboration and control of sweet-substance-induced antinociception, male albino Wistar rats weighing 180-200 g received sucrose solution (250 g/L) for 14 days as their only source of liquid. After the chronic consumption of sucrose solution, each animal was pretreated with unilateral microinjection of methiothepin mesylate (5.0 microg/0.2 microL), or methysergide maleate (5.0 microg/0.2 microL) in the dorsal raphe nucleus. Each rat consumed an average of 15.6g sucrose/day. Their tail withdrawal latencies in the tail-flick test were measured immediately before and after this treatment. An analgesia index was calculated from the withdrawal latencies before and after the pharmacological treatment. The blockade of serotonergic receptor in the dorsal raphe nucleus with methysergide after the chronic intake of sucrose decreased the sweet-induced antinociception. However, microinjections of methiothepin in the dorsal raphe nucleus did not cause a similar effect on the tail-flick latencies after the chronic intake of sucrose solution, increasing the sweet-substance-induced analgesia. These results indicate the involvement of serotonin as a neurotransmitter in the sucrose-produced antinociception. Considering that the blockade of pre-synaptic serotonergic receptors of the neural networks of the dorsal raphe nucleus with methiothepin did not decrease the sweet-substance-induced antinociception, and the central blockade of post-synaptic serotonergic receptors decreased the sucrose-induced analgesia, the modulation of the release of serotonin in the neural substrate of the dorsal raphe nucleus seems to be crucial for the organization of this interesting antinociceptive process.

  1. About rats and jackfruit trees: modeling the carrying capacity of a Brazilian Atlantic Forest spiny-rat Trinomys dimidiatus (Günther, 1877) - Rodentia, Echimyidae - population with varying jackfruit tree (Artocarpus heterophyllus L.) abundances.

    PubMed

    Mello, J H F; Moulton, T P; Raíces, D S L; Bergallo, H G

    2015-01-01

    We carried out a six-year study aimed at evaluating if and how a Brazilian Atlantic Forest small mammal community responded to the presence of the invasive exotic species Artocarpus heterophyllus, the jackfruit tree. In the surroundings of Vila Dois Rios, Ilha Grande, RJ, 18 grids were established, 10 where the jackfruit tree was present and eight were it was absent. Previous results indicated that the composition and abundance of this small mammal community were altered by the presence and density of A. heterophyllus. One observed effect was the increased population size of the spiny-rat Trinomys dimidiatus within the grids where the jackfruit trees were present. Therefore we decided to create a mathematical model for this species, based on the Verhulst-Pearl logistic equation. Our objectives were i) to calculate the carrying capacity K based on real data of the involved species and the environment; ii) propose and evaluate a mathematical model to estimate the population size of T. dimidiatus based on the monthly seed production of jackfruit tree, Artocarpus heterophyllus and iii) determinate the minimum jackfruit tree seed production to maintain at least two T. dimidiatus individuals in one study grid. Our results indicated that the predicted values by the model for the carrying capacity K were significantly correlated with real data. The best fit was found considering 20~35% energy transfer efficiency between trophic levels. Within the scope of assumed premises, our model showed itself to be an adequate simulator for Trinomys dimidiatus populations where the invasive jackfruit tree is present. PMID:25945639

  2. LINE-1 distribution in six rodent genomes follow a species-specific pattern.

    PubMed

    Vieira-da-Silva, A; Adega, F; Guedes-Pinto, H; Chaves, R

    2016-03-01

    L1 distribution in mammal's genomes is yet a huge riddle. However, these repetitive sequences were already found in all chromosomic regions, and in general, they seem to be nonrandomly distributed in the genome. It also seems that after insertion and when they are not deleterious, they are always involved in dynamic processes occurring on that particular chromosomic region. Furthermore, it seems that large-scale genome rearrangements and L1 activity and accumulation are somehow interconnected. In the present study, we analysed L1 genomic distribution in Tatera gambiana (Muridae, Gerbillinae), Acomys sp. (Muridae, Deomyinae), Cricetomys sp. (Nesomyidae, Cricetomyinae), Microtus arvalis (Cricetidae, Arvicolinae), Phodopus roborovskii and P. sungorus (Cricetidae, Cricetinae). All the species studied here seems to exhibit a species-specific pattern.Possible mechanisms, and processes involved in L1 distribution and preferential accumulation in certain regions are di scussed. PMID:27019429

  3. Spot-on Treatments of Diflubenzuron and Permethrin to Control a Guinea Pig Louse, Gliricola Porcelli (Phthiraptera: Gyropidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Guinea pigs (Cavia porcellus (L.)) (Rodentia: Caviidae) are pets and laboratory animals. They can be infested by a chewing louse, Gliricola porcelli (Schrank) (Phthiraptera: Gyropidae), which is fairly common in some animal rearing facilities, pet stores, and on wild guinea pigs. Infestation with G....

  4. Karyotypic evolution of the family Sciuridae: inferences from the genome organizations of ground squirrels.

    PubMed

    Li, T; Wang, J; Su, W; Nie, W; Yang, F

    2006-01-01

    Cross-species chromosome painting has made a great contribution to our understanding of the evolution of karyotypes and genome organizations of mammals. Several recent papers of comparative painting between tree and flying squirrels have shed some light on the evolution of the family Sciuridae and the order Rodentia. In the present study we have extended the comparative painting to the Himalayan marmot (Marmotahimalayana) and the African ground squirrel (Xerus cf. erythropus), i.e. representative species from another important squirrel group--the ground squirrels--, and have established genome-wide comparative chromosome maps between human, eastern gray squirrel, and these two ground squirrels. The results show that 1) the squirrels so far studied all have conserved karyotypes that resemble the ancestral karyotype of the order Rodentia; 2) the African ground squirrels could have retained the ancestral karyotype of the family Sciuridae. Furthermore, we have mapped the evolutionary rearrangements onto a molecular-based consensus phylogenetic tree of the family Sciuridae.

  5. Comparative genetics of longevity and cancer: insights from long-lived rodents

    PubMed Central

    Gorbunova, Vera; Seluanov, Andrei; Zhang, Zhengdong; Gladyshev, Vadim N.; Vijg, Jan

    2015-01-01

    Mammals have evolved a dramatic diversity of aging rates. Within the single order of Rodentia maximum lifespans differ from four years in mice to 32 years in naked mole rats. Cancer rates also differ significantly, from cancer-prone mice to virtually cancer-proof naked and blind mole rats. Recent progress in rodent comparative biology, in combination with the emergence of whole genome sequence information, has opened opportunities for the discovery of genetic factors controlling longevity and cancer susceptibility. PMID:24981598

  6. [Presence in a rodent of Chili of the nematode Inglamidinae (sub. fam. nov.) belonging to Amidostomatidae, a family known to be found in mammals of Australia].

    PubMed

    Durette-Desset, M C; Denke, M A; Murua, R

    1976-01-01

    The Inglamidinae n. sub-fam., a new sub-family of Amidostomatidae from chilean Cricetidae is described with Inglamidum akodon gen. et sp. n. as the type genus and species. Out of the 23 Akodon captured in the same area, three samples of this nematode have been collected from two different species. These findings confirm that we are dealing with a well-adapted parasite and exclude the possibility of a fortuitous catch or an accidental transfer. This family displays two significant groups of taxonomic characters, including archaic characters such as cephalic structures which unite them to the Amidostomatidae, and on the other hand some more recently elaborated characters such as monodelphism and shape of synlophe and spicules which relate them to the Heligmosoms and more significantly to the line Viannaia-Viannella parasite of South-American Marsupials. We interpret this species as a "parasite of capture" and we assume that very similar species might occur in other endemic Mammals, mostly Marsupials. On a paleobiogeographical point of view this interpretation would make due allowance for postulating that the Amidostomatidae from Mammals have originated during the Secondary concurrently with the Marsupial expansion. These ancestral Nematodes would have given birth to the other Trichostrongyloidea through reduction of buccal cavity, and to the Ancylostomatoidea by further elaboration of buccal apparatus. Contrary to Inglis's hypothesis we are in favour of the genera Globocephaloides and Hypodontus to be assigned to the Globocephalinae and Uncinariinae (Ancylostomatidae) respectively, rather than to the Amidostomatidae. The occurrence of an Amidostomatidae in a South American Cricetidae is somewhat quite unexpected, mostly because this family is known to occur from australian Mammals only and also because the parasited Mammals are the most primitive of the group (Monotremes and Marsupials). PMID:984673

  7. Why Can’t Rodents Vomit? A Comparative Behavioral, Anatomical, and Physiological Study

    PubMed Central

    Horn, Charles C.; Kimball, Bruce A.; Wang, Hong; Kaus, James; Dienel, Samuel; Nagy, Allysa; Gathright, Gordon R.; Yates, Bill J.; Andrews, Paul L. R.

    2013-01-01

    The vomiting (emetic) reflex is documented in numerous mammalian species, including primates and carnivores, yet laboratory rats and mice appear to lack this response. It is unclear whether these rodents do not vomit because of anatomical constraints (e.g., a relatively long abdominal esophagus) or lack of key neural circuits. Moreover, it is unknown whether laboratory rodents are representative of Rodentia with regards to this reflex. Here we conducted behavioral testing of members of all three major groups of Rodentia; mouse-related (rat, mouse, vole, beaver), Ctenohystrica (guinea pig, nutria), and squirrel-related (mountain beaver) species. Prototypical emetic agents, apomorphine (sc), veratrine (sc), and copper sulfate (ig), failed to produce either retching or vomiting in these species (although other behavioral effects, e.g., locomotion, were noted). These rodents also had anatomical constraints, which could limit the efficiency of vomiting should it be attempted, including reduced muscularity of the diaphragm and stomach geometry that is not well structured for moving contents towards the esophagus compared to species that can vomit (cat, ferret, and musk shrew). Lastly, an in situ brainstem preparation was used to make sensitive measures of mouth, esophagus, and shoulder muscular movements, and phrenic nerve activity–key features of emetic episodes. Laboratory mice and rats failed to display any of the common coordinated actions of these indices after typical emetic stimulation (resiniferatoxin and vagal afferent stimulation) compared to musk shrews. Overall the results suggest that the inability to vomit is a general property of Rodentia and that an absent brainstem neurological component is the most likely cause. The implications of these findings for the utility of rodents as models in the area of emesis research are discussed. PMID:23593236

  8. Why can't rodents vomit? A comparative behavioral, anatomical, and physiological study.

    PubMed

    Horn, Charles C; Kimball, Bruce A; Wang, Hong; Kaus, James; Dienel, Samuel; Nagy, Allysa; Gathright, Gordon R; Yates, Bill J; Andrews, Paul L R

    2013-01-01

    The vomiting (emetic) reflex is documented in numerous mammalian species, including primates and carnivores, yet laboratory rats and mice appear to lack this response. It is unclear whether these rodents do not vomit because of anatomical constraints (e.g., a relatively long abdominal esophagus) or lack of key neural circuits. Moreover, it is unknown whether laboratory rodents are representative of Rodentia with regards to this reflex. Here we conducted behavioral testing of members of all three major groups of Rodentia; mouse-related (rat, mouse, vole, beaver), Ctenohystrica (guinea pig, nutria), and squirrel-related (mountain beaver) species. Prototypical emetic agents, apomorphine (sc), veratrine (sc), and copper sulfate (ig), failed to produce either retching or vomiting in these species (although other behavioral effects, e.g., locomotion, were noted). These rodents also had anatomical constraints, which could limit the efficiency of vomiting should it be attempted, including reduced muscularity of the diaphragm and stomach geometry that is not well structured for moving contents towards the esophagus compared to species that can vomit (cat, ferret, and musk shrew). Lastly, an in situ brainstem preparation was used to make sensitive measures of mouth, esophagus, and shoulder muscular movements, and phrenic nerve activity-key features of emetic episodes. Laboratory mice and rats failed to display any of the common coordinated actions of these indices after typical emetic stimulation (resiniferatoxin and vagal afferent stimulation) compared to musk shrews. Overall the results suggest that the inability to vomit is a general property of Rodentia and that an absent brainstem neurological component is the most likely cause. The implications of these findings for the utility of rodents as models in the area of emesis research are discussed. PMID:23593236

  9. Anatomy and Disorders of the Oral Cavity of Rat-like and Squirrel-like Rodents.

    PubMed

    Mancinelli, Elisabetta; Capello, Vittorio

    2016-09-01

    The order Rodentia comprises more than 2000 species divided into 3 groups based on anatomic and functional differences of the masseter muscle. Myomorph and sciuromorph species have elodont incisors and anelodont cheek teeth, unlike hystrichomorph species which have full anelodont dentition. Diseases of incisors and cheek teeth of rat-like and squirrel-like rodents result in a wide variety of symptoms and clinical signs. Appropriate diagnostic testing and imaging techniques are required to obtain a definitive diagnosis, formulate a prognosis, and develop a treatment plan. A thorough review of elodontoma, odontoma, and pseudo-odontoma is provided, including treatment of pseudo-odontomas in prairie dogs. PMID:27497210

  10. Sexing the Sciuridae: a simple and accurate set of molecular methods to determine sex in tree squirrels, ground squirrels and marmots.

    PubMed

    Gorrell, Jamieson C; Boutin, Stan; Raveh, Shirley; Neuhaus, Peter; Côté, Steeve D; Coltman, David W

    2012-09-01

    We determined the sequence of the male-specific minor histocompatibility complex antigen (Smcy) from the Y chromosome of seven squirrel species (Sciuridae, Rodentia). Based on conserved regions inside the Smcy intron sequence, we designed PCR primers for sex determination in these species that can be co-amplified with nuclear loci as controls. PCR co-amplification yields two products for males and one for females that are easily visualized as bands by agarose gel electrophoresis. Our method provides simple and reliable sex determination across a wide range of squirrel species.

  11. Anatomy and Disorders of the Oral Cavity of Rat-like and Squirrel-like Rodents.

    PubMed

    Mancinelli, Elisabetta; Capello, Vittorio

    2016-09-01

    The order Rodentia comprises more than 2000 species divided into 3 groups based on anatomic and functional differences of the masseter muscle. Myomorph and sciuromorph species have elodont incisors and anelodont cheek teeth, unlike hystrichomorph species which have full anelodont dentition. Diseases of incisors and cheek teeth of rat-like and squirrel-like rodents result in a wide variety of symptoms and clinical signs. Appropriate diagnostic testing and imaging techniques are required to obtain a definitive diagnosis, formulate a prognosis, and develop a treatment plan. A thorough review of elodontoma, odontoma, and pseudo-odontoma is provided, including treatment of pseudo-odontomas in prairie dogs.

  12. Lung and hearth nematodes in some Spanish mammals.

    PubMed

    Alvarez, F; Iglesias, R; Bos, J; Rey, J; Sanmartin Durán, M L

    1991-01-01

    Thirteen host species belonging to the orders Rodentia, Insectivora and Carnivora from various localities in Galicia (NW Spain) were examined for heart and lung parasites. The following species were found: Parastrongylus dujardini (5.5%) in Apodemus sylvaticus, Crenosoma striatum in Erinaceus europaeus (83%), Angiostrongylus vasorum, Crenosoma vulpis and Eucoleus aerophilus in Vulpes vulpes (3, 3.46 and 0.50%, respectively), Crenosoma taiga in Putorius putorius (100%) and Crenosoma sp. in Meles meles (25%). In Crocidura russula nematode larvae were found (3.3%). Mus musculus, Rattus norvegicus, Rattus rattus, Talpa caeca, Sorex araneus, Genetta genetta and Canis lupus were not parasitized by lung or heart parasites.

  13. Clinical aspects of rodent dental anatomy.

    PubMed

    Crossley, D A

    1995-12-01

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

  14. Phylogenetic positions of insectivora in eutheria inferred from mitochondrial cytochrome c oxidase subunit II gene.

    PubMed

    Onuma, M; Kusakabe, T; Kusakabe, S

    1998-02-01

    For the elucidation of the phylogenetic position of insectivora in eutheria, we have sequenced the cytochrome c oxidase subunit II (COII) gene of mitochondria for three insectivoran species [musk screw (Suncus murinus), shrew mole (Urotrichus talpoides), Japanese mole (Mogera wogura)] and analyzed these amino acid sequences with neighbor-joining (NJ) method and maximum likelihood (ML) method. NJ analysis shows polyphyly of Insectivora and Chiroptera. Assuming that each of Primates, Ferungulata, Chiroptera, Insectivora and Rodentia is a monophyletic group, ML analysis suggests that Chiroptera is a sister group of Insectivora and that Ferungulata is the closest outgroup to the (Insectivora and Chiroptera) clade.

  15. Karyotypic evolution of the family Sciuridae: inferences from the genome organizations of ground squirrels.

    PubMed

    Li, T; Wang, J; Su, W; Nie, W; Yang, F

    2006-01-01

    Cross-species chromosome painting has made a great contribution to our understanding of the evolution of karyotypes and genome organizations of mammals. Several recent papers of comparative painting between tree and flying squirrels have shed some light on the evolution of the family Sciuridae and the order Rodentia. In the present study we have extended the comparative painting to the Himalayan marmot (Marmotahimalayana) and the African ground squirrel (Xerus cf. erythropus), i.e. representative species from another important squirrel group--the ground squirrels--, and have established genome-wide comparative chromosome maps between human, eastern gray squirrel, and these two ground squirrels. The results show that 1) the squirrels so far studied all have conserved karyotypes that resemble the ancestral karyotype of the order Rodentia; 2) the African ground squirrels could have retained the ancestral karyotype of the family Sciuridae. Furthermore, we have mapped the evolutionary rearrangements onto a molecular-based consensus phylogenetic tree of the family Sciuridae. PMID:16484783

  16. Variance of molecular datings, evolution of rodents and the phylogenetic affinities between Ctenodactylidae and Hystricognathi.

    PubMed

    Huchon, D; Catzeflis, F M; Douzery, E J

    2000-02-22

    The von Willebrand factor (vWF) gene has been used to understand the origin and timing of Rodentia evolution in the context of placental phylogeny vWF exon 28 sequences of 15 rodent families and eight non-rodent eutherian clades are analysed with two different molecular dating methods (uniform clock on a linearized tree; quartet dating). Three main conclusions are drawn from the study of this nuclear exon. First, Ctenodactylidae (gundis) and Hystricognathi (e.g. porcupines, guinea-pigs, chinchillas) robustly cluster together in a newly recognized clade, named 'Ctenohystrica'. The Sciurognathi monophyly is subsequently rejected. Pedetidae (springhares) is an independent and early diverging rodent lineage, suggesting a convergent evolution of the multiserial enamel of rodent incisors. Second, molecular date estimates are here more influenced by accuracy and choice of the palaeontological temporal references used to calibrate the molecular clock than by either characters analysed (nucleotides versus amino acids) or species sampling. The caviomorph radiation at 31 million years (Myr) and the pig porpoise split at 63 Myr appear to be reciprocally compatible dates. Third, during the radiation of Rodentia, at least three lineages (Gliridae, Sciuroidea and Ctenohystrica) emerged close to the Cretaceous-Tertiary boundary, and their common ancestor separated from other placental orders in the Late Cretaceous.

  17. Molecular evolution of the nuclear von Willebrand factor gene in mammals and the phylogeny of rodents.

    PubMed

    Huchon, D; Catzeflis, F M; Douzery, E J

    1999-05-01

    Nucleotide sequences of exon 28 of the von Willebrand Factor (vWF) were analyzed for a representative sampling of rodent families and eutherian orders, with one marsupial sequence as outgroup. The aim of this study was to test if inclusion of an increased taxonomic diversity in molecular analyses would shed light on three uncertainties concerning rodent phylogeny: (1) relationships between rodent families, (2) Rodentia monophyly, and (3) the sister group relationship of rodents and lagomorphs. The results did not give evidence of any particular rodent pattern of molecular evolution relative to a general eutherian pattern. Base compositions and rates of evolution of vWF sequences of rodents were in the range of placental variation. The 10 rodent families studied here cluster in five clades: Hystricognathi, Sciuridae and Aplodontidae (Sciuroidea), Muridae, Dipodidae, and Gliridae. Among hystricognaths, the following conclusions are drawn: a single colonization event in South America by Caviomorpha, a paraphyly of Old World and New World porcupines, and an African origin for Old World porcupines. Despite a broader taxonomic sampling diversity, we did not obtain a robust answer to the question of Rodentia monophyly, but in the absence of any other alternative, we cannot reject the hypothesis of a single origin of rodents. Moreover, the phylogenetic position of Lagomorpha remains totally unsettled.

  18. Rodent phylogeny and a timescale for the evolution of Glires: evidence from an extensive taxon sampling using three nuclear genes.

    PubMed

    Huchon, Dorothée; Madsen, Ole; Sibbald, Mark J J B; Ament, Kai; Stanhope, Michael J; Catzeflis, François; de Jong, Wilfried W; Douzery, Emmanuel J P

    2002-07-01

    Rodentia is the largest order of placental mammals, with approximately 2,050 species divided into 28 families. It is also one of the most controversial with respect to its monophyly, relationships between families, and divergence dates. Here, we have analyzed and compared the performance of three nuclear genes (von Willebrand Factor, interphotoreceptor retinoid-binding protein, and Alpha 2B adrenergic receptor) for a large taxonomic sampling, covering the whole rodent and placental diversity. The phylogenetic results significantly support rodent monophyly, the association of Rodentia with Lagomorpha (the Glires clade), and a Glires + Euarchonta (Primates, Dermoptera, and Scandentia) clade. The resolution of relationships among rodents is also greatly improved. The currently recognized families are divided here into seven well-defined clades (Anomaluromorpha, Castoridae, Ctenohystrica, Geomyoidea, Gliridae, Myodonta, and Sciuroidea) that can be grouped into three major clades: Ctenohystrica, Gliridae + Sciuroidea, and a mouse-related clade (Anomaluromorpha, Castoridae + Geomyoidea, and Myodonta). Molecular datings based on these three genes suggest that the rodent radiation took place at the transition between Paleocene and Eocene. The divergence between rodents and lagomorphs is placed just at the K-T boundary and the first splits among placentals in the Late Cretaceous. Our results thus tend to reconcile molecular and morphological-paleontological insights.

  19. Molecular Individual-Based Approach on Triatoma brasiliensis: Inferences on Triatomine Foci, Trypanosoma cruzi Natural Infection Prevalence, Parasite Diversity and Feeding Sources

    PubMed Central

    Almeida, Carlos Eduardo; Faucher, Leslie; Lavina, Morgane; Costa, Jane; Harry, Myriam

    2016-01-01

    We used an individual-based molecular multisource approach to assess the epidemiological importance of Triatoma brasiliensis collected in distinct sites and ecotopes in Rio Grande do Norte State, Brazil. In the semi-arid zones of Brazil, this blood sucking bug is the most important vector of Trypanosoma cruzi—the parasite that causes Chagas disease. First, cytochrome b (cytb) and microsatellite markers were used for inferences on the genetic structure of five populations (108 bugs). Second, we determined the natural T. cruzi infection prevalence and parasite diversity in 126 bugs by amplifying a mini-exon gene from triatomine gut contents. Third, we identified the natural feeding sources of 60 T. brasiliensis by using the blood meal content via vertebrate cytb analysis. Demographic inferences based on cytb variation indicated expansion events in some sylvatic and domiciliary populations. Microsatellite results indicated gene flow between sylvatic and anthropic (domiciliary and peridomiciliary) populations, which threatens vector control efforts because sylvatic population are uncontrollable. A high natural T. cruzi infection prevalence (52–71%) and two parasite lineages were found for the sylvatic foci, in which 68% of bugs had fed on Kerodon rupestris (Rodentia: Caviidae), highlighting it as a potential reservoir. For peridomiciliary bugs, Galea spixii (Rodentia: Caviidae) was the main mammal feeding source, which may reinforce previous concerns about the potential of this animal to link the sylvatic and domiciliary T. cruzi cycles. PMID:26891047

  20. Species identification key of Korean mammal hair.

    PubMed

    Lee, Eunok; Choi, Tae-Young; Woo, Donggul; Min, Mi-Sook; Sugita, Shoei; Lee, Hang

    2014-05-01

    The hair microstructures of Korean terrestrial mammals from 23 species (22 wild and one domestic) were analyzed using light and scanning electron microscopy (SEM) to construct a hair identification key. The hairs were examined using the medulla structures and cuticular scales of guard hairs from the dorsal regions of mature adult animals. All cuticular scale structures in the hair of Rodentia, Lagomorpha, Carnivora and Insectivora showed the petal pattern, and those of Artiodactyla and Chiroptera showed the wave pattern and coronal pattern, respectively. Rodentia, Lagomorpha and Carnivora showed multicellular, and Insectivora and Artiodactyla showed unicellular regular, mesh or columnar in the medulla structures, respectively. Chiroptera did not show the medulla structures in their hair. We found that it is possible to distinguish between species and order based on general appearance, medulla structures and cuticular scales. Thus, we constructed a hair identification key with morphological characteristics from each species. This study suggests that hair identification keys could be useful in fields, such as forensic science, food safety and foraging ecology.

  1. Seed predation by mammals in forest fragments in Monteverde, Costa Rica.

    PubMed

    Chinchilla, Federico A

    2009-09-01

    Few studies have evaluated seed predation in fragmented landscapes, in which lower species diversity is expected to modifying ecological interactions. The rates of seed removal by mammals were investigated in a continuous forest and two fragmented patches of Premontane Tropical Moist Forest, in Monteverde, Costa Rica. The composition of mammalian seed-predators in each site was recorded during 16 months. The removal of four native tree species of experimental seeds: Ocotea valeriana and Ocotea whitei (Lauraceae), Panopsis costaricensis (Proteaceae) and Billia colombiana (Hippocastanaceae) in forest understories was followed during two annual fruiting seasons for each species. Results indicated similar species composition of seed-predators between continuous forest, the largest fragment (350 ha). However the smaller fragment (20 ha), had fewer seed predators. In this fragment, the specialized seed predator Heteromys desmarestianus (Rodentia) was more abundant. Unexpectedly, seed-predation in the two forest fragments and the continuous forest did not differ statistically for any of the seed species. Apparently, the higher abundance of small seed-predators in the fragments was compensated by the absence of medium and large seed-predators, like Agouti paca, Dasyprocta punctata (both Rodentia) and Pecari tajacu (Artiodactyla) recorded in continuous forest. Removal of experimentally-placed seeds was higher when the number of naturally occurring seeds in the sites was lower. This result could best be attributed to differential satiation of seed predators rather than differences in richness or abundance of seed predators.

  2. Molecular Individual-Based Approach on Triatoma brasiliensis: Inferences on Triatomine Foci, Trypanosoma cruzi Natural Infection Prevalence, Parasite Diversity and Feeding Sources.

    PubMed

    Almeida, Carlos Eduardo; Faucher, Leslie; Lavina, Morgane; Costa, Jane; Harry, Myriam

    2016-02-01

    We used an individual-based molecular multisource approach to assess the epidemiological importance of Triatoma brasiliensis collected in distinct sites and ecotopes in Rio Grande do Norte State, Brazil. In the semi-arid zones of Brazil, this blood sucking bug is the most important vector of Trypanosoma cruzi--the parasite that causes Chagas disease. First, cytochrome b (cytb) and microsatellite markers were used for inferences on the genetic structure of five populations (108 bugs). Second, we determined the natural T. cruzi infection prevalence and parasite diversity in 126 bugs by amplifying a mini-exon gene from triatomine gut contents. Third, we identified the natural feeding sources of 60 T. brasiliensis by using the blood meal content via vertebrate cytb analysis. Demographic inferences based on cytb variation indicated expansion events in some sylvatic and domiciliary populations. Microsatellite results indicated gene flow between sylvatic and anthropic (domiciliary and peridomiciliary) populations, which threatens vector control efforts because sylvatic population are uncontrollable. A high natural T. cruzi infection prevalence (52-71%) and two parasite lineages were found for the sylvatic foci, in which 68% of bugs had fed on Kerodon rupestris (Rodentia: Caviidae), highlighting it as a potential reservoir. For peridomiciliary bugs, Galea spixii (Rodentia: Caviidae) was the main mammal feeding source, which may reinforce previous concerns about the potential of this animal to link the sylvatic and domiciliary T. cruzi cycles.

  3. Species identification key of Korean mammal hair.

    PubMed

    Lee, Eunok; Choi, Tae-Young; Woo, Donggul; Min, Mi-Sook; Sugita, Shoei; Lee, Hang

    2014-05-01

    The hair microstructures of Korean terrestrial mammals from 23 species (22 wild and one domestic) were analyzed using light and scanning electron microscopy (SEM) to construct a hair identification key. The hairs were examined using the medulla structures and cuticular scales of guard hairs from the dorsal regions of mature adult animals. All cuticular scale structures in the hair of Rodentia, Lagomorpha, Carnivora and Insectivora showed the petal pattern, and those of Artiodactyla and Chiroptera showed the wave pattern and coronal pattern, respectively. Rodentia, Lagomorpha and Carnivora showed multicellular, and Insectivora and Artiodactyla showed unicellular regular, mesh or columnar in the medulla structures, respectively. Chiroptera did not show the medulla structures in their hair. We found that it is possible to distinguish between species and order based on general appearance, medulla structures and cuticular scales. Thus, we constructed a hair identification key with morphological characteristics from each species. This study suggests that hair identification keys could be useful in fields, such as forensic science, food safety and foraging ecology. PMID:24451929

  4. DNA "fingerprinting" reveals high levels of inbreeding in colonies of the eusocial naked mole-rat.

    PubMed

    Reeve, H K; Westneat, D F; Noon, W A; Sherman, P W; Aquadro, C F

    1990-04-01

    Using the technique of DNA fingerprinting, we investigated the genetic structure within and among four wild-caught colonies (n = 50 individuals) of a eusocial mammal, the naked mole-rat (Heterocephalus glaber; Rodentia: Bathyergidae). We found that DNA fingerprints of colony-mates were strikingly similar and that between colonies they were much more alike than fingerprints of non-kin in other free-living vertebrates. Extreme genetic similarity within colonies is due to close genetic relationship (mean relatedness estimate +/- SE, r = 0.81 +/- 0.10), which apparently results from consanguineous mating. The inbreeding coefficient (F = 0.45 +/- 0.18) is the highest yet recorded among wild mammals. The genetic structure of naked mole-rat colonies lends support to kin selection and ecological constraints models for the evolution of cooperative breeding and eusociality. PMID:2320570

  5. Further description of Aspidodera raillieti (Nematoda: Aspidoderidae) from Didelphis marsupialis (Mammalia: Didelphidae) by light and scanning electron microscopy.

    PubMed

    Chagas-Moutinho, V A; Oliveira-Menezes, A; Cárdenas, M Q; Lanfredi, R M

    2007-10-01

    Nematodes of the family Aspidoderidae (Nematoda: Heterakoidea) Freitas 1956 are widely distributed from Americas. The species of the genus Aspidodera Railliet and Henry 1912 are parasites of mammals of the orders Edentata, Marsupialia, and Rodentia. In the present work, Aspidodera raillieti (L. Travassos, Mem Inst Oswaldo Cruz 5(3):271-318, 1913), collected from the large intestine of Didelphis marsupialis (Mammalia: Didelphidae) from Valle del Cauca, Colombia, is redescribed. The association of light and scanning electron microscopy (SEM) allowed a detailed analysis of the morphology and ultrastructure of this nematode. Some taxonomic features, such as cephalic region, topography of the cuticle, sucker, spicules, posterior end of males, localization of vulva, the anus, and posterior end of females were observed. Important structures such as amphid, details of cephalic region, phasmid, and number and localization of caudal papillae are documented by SEM, for the first time adding characters to identify this species. Colombia is a new geographical record for A. raillieti.

  6. Rodents for comparative aging studies: from mice to beavers

    PubMed Central

    Bozzella, Michael J.; Seluanov, Andrei

    2008-01-01

    After humans, mice are the best-studied mammalian species in terms of their biology and genetics. Gerontological research has used mice and rats extensively to generate short- and long-lived mutants, study caloric restriction and more. Mice and rats are valuable model organisms thanks to their small size, short lifespans and fast reproduction. However, when the goal is to further extend the already long human lifespan, studying fast aging species may not provide all the answers. Remarkably, in addition to the fast-aging species, the order Rodentia contains multiple long-lived species with lifespans exceeding 20 years (naked mole-rat, beavers, porcupines, and some squirrels). This diversity opens great opportunities for comparative aging studies. Here we discuss the evolution of lifespan in rodents, review the biology of slow-aging rodents, and show an example of how the use of a comparative approach revealed that telomerase activity coevolved with body mass in rodents. PMID:19424861

  7. The largest fossil rodent

    PubMed Central

    Rinderknecht, Andrés; Blanco, R. Ernesto

    2008-01-01

    The discovery of an exceptionally well-preserved skull permits the description of the new South American fossil species of the rodent, Josephoartigasia monesi sp. nov. (family: Dinomyidae; Rodentia: Hystricognathi: Caviomorpha). This species with estimated body mass of nearly 1000 kg is the largest yet recorded. The skull sheds new light on the anatomy of the extinct giant rodents of the Dinomyidae, which are known mostly from isolated teeth and incomplete mandible remains. The fossil derives from San José Formation, Uruguay, usually assigned to the Pliocene–Pleistocene (4–2 Myr ago), and the proposed palaeoenvironment where this rodent lived was characterized as an estuarine or deltaic system with forest communities. PMID:18198140

  8. Chigger mites (Acari, Trombiculidae) parasitizing small mammals in the Eastern Hindu Kush and some other Afghan areas.

    PubMed

    Daniel, Milan; Stekolnikov, Alexandr A; Hakimitabar, Masoud; Saboori, Alireza

    2010-10-01

    Chigger mites of Afghanistan were studied on the base of collections made in Eastern and Central Hindu Kush, Kabul, and some other localities. Fifteen chigger species parasitizing nine species of Rodentia, two species of Lagomorpha, and one species of Soricomorpha were found, including 13 species which were not previously recorded in Afghanistan. Eco-geographical variability is observed in Shunsennia oudemansi: Individuals of this species from high-mountain localities of Eastern Hindu Kush are characterized by larger values of most morphometric characters than the specimens collected in Kabul. Vertical and horizontal distribution of chiggers and chigger-host relationships in Eastern Hindu Kush is discussed. Comparison of our data with that on chigger fauna in the region of Tirich Mir clearly demonstrates the role of the Eastern Hindu Kush main ridge as a border between different chigger faunas. PMID:20737277

  9. Hepatitis B virus lineages in mammalian hosts: Potential for bidirectional cross-species transmission

    PubMed Central

    Bonvicino, Cibele R; Moreira, Miguel A; Soares, Marcelo A

    2014-01-01

    The hepatitis B virus (HBV) is a cosmopolitan infectious agent currently affecting over 350 million people worldwide, presently accounting for more than two billion infections. In addition to man, other hepatitis virus strains infect species of several mammalian families of the Primates, Rodentia and Chiroptera orders, in addition to birds. The mounting evidence of HBV infection in African, Asian and neotropical primates draws attention to the potential cross-species, zoonotic transmission of these viruses to man. Moreover, recent evidence also suggests the humans may also function as a source of viral infection to other mammals, particularly to domestic animals like poultry and swine. In this review, we list all evidence of HBV and HBV-like infection of nonhuman mammals and discuss their potential roles as donors or recipients of these viruses to humans and to other closely-related species. PMID:24976704

  10. Complete mitochondrial genome sequence of the Chinese scrub vole (Neodon irene).

    PubMed

    Fan, Longqing; Fan, Zhenxin; Yue, Hao; Zhang, Xiuyue; Liu, Yang; Sun, Zhiyu; Liu, Shaoying; Yue, Bisong

    2011-06-01

    The Chinese scrub vole (Neodon irene) belongs to the subfamily Arvicolinae, which is restricted to mountain areas at high altitudes (2800-4000). In this study, we sequenced the complete mitochondrial genome of N. irene. It was determined to be 16,367 bases. The nucleotide sequence data of 12 heavy-strand protein-coding genes of N. irene and other 22 rodents were used for phylogenetic analysis. Bayesian inference (BI) and maximum likelihood (ML) were used. Both the BI and ML trees demonstrated that Microtus rossiaemeridionalis and Microtus kikuchii did not cluster together with each other. On the contrary, M. rossiaemeridionalis showed close relationship with N. irene. In the present study, only one sequence from Neodon and two sequences from Microtus were included in the phylogenetic analysis which should contribute to the unusual relationship. Therefore, in order to better understand the phylogenetic relationship within Rodentia, more rodents' complete mitochondrial genomes are required.

  11. Rodents for comparative aging studies: from mice to beavers.

    PubMed

    Gorbunova, Vera; Bozzella, Michael J; Seluanov, Andrei

    2008-09-01

    After humans, mice are the best-studied mammalian species in terms of their biology and genetics. Gerontological research has used mice and rats extensively to generate short- and long-lived mutants, study caloric restriction and more. Mice and rats are valuable model organisms thanks to their small size, short lifespans and fast reproduction. However, when the goal is to further extend the already long human lifespan, studying fast aging species may not provide all the answers. Remarkably, in addition to the fast-aging species, the order Rodentia contains multiple long-lived species with lifespans exceeding 20 years (naked mole-rat, beavers, porcupines, and some squirrels). This diversity opens great opportunities for comparative aging studies. Here we discuss the evolution of lifespan in rodents, review the biology of slow-aging rodents, and show an example of how the use of a comparative approach revealed that telomerase activity coevolved with body mass in rodents. PMID:19424861

  12. Cryptosporidium muris in a reticulated giraffe (Giraffa camelopardalis reticulata).

    PubMed

    Kodádková, A; Kvác, M; Ditrich, O; Sak, B; Xiao, L

    2010-02-01

    Cryptosporidium spp. infection in captive exotic mammals was investigated using staining and molecular biological methods. A total of 323 fecal samples from 100 mammalian species (62 Artiodactyla, 33 Rodentia, 3 Perissodactyla, and 2 Paenungultata) in 4 zoological gardens in the Czech Republic was examined. Only in a reticulated giraffe (Giraffa camelopardalis reticulata) sample was Cryptosporidium sp. infection detected. The partial small subunit rRNA sequence obtained from the isolate was identical to sequences of Cryptosporidium muris in rock hyrax (Procavia capensis) and Bactrian camel (Camelus bactrianus). Neonatal BALB/c mice inoculated with 1 x 10(3) fresh oocysts of the C. muris giraffe isolate did not produce a detectable infection. PMID:19685941

  13. Classification tree methods provide a multifactorial approach to predicting insular body size evolution in rodents.

    PubMed

    Durst, Paul A P; Roth, V Louise

    2012-04-01

    Many hypotheses have been proposed to explain size changes in insular mammals, but no single variable suffices to explain the diversity of responses, particularly within Rodentia. Here in a data set on insular rodents, we observe strong consistency in the direction of size change within islands and within species but (outside of Heteromyidae) little consistency at broader taxonomic scales. Using traits of islands and of species in a classification tree analysis, we find the most important factor predicting direction of change to be mainland body mass (large rodents decrease, small ones increase); other variables (island climate, number of rodent species, and area) were significant, although their roles as revealed by the classification tree were context dependent. Ecological interactions appear relatively uninformative, and on any given island, the largest and smallest rodent species converged or diverged in size with equal frequency. Our approach provides a promising framework for continuing examination of insular body size evolution. PMID:22437183

  14. Molecular Identification of Food Sources in Triatomines in the Brazilian Northeast: Roles of Goats and Rodents in Chagas Disease Epidemiology

    PubMed Central

    Valença-Barbosa, Carolina; Fernandes, Fabiano Araújo; Santos, Helena Lucia Carneiro; Sarquis, Otília; Harry, Myriam; Almeida, Carlos Eduardo; Lima, Marli Maria

    2015-01-01

    We used the gut contents of triatomines collected from rural areas of Ceará State, northeastern Brazil, to identify their putative hosts via vertebrate cytb gene sequencing. Successful direct sequencing was obtained for 48% of insects, comprising 50 Triatoma brasiliensis, 7 Triatoma pseudomaculata, and 1 Rhodnius nasutus. Basic local alignment search tool (BLAST) procedure revealed that domestic animals, such as chickens (Gallus gallus) and goats (Capra hircus), are the main food source, including in sylvatic environment. Native hosts were also detected in peridomestic environment such as reptiles (Tropidurus sp. and Iguana iguana) and the Galea spixii (Rodentia: Caviidae). The role of goats and Galea spixii in Chagas disease epidemiology calls for further studies, because these mammals likely link the sylvatic and domestic Trypanosoma cruzi cycles. PMID:26350453

  15. The prevalence of Balantidium coli infection in fifty-six mammalian species.

    PubMed

    Nakauchi, K

    1999-01-01

    A total of 375 fecal samples of 56 mammalian species belonging to 17 families of 4 orders were examined for the detection of Balantidium coli from December 1994 to August 1995. As a result, B. coli was found from 6 species belonging to 4 families of 2 orders (Primates and Artiodactyla) of host animals examined. White-handed gibbon (Hylobates lar), squirrel monkey (Saimiri sciurea) and Japanese macaque (Macaca fuscata) were new hosts for B. coli. All the wild boar (Sus scrofa) and chimpanzee (Pan troglodytes) examined were positive. The highest number of B. coli was obtained from a chimpanzee (1,230/g feces). No B. coli was detected from the animals of orders Rodentia and Carnivora including dogs and cats. The rarity of B. coli infection in breeding animals in Japan. suggests that there is no serious problem in controlling infections. PMID:10027167

  16. DNA "fingerprinting" reveals high levels of inbreeding in colonies of the eusocial naked mole-rat.

    PubMed Central

    Reeve, H K; Westneat, D F; Noon, W A; Sherman, P W; Aquadro, C F

    1990-01-01

    Using the technique of DNA fingerprinting, we investigated the genetic structure within and among four wild-caught colonies (n = 50 individuals) of a eusocial mammal, the naked mole-rat (Heterocephalus glaber; Rodentia: Bathyergidae). We found that DNA fingerprints of colony-mates were strikingly similar and that between colonies they were much more alike than fingerprints of non-kin in other free-living vertebrates. Extreme genetic similarity within colonies is due to close genetic relationship (mean relatedness estimate +/- SE, r = 0.81 +/- 0.10), which apparently results from consanguineous mating. The inbreeding coefficient (F = 0.45 +/- 0.18) is the highest yet recorded among wild mammals. The genetic structure of naked mole-rat colonies lends support to kin selection and ecological constraints models for the evolution of cooperative breeding and eusociality. Images PMID:2320570

  17. First record of metacestodes of Mesocestoides sp. in the common starling (Sturnus vulgaris) in Europe, with an 18S rDNA characterisation of the isolate.

    PubMed

    Literák, Ivan; Olson, Peter D; Georgiev, Boyko B; Spakulová, Marta

    2004-03-01

    Metacestodes of Mesocestoides sp. were recorded from Sturnus vulgaris (Passeriformes: Stumidae) in the Czech Republic in April 2002. They were found in a cutaneous cyst and in the thoracic region of the body cavity of the bird. This is the first record of metacestodes of Mesocestoides sp. in this host species in Europe as well as the first finding of the formation of a cutaneous cyst provoked by this parasite. Additional specimens from Apodemus agrarius (Mammalia: Rodentia) from Bulgaria and Lacerta agilis (Reptilia: Squamata) from the Czech Republic were compared with that from S. vulgaris. Sequence data from the V4 variable region (18S rDNA) were used to compare genetic variability among these and previously characterized isolates of Mesocestoides spp. A number of distinct clades were recognized, with metacestodes from L. agilis showing the highest degree of relative divergence. PMID:15139376

  18. Distribution and ecology of small mammals in Albania.

    PubMed

    Rogozi, Elton; Bego, Ferdinand; Papa, Anna; Mersini, Kujtim; Bino, Silvia

    2013-01-01

    In order to gain an insight into the population dynamics and habitat preferences of rodents in Albania, small mammals were collected during 2006-2009 in various districts of the country. Of the 15 species of small mammals captured (12 in Rodentia and 3 in Insectivora order), the yellow-necked mouse (Apodemus flavicollis) was the most frequently collected, representing 50% of the 325 small mammals captured, followed by the wood mouse (Apodemus sylvaticus) (20.62%). Apodemus flavicollis is the primary reservoir for Dobrava-Belgrade virus which causes to humans hemorrhagic fever with renal syndrome; the places with A. flavicollis abundance were those with records of the human disease. Knowledge of the reservoir ecology in a country facilitates risk assessments for rodent-borne diseases.

  19. Sentinel species for in-situ genotoxic environmental monitoring

    SciTech Connect

    Lower, W.R.; Yanders, A.F. ); Sandhu, S.S. )

    1988-09-01

    A sentinel species has been defined in a draft report of the Society of Environmental Toxicology and Chemistry on Research Priorities in Environmental Risk as --- a plant, animal or microbe that can be used as an indicator of exposure or toxicity of a xenobiotic owing to its sensitivity, initial position in the community, likelihood of exposure, or abundance sufficient to allow statistical interpretation. Three organisms are presented here as candidates for sentinel species: the monocot Tradescantia (family Commelinacea, spiderwort), of which there are four strains or species used: Ictalurus nebulosus (family Ictaluraidae, the brown bullhead catfish); Peromyscus maniculatus, peromyscus leucopus (family Cricetidae, deer mouse, white-footed mouse) which occur over 85% of the continental US including Alaska, and with the two species sympatric over 60% of their geographic ranges. Candidates for consideration for sentinel bioassays presented here are the electron transport system of photosynthesis, sister chromatid exchange, micronuclei formation in animal cells, micronuclei formation in pollen mother cells, tumor formation, hemoglobin synthesis, nucleic acid and protein adduct formation and cytochrome P-450 dependent monoxygenase induction.

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

    PubMed

    Zhang, Yong-Zhen

    2014-07-17

    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.

  1. Leptospira spp. in Rodents and Shrews in Germany

    PubMed Central

    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

    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

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

    PubMed

    Zhang, Yong-Zhen

    2014-07-17

    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

  3. Late Oligocene and Early Miocene Muroidea of the Zinda Pir Dome

    PubMed Central

    Lindsay, Everett H.; Flynn, Lawrence J.

    2016-01-01

    A series of Oligocene through Early Miocene terrestrial deposits preserved in the foothills of the Zinda Pir Dome of western Pakistan produce multiple, superposed fossil mammal localities. These include small mammal assemblages that shed light on the evolution of rodent lineages, especially Muroidea, in South Asia. Nine small mammal localities span approximately 28–19 Ma, an interval encompassing the Oligocene–Miocene boundary. The Early Miocene rodent fossil assemblages are dominated by muroid rodents, but muroids are uncommon and archaic in earlier Oligocene horizons. The Zinda Pir sequence includes the evolutionary transition to modern Muroidea at about the Oligocene–Miocene boundary. We review the muroid record for the Zinda Pir Dome, which includes the early radiation of primitive bamboo rats (Rhizomyinae) and early members of the modern muroid radiation, which lie near crown Cricetidae and Muridae. The Zinda Pir record dates diversification of modern muroids in the Indian Subcontintent and establishment by 19 Ma of muroid assemblages characteristic of the later Siwaliks. PMID:26681836

  4. The role of wild mammals in the maintenance of Rift Valley fever virus.

    PubMed

    Olive, Marie-Marie; Goodman, Steven M; Reynes, Jean-Marc

    2012-04-01

    Rift Valley fever virus (RVFV) is a zoonotic arbovirus affecting primarily domestic ruminants and humans. Numerous vector species are known or implicated in the transmission of RVFV. The role of mammals in the maintenance of RVFV, and the existence of a wild mammal reservoir in the epidemiologic cycle of RVFV, remain largely unknown. Our objective is to present a detailed review of studies undertaken on RVFV, often associated with wild mammals, with the aim of focusing future research on potential reservoirs of the virus. Natural and experimental infections related to RVFV in several mammalian orders, including Artiodactyla, Chiroptera, Rodentia, Primata (nonhuman), Perissodactyla, Carnivora, Proboscidea, Erinaceomorpha, and Lagomorpha, are reviewed; the first four orders have received the greatest attention. The possible role of wild ruminants, especially African buffalo (Syncerus caffer), is also discussed. Conflicting results have been published concerning rodents but, based on the literature, the likely candidate species include the African genera Arvicanthis and Micaelamys and the widely introduced roof rat (Rattus rattus). Members of the orders Chiroptera and Rodentia should receive greater attention associated with new research programs. For the other orders mentioned above, few data are available. We are unaware of any investigation concerning the orders Afrosoricida and Soricomorpha, which are represented in the geographic area of RVFV and can be abundant. As a first step to resolve the question of wild mammals as a reservoir of RVFV, serologic and virologic surveys should be promoted during epizootic periods to document infected wild animals and, in the case of positive results, extended to interepidemic periods to explore the role of wild animals as possible reservoirs.

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

    PubMed Central

    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

    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. PMID:18452598

  6. The hip adductor muscle group in caviomorph rodents: anatomy and homology.

    PubMed

    García-Esponda, César M; Candela, Adriana M

    2015-06-01

    Anatomical comparative studies including myological data of caviomorph rodents are relatively scarce, leading to a lack of use of muscular features in cladistic and morphofunctional analyses. In rodents, the hip adductor muscles constitute an important group of the hindlimb musculature, having an important function during the beginning of the stance phase. These muscles are subdivided in several distinct ways in the different clades of rodents, making the identification of their homologies hard to establish. In this contribution we provide a detailed description of the anatomical variation of the hip adductor muscle group of different genera of caviomorph rodents and identify the homologies of these muscles in the context of Rodentia. On this basis, we identify the characteristic pattern of the hip adductor muscles in Caviomorpha. Our results indicate that caviomorphs present a singular pattern of the hip adductor musculature that distinguishes them from other groups of rodents. They are characterized by having a single m. adductor brevis that includes solely its genicular part. This muscle, together with the m. gracilis, composes a muscular sheet that is medial to all other muscles of the hip adductor group. Both muscles probably have a synergistic action during locomotion, where the m. adductor brevis reinforces the multiple functions of the m. gracilis in caviomorphs. Mapping of analyzed myological characters in the context of Rodentia indicates that several features are recovered as potential synapomorphies of caviomorphs. Thus, analysis of the myological data described here adds to the current knowledge of caviomorph rodents from anatomical and functional points of view, indicating that this group has features that clearly differentiate them from other rodents. PMID:25911542

  7. Eco-epidemiological survey of Leishmania (Viannia) braziliensis American cutaneous and mucocutaneous leishmaniasis in Ribeira Valley River, Paraná State, Brazil.

    PubMed

    de Castro, Edilene Alcântara; Luz, Ennio; Telles, Flávio Queiroz; Pandey, Ashok; Biseto, Alceu; Dinaiski, Marlene; Sbalqueiro, Ives; Soccol, Vanete Thomaz

    2005-02-01

    Leishmaniasis is endemic since last century in Adrianópolis Municipality, Ribeira Valley and is a serious public health. A study carried out during 1993-2003 on epidemiological surveys conducted in rural communities showed 339 new cases of cutaneous leishmaniasis (CL) detected from four municipalities (Adrianópolis, Cerro Azul, Doutor Ulysses and Rio Branco do Sul). A larger prevalence of cutaneous lesions was observed in rural workers (36%), women with domestic activities (18%), and younger students (31%). Multiple lesions were noticed in 53% of patients, but only one case of mucocutaneous leishmaniasis was reported. Twenty stocks were isolated from patients with characteristics lesions and were identified as Leishmania (Viannia) braziliensis using multi-locus enzyme electrophoresis (MLEE) and Random Amplified DNA (RAPD). In Phlebotominae survey, five species were obtained. Lutzomyia intermedia sl. represented 97.5% in peridomiciliar area and 100% in domicile. A canine serological survey made (Indirect Immunofluorescence Antibody Test, IFAT and Enzyme Linked Immunosorbent Assay, ELISA) in six rural county of Adrianópolis Municipality during 1998-1999 showed that 15.1% (24/159) of dogs were sera reactive. No lesions were observed in dogs and no parasite was isolated from lymph node aspirates and biopsies. In wild reservoirs study, only seven animals (Cricetidae, Desmodus sp. and edentates) were captured, but no parasites were found in culture from deep organs. The paper presents results of our 10 years study on cutaneous leishmaniasis survey in the Ribeira River Valley, East Region of Paraná State, Brazil. Environment changes in this region are also discussed. PMID:15652328

  8. Prevalence of antibody to hantaviruses in humans and rodents in the Caribbean region of Colombia determined using Araraquara and Maciel virus antigens

    PubMed Central

    Guzmán, Camilo; Mattar, Salim; Levis, Silvana; Pini, Noemí; Figueiredo, Tadeu; Mills, James; Salazar-Bravo, Jorge

    2013-01-01

    We tested sera from 286 agricultural workers and 322 rodents in the department of Córdoba, northeastern Colombia, for antibodies against two hantaviruses. The sera were analysed by indirect ELISA using the lysate of Vero E6 cells infected with Maciel virus (MACV) or the N protein of Araraquara virus (ARAV) as antigens for the detection of antibodies against hantaviruses. Twenty-four human sera were IgG positive using one or both antigens. We detected anti-MACV IgG antibodies in 10 sera (3.5%) and anti-ARAV antibodies in 21 sera (7.34%). Of the 10 samples that were positive for MACV, seven (70%) were cross-reactive with ARAV; seven of the 21 ARAV-positive samples were cross-reactive with MACV. Using an ARAV IgM ELISA, two of the 24 human sera (8.4%) were positive. We captured 322 rodents, including 210 Cricetidae (181 Zygodontomys brevicauda, 28 Oligoryzomys fulvescens and 1 Oecomys trinitatis), six Heteromys anomalus (Heteromyidae), one Proechimys sp. (Echimyidae) and 105 Muridae (34 Rattus rattus and 71 Mus musculus). All rodent sera were negative for both antigens. The 8.4% detection rate of hantavirus antibodies in humans is much higher than previously found in serosurveys in North America, suggesting that rural agricultural workers in northeastern Colombia are frequently exposed to hantaviruses. Our results also indicate that tests conducted with South American hantavirus antigens could have predictive value and could represent a useful alternative for the diagnosis of hantavirus infection in Colombia. PMID:23579795

  9. Sexual selection and the adaptive evolution of PKDREJ protein in primates and rodents.

    PubMed

    Vicens, Alberto; Gómez Montoto, Laura; Couso-Ferrer, Francisco; Sutton, Keith A; Roldan, Eduardo R S

    2015-02-01

    PKDREJ is a testis-specific protein thought to be located on the sperm surface. Functional studies in the mouse revealed that loss of PKDREJ has effects on sperm transport and the ability to undergo an induced acrosome reaction. Thus, PKDREJ has been considered a potential target of post-copulatory sexual selection in the form of sperm competition. Proteins involved in reproductive processes often show accelerated evolution. In many cases, this rapid divergence is promoted by positive selection which may be driven, at least in part, by post-copulatory sexual selection. We analysed the evolution of the PKDREJ protein in primates and rodents and assessed whether PKDREJ divergence is associated with testes mass relative to body mass, which is a reliable proxy of sperm competition levels. Evidence of an association between the evolutionary rate of the PKDREJ gene and testes mass relative to body mass was not found in primates. Among rodents, evidence of positive selection was detected in the Pkdrej gene in the family Cricetidae but not in Muridae. We then assessed whether Pkdrej divergence is associated with episodes of sperm competition in these families. We detected a positive significant correlation between the evolutionary rates of Pkdrej and testes mass relative to body mass in cricetids. These findings constitute the first evidence of post-copulatory sexual selection influencing the evolution of a protein that participates in the mechanisms regulating sperm transport and the acrosome reaction, strongly suggesting that positive selection may act on these fertilization steps, leading to advantages in situations of sperm competition. PMID:25304980

  10. [Decorative forms of hamsters Phodopus (Mammalia, Cricetinae): an analysis of genetic lines distribution and peculiarities of hair changes].

    PubMed

    Feoktistova, N Iu; Chernova, O F; Meshcherskiĭ, I G

    2012-01-01

    Three species of dwarf hamsters (genus Phodopus, family Cricetidae) inhabit some regions of Russia, Kazakhstan, Mongolia, and China, each having quite extensive range. In recent decades, the dwarf hamsters became widely spread all over the world, initially as laboratory animals and later as popular pets. By now, there is lot of decorative breed lines and colored forms of these animals. Comparison of mtDNA nucleotide sequences of dwarf hamsters acquired in pet shops of some countries in Europe, South-East Asia and North America with distribution of mtDNA haplotypes within natural ranges showed the limitation of decorative line founders' points of origin by one region for each of the species. All haplotypes found in decorative Dzungarian hamsters (Ph. sungorus) purchased ounside Russia coincide with or are significantly close to haplotypes spread in the southern part of West Siberia (Russia) and adjacent regions of Kazakhstan; haplotypes of decorative Campbell's hamster (Ph. campbelli) belong to haplogroup of this species natural populations inhabiting South Tyva (Russia); and all studied decorative Desert hamsters (Ph. roborovskii) had one hapotype specific for South-Eastern Kazakhstan. The review of the history of researches on dwarf hamsters biology allows to determine delivery of hamsters from mentioned regions to scientific laboratories and zoos by certain expeditions and/or researchers. Unlike hamsters with natural hair color, the colored hamsters have no normal hair. Their hair is dull and straggly. The hair differentiation (presence of different hair types and their size characteristics) gets broken and results in deformation, bending, and splitting of the shaft, cracks in cuticle, change of configuration and location of medulla, uneven development of cortex. It is assumed that these destructive changes are associated with genetic characteristics of these hamsters' colored forms.

  11. Prevalence of antibody to hantaviruses in humans and rodents in the Caribbean region of Colombia determined using Araraquara and Maciel virus antigens.

    PubMed

    Guzmán, Camilo; Mattar, Salim; Levis, Silvana; Pini, Noemí; Figueiredo, Tadeu; Mills, James; Salazar-Bravo, Jorge

    2013-04-01

    We tested sera from 286 agricultural workers and 322 rodents in the department of Córdoba, northeastern Colombia, for antibodies against two hantaviruses. The sera were analysed by indirect ELISA using the lysate of Vero E6 cells infected with Maciel virus (MACV) or the N protein of Araraquara virus (ARAV) as antigens for the detection of antibodies against hantaviruses. Twenty-four human sera were IgG positive using one or both antigens. We detected anti-MACV IgG antibodies in 10 sera (3.5%) and anti-ARAV antibodies in 21 sera (7.34%). Of the 10 samples that were positive for MACV, seven (70%) were cross-reactive with ARAV; seven of the 21 ARAV-positive samples were cross-reactive with MACV. Using an ARAV IgM ELISA, two of the 24 human sera (8.4%) were positive. We captured 322 rodents, including 210 Cricetidae (181 Zygodontomys brevicauda, 28 Oligoryzomys fulvescens and 1 Oecomys trinitatis), six Heteromys anomalus (Heteromyidae), one Proechimys sp. (Echimyidae) and 105 Muridae (34 Rattus rattus and 71 Mus musculus). All rodent sera were negative for both antigens. The 8.4% detection rate of hantavirus antibodies in humans is much higher than previously found in serosurveys in North America, suggesting that rural agricultural workers in northeastern Colombia are frequently exposed to hantaviruses. Our results also indicate that tests conducted with South American hantavirus antigens could have predictive value and could represent a useful alternative for the diagnosis of hantavirus infection in Colombia.

  12. Function and expression of CD1d and invariant natural killer T-cell receptor in the cotton rat (Sigmodon hispidus).

    PubMed

    Fichtner, Alina Suzann; Paletta, Daniel; Starick, Lisa; Schumann, Richard F; Niewiesk, Stefan; Herrmann, Thomas

    2015-12-01

    The cotton rat (Sigmodon hispidus) belongs to the rodent family of Cricetidae and provides a powerful model to study the pathogenesis of human respiratory viruses and measles virus. Recent studies in other rodent models have suggested a role for invariant natural killer T (iNKT) cells in antiviral immunity and vaccination against respiratory virus infections. Using new experimental tools, we provide the first evidence for a functional CD1d cell molecule (crCD1d) and iNKT T-cell receptor in cotton rats. The crCD1d cDNA sequence was identified and crCD1d transductants showed that monoclonal antibody WTH-2 stains crCD1d as efficiently as mouse or rat CD1d. The expression of crCD1d was clearly weaker for thymocytes and B cells, and higher for T cells, which is different to what is found in murine species. The antigen-presenting capacity of crCD1d was demonstrated with crCD1d-immunoglobulin dimers loaded with the glycolipid PBS57, which bound iNKT T-cell receptors. Evidence for functional cotton rat iNKT cells was provided by detection of interferon-γ and interleukin-4 in cultures of splenocytes stimulated with PBS57 and α-galactosylceramide and by specific staining of about 0·2% of splenocytes with PBS57-loaded crCD1d dimers. Canonical AV14/AJ18 rearrangements were identified and found to contain multiple members of the AV14 (AV11) family. One of them was expressed and found to bind CD1d dimers. In summary, these data provide the first evidence for functional CD1d molecules and iNKT T-cell receptors in cotton rats and provide the tools to analyse them both in the cotton rat model of infectious diseases.

  13. Patterns of Chromosomal Evolution in Sigmodon, Evidence from Whole Chromosome Paints

    PubMed Central

    Swier, V.J.; Bradley, R.D.; Rens, W.; Elder, F.F.B.; Baker, R.J.

    2009-01-01

    Of the superfamily Muroidea (31 genera, 1578 species), the Sigmodontinae (74 genera, 377 species) is the second largest subfamily in number of species and represents a significant radiation of rodent biodiversity. Only 2 of the 74 genera are found in both North and South America (Sigmodon and Oryzomys) and the remainder are exclusively from South America. In recent molecular studies, the genus Sigmodon (Cricetidae, Sigmodontinae) has been considered sister to many other South American Sigmodontines [Steppan et al., 2004]. We examine the chromosomal evolution of 9 species of Sigmodon utilizing chromosomal paints isolated from S. hispidus, proposed to be similar to the ancestral karyotype [Elder, 1980]. Utilizing a phylogenetic hypothesis of a molecular phylogeny of Sigmodon [Henson and Bradley, 2009], we mapped shared chromosomal rearrangements of taxa on a molecular tree to estimate the evolutionary position of each rearrangement. For several species (S. hirsutus, S. leucotis, S. ochrognathus, S. peruanus, and S. toltecus), the karyotype accumulated few or no changes, but in three species (S. arizonae, S. fulviventer, and S. mascotensis) numerous karyotype rearrangements were observed. These rearrangements involved heterochromatic additions, centric fusions, tandem fusions, pericentric inversions, as well as the addition of interstitial DNA not identified by chromosome paints or C-banding. The hypothesis that the ancestral karyotype for this complex had a diploid number of 52, a fundamental number of 52, and a G-band pattern of which most, if not all are similar to that present in modern day S. hispidus fails to be rejected. This hypothesis remains viable as an explanation of chromosomal evolution in Sigmodontine rodents. PMID:19617697

  14. An explanation of the relationship between mass, metabolic rate and characteristic length for placental mammals

    PubMed Central

    2015-01-01

    The Mass, Metabolism and Length Explanation (MMLE) was advanced in 1984 to explain the relationship between metabolic rate and body mass for birds and mammals. This paper reports on a modernized version of MMLE. MMLE deterministically computes the absolute value of Basal Metabolic Rate (BMR) and body mass for individual animals. MMLE is thus distinct from other examinations of these topics that use species-averaged data to estimate the parameters in a statistically best fit power law relationship such as BMR = a(bodymass)b. Beginning with the proposition that BMR is proportional to the number of mitochondria in an animal, two primary equations are derived that compute BMR and body mass as functions of an individual animal’s characteristic length and sturdiness factor. The characteristic length is a measureable skeletal length associated with an animal’s means of propulsion. The sturdiness factor expresses how sturdy or gracile an animal is. Eight other parameters occur in the equations that vary little among animals in the same phylogenetic group. The present paper modernizes MMLE by explicitly treating Froude and Strouhal dynamic similarity of mammals’ skeletal musculature, revising the treatment of BMR and using new data to estimate numerical values for the parameters that occur in the equations. A mass and length data set with 575 entries from the orders Rodentia, Chiroptera, Artiodactyla, Carnivora, Perissodactyla and Proboscidea is used. A BMR and mass data set with 436 entries from the orders Rodentia, Chiroptera, Artiodactyla and Carnivora is also used. With the estimated parameter values MMLE can calculate characteristic length and sturdiness factor values so that every BMR and mass datum from the BMR and mass data set can be computed exactly. Furthermore MMLE can calculate characteristic length and sturdiness factor values so that every body mass and length datum from the mass and length data set can be computed exactly. Whether or not MMLE can

  15. Evolution of genome organizations of squirrels (Sciuridae) revealed by cross-species chromosome painting.

    PubMed

    Li, Tangliang; O'Brien, Patricia C M; Biltueva, Larisa; Fu, Beiyuan; Wang, Jinhuan; Nie, Wenhui; Ferguson-Smith, Malcolm A; Graphodatsky, Alexander S; Yang, Fengtang

    2004-01-01

    With complete sets of chromosome-specific painting probes derived from flow-sorted chromosomes of human and grey squirrel (Sciurus carolinensis), the whole genome homologies between human and representatives of tree squirrels (Sciurus carolinensis, Callosciurus erythraeus), flying squirrels (Petaurista albiventer) and chipmunks (Tamias sibiricus) have been defined by cross-species chromosome painting. The results show that, unlike the highly rearranged karyotypes of mouse and rat, the karyotypes of squirrels are highly conserved. Two methods have been used to reconstruct the genome phylogeny of squirrels with the laboratory rabbit (Oryctolagus cuniculus) as the out-group: (1) phylogenetic analysis by parsimony using chromosomal characters identified by comparative cytogenetic approaches; (2) mapping the genome rearrangements onto recently published sequence-based molecular trees. Our chromosome painting results, in combination with molecular data, show that flying squirrels are phylogenetically close to New World tree squirrels. Chromosome painting and G-banding comparisons place chipmunks (Tamias sibiricus ), with a derived karyotype, outside the clade comprising tree and flying squirrels. The superorder Glires (orde Rodentia + order Lagomorpha) is firmly supported by two conserved syntenic associations between human chromosomes 1 and 10p homologues, and between 9 and 11 homologues. PMID:15241012

  16. Differentiated evolutionary relationships among chordates from comparative alignments of multiple sequences of MyoD and MyoG myogenic regulatory factors.

    PubMed

    Oliani, L C; Lidani, K C F; Gabriel, J E

    2015-10-16

    MyoD and MyoG are transcription factors that have essential roles in myogenic lineage determination and muscle differentiation. The purpose of this study was to compare multiple amino acid sequences of myogenic regulatory proteins to infer evolutionary relationships among chordates. Protein sequences from Mus musculus (P10085 and P12979), human Homo sapiens (P15172 and P15173), bovine Bos taurus (Q7YS82 and Q7YS81), wild pig Sus scrofa (P49811 and P49812), quail Coturnix coturnix (P21572 and P34060), chicken Gallus gallus (P16075 and P17920), rat Rattus norvegicus (Q02346 and P20428), domestic water buffalo Bubalus bubalis (D2SP11 and A7L034), and sheep Ovis aries (Q90477 and D3YKV7) were searched from a non-redundant protein sequence database UniProtKB/Swiss-Prot, and subsequently analyzed using the Mega6.0 software. MyoD evolutionary analyses revealed the presence of three main clusters with all mammals branched in one cluster, members of the order Rodentia (mouse and rat) in a second branch linked to the first, and birds of the order Galliformes (chicken and quail) remaining isolated in a third. MyoG evolutionary analyses aligned sequences in two main clusters, all mammalian specimens grouped in different sub-branches, and birds clustered in a second branch. These analyses suggest that the evolution of MyoD and MyoG was driven by different pathways.

  17. Differentiated evolutionary relationships among chordates from comparative alignments of multiple sequences of MyoD and MyoG myogenic regulatory factors.

    PubMed

    Oliani, L C; Lidani, K C F; Gabriel, J E

    2015-01-01

    MyoD and MyoG are transcription factors that have essential roles in myogenic lineage determination and muscle differentiation. The purpose of this study was to compare multiple amino acid sequences of myogenic regulatory proteins to infer evolutionary relationships among chordates. Protein sequences from Mus musculus (P10085 and P12979), human Homo sapiens (P15172 and P15173), bovine Bos taurus (Q7YS82 and Q7YS81), wild pig Sus scrofa (P49811 and P49812), quail Coturnix coturnix (P21572 and P34060), chicken Gallus gallus (P16075 and P17920), rat Rattus norvegicus (Q02346 and P20428), domestic water buffalo Bubalus bubalis (D2SP11 and A7L034), and sheep Ovis aries (Q90477 and D3YKV7) were searched from a non-redundant protein sequence database UniProtKB/Swiss-Prot, and subsequently analyzed using the Mega6.0 software. MyoD evolutionary analyses revealed the presence of three main clusters with all mammals branched in one cluster, members of the order Rodentia (mouse and rat) in a second branch linked to the first, and birds of the order Galliformes (chicken and quail) remaining isolated in a third. MyoG evolutionary analyses aligned sequences in two main clusters, all mammalian specimens grouped in different sub-branches, and birds clustered in a second branch. These analyses suggest that the evolution of MyoD and MyoG was driven by different pathways. PMID:26505406

  18. Physiologic Reference Ranges for Captive Black-Tailed Prairie Dogs (Cynomys ludovicianus)

    PubMed Central

    Keckler, M Shannon; Gallardo-Romero, Nadia F; Langham, Gregory L; Damon, Inger K; Karem, Kevin L; Carroll, Darin S

    2010-01-01

    The black-tailed prairie dog (Cynomys ludovicianus) is a member of the order Rodentia and the family Sciuridae. Ecologically, prairie dogs are a keystone species in prairie ecology. This species is used as an animal model for human gallbladder disease and diseases caused by infection with Clostridium difficile, Yersinia pestis, Francisella tularensis, and most recently, Orthopoxvirus. Despite increasing numbers of prairie dogs used in research and kept as pets, few data are available on their baseline physiology in animal facility housing conditions. To establish baseline physiologic reference ranges, we designed a study using 18 wild-caught black-tailed prairie dogs. Telemetry data were analyzed to establish circadian rhythms for activity and temperature. In addition, hematologic and serum chemistry analyses were performed. Baseline measurements were used to establish the mean for each animal, which then were compiled and analyzed to determine the reference ranges. Here we present physiologic data on serum chemistry and hematology profiles, as well as weight, core body temperature, and daily activity patterns for black-tailed prairie dogs. These results reflect the use of multiple measurements from species- and age-matched prairie dogs and likely will be useful to ecologists, scientists interested in using this animal model in research, and veterinarians caring for pet prairie dogs. PMID:20587156

  19. Hibernation does not affect memory retention in bats.

    PubMed

    Ruczynski, Ireneusz; Siemers, Björn M

    2011-02-23

    Long-term memory can be critically important for animals in a variety of contexts, and yet the extreme reduction in body temperature in hibernating animals alters neurochemistry and may therefore impair brain function. Behavioural studies on memory impairment associated with hibernation have been almost exclusively conducted on ground squirrels (Rodentia) and provide conflicting results, including clear evidence for memory loss. Here, we for the first time tested memory retention after hibernation for a vertebrate outside rodents-bats (Chiroptera). In the light of the high mobility, ecology and long life of bats, we hypothesized that maintenance of consolidated memory through hibernation is under strong natural selection. We trained bats to find food in one out of three maze arms. After training, the pre-hibernation performance of all individuals was at 100 per cent correct decisions. After this pre-test, one group of bats was kept, with two interruptions, at 7°C for two months, while the other group was kept under conditions that prevented them from going into hibernation. The hibernated bats performed at the same high level as before hibernation and as the non-hibernated controls. Our data suggest that bats benefit from an as yet unknown neuroprotective mechanism to prevent memory loss in the cold brain.

  20. A new genus and species of demodecid mites from the tongue of a house mouse Mus musculus: description of adult and immature stages with data on parasitism.

    PubMed

    Izdebska, J N; Rolbiecki, L

    2016-06-01

    The study of the parasitofauna of the house mouse Mus musculus (Rodentia: Muridae) Linnaeus is particularly important owing to its multiple relationships with humans - as a cosmopolitan, synanthropic rodent, bred for pets, food for other animals or laboratory animal. This article proposes and describes a new genus and species of the parasitic mite based on adult and immature stages from the house mouse. Glossicodex musculi gen. n., sp. n. is a medium-sized demodecid mite (adult stages on average 199 µm in length) found in mouse tissue of the tongue. It is characterized by two large, hooked claws on each tarsus of the legs; the legs are relatively massive, consisting of large, non-overlapping segments. The palps consist of three slender, clearly separated, relatively narrow segments, wherein their coxal segments are also quite narrow and spaced. Also, segments of the palps of larva and nymphs are clearly isolated, and on the terminal segment, trident claws that resemble legs' claws can be found. On the ventral side, in immature stages, triangular scuta, topped with sclerotized spur, can be also observed. Glossicodex musculi was noted in 10.8% of mice with a mean infection intensity of 2.2 parasites per host.

  1. Cost of digging is determined by intrinsic factors rather than by substrate quality in two subterranean rodent species.

    PubMed

    Zelová, Jitka; Sumbera, Radim; Okrouhlík, Jan; Burda, Hynek

    2010-01-12

    Searching for food by extensive digging is one of the most important aspects of life of subterranean rodents. We studied the effect of extrinsic (substrate quality) and intrinsic factors (sex and body mass) upon the cost of burrowing, expressed as digging metabolic rate (DMR) in two African mole-rat species (Bathyergidae, Rodentia) with distinct social structures. The sexually dimorphic giant mole-rat (Fukomys mechowii) is a highly social species, whereas the almost monomorphic silvery mole-rat (Heliophobius argenteocinereus) is a solitary bathyergid. Burrowing in F. mechowii was more costly (DMR was greater) than in H. argenteocinereus, but there was no difference in burrowing speed between both species. DMR within a particular species was dependent upon body mass, but independent of sex. Different substrate quality had no effect upon DMR in either species, yet it affected burrowing speed. We conclude that less effective digging in F. mechowii can be compensated by the joint workforce of other family members. Alternatively, H. argenteocinereus, being a more effective digger, can afford a solitary way of life.

  2. Unexpected primitive rodents in the Quaternary of Argentina

    NASA Astrophysics Data System (ADS)

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

    2005-10-01

    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.

  3. The power of social structure: how we became an intelligent lineage

    NASA Astrophysics Data System (ADS)

    de Sousa António, Marina Resendes; Schulze-Makuch, Dirk

    2011-01-01

    New findings pertinent to the human lineage origin (Ardipithecus ramidus) prompt a new analysis of the extrapolation of the social behavior of our closest relatives, the great apes, into human ‘natural social behavior’. With the new findings it becomes clear that human ancestors had very divergent social arrangements from the ones we observe today in our closest genetic relatives. The social structure of chimpanzees and gorillas is characterized by male competition. Aggression and the instigation of fear are common place. The morphology of A. ramidus points in the direction of a social system characterized by female-choice instead of male-male competition. This system tends to be characterized by reduced aggression levels, leading to more stable arrangements. It is postulated here that the social stability with accompanying group cohesion propitiated by this setting is favorable to the investment in more complex behaviors, the development of innovative approaches to solve familiar problems, an increase in exploratory behavior, and eventually higher intelligence and the use of sophisticated tools and technology. The concentration of research efforts into the study of social animals with similar social systems (e.g., New World social monkeys (Callitrichidae), social canids (Canidae) and social rodents (Rodentia)) are likely to provide new insights into the understanding of what factors determined our evolution into an intelligent species capable of advanced technology.

  4. Implications of Hybridization, NUMTs, and Overlooked Diversity for DNA Barcoding of Eurasian Ground Squirrels

    PubMed Central

    Ermakov, Oleg A.; Simonov, Evgeniy; Surin, Vadim L.; Titov, Sergey V.; Brandler, Oleg V.; Ivanova, Natalia V.; Borisenko, Alex V.

    2015-01-01

    The utility of DNA Barcoding for species identification and discovery has catalyzed a concerted effort to build the global reference library; however, many animal groups of economical or conservational importance remain poorly represented. This study aims to contribute DNA barcode records for all ground squirrel species (Xerinae, Sciuridae, Rodentia) inhabiting Eurasia and to test efficiency of this approach for species discrimination. Cytochrome c oxidase subunit 1 (COI) gene sequences were obtained for 97 individuals representing 16 ground squirrel species of which 12 were correctly identified. Taxonomic allocation of some specimens within four species was complicated by geographically restricted mtDNA introgression. Exclusion of individuals with introgressed mtDNA allowed reaching a 91.6% identification success rate. Significant COI divergence (3.5–4.4%) was observed within the most widespread ground squirrel species (Spermophilus erythrogenys, S. pygmaeus, S. suslicus, Urocitellus undulatus), suggesting the presence of cryptic species. A single putative NUMT (nuclear mitochondrial pseudogene) sequence was recovered during molecular analysis; mitochondrial COI from this sample was amplified following re-extraction of DNA. Our data show high discrimination ability of 100 bp COI fragments for Eurasian ground squirrels (84.3%) with no incorrect assessments, underscoring the potential utility of the existing reference librariy for the development of diagnostic ‘mini-barcodes’. PMID:25617768

  5. Expression of acid phosphatase in the seminiferous epithelium of vertebrates.

    PubMed

    Peruquetti, R L; Taboga, S R; Azeredo-Oliveira, M T V

    2010-01-01

    Acid phosphatases (AcPs) are known to provide phosphate to tissues that have high energy requirements, especially during development, growth and maturation. During spermatogenesis AcP activity is manifested in heterophagous lysosomes of Sertoli cells. This phagocytic function appears to be hormone-independent. We examined the expression pattern of AcP during the reproductive period of four species belonging to different vertebrate groups: Tilapia rendalli (Teleostei, Cichlidae), Dendropsophus minutus (Amphibia, Anura), Meriones unguiculatus (Mammalia, Rodentia), and Oryctolagus cuniculus (Mammalia, Lagomorpha). To demonstrate AcP activity, cryosections were processed for enzyme histochemistry by a modification of the method of Gömöri. AcP activity was similar in the testes of these four species. Testes of T. rendalli, D. minutus and M. unguiculatus showed an intense reaction in the Sertoli cell region. AcP activity was detected in the testes of D. minutus and O. cuniculus in seminiferous epithelium regions, where cells are found in more advanced stages of development. The seminiferous epithelium of all four species exhibited AcP activity, mainly in the cytoplasm of either Sertoli cells or germ cells. These findings reinforce the importance of AcP activity during the spermatogenesis process in vertebrates. PMID:20391346

  6. Bartonella infection in small mammals and their ectoparasites in Lithuania.

    PubMed

    Lipatova, Indre; Paulauskas, Algimantas; Puraite, Irma; Radzijevskaja, Jana; Balciauskas, Linas; Gedminas, Vaclovas

    2015-01-01

    The Bartonella pathogen is an emerging zoonotic agent. Epidemiological studies worldwide have demonstrated that small mammals are reservoir hosts of Bartonella spp. and their ectoparasites are potential vectors. The aim of this study was to investigate the prevalence of Bartonella infections in small mammals (Rodentia, Insectivora) and their ectoparasites (fleas and ticks) in Lithuania. A total of 430 small mammals representing nine species were captured with live-traps in Lithuania during 2013-2014. A total of 151 fleas representing eight species were collected from 109 (25.8%) small mammals. Five hundred and seventy ticks (Ixodes ricinus) were collected from 68 (16.1%) small mammals. Bartonella DNA was detected in 102 (23.7%) small mammals, 44 (29.1%) fleas and five (3.7%) pooled tick samples. Sequence analysis of 16S-23S rRNA ITS region showed that sequences were identical or similar to Bartonella grahamii, Bartonella taylorii and Bartonella rochalimae. This study is the first investigating the distribution and diversity of Bartonella species in small mammals and their ectoparasites in Lithuania. B. grahamii, B. taylorii, and B. rochalimae were detected in small mammals and their fleas, and B. grahamii in ticks obtained from small mammals. PMID:26344603

  7. Evolution of recombination in eutherian mammals: insights into mechanisms that affect recombination rates and crossover interference.

    PubMed

    Segura, Joana; Ferretti, Luca; Ramos-Onsins, Sebastián; Capilla, Laia; Farré, Marta; Reis, Fernanda; Oliver-Bonet, Maria; Fernández-Bellón, Hugo; Garcia, Francisca; Garcia-Caldés, Montserrat; Robinson, Terence J; Ruiz-Herrera, Aurora

    2013-11-22

    Recombination allows faithful chromosomal segregation during meiosis and contributes to the production of new heritable allelic variants that are essential for the maintenance of genetic diversity. Therefore, an appreciation of how this variation is created and maintained is of critical importance to our understanding of biodiversity and evolutionary change. Here, we analysed the recombination features from species representing the major eutherian taxonomic groups Afrotheria, Rodentia, Primates and Carnivora to better understand the dynamics of mammalian recombination. Our results suggest a phylogenetic component in recombination rates (RRs), which appears to be directional, strongly punctuated and subject to selection. Species that diversified earlier in the evolutionary tree have lower RRs than those from more derived phylogenetic branches. Furthermore, chromosome-specific recombination maps in distantly related taxa show that crossover interference is especially weak in the species with highest RRs detected thus far, the tiger. This is the first example of a mammalian species exhibiting such low levels of crossover interference, highlighting the uniqueness of this species and its relevance for the study of the mechanisms controlling crossover formation, distribution and resolution.

  8. Seed predation and fruit damage of Solanum lycocarpum (Solanaceae) by rodents in the cerrado of central Brazil

    NASA Astrophysics Data System (ADS)

    Briani and, Denis C., Jr.; Guimarães, Paulo R.

    2007-01-01

    Although neotropical savannas and grasslands, collectively referred to as cerrado, are rich in seed-eating species of rodents, little is known about seed predation and its determinants in this habitat. In this study, we investigated seed predation and damage to fruits of the widespread shrub Solanum lycocarpum. In addition, the influence of two possible determinants (distance from the parental plant and total crop size) on the feeding behaviour of Oryzomys scotti (Rodentia, Sigmodontinae) was also examined. O. scotti were captured more frequently close to the shrubs or on shrub crops, indicating that these rodents were attracted to the shrubs and that seed predation was probably distance-dependent. Moreover, the proportion of damaged fruit on the plant decreased as the total crop size increased; consequently, more productive plants were attacked proportionally less by rodents. This pattern of fruit damage may reflect predator satiation caused by the consumption of a large amount of pulp. Alternatively, secondary metabolites in S. lycocarpum fruits may reduce the pulp consumption per feeding event, thereby limiting the number of fruits damaged.

  9. Checklist of helminths found in Patagonian wild mammals.

    PubMed

    Fugassa, Martin H

    2015-01-01

    Using available reports, a checklist of the recorded helminth parasites of wild mammals from Patagonia was generated. Records of parasites found in Patagonia were included, together with records from mammals in áreas outside of Patagonia but whose range extends into Patagonia. Information about the host, localities, and references were also included. A total of 1323 records (224 Cestoda, 167 Trematoda, 894 Nematoda, 34 Acanthocephala, and 4 Pentastomida) belonging to 452 helminth species (77 Cestoda, 76 Trematoda, 277 Nematoda, 21 Acanthocephala, and 1 Pentastomida) found in 57 native mammals (22 Rodentia, 4 Didelphimorphia 1 Microbiotheria, 7 Chiroptera, 5 Cingulata, and 13 Carnivora) were listed. However, only 10.6 % of the reports were conducted on samples from Patagonia and corresponded to 25% of mammals in the region. In addition, many studies were made on a few species and, for example, 52% corresponded to studies made on Lama guanicoe. This suggests the need to increase efforts to know the parasitic fauna in a peculiar region as is the Patagonia. This is the first compilation of the helminth parasites of mammals in Argentine Patagonia and is important for parasitological and paleoparasitological studies. PMID:26623857

  10. Evolution of hantaviruses: co-speciation with reservoir hosts for more than 100 MYR.

    PubMed

    Plyusnin, Alexander; Sironen, Tarja

    2014-07-17

    The most recent (9th) Report of the International Committee on Taxonomy of Viruses (ICTV) lists 23 established and 30 provisional species in the genus Hantavirus (family Bunyaviridae) (Plyusnin et al., 2012). These virus species are harbored by altogether 51 species of rodents, shrews and moles and thus in most cases it is a relationship of "one hantavirus-one host". Such a tight bond between the two, in combination with the observed association between whole groups of hantaviruses and (sub)families of rodents, helped to develop the widely accepted view of a long-term co-evolution (co-speciation) of these viruses with their hosts. Accumulating evidence of host-switching events, both recent and ancient, however challenged some of the earlier views on hantavirus evolution. In this paper we discuss the concept of hantavirus-host co-speciation and propose a scenario of hantavirus evolution based on the currently available genetic information. This scenario is based on the hypothesis that hantaviruses are very ancient viruses which already existed at the estimated diversification point of major placental clades, of which one includes the ancestors of the order Rodentia and another the ancestors of both orders Eulipotyphla and Chiroptera; the diversification occurred approximately at 90-100 MYA. We also speculate that the evolutionary history of hantaviruses extents even deeper in the past, beyond this time-point, and included the transmission of a (pre)bunyavirus from an insect host to a mammal host.

  11. Ecological diversity of Trypanosoma cruzi transmission in the Amazon basin. The main scenaries in the Brazilian Amazon.

    PubMed

    Coura, J R; Junqueira, A C V

    2015-11-01

    The ecological diversity of Trypanosoma cruzi transmission in the Brazilian Amazon region is directly interlinked with the parasite's extensive reservoir, composed of 33 species of wild mammals within the following orders: Marsupialia, Chiroptera, Rodentia, Xenarthra, Carnivora and Primates; and of 16 species of wild triatomines, of which ten may be infected with T. cruzi. Four scenarios for the diversity of T. cruzi transmission in the Brazilian Amazon region are evident: (i) T. cruzi transmission between vectors and wild mammals, which is characterized as a wild enzooty encompassing the entire Amazon basin; (ii) accidental T. cruzi transmission from vectors and wild mammals to humans, when they invade the wild ecotope or when these vectors and wild mammals invade human homes; (iii) occupational Chagas disease among piassava (Leopoldinia piassaba) palm fiber gatherers, transmitted by the vector Rhodnius brethesi, for which these palm trees are the specific ecotope; (IV) oral T. cruzi transmission to humans through food contamination, particularly in juices from plants such as assai, which today is considered to be endemic in the Brazilian Amazon region, with more than 1500 cases notified.

  12. The evolution of mammalian body temperature: the Cenozoic supraendothermic pulses.

    PubMed

    Lovegrove, Barry G

    2012-05-01

    In this study, I investigated the source(s) of variation in the body temperatures of mammals. I also attempted to reconstruct ancestral normothermic rest-phase body temperature states using a maximum parsimony approach. Body temperature at the familial level is not correlated with body mass. For small mammals, except the Macroscelidae, previously identified correlates, such as climate adaptation and zoogeography explained some, but not all, T(b) apomorphies. At the species level in large cursorial mammals, there was a significant correlation between body temperature and the ratio between metatarsal length and femur length, the proxy for stride length and cursoriality. With the exception of two primate families, all supraendothermic (T(b) > 37.9°C) mammals are cursorial, including Artiodactyla, Lagomorpha, some large Rodentia, and Carnivora. The ruminant supraendothermic cursorial pulse is putatively associated with global cooling and vegetation changes following the Paleocene-Eocene Thermal Maximum. Reconstructed ancestral body temperatures were highly unrealistic deep within the mammalian phylogeny because of the lack of fossil T(b) data that effectively creates ghost lineages. However, it is anticipated that the method of estimating body temperature from the abundance of ¹³C-¹⁸O bonds in the carbonate component of tooth bioapatite in both extant and extinct animals may be a very promising tool for estimating the T(b) of extinct mammals. Fossil T(b) data are essential for discerning derived T(b) reversals from ancestral states, and verifying the dates of supraendothermic pulses.

  13. New Species of Rotundomys (Cricetinae) from the Late Miocene of Spain and Its Bearing on the Phylogeny of Cricetulodon and Rotundomys

    PubMed Central

    López-Antoñanzas, Raquel; Peláez-Campomanes, Pablo; Álvarez-Sierra, Ángeles

    2014-01-01

    The material of Rotundomys (Rodentia, Cricetinae) from the Late Miocene fossiliferous complex of Cerro de los Batallones (Madrid, Spain) is described and compared with all species currently placed in the genera Rotundomys and Cricetulodon. Both the morphology and size variation encompassed in the collection of specimens from Batallones suggest they belong to a single taxon different from the other known species of these genera. A new species Rotundomys intimus sp. nov. is, therefore, named for it. A cladistic analysis, which is the first ever published concernig these taxa, has been conducted to clear up the phylogenetic position of the new species. Our results suggest that Rotundomys intimus sp. nov. inserts between R. mundi and R. sabatieri as a relatively primitive taxon inside the clade Rotundomys. The new taxon is more derived than R. mundi in having a transversal connection between the metalophulid and the anterolophulid on some m1 but more primitive than R. sabatieri and the most evolved species of Rotundomys (R. montisrotuni +R.bressanus) in its less developed lophodonty showing distinct cusps, shallower valleys, and the presence of a subdivided anteroloph on the M1. The species of Cricetulodon do not form a monophyletic group. As a member of Rotundomys, Rotundomys intimus sp. nov. is more derived than all of these taxa in its greater lophodonty and the complete loss of the anterior protolophule, mesolophs, and mesolophids. PMID:25389967

  14. A Revised Checklist of Chigger Mites (Acari: Trombiculidae) From Thailand, with the Description of Three New Species.

    PubMed

    Chaisiri, Kittipong; Stekolnikov, Alexandr A; Makepeace, Benjamin L; Morand, Serge

    2016-03-01

    Chigger mites of Thailand were studied on the basis of larvae collected from 19 small mammal species (17 species of Rodentia, 1 species of Erinaceomorpha, and 1 species of Scandentia) and revision of published data. Samples of 38 trombiculid species were collected from 11 provinces. Three new species were described: Trombiculindus kosapani sp. nov., Helenicula naresuani sp. nov., and Walchia chavali sp. nov. Ten species were recorded in Thailand for the first time: Leptotrombidium sialkotense Vercammen-Grandjean and Langston, 1976; Leptotrombidium subangulare Wen and Xiang, 1984; Leptotrombidium tenompaki Stekolnikov, 2013; Leptotrombidium turdicola Vercammen-Grandjean and Langston, 1976; Leptotrombidium yunlingense Yu, Yang, Zhang and Hu, 1981; Lorillatum hekouensis Yu, Chen and Lin, 1996; Helenicula pilosa (Abonnenc and Taufflieb, 1957); Gahrliepia xiaowoi Wen and Xiang, 1984; Walchia minuscuta Chen, 1978; and Walchia ventralis (Womersley, 1952). In all, 99 chigger mite species were considered; the presence of 93 species was established in Thailand by original data or properly documented records in the scientific literature. Evidence for 64 species records of 147 from a previous checklist of Thai chiggers (Tanskul 1993) remains unknown. Distribution of chigger species by geographical regions of Thailand is discussed.

  15. Coordinated scaling of cortical and cerebellar numbers of neurons.

    PubMed

    Herculano-Houzel, Suzana

    2010-01-01

    While larger brains possess concertedly larger cerebral cortices and cerebella, the relative size of the cerebral cortex increases with brain size, but relative cerebellar size does not. In the absence of data on numbers of neurons in these structures, this discrepancy has been used to dispute the hypothesis that the cerebral cortex and cerebellum function and have evolved in concert and to support a trend towards neocorticalization in evolution. However, the rationale for interpreting changes in absolute and relative size of the cerebral cortex and cerebellum relies on the assumption that they reflect absolute and relative numbers of neurons in these structures across all species - an assumption that our recent studies have shown to be flawed. Here I show for the first time that the numbers of neurons in the cerebral cortex and cerebellum are directly correlated across 19 mammalian species of four different orders, including humans, and increase concertedly in a similar fashion both within and across the orders Eulipotyphla (Insectivora), Rodentia, Scandentia and Primata, such that on average a ratio of 3.6 neurons in the cerebellum to every neuron in the cerebral cortex is maintained across species. This coordinated scaling of cortical and cerebellar numbers of neurons provides direct evidence in favor of concerted function, scaling and evolution of these brain structures, and suggests that the common notion that equates cognitive advancement with neocortical expansion should be revisited to consider in its stead the coordinated scaling of neocortex and cerebellum as a functional ensemble.

  16. Coordinated Scaling of Cortical and Cerebellar Numbers of Neurons

    PubMed Central

    Herculano-Houzel, Suzana

    2010-01-01

    While larger brains possess concertedly larger cerebral cortices and cerebella, the relative size of the cerebral cortex increases with brain size, but relative cerebellar size does not. In the absence of data on numbers of neurons in these structures, this discrepancy has been used to dispute the hypothesis that the cerebral cortex and cerebellum function and have evolved in concert and to support a trend towards neocorticalization in evolution. However, the rationale for interpreting changes in absolute and relative size of the cerebral cortex and cerebellum relies on the assumption that they reflect absolute and relative numbers of neurons in these structures across all species – an assumption that our recent studies have shown to be flawed. Here I show for the first time that the numbers of neurons in the cerebral cortex and cerebellum are directly correlated across 19 mammalian species of four different orders, including humans, and increase concertedly in a similar fashion both within and across the orders Eulipotyphla (Insectivora), Rodentia, Scandentia and Primata, such that on average a ratio of 3.6 neurons in the cerebellum to every neuron in the cerebral cortex is maintained across species. This coordinated scaling of cortical and cerebellar numbers of neurons provides direct evidence in favor of concerted function, scaling and evolution of these brain structures, and suggests that the common notion that equates cognitive advancement with neocortical expansion should be revisited to consider in its stead the coordinated scaling of neocortex and cerebellum as a functional ensemble. PMID:20300467

  17. Microsatellite-encoded domain in rodent Sry functions as a genetic capacitor to enable the rapid evolution of biological novelty.

    PubMed

    Chen, Yen-Shan; Racca, Joseph D; Sequeira, Paul W; Phillips, Nelson B; Weiss, Michael A

    2013-08-13

    The male program of therian mammals is determined by Sry, a transcription factor encoded by the Y chromosome. Specific DNA binding is mediated by a high mobility group (HMG) box. Expression of Sry in the gonadal ridge activates a Sox9-dependent gene regulatory network leading to testis formation. A subset of Sry alleles in superfamily Muroidea (order Rodentia) is remarkable for insertion of an unstable DNA microsatellite, most commonly encoding (as in mice) a CAG repeat-associated glutamine-rich domain. We provide evidence, based on an embryonic pre-Sertoli cell line, that this domain functions at a threshold length as a genetic capacitor to facilitate accumulation of variation elsewhere in the protein, including the HMG box. The glutamine-rich domain compensates for otherwise deleterious substitutions in the box and absence of nonbox phosphorylation sites to ensure occupancy of DNA target sites. Such compensation enables activation of a male transcriptional program despite perturbations to the box. Whereas human SRY requires nucleocytoplasmic shuttling and coupled phosphorylation, mouse Sry contains a defective nuclear export signal analogous to a variant human SRY associated with inherited sex reversal. We propose that the rodent glutamine-rich domain has (i) fostered accumulation of cryptic intragenic variation and (ii) enabled unmasking of such variation due to DNA replicative slippage. This model highlights genomic contingency as a source of protein novelty at the edge of developmental ambiguity and may underlie emergence of non-Sry-dependent sex determination in the radiation of Muroidea. PMID:23901118

  18. More Novel Hantaviruses and Diversifying Reservoir Hosts — Time for Development of Reservoir-Derived Cell Culture Models?

    PubMed Central

    Eckerle, Isabella; Lenk, Matthias; Ulrich, Rainer G.

    2014-01-01

    Due to novel, improved and high-throughput detection methods, there is a plethora of newly identified viruses within the genus Hantavirus. Furthermore, reservoir host species are increasingly recognized besides representatives of the order Rodentia, now including members of the mammalian orders Soricomorpha/Eulipotyphla and Chiroptera. Despite the great interest created by emerging zoonotic viruses, there is still a gross lack of in vitro models, which reflect the exclusive host adaptation of most zoonotic viruses. The usually narrow host range and genetic diversity of hantaviruses make them an exciting candidate for studying virus-host interactions on a cellular level. To do so, well-characterized reservoir cell lines covering a wide range of bat, insectivore and rodent species are essential. Most currently available cell culture models display a heterologous virus-host relationship and are therefore only of limited value. Here, we review the recently established approaches to generate reservoir-derived cell culture models for the in vitro study of virus-host interactions. These successfully used model systems almost exclusively originate from bats and bat-borne viruses other than hantaviruses. Therefore we propose a parallel approach for research on rodent- and insectivore-borne hantaviruses, taking the generation of novel rodent and insectivore cell lines from wildlife species into account. These cell lines would be also valuable for studies on further rodent-borne viruses, such as orthopox- and arenaviruses. PMID:24576845

  19. Ecological diversity of Trypanosoma cruzi transmission in the Amazon basin. The main scenaries in the Brazilian Amazon.

    PubMed

    Coura, J R; Junqueira, A C V

    2015-11-01

    The ecological diversity of Trypanosoma cruzi transmission in the Brazilian Amazon region is directly interlinked with the parasite's extensive reservoir, composed of 33 species of wild mammals within the following orders: Marsupialia, Chiroptera, Rodentia, Xenarthra, Carnivora and Primates; and of 16 species of wild triatomines, of which ten may be infected with T. cruzi. Four scenarios for the diversity of T. cruzi transmission in the Brazilian Amazon region are evident: (i) T. cruzi transmission between vectors and wild mammals, which is characterized as a wild enzooty encompassing the entire Amazon basin; (ii) accidental T. cruzi transmission from vectors and wild mammals to humans, when they invade the wild ecotope or when these vectors and wild mammals invade human homes; (iii) occupational Chagas disease among piassava (Leopoldinia piassaba) palm fiber gatherers, transmitted by the vector Rhodnius brethesi, for which these palm trees are the specific ecotope; (IV) oral T. cruzi transmission to humans through food contamination, particularly in juices from plants such as assai, which today is considered to be endemic in the Brazilian Amazon region, with more than 1500 cases notified. PMID:26254002

  20. A palaeoparasitological analysis of rodent coprolites from the Cueva Huenul 1 archaeological site in Patagonia (Argentina).

    PubMed

    Beltrame, María Ornela; Sardella, Norma Haydée; Fugassa, Martín Horacio; Barberena, Ramiro

    2012-08-01

    The aim of the present study was to examine the parasite fauna present in rodent coprolites collected from Cueva Huenul 1 (CH1), northern Neuquén (Patagonia, Argentina), an archaeological site that provides stratified sequences of archaeological and palaeontological remains dating from the Late Pleistocene/Early Holocene Transition to the Late Holocene period. Twenty rodent coprolites collected from different sedimentary units from the site, with ages ranging from 13.844 ± 75-1.416 ± 37 years BP, were examined for parasites. Each coprolite was processed as a whole: rehydrated, homogenised, spontaneously sedimented and examined using light microscopy. The coprolites and the eggs of any parasites present were described, measured and photographed. In all, 158 parasite eggs were found in 10 coprolites. The faeces were positive for Viscachataenia quadrata Denegri, Dopchiz, Elissondo & Beveridge and Monoecocestus sp. Beddard (Cestoda: Anoplocephalidae) and for Heteroxynema (Cavioxyura) viscaciae Sutton & Hugot (Nematoda: Oxyuridae). The coprolites examined were tentatively attributed to Lagidium viscacia Molina (Mammalia, Rodentia, Caviomorpha, Chinchillidae). The life cycles of these parasites are discussed.

  1. Guerrerostrongylus marginalis n. sp. (Trichostrongyloidea: Heligmonellidae) from the Guianan arboreal mouse (Oecomys auyantepui) from French Guiana

    PubMed Central

    2016-01-01

    Based on the number and arrangement of cuticular ridges and configuration of the dorsal ray, nematode specimens collected from the small intestine of eight Guianan arboreal mice, Oecomys auyantepui (Rodentia: Sigmodontinae), in French Guiana are herein described and characterized. Guerrerostrongylus marginalis n. sp. (Heligmosomoidea: Heligmonellidae) shows a synlophe consisting of more than 40 ridges and a unique bursal arrangement with ray 8 (externo-dorsal) extending to the edge of the bursal margin, and appearing more prominent than the dorsal ray. This bursal arrangement is common in members of Hassalstrongylus Durette-Desset, 1971, but uncommon in the other four species in Guerrerostrongylus Sutton & Durette-Desset, 1991. The placement of the new species in Guerrerostrongylus is based on the number and nature of cuticular ridges and the ray arrangement and symmetry of the caudal bursa. Diagnostic characteristics of Guerrerostrongylus marginalis n. sp. include the length of ray 8 relative to bursal margin, the relative size of the spicules and vestibule, and the number of eggs in the uterus. We propose an amendment to the generic diagnosis of Guerrerostrongylus to modify the characters of the long rays 6 (postero-lateral), rays 8 (externo-dorsal), and dorsal ray as diagnostic, since at least ray 6 appears to be short in two different species in the genus, namely G. ulysi Digiani, Notarnicola & Navone, 2012 and G. marginalis n. sp. PMID:26956220

  2. The ecology of the Trypanosoma cruzi transmission cycle: Dispersion of zymodeme 3 (Z3) in wild hosts from Brazilian biomes.

    PubMed

    Lisboa, Cristiane Varella; Xavier, Samanta Cristina das Chagas; Herrera, Heitor Miraglia; Jansen, Ana Maria

    2009-10-28

    Two main genotypes in Trypanosoma cruzi subpopulations can be distinguished by PCR amplification of sequences from the mini-exon gene non-transcribed spacer, respectively, T. cruzi I (TCI) and T. cruzi II (TCII). This technique is also capable of distinguishing a third assemblage of subpopulations that do not fit in these genotypes and that remain known as zymodeme Z3 (Z3). The distribution pattern as well as the mammalian host range of this latter T. cruzi sublineage still remains unclear. Thus, the intention of our study was to increase the information regarding these aspects. The mini-exon analysis of T. cruzi isolates obtained from sylvatic animals in the Amazon Forest, Atlantic Rainforest, Caatinga and Pantanal showed that prevalence of the Z3 subpopulation in nature was low (15 out of 225 isolates, corresponding to 7%). A higher prevalence of Z3 was observed in the Caatinga (15%) and the Pantanal (12%). Infection by Z3 was observed in mammalian hosts included in Carnivora, Chiroptera, Didelphimorphia, Rodentia and Xernathra. The T. cruzi Z3 subpopulation was observed also in mixed infections (33%) with TCI (n=2) and TCII (n=3). These results demonstrate that T. cruzi Z3 displays a wider distribution and host range than formerly understood as it has been demonstrated to be able infect species included in five orders of mammalian host species dispersed through all forest strata of the four Brazilian biomes evaluated.

  3. Biostratigraphy and biochronology of the Monte Hermoso Formation (early Pliocene) at its type locality, Buenos Aires Province, Argentina

    NASA Astrophysics Data System (ADS)

    Tomassini, Rodrigo L.; Montalvo, Claudia I.; Deschamps, Cecilia M.; Manera, Teresa

    2013-12-01

    The Monte Hermoso Formation, cropping out at its type locality of Farola Monte Hermoso (Buenos Aires Province), is a classical fossiliferous unit of the South American Neogene, highlighted by the abundance and diversity of its vertebrate remains. However, its biostratigraphy and age have been largely debated, and numerous discrepancies and controversies have been stated. In this regard, the result of the analysis of new materials recovered from the different levels of this formation, following a strict control of stratigraphic provenance, is here reported. As well, the provenance of specimens of previous collections has been evaluated. The studied assemblage consists of Osteichthyes, Amphibia, Reptilia, Aves and Mammalia. These latter are the most numerous and belong to the Didelphimorphia, Polydolopimorphia, Rodentia, Notoungulata, Litopterna and Xenarthra. The recorded taxa suggest no important faunistic variations among the different levels of the Monte Hermoso Formation that would imply significant chronological differences, and hence, justify the recognition of two biostratigraphic units. The analysis of the first and last records as well as the taxa considered as exclusive, does not support the validity of the biozones of Trigodon gaudryi and Neocavia depressidens previously proposed. On this basis, a new scheme for the Monte Hermoso Formation at its type locality is proposed, including a new single biostratigraphic unit. This unit is the Eumysops laeviplicatus Range Zone, which represents the biostratigraphic base for the Montehermosan Stage/Age of the early Pliocene.

  4. Environment-related and host-related factors affecting the occurrence of lice on rodents in Central Europe.

    PubMed

    Stanko, Michal; Fričová, Jana; Miklisová, Dana; Khokhlova, Irina S; Krasnov, Boris R

    2015-06-01

    We studied the effects of environment- (habitat, season) and host-related (sex, body mass) factors on the occurrence of four species of lice (Insecta:Phthiraptera:Anoplura) on six rodent species (Rodentia:Muridae). We asked how these factors influence the occurrence of lice on an individual host and whether different rodent-louse associations demonstrate consistent trends in these effects. We found significant effects of at least one environment-related and at least one host-related factor on the louse occurrence in five of six host-louse associations. The effect of habitat was significant in two associations with the occurrence of lice being more frequent in lowland than in mountain habitats. The effect of season was significant in five associations with a higher occurrence of infestation during the warm season in four associations and the cold season in one association. Host sex affected significantly the infestation by lice in three associations with a higher frequency of infestation in males. Host body mass affected the occurrence of lice in all five associations, being negative in wood mice and positive in voles. In conclusion, lice were influenced not only by the host- but also by environment-related factors. The effects of the latter could be mediated via life history parameters of a host.

  5. More novel hantaviruses and diversifying reservoir hosts--time for development of reservoir-derived cell culture models?

    PubMed

    Eckerle, Isabella; Lenk, Matthias; Ulrich, Rainer G

    2014-01-01

    Due to novel, improved and high-throughput detection methods, there is a plethora of newly identified viruses within the genus Hantavirus. Furthermore, reservoir host species are increasingly recognized besides representatives of the order Rodentia, now including members of the mammalian orders Soricomorpha/Eulipotyphla and Chiroptera. Despite the great interest created by emerging zoonotic viruses, there is still a gross lack of in vitro models, which reflect the exclusive host adaptation of most zoonotic viruses. The usually narrow host range and genetic diversity of hantaviruses make them an exciting candidate for studying virus-host interactions on a cellular level. To do so, well-characterized reservoir cell lines covering a wide range of bat, insectivore and rodent species are essential. Most currently available cell culture models display a heterologous virus-host relationship and are therefore only of limited value. Here, we review the recently established approaches to generate reservoir-derived cell culture models for the in vitro study of virus-host interactions. These successfully used model systems almost exclusively originate from bats and bat-borne viruses other than hantaviruses. Therefore we propose a parallel approach for research on rodent- and insectivore-borne hantaviruses, taking the generation of novel rodent and insectivore cell lines from wildlife species into account. These cell lines would be also valuable for studies on further rodent-borne viruses, such as orthopox- and arenaviruses. PMID:24576845

  6. Evolution of hantaviruses: co-speciation with reservoir hosts for more than 100 MYR.

    PubMed

    Plyusnin, Alexander; Sironen, Tarja

    2014-07-17

    The most recent (9th) Report of the International Committee on Taxonomy of Viruses (ICTV) lists 23 established and 30 provisional species in the genus Hantavirus (family Bunyaviridae) (Plyusnin et al., 2012). These virus species are harbored by altogether 51 species of rodents, shrews and moles and thus in most cases it is a relationship of "one hantavirus-one host". Such a tight bond between the two, in combination with the observed association between whole groups of hantaviruses and (sub)families of rodents, helped to develop the widely accepted view of a long-term co-evolution (co-speciation) of these viruses with their hosts. Accumulating evidence of host-switching events, both recent and ancient, however challenged some of the earlier views on hantavirus evolution. In this paper we discuss the concept of hantavirus-host co-speciation and propose a scenario of hantavirus evolution based on the currently available genetic information. This scenario is based on the hypothesis that hantaviruses are very ancient viruses which already existed at the estimated diversification point of major placental clades, of which one includes the ancestors of the order Rodentia and another the ancestors of both orders Eulipotyphla and Chiroptera; the diversification occurred approximately at 90-100 MYA. We also speculate that the evolutionary history of hantaviruses extents even deeper in the past, beyond this time-point, and included the transmission of a (pre)bunyavirus from an insect host to a mammal host. PMID:24463501

  7. A cytoarchitectonic and TH-immunohistochemistry characterization of the dopamine cell groups in the substantia nigra, ventral tegmental area and retrorubral field in the rock cavy (Kerodon rupestris).

    PubMed

    Cavalcanti, José R L P; Soares, Joacil G; Oliveira, Francisco G; Guzen, Fausto P; Pontes, André L B; Sousa, Twyla B; Cavalcante, Jeferson S; Nascimento, Expedito S; Cavalcante, Judney C; Costa, Miriam S M O

    2014-01-01

    The 3-hydroxytyramine/dopamine is a monoamine of the catecholamine group and it is a precursor of the noradrenaline and adrenaline synthesis, in which the enzyme tyrosine hydroxylase acts as a rate-limiting enzyme. The dopaminergic nuclei retrorubral field (A8 group), substantia nigra pars compacta (A9 group) and ventral tegmental area (A10 group) are involved in three complex circuitries named mesostriatal, mesocortical and mesolimbic, which are directly related to various behavioral manifestations such as motor control, reward signaling in behavioral learning, motivation and pathological manifestations of Parkinson's disease and schizophrenia. The aim of this study was to describe the delimitation of A8, A9 and A10 groups and the morphology of their neurons in the brain of the rock cavy (Kerodon rupestris), a typical Brazilian Northeast rodent belonging to the suborder Hystricomorpha, family Caviidae. Coronal and sagittal sections of the rock cavy brains were submitted to Nissl staining and TH immunohistochemistry. The organization of these dopaminergic nuclei in the rock cavy brain is very similar to that found in other animals of the Rodentia order, except for the presence of the tail of the substantia nigra, which is found only in the species under study. The results revealed that, apart some morphological variations, A8, A9 and A10 groups are phylogenetically stable brain structures. PMID:24444614

  8. Genomic and bioinformatic analysis of NADPH-cytochrome P450 reductase in Anopheles stephensi (Diptera: Culicidae).

    PubMed

    Suwanchaichinda, C; Brattsten, L B

    2014-01-01

    The cytochrome P450 monooxygenase (P450) enzyme system is a major mechanism of xenobiotic biotransformation. The nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P450 reductase (CPR) is required for transfer of electrons from NADPH to P450. One CPR gene was identified in the genome of the malaria-transmitting mosquito Anopheles stephensi Liston (Diptera: Culicidae). The gene encodes a polypeptide containing highly conserved flavin mononucleotide-, flavin adenine dinucleotide-, and NADPH-binding domains, a unique characteristic of the reductase. Phylogenetic analysis revealed that the A. stephensi and other known mosquito CPRs belong to a monophyletic group distinctly separated from other insects in the same order, Diptera. Amino acid residues of CPRs involved in binding of P450 and cytochrome c are conserved between A. stephensi and the Norway rat Rattus norvegicus Berkenhout (Rodentia: Muridae). However, gene structure particularly within the coding region is evidently different between the two organisms. Such difference might arise during the evolution process as also seen in the difference of P450 families and isoforms found in these organisms. CPR in the mosquito A. stephensi is expected to be active and serve as an essential component of the P450 system.

  9. Proliferation and apoptosis in early molar morphogenesis-- voles as models in odontogenesis.

    PubMed

    Setkova, Jana; Lesot, Herve; Matalova, Eva; Witter, Kirsti; Matulova, Petra; Misek, Ivan

    2006-01-01

    Proliferation and apoptosis play crucial roles in the development of multicellular organisms. Their precise balance is necessary for tissue homeostasis throughout life. The developing dentition is a suitable model to study proliferation and apoptosis during embryogenesis, but the corresponding studies have been carried out principally in the mouse. The present study aimed to examine proliferation and apoptosis in the vole (Microtus sp., Rodentia) during the early morphogenesis of the first upper molar and compare it to what is known from the mouse. To this end, apoptosis and proliferation were investigated using histology and computer-aided 3D reconstruction. Mitoses accumulated predominantly in the developing cervical loop. Apoptosis during early odontogenesis showed highly specific spatio-temporal patterns in the dental epithelium. Apoptotic bodies were localised in non-dividing cell populations. They accumulated in the same places as described in the mouse: antemolar vestiges (ED 12.5 15.5), enamel knot (ED 14.5 15.5), stalk and palatally along the whole first molar tooth germ longitudinal axis (ED 15 - 15.5). Early tooth development in the field vole, including the distribution of apoptosis and mitosis, is very similar to that reported in the mouse, with the exception of the antemolar region. The microtine antemolar vestige is preserved longer than the murine one. It is conceivable that additional distinct differences in morphogenetic processes appear later in tooth development.

  10. Cellular scaling rules for rodent brains.

    PubMed

    Herculano-Houzel, Suzana; Mota, Bruno; Lent, Roberto

    2006-08-01

    How do cell number and size determine brain size? Here, we show that, in the order Rodentia, increased size of the cerebral cortex, cerebellum, and remaining areas across six species is achieved through greater numbers of neurons of larger size, and much greater numbers of nonneuronal cells of roughly invariant size, such that the ratio between total neuronal and nonneuronal mass remains constant across species. Although relative cerebellar size remains stable among rodents, the number of cerebellar neurons increases with brain size more rapidly than in the cortex, such that the cerebellar fraction of total brain neurons increases with brain size. In contrast, although the relative cortical size increases with total brain size, the cortical fraction of total brain neurons remains constant. We propose that the faster increase in average neuronal size in the cerebral cortex than in the cerebellum as these structures gain neurons and the rapidly increasing glial numbers that generate glial mass to match total neuronal mass at a fixed glia/neuron total mass ratio are fundamental cellular constraints that lead to the relative expansion of cerebral cortical volume across species.

  11. Wild and synanthropic reservoirs of Leishmania species in the Americas

    PubMed Central

    Roque, André Luiz R.; Jansen, Ana Maria

    2014-01-01

    The definition of a reservoir has changed significantly in the last century, making it necessary to study zoonosis from a broader perspective. One important example is that of Leishmania, zoonotic multi-host parasites maintained by several mammal species in nature. The magnitude of the health problem represented by leishmaniasis combined with the complexity of its epidemiology make it necessary to clarify all of the links in transmission net, including non-human mammalian hosts, to develop effective control strategies. Although some studies have described dozens of species infected with these parasites, only a minority have related their findings to the ecological scenario to indicate a possible role of that host in parasite maintenance and transmission. Currently, it is accepted that a reservoir may be one or a complex of species responsible for maintaining the parasite in nature. A reservoir system should be considered unique on a given spatiotemporal scale. In fact, the transmission of Leishmania species in the wild still represents an complex enzootic “puzzle”, as several links have not been identified. This review presents the mammalian species known to be infected with Leishmania spp. in the Americas, highlighting those that are able to maintain and act as a source of the parasite in nature (and are thus considered potential reservoirs). These host/reservoirs are presented separately in each of seven mammal orders – Marsupialia, Cingulata, Pilosa, Rodentia, Primata, Carnivora, and Chiroptera – responsible for maintaining Leishmania species in the wild. PMID:25426421

  12. Kangaroo rats exhibit spongiform degeneration of the central auditory system similar to that found in gerbils.

    PubMed

    McGinn, M D; Faddis, B T

    1997-02-01

    Kangaroo rats develop spongiform degeneration of the central auditory system similar to that seen in the gerbil. Light microscopic and transmission electron microscopic study of the cochlear nucleus and auditory nerve root (ANR) of Dipodomys deserti and D. merriami show that spongiform lesions develop in dendrites and oligodendrocytes of the cochlear nucleus and in oligodendrocytes of the ANR that are morphologically indistinguishable from those extensively described in the Mongolian gerbil, Meriones unguiculatus. As in Mongolian gerbils, the spongiform degeneration in Dipodomys were much more numerous in animals continually exposed to modest levels of low-frequency noise (< 75 dB SPL). The kangaroo rats with extensive spongiform degeneration also show slightly, but significantly, elevated auditory brainstem evoked response (ABR) thresholds to low-frequency stimuli, a result also found in Mongolian gerbils. These results suggest that the elevated ABR thresholds may be the result of spongiform degeneration. Because low-frequency noise-induced spongiform degeneration has now been shown in the cochlear nucleus of animals from separate families of Rodentia (Heteromyidae and Muridae), the possibility should be investigated that similar noise-induced degenerative changes occur in the central auditory system of other mammals with good low-frequency hearing.

  13. Comparison of the ITS1 and ITS2 rDNA in Emeria callospermophili (Apicomplexa: Eimeriidae) from Sciurid Rodents

    PubMed Central

    Motriuk-Smith, Dagmara; Seville, R Scott; Quealy, Leah; Oliver, Clinton E.

    2011-01-01

    The taxonomy of the coccidia has historically been morphologically based. The purpose of this study was to establish if conspecificity of isolates of Eimeria callospermophili from 4 ground-dwelling squirrel hosts (Rodentia: Sciuridae) is supported by comparison of rDNA sequence data and to examine how this species relates to eimerian species from other sciurid hosts. Eimeria callospermophili was isolated from 4 wild caught hosts, i.e., Urocitellus elegans, Cynomys leucurus, Marmota flaviventris, and Cynomys ludovicianus. The ITS1 and ITS2 genomic rDNA sequences were PCR generated, sequenced, and analyzed. The highest intraspecific pairwise distance values of 6.0% in ITS1 and 7.1% in ITS2 were observed in C. leucurus. Interspecific pairwise distance values greater than 5% do not support E. callospermophili conspecificity. Generated E. callospermophili sequences were compared to Eimeria lancasterensis from Sciuris niger and Sciurus niger cinereus, and Eimeria ontarioensis from S. niger. A single well-supported clade was formed by E. callospermophili amplicons in Neighbor Joining and Maximum Parsimony analyses. However, within the clade there was little evidence of host or geographic structuring of the species. PMID:21506777

  14. Parentage analysis of Ansell's mole-rat family groups indicates a high reproductive skew despite relatively relaxed ecological constraints on dispersal.

    PubMed

    Patzenhauerová, Hana; Šklíba, Jan; Bryja, Josef; Šumbera, Radim

    2013-10-01

    To better understand evolutionary pathways leading to eusociality, interspecific comparisons are needed, which would use a common axis, such as that of reproductive skew, to array species. African mole-rats (Bathyergidae, Rodentia) provide an outstanding model of social evolution because of a wide range of social organizations within a single family; however, their reproductive skew is difficult to estimate, due to their cryptic lifestyle. A maximum skew could theoretically be reached in groups where reproduction is monopolized by a stable breeding pair, but the value could be decreased by breeding-male and breeding-female turnover, shared reproduction and extra-group mating. The frequency of such events should be higher in species or populations inhabiting mesic environments with relaxed ecological constraints on dispersal. To test this prediction, we studied patterns of parentage and relatedness within 16 groups of Ansell's mole-rat (Fukomys anselli) in mesic miombo woodland. Contrary to expectation, there was no shared reproduction (more than one breeder of a particular sex) within the studied groups, and proportion of immigrants and offspring not assigned to current breeding males was low. The within-group parentage and relatedness patterns observed resemble arid populations of 'eusocial' Fukomys damarensis, rather than a mesic population of 'social' Cryptomys hottentotus. As a possible explanation, we propose that the extent ecological conditions affect reproductive skew may be markedly affected by life history and natural history traits of the particular species and genera.

  15. Implications of hybridization, NUMTs, and overlooked diversity for DNA Barcoding of Eurasian ground squirrels.

    PubMed

    Ermakov, Oleg A; Simonov, Evgeniy; Surin, Vadim L; Titov, Sergey V; Brandler, Oleg V; Ivanova, Natalia V; Borisenko, Alex V

    2015-01-01

    The utility of DNA Barcoding for species identification and discovery has catalyzed a concerted effort to build the global reference library; however, many animal groups of economical or conservational importance remain poorly represented. This study aims to contribute DNA barcode records for all ground squirrel species (Xerinae, Sciuridae, Rodentia) inhabiting Eurasia and to test efficiency of this approach for species discrimination. Cytochrome c oxidase subunit 1 (COI) gene sequences were obtained for 97 individuals representing 16 ground squirrel species of which 12 were correctly identified. Taxonomic allocation of some specimens within four species was complicated by geographically restricted mtDNA introgression. Exclusion of individuals with introgressed mtDNA allowed reaching a 91.6% identification success rate. Significant COI divergence (3.5-4.4%) was observed within the most widespread ground squirrel species (Spermophilus erythrogenys, S. pygmaeus, S. suslicus, Urocitellus undulatus), suggesting the presence of cryptic species. A single putative NUMT (nuclear mitochondrial pseudogene) sequence was recovered during molecular analysis; mitochondrial COI from this sample was amplified following re-extraction of DNA. Our data show high discrimination ability of 100 bp COI fragments for Eurasian ground squirrels (84.3%) with no incorrect assessments, underscoring the potential utility of the existing reference librariy for the development of diagnostic 'mini-barcodes'.

  16. Checklist of helminths found in Patagonian wild mammals.

    PubMed

    Fugassa, Martin H

    2015-09-03

    Using available reports, a checklist of the recorded helminth parasites of wild mammals from Patagonia was generated. Records of parasites found in Patagonia were included, together with records from mammals in áreas outside of Patagonia but whose range extends into Patagonia. Information about the host, localities, and references were also included. A total of 1323 records (224 Cestoda, 167 Trematoda, 894 Nematoda, 34 Acanthocephala, and 4 Pentastomida) belonging to 452 helminth species (77 Cestoda, 76 Trematoda, 277 Nematoda, 21 Acanthocephala, and 1 Pentastomida) found in 57 native mammals (22 Rodentia, 4 Didelphimorphia 1 Microbiotheria, 7 Chiroptera, 5 Cingulata, and 13 Carnivora) were listed. However, only 10.6 % of the reports were conducted on samples from Patagonia and corresponded to 25% of mammals in the region. In addition, many studies were made on a few species and, for example, 52% corresponded to studies made on Lama guanicoe. This suggests the need to increase efforts to know the parasitic fauna in a peculiar region as is the Patagonia. This is the first compilation of the helminth parasites of mammals in Argentine Patagonia and is important for parasitological and paleoparasitological studies.

  17. Bartonella infection in small mammals and their ectoparasites in Lithuania.

    PubMed

    Lipatova, Indre; Paulauskas, Algimantas; Puraite, Irma; Radzijevskaja, Jana; Balciauskas, Linas; Gedminas, Vaclovas

    2015-01-01

    The Bartonella pathogen is an emerging zoonotic agent. Epidemiological studies worldwide have demonstrated that small mammals are reservoir hosts of Bartonella spp. and their ectoparasites are potential vectors. The aim of this study was to investigate the prevalence of Bartonella infections in small mammals (Rodentia, Insectivora) and their ectoparasites (fleas and ticks) in Lithuania. A total of 430 small mammals representing nine species were captured with live-traps in Lithuania during 2013-2014. A total of 151 fleas representing eight species were collected from 109 (25.8%) small mammals. Five hundred and seventy ticks (Ixodes ricinus) were collected from 68 (16.1%) small mammals. Bartonella DNA was detected in 102 (23.7%) small mammals, 44 (29.1%) fleas and five (3.7%) pooled tick samples. Sequence analysis of 16S-23S rRNA ITS region showed that sequences were identical or similar to Bartonella grahamii, Bartonella taylorii and Bartonella rochalimae. This study is the first investigating the distribution and diversity of Bartonella species in small mammals and their ectoparasites in Lithuania. B. grahamii, B. taylorii, and B. rochalimae were detected in small mammals and their fleas, and B. grahamii in ticks obtained from small mammals.

  18. New species of Rotundomys (Cricetinae) from the Late Miocene of Spain and its bearing on the phylogeny of Cricetulodon and Rotundomys.

    PubMed

    López-Antoñanzas, Raquel; Peláez-Campomanes, Pablo; Álvarez-Sierra, Ángeles

    2014-01-01

    The material of Rotundomys (Rodentia, Cricetinae) from the Late Miocene fossiliferous complex of Cerro de los Batallones (Madrid, Spain) is described and compared with all species currently placed in the genera Rotundomys and Cricetulodon. Both the morphology and size variation encompassed in the collection of specimens from Batallones suggest they belong to a single taxon different from the other known species of these genera. A new species Rotundomys intimus sp. nov. is, therefore, named for it. A cladistic analysis, which is the first ever published concernig these taxa, has been conducted to clear up the phylogenetic position of the new species. Our results suggest that Rotundomys intimus sp. nov. inserts between R. mundi and R. sabatieri as a relatively primitive taxon inside the clade Rotundomys. The new taxon is more derived than R. mundi in having a transversal connection between the metalophulid and the anterolophulid on some m1 but more primitive than R. sabatieri and the most evolved species of Rotundomys (R. montisrotuni +R.bressanus) in its less developed lophodonty showing distinct cusps, shallower valleys, and the presence of a subdivided anteroloph on the M1. The species of Cricetulodon do not form a monophyletic group. As a member of Rotundomys, Rotundomys intimus sp. nov. is more derived than all of these taxa in its greater lophodonty and the complete loss of the anterior protolophule, mesolophs, and mesolophids. PMID:25389967

  19. Collagen Fingerprinting: A New Screening Technique for Radiocarbon Dating Ancient Bone.

    PubMed

    Harvey, Virginia L; Egerton, Victoria M; Chamberlain, Andrew T; Manning, Phillip L; Buckley, Michael

    2016-01-01

    Collagen is the dominant organic component of bone and is intimately locked within the hydroxyapatite structure of this ubiquitous biomaterial that dominates archaeological and palaeontological assemblages. Radiocarbon analysis of extracted collagen is one of the most common approaches to dating bone from late Pleistocene or Holocene deposits, but dating is relatively expensive compared to other biochemical techniques. Numerous analytical methods have previously been investigated for the purpose of screening out samples that are unlikely to yield reliable dates including histological analysis, UV-stimulated fluorescence and, most commonly, the measurement of percentage nitrogen (%N) and ratio of carbon to nitrogen (C:N). Here we propose the use of collagen fingerprinting (also known as Zooarchaeology by Mass Spectrometry, or ZooMS, when applied to species identification) as an alternative screening method for radiocarbon dating, due to its ability to provide information on collagen presence and quality, alongside species identification. The method was tested on a series of sub-fossil bone specimens from cave systems on Cayman Brac (Cayman Islands), chosen due to the observable range in diagenetic alteration, and in particular, the extent of mineralisation. Six (14)C dates, of 18 initial attempts, were obtained from remains of extinct hutia, Capromys sp. (Rodentia; Capromyidae), recovered from five distinct caves on Cayman Brac, and ranging from 393 ± 25 to 1588 ± 26 radiocarbon years before present (yr BP). All of the bone samples that yielded radiocarbon dates generated excellent collagen fingerprints, and conversely those that gave poor fingerprints also failed dating. Additionally, two successfully fingerprinted bone samples were screened out from a set of 81. Both subsequently generated (14)C dates, demonstrating successful utilisation of ZooMS as an alternative screening mechanism to identify bone samples that are suitable for 1(4)C analysis.

  20. Dung beetles (Coleoptera: Scarabaeidae) attracted to dung of the largest herbivorous rodent on earth: a comparison with human feces.

    PubMed

    Puker, Anderson; Correa, César M A; Korasaki, Vanesca; Ferreira, Kleyton R; Oliveira, Naiara G

    2013-12-01

    The capybara, Hydrochoerus hydrochaeris (L.) (Rodentia: Caviidae), is the largest herbivorous rodent on Earth and abundant in the Neotropical region, which can provide a stable food source of dung for dung beetle communities (Coleoptera: Scarabaeidae: Scarabaeinae). However, the use of capybara dung by dung beetles is poorly known. Here, we present data on the structure of the dung beetle community attracted to capybara dung and compare with the community attracted to human feces. Dung beetles were captured with pitfall traps baited with fresh capybara dung and human feces in pastures with exotic grass (Brachiaria spp.), patches of Brazilian savanna (Cerrado), and points of degraded riparian vegetation along the Aquidauana river in Anastácio and Aquidauana, Mato Grosso do Sul, Brazil. In traps baited with human feces, 13,809 individuals of 31 species were captured, and in those baited with capybara dung 1,027 individuals belonging to 26 species were captured. The average number of individuals and species captured by the traps baited with human feces was greater than for capybara dung in all habitats studied. Composition of the communities attracted to human feces and capybara dung formed distinct groups in all habitats. Despite the smaller number of species and individuals captured in capybara dung when compared with human feces, capybara dung was attractive to dung beetles. In Brazil, the legalization of hunting these rodents has been debated, which would potentially affect the community and consequently the ecological functions performed by dung beetles that use the feces of these animals as a resource. In addition, the knowledge of the communities associated with capybaras may be important in predicting the consequences of future management of their populations.

  1. Complete mitochondrial genome of the Eurasian flying squirrel Pteromys volans (Sciuromorpha, Sciuridae) and revision of rodent phylogeny.

    PubMed

    Ryu, Shi Hyun; Kwak, Min Jung; Hwang, Ui Wook

    2013-02-01

    In this study, the complete mitochondrial genome of the Eurasian flying squirrel Pteromys volans (Rodentia, Sciuromorpha, Sciuridae) was sequenced and characterized in detail. The entire mitochondrial genome of P. volans consisted of 16,513 bp and contained 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and two non-coding regions. Its gene arrangement pattern was consistent with the mammalian ground pattern. The overall base composition and AT contents were similar to those of other rodent mitochondrial genomes. The light-strand origin generally identified between tRNA ( Asn ) and tRNA ( Cys ) consisted of a secondary structure with an 11-bp stem and an 11-bp loop. The large control region was constructed of three characteristic domains, ETAS, CD, and CSB without any repeat sequences. Each domain contained ETAS1, subsequences A, B, and C, and CSB1, respectively. In order to examine phylogenetic contentious issues of the monophyly of rodents and phylogenetic relationships among five rodent suborders, here, phylogenetic analyses based on nucleotide sequence data of the 35 rodent and 3 lagomorph mitochondrial genomes were performed using the Bayesian inference and maximum likelihood method. The result strongly supported the rodent monophyly with high node confidence values (BP 100 % in ML and BPP 1.00 in BI) and also monophylies of four rodent suborders (BP 85-100 % in ML and BPP 1.00 in BI), except for Anomalumorpha in which only one species was examined here. Also, phylogenetic relationships among the five rodent suborders were suggested and discussed in detail. PMID:23114915

  2. Evidence for rodent-common and species-typical limb and digit use in eating, derived from a comparative analysis of ten rodent species.

    PubMed

    Whishaw, I Q; Sarna, J R; Pellis, S M

    1998-11-01

    Order Rodentia comprises a vast portion of mammalian species (1814 species), which occupy extremely diverse habitats requiring very distinct motor specializations (e.g. burrowing, hopping, climbing, flying and swimming). Although early classification of paw use ability suggests rodents are impoverished relative to primates and make little use of their paws, there have been no systematic investigations of paw use in rodents. The present study was undertaken to describe limb/paw movements in a variety of common rodents. The movements used for handling sunflower seeds and other foods were videorecorded and analyzed in the guinea pig (Cavia porcellus), Mongolian gerbil (Meriones unguiculatus), Syrian hamster (Mesocricetus auratus), laboratory mouse (Mus musculus), laboratory rat (Rattus norvegicus), gray squirrel (Sciurus carolinensis), red squirrel (Tamiasciurus hudsonicus), Richardson's ground squirrel (Spermophilus richardsonni), prairie dog (Cynomus parvidens), and Canadian beaver (Castor americanus). The results suggested five order-common movements of food handling: (1) locating food by sniffing, (2) grasping food by mouth, (3) sitting back on the haunches to eat, (4) grasping the food using an elbow-in movement, and (5) manipulate the food with the digits. Different species displayed species-typical specializations including (1) bilateral grasping with the paws (gerbil), (2) unilateral grasping with a paw (beaver), (3) unilateral holding (ground squirrels), (4) various grip and digit postures (all species), (5) unilateral object removal from the mouth (gerbil), (6) bilateral thumb holding (squirrels), and (7) simultaneous holding/manipulation of two objects (squirrels). Only the guinea pig did not handle food with its paws, suggesting its behavior is regressive. The existence of a core pattern of paw and digit use in rodents suggests that skilled limb and paw movements originate at least with the common ancestors of the rodent, and likely the common ancestor to

  3. Historical biogeography of the strepsirhine primates of Madagascar.

    PubMed

    Tattersall, Ian

    2006-01-01

    Lying some 400 km off the coast of southeastern Africa, Madagascar is the world's largest oceanic island. It has been in roughly the same position relative to its parent continent for 120 million years, and as a consequence its mammal fauna is unusual in composition, with a low number of major taxa but a high diversity at lower taxonomic levels. Among Madagascar's native terrestrial mammals, only the orders Primates, Rodentia, Carnivora and Insectivora are represented (plus, until recently, the enigmatic and endemic Bibymalagasia, and Artiodactyla in the form of semiaquatic pygmy hippopotamuses). This reflects the fact that terrestrial mammals are notoriously poor over-water dispersers; yet at the same time the ancestors of all of Madagascar's mammals had to have crossed a wide oceanic barrier to get to the island at various points during the Tertiary. Here I examine the palaeogeographic evidence for potential land bridge or 'stepping-stone' connections with adjacent continents from the Mesozoic through the Cenozoic, and review the fossil records and phylogenies of each of Madagascar's mammalian groups in an attempt to estimate the minimum number of crossings necessary to produce the island's current faunal composition. Probable monophyletic origins for each major group, and thus a smaller rather than a larger number of crossings of the Mozambique Channel, imply that this water barrier has acted as a powerful filter; so powerful that it is unclear whether any crossings would have been possible without some form of subaerial connection, however ephemeral, at least from time to time during the Tertiary. Clarification of how Madagascar's terrestrial mammal fauna may have originated is thus as likely to emerge from the geology of the seafloor surrounding the island as it is to come from the fossil record or from the internal and external relationships of its various components.

  4. New Insights into the Phylogeny and Gene Context Analysis of Binder of Sperm Proteins (BSPs)

    PubMed Central

    Arruga, Diana; Pérez-Pé, Rosaura; Sánchez-Ferrer, Álvaro; Muiño-Blanco, Teresa; Cebrián-Pérez, José A.

    2015-01-01

    Seminal plasma (SP) proteins support the survival of spermatozoa acting not only at the plasma membrane but also by inhibition of capacitation, resulting in higher fertilizing ability. Among SP proteins, BSP (binder of sperm) proteins are the most studied, since they may be useful for the improvement of semen diluents, storage and subsequent fertilization results. However, an updated and detailed phylogenetic analysis of the BSP protein superfamily has not been carried out with all the sequences described in the main databases. The update view shows for the first time an equally distributed number of sequences between the three families: BSP, and their homologs 1 (BSPH1) and 2 (BSPH2). The BSP family is divided in four subfamilies, BSP1 subfamily being the predominant, followed by subfamilies BSP3, BSP5 and BSP2. BSPH proteins were found among placental mammals (Eutheria) belonging to the orders Proboscidea, Primates, Lagomorpha, Rodentia, Chiroptera, Perissodactyla and Cetartiodactyla. However, BSPH2 proteins were also found in the Scandentia order and Metatheria clade. This phylogenetic analysis, when combined with a gene context analysis, showed a completely new evolutionary scenario for the BSP superfamily of proteins with three defined different gene patterns, one for BSPs, one for BSPH1/BSPH2/ELSPBP1 and another one for BSPH1/BSPH2 without ELSPBP1. In addition, the study has permitted to define concise conserved blocks for each family (BSP, BSPH1 and BSPH2), which could be used for a more reliable assignment for the incoming sequences, for data curation of current databases, and for cloning new BSPs, as the one described in this paper, ram seminal vesicle 20 kDa protein (RSVP20, Ovis aries BSP5b). PMID:26333091

  5. Quest for Orthologs Entails Quest for Tree of Life: In Search of the Gene Stream

    PubMed Central

    Boeckmann, Brigitte; Marcet-Houben, Marina; Rees, Jonathan A.; Forslund, Kristoffer; Huerta-Cepas, Jaime; Muffato, Matthieu; Yilmaz, Pelin; Xenarios, Ioannis; Bork, Peer; Lewis, Suzanna E.; Gabaldón, Toni

    2015-01-01

    Quest for Orthologs (QfO) is a community effort with the goal to improve and benchmark orthology predictions. As quality assessment assumes prior knowledge on species phylogenies, we investigated the congruency between existing species trees by comparing the relationships of 147 QfO reference organisms from six Tree of Life (ToL)/species tree projects: The National Center for Biotechnology Information (NCBI) taxonomy, Opentree of Life, the sequenced species/species ToL, the 16S ribosomal RNA (rRNA) database, and trees published by Ciccarelli et al. (Ciccarelli FD, et al. 2006. Toward automatic reconstruction of a highly resolved tree of life. Science 311:1283–1287) and by Huerta-Cepas et al. (Huerta-Cepas J, Marcet-Houben M, Gabaldon T. 2014. A nested phylogenetic reconstruction approach provides scalable resolution in the eukaryotic Tree Of Life. PeerJ PrePrints 2:223) Our study reveals that each species tree suggests a different phylogeny: 87 of the 146 (60%) possible splits of a dichotomous and rooted tree are congruent, while all other splits are incongruent in at least one of the species trees. Topological differences are observed not only at deep speciation events, but also within younger clades, such as Hominidae, Rodentia, Laurasiatheria, or rosids. The evolutionary relationships of 27 archaea and bacteria are highly inconsistent. By assessing 458,108 gene trees from 65 genomes, we show that consistent species topologies are more often supported by gene phylogenies than contradicting ones. The largest concordant species tree includes 77 of the QfO reference organisms at the most. Results are summarized in the form of a consensus ToL (http://swisstree.vital-it.ch/species_tree) that can serve different benchmarking purposes. PMID:26133389

  6. A First Generation Comparative Chromosome Map between Guinea Pig (Cavia porcellus) and Humans

    PubMed Central

    Romanenko, Svetlana A.; Perelman, Polina L.; Trifonov, Vladimir A.; Serdyukova, Natalia A.; Li, Tangliang; Fu, Beiyuan; O’Brien, Patricia C. M.; Ng, Bee L.; Nie, Wenhui; Liehr, Thomas; Stanyon, Roscoe; Graphodatsky, Alexander S.; Yang, Fengtang

    2015-01-01

    The domesticated guinea pig, Cavia porcellus (Hystricomorpha, Rodentia), is an important laboratory species and a model for a number of human diseases. Nevertheless, genomic tools for this species are lacking; even its karyotype is poorly characterized. The guinea pig belongs to Hystricomorpha, a widespread and important group of rodents; so far the chromosomes of guinea pigs have not been compared with that of other hystricomorph species or with any other mammals. We generated full sets of chromosome-specific painting probes for the guinea pig by flow sorting and microdissection, and for the first time, mapped the chromosomal homologies between guinea pig and human by reciprocal chromosome painting. Our data demonstrate that the guinea pig karyotype has undergone extensive rearrangements: 78 synteny-conserved human autosomal segments were delimited in the guinea pig genome. The high rate of genome evolution in the guinea pig may explain why the HSA7/16 and HSA16/19 associations presumed ancestral for eutherians and the three syntenic associations (HSA1/10, 3/19, and 9/11) considered ancestral for rodents were not found in C. porcellus. The comparative chromosome map presented here is a starting point for further development of physical and genetic maps of the guinea pig as well as an aid for genome assembly assignment to specific chromosomes. Furthermore, the comparative mapping will allow a transfer of gene map data from other species. The probes developed here provide a genomic toolkit, which will make the guinea pig a key species to unravel the evolutionary biology of the Hystricomorph rodents. PMID:26010445

  7. Occurrence of ectoparasitic arthropods associated with rodents in Hail region northern Saudi Arabia.

    PubMed

    Asiry, Khalid A; Fetoh, Badr El-Sabah A

    2014-09-01

    Ectoparasitic arthropods are a diverse element of the Saudi fauna. Due to this, a survey of ectoparasites associated with rodents was conducted as a preliminary study in five districts of Hail region of northern Saudi Arabia for the first time. Ectoparasites extracted from 750 rodents were sampled and identified by recording their frequency of appearance. Results revealed that 1,287 ectoparasites infested 316 of the captured rodent hosts. These ectoparasites parasitized on four species of rodents including three species of rats Rattus rattus rattus, Rattus rattus frugivorus, and Rattus rattus alexandrinus and one species of mouse Acomys dimidiatus (Rodentia: Muridae). The ectoparasites belong to four different groups: ticks, fleas, lice, and mites. Ticks were the highest in the number, while fleas were the lowest among all the extracted ectoparasite groups. The collected ectoparasitic arthropods consisted of seven species. Ticks were of two species: Rhipicephalus turanicus and Rhipicephalus sanguineus (Acari: Ixodidae), fleas were of two species: Xenopsylla cheopis and Xenopsyllus conformis mycerini (Siphonaptera: Pulicidae), lice was a single species: Polyplax serrata (Anoplura: Hoplopleuridae), and mites were of two species: Laelaps nuttali and Laelaps echidninus (Mesostigmata: Laelapidae). The findings of the study showed that the intensity of infestation was varied between rodent host sexes, wherein females had the highest rate of parasitic infestation, and the parasitic index of appearance was very high for one group of parasites (i.e., ticks). The parasitic prevalence was 42.13 % on rodents, and mites were the most prevalent parasite species. Overall, this study was carried out to establish baseline data for ectoparasite-infested rodents in Hail region, Saudi Arabia, and may help for appropriate planning to control zoonotic diseases in this area.

  8. Threat diversity will erode mammalian phylogenetic diversity in the near future.

    PubMed

    Jono, Clémentine M A; Pavoine, Sandrine

    2012-01-01

    To reduce the accelerating rate of phylogenetic diversity loss, many studies have searched for mechanisms that could explain why certain species are at risk, whereas others are not. In particular, it has been demonstrated that species might be affected by both extrinsic threat factors as well as intrinsic biological traits that could render a species more sensitive to extinction; here, we focus on extrinsic factors. Recently, the International Union for Conservation of Nature developed a new classification of threat types, including climate change, urbanization, pollution, agriculture and aquaculture, and harvesting/hunting. We have used this new classification to analyze two main factors that could explain the expected future loss of mammalian phylogenetic diversity: 1. differences in the type of threats that affect mammals and 2. differences in the number of major threats that accumulate for a single species. Our results showed that Cetartiodactyla, Diprotodontia, Monotremata, Perissodactyla, Primates, and Proboscidea could lose a high proportion of their current phylogenetic diversity in the coming decades. In contrast, Chiroptera, Didelphimorphia, and Rodentia could lose less phylogenetic diversity than expected if extinctions were random. Some mammalian clades, including Marsupiala, Chiroptera, and a subclade of Primates, are affected by particular threat types, most likely due solely to their geographic locations and associations with particular habitats. However, regardless of the geography, habitat, and taxon considered, it is not the threat type, but the threat diversity that determines the extinction risk for species and clades. Thus, some mammals might be randomly located in areas subjected to a large diversity of threats; they might also accumulate detrimental traits that render them sensitive to different threats, which is a characteristic that could be associated with large body size. Any action reducing threat diversity is expected to have a

  9. Evolution of C, D and S-type cystatins in mammals: an extensive gene duplication in primates.

    PubMed

    de Sousa-Pereira, Patrícia; Abrantes, Joana; Pinheiro, Ana; Colaço, Bruno; Vitorino, Rui; Esteves, Pedro J

    2014-01-01

    Cystatins are a family of inhibitors of cysteine peptidases that comprises the salivary cystatins (D and S-type cystatins) and cystatin C. These cystatins are encoded by a multigene family (CST3, CST5, CST4, CST1 and CST2) organized in tandem in the human genome. Their presence and functional importance in human saliva has been reported, however the distribution of these proteins in other mammals is still unclear. Here, we performed a proteomic analysis of the saliva of several mammals and studied the evolution of this multigene family. The proteomic analysis detected S-type cystatins (S, SA, and SN) in human saliva and cystatin D in rat saliva. The evolutionary analysis showed that the cystatin C encoding gene is present in species of the most representative mammalian groups, i.e. Artiodactyla, Rodentia, Lagomorpha, Carnivora and Primates. On the other hand, D and S-type cystatins are mainly retrieved from Primates, and especially the evolution of S-type cystatins seems to be a dynamic process as seen in Pongo abelii genome where several copies of CST1-like gene (cystatin SN) were found. In Rodents, a group of cystatins previously identified as D and S has also evolved. Despite the high divergence of the amino acid sequence, their position in the phylogenetic tree and their genome organization suggests a common origin with those of the Primates. These results suggest that the D and S type cystatins have emerged before the mammalian radiation and were retained only in Primates and Rodents. Although the mechanisms driving the evolution of cystatins are unknown, it seems to be a dynamic process with several gene duplications evolving according to the birth-and-death model of evolution. The factors that led to the appearance of a group of saliva-specific cystatins in Primates and its rapid evolution remain undetermined, but may be associated with an adaptive advantage. PMID:25329717

  10. Evolution of C, D and S-type cystatins in mammals: an extensive gene duplication in primates.

    PubMed

    de Sousa-Pereira, Patrícia; Abrantes, Joana; Pinheiro, Ana; Colaço, Bruno; Vitorino, Rui; Esteves, Pedro J

    2014-01-01

    Cystatins are a family of inhibitors of cysteine peptidases that comprises the salivary cystatins (D and S-type cystatins) and cystatin C. These cystatins are encoded by a multigene family (CST3, CST5, CST4, CST1 and CST2) organized in tandem in the human genome. Their presence and functional importance in human saliva has been reported, however the distribution of these proteins in other mammals is still unclear. Here, we performed a proteomic analysis of the saliva of several mammals and studied the evolution of this multigene family. The proteomic analysis detected S-type cystatins (S, SA, and SN) in human saliva and cystatin D in rat saliva. The evolutionary analysis showed that the cystatin C encoding gene is present in species of the most representative mammalian groups, i.e. Artiodactyla, Rodentia, Lagomorpha, Carnivora and Primates. On the other hand, D and S-type cystatins are mainly retrieved from Primates, and especially the evolution of S-type cystatins seems to be a dynamic process as seen in Pongo abelii genome where several copies of CST1-like gene (cystatin SN) were found. In Rodents, a group of cystatins previously identified as D and S has also evolved. Despite the high divergence of the amino acid sequence, their position in the phylogenetic tree and their genome organization suggests a common origin with those of the Primates. These results suggest that the D and S type cystatins have emerged before the mammalian radiation and were retained only in Primates and Rodents. Although the mechanisms driving the evolution of cystatins are unknown, it seems to be a dynamic process with several gene duplications evolving according to the birth-and-death model of evolution. The factors that led to the appearance of a group of saliva-specific cystatins in Primates and its rapid evolution remain undetermined, but may be associated with an adaptive advantage.

  11. Preliminary inventory of mammals from Yurubí National Park, Yaracuy, Venezuela with some comments on their natural history.

    PubMed

    García, Franger J; Delgado-Jaramillo, Mariana; Machado, Marjorie; Aular, Luis

    2012-03-01

    In Venezuela, mammals represent an important group of wildlife with high anthropogenic pressures that threaten their permanence. Focused on the need to generate baseline information that allows us to contribute to document and conserve the richness of local wildlife, we conducted a mammalogical inventory in Yurubí National Park, located in Yaracuy State in Venezuela. We carried out fieldworks in three selected vegetation types: an evergreen forest at 197m, a semi-deciduous forest ranging between 100-230m, and a cloud forest at 1 446m. We used Victor, Sherman, Havahart and pitfall traps for the capture of small non-volant mammals and mist nets for bats. In addition, we carried out interviews with local residents and direct-indirect observations for medium-large sized mammals. At least 79 species inhabit the area, representing 28% of the species recorded for the North side of the country. Chiroptera (39 spp.), Carnivora (13 spp.) and Rodentia (9 spp.) were the orders with the highest richness, as expected for the Neotropics. The evergreen forest had the greatest species richness (n=68), with a sampling effort of 128 net-hours, 32 bucket-days, 16 hours of observations, and three persons interviewed, followed by cloud forest (n=45) with 324 net-hours, 790 traps-night, 77 bucket-days, 10 hours of observations, and one person interviewed. The lowest richness value was in the semi-deciduous forest (n=41), with 591 traps-night, 15 net-hours, 10 hours of observations and three persons interviewed. Data and observations obtained in this inventory (e.g., endemism, species known as "surrogate species" threatened in Venezuela) give an important role at the Yurubí National Park in the maintenance and conservation of local ecosystems and wildlife, threatened by human pressures in the Cordillera de la Costa.

  12. New Insights into the Phylogeny and Gene Context Analysis of Binder of Sperm Proteins (BSPs).

    PubMed

    Serrano, Edith; Martínez, Ana B; Arruga, Diana; Pérez-Pé, Rosaura; Sánchez-Ferrer, Álvaro; Muiño-Blanco, Teresa; Cebrián-Pérez, José A

    2015-01-01

    Seminal plasma (SP) proteins support the survival of spermatozoa acting not only at the plasma membrane but also by inhibition of capacitation, resulting in higher fertilizing ability. Among SP proteins, BSP (binder of sperm) proteins are the most studied, since they may be useful for the improvement of semen diluents, storage and subsequent fertilization results. However, an updated and detailed phylogenetic analysis of the BSP protein superfamily has not been carried out with all the sequences described in the main databases. The update view shows for the first time an equally distributed number of sequences between the three families: BSP, and their homologs 1 (BSPH1) and 2 (BSPH2). The BSP family is divided in four subfamilies, BSP1 subfamily being the predominant, followed by subfamilies BSP3, BSP5 and BSP2. BSPH proteins were found among placental mammals (Eutheria) belonging to the orders Proboscidea, Primates, Lagomorpha, Rodentia, Chiroptera, Perissodactyla and Cetartiodactyla. However, BSPH2 proteins were also found in the Scandentia order and Metatheria clade. This phylogenetic analysis, when combined with a gene context analysis, showed a completely new evolutionary scenario for the BSP superfamily of proteins with three defined different gene patterns, one for BSPs, one for BSPH1/BSPH2/ELSPBP1 and another one for BSPH1/BSPH2 without ELSPBP1. In addition, the study has permitted to define concise conserved blocks for each family (BSP, BSPH1 and BSPH2), which could be used for a more reliable assignment for the incoming sequences, for data curation of current databases, and for cloning new BSPs, as the one described in this paper, ram seminal vesicle 20 kDa protein (RSVP20, Ovis aries BSP5b). PMID:26333091

  13. Deterioration of the Gαo Vomeronasal Pathway in Sexually Dimorphic Mammals

    PubMed Central

    Suárez, Rodrigo; Fernández-Aburto, Pedro; Manger, Paul R.; Mpodozis, Jorge

    2011-01-01

    In mammals, social and sexual behaviours are largely mediated by the vomeronasal system (VNS). The accessory olfactory bulb (AOB) is the first synaptic locus of the VNS and ranges from very large in Caviomorph rodents, small in carnivores and ungulates, to its complete absence in apes, elephants, most bats and aquatic species. Two pathways have been described in the VNS of mammals. In mice, vomeronasal neurons expressing Gαi2 protein project to the rostral portion of the AOB and respond mostly to small volatile molecules, whereas neurons expressing Gαo project to the caudal AOB and respond mostly to large non-volatile molecules. However, the Gαo-expressing pathway is absent in several species (horses, dogs, musk shrews, goats and marmosets) but no hypotheses have been proposed to date to explain the loss of that pathway. We noted that the species that lost the Gαo pathway belong to Laurasiatheria and Primates lineages, both clades with ubiquitous sexual dimorphisms across species. To assess whether similar events of Gαo pathway loss could have occurred convergently in dimorphic species we studied G-protein expression in the AOB of two species that independently evolved sexually dimorphic traits: the California ground squirrel Spermophilus beecheyi (Rodentia; Sciurognathi) and the cape hyrax Procavia capensis (Afrotheria; Hyracoidea). We found that both species show uniform expression of Gαi2-protein throughout AOB glomeruli, while Gαo expression is restricted to main olfactory glomeruli only. Our results suggest that the degeneration of the Gαo-expressing vomeronasal pathway has occurred independently at least four times in Eutheria, possibly related to the emergence of sexual dimorphisms and the ability of detecting the gender of conspecifics at distance. PMID:22039487

  14. Collagen Fingerprinting: A New Screening Technique for Radiocarbon Dating Ancient Bone

    PubMed Central

    Harvey, Virginia L.; Egerton, Victoria M.; Chamberlain, Andrew T.; Manning, Phillip L.; Buckley, Michael

    2016-01-01

    Collagen is the dominant organic component of bone and is intimately locked within the hydroxyapatite structure of this ubiquitous biomaterial that dominates archaeological and palaeontological assemblages. Radiocarbon analysis of extracted collagen is one of the most common approaches to dating bone from late Pleistocene or Holocene deposits, but dating is relatively expensive compared to other biochemical techniques. Numerous analytical methods have previously been investigated for the purpose of screening out samples that are unlikely to yield reliable dates including histological analysis, UV-stimulated fluorescence and, most commonly, the measurement of percentage nitrogen (%N) and ratio of carbon to nitrogen (C:N). Here we propose the use of collagen fingerprinting (also known as Zooarchaeology by Mass Spectrometry, or ZooMS, when applied to species identification) as an alternative screening method for radiocarbon dating, due to its ability to provide information on collagen presence and quality, alongside species identification. The method was tested on a series of sub-fossil bone specimens from cave systems on Cayman Brac (Cayman Islands), chosen due to the observable range in diagenetic alteration, and in particular, the extent of mineralisation. Six 14C dates, of 18 initial attempts, were obtained from remains of extinct hutia, Capromys sp. (Rodentia; Capromyidae), recovered from five distinct caves on Cayman Brac, and ranging from 393 ± 25 to 1588 ± 26 radiocarbon years before present (yr BP). All of the bone samples that yielded radiocarbon dates generated excellent collagen fingerprints, and conversely those that gave poor fingerprints also failed dating. Additionally, two successfully fingerprinted bone samples were screened out from a set of 81. Both subsequently generated 14C dates, demonstrating successful utilisation of ZooMS as an alternative screening mechanism to identify bone samples that are suitable for 14C analysis. PMID:26938469

  15. Discovery of mammalian hosts to Gnathostoma nipponicum larvae and prevalence of the larvae in rodents and insectivores.

    PubMed

    Oyamada, T; Kobayashi, H; Kindou, T; Kudo, N; Yoshikawa, H; Yoshikawa, T

    1996-09-01

    From September 1993 to November 1995, to clarify the natural infection of Gnathostoma nipponicum (G.n.) larvae in small wild mammals, a total of 313 animals consisted of three species of rodents and two species of insectivores, collected from an endemic area of this nematode in Aomori Prefecture, were investigated. Two species, Rattus norvegicus (R.n.) and Chimarrogale himalayica (C.h.) were infected with G.n. larvae, and the infection rate was extremely high with 27.2% and 72.7% in the former and latter. The infected animals harbored the larvae of 2-10 (mean: 6.0) in R.N. and 2-40 (10.6) in C.h., and a total of 273 larvae was recovered. The all larvae (18) from R.n. and the vast majority of the larvae (216/255: 82.4%) from C.h. were recovered from the musculature, and many encapsulated larvae were found in these portions of C.h. Taxonomically, all the larvae were identified as the advance third-stage larvae (AdL3) of G.n. The body length was 1,056-2,110 microns, and was larger than those of the naturally-infected AdL3 reported from cold-blooded animals. No morphological alterations or death of the larva was observed. From these results, it would seem that R.n. and C.h. are highly susceptible to G.n. larvae, and has very suitable characteristics as the hosts. Furthermore, a hypothesis is advanced that these mammals serves as the plausible paratenic hosts in the life cycle of G.n. This report is the first record of R.n. (Rodentia) and C.h. (Insectivora) naturally-infected with AdL3 of G.n.

  16. Dung beetles (Coleoptera: Scarabaeidae) attracted to dung of the largest herbivorous rodent on earth: a comparison with human feces.

    PubMed

    Puker, Anderson; Correa, César M A; Korasaki, Vanesca; Ferreira, Kleyton R; Oliveira, Naiara G

    2013-12-01

    The capybara, Hydrochoerus hydrochaeris (L.) (Rodentia: Caviidae), is the largest herbivorous rodent on Earth and abundant in the Neotropical region, which can provide a stable food source of dung for dung beetle communities (Coleoptera: Scarabaeidae: Scarabaeinae). However, the use of capybara dung by dung beetles is poorly known. Here, we present data on the structure of the dung beetle community attracted to capybara dung and compare with the community attracted to human feces. Dung beetles were captured with pitfall traps baited with fresh capybara dung and human feces in pastures with exotic grass (Brachiaria spp.), patches of Brazilian savanna (Cerrado), and points of degraded riparian vegetation along the Aquidauana river in Anastácio and Aquidauana, Mato Grosso do Sul, Brazil. In traps baited with human feces, 13,809 individuals of 31 species were captured, and in those baited with capybara dung 1,027 individuals belonging to 26 species were captured. The average number of individuals and species captured by the traps baited with human feces was greater than for capybara dung in all habitats studied. Composition of the communities attracted to human feces and capybara dung formed distinct groups in all habitats. Despite the smaller number of species and individuals captured in capybara dung when compared with human feces, capybara dung was attractive to dung beetles. In Brazil, the legalization of hunting these rodents has been debated, which would potentially affect the community and consequently the ecological functions performed by dung beetles that use the feces of these animals as a resource. In addition, the knowledge of the communities associated with capybaras may be important in predicting the consequences of future management of their populations. PMID:24468553

  17. Threat diversity will erode mammalian phylogenetic diversity in the near future.

    PubMed

    Jono, Clémentine M A; Pavoine, Sandrine

    2012-01-01

    To reduce the accelerating rate of phylogenetic diversity loss, many studies have searched for mechanisms that could explain why certain species are at risk, whereas others are not. In particular, it has been demonstrated that species might be affected by both extrinsic threat factors as well as intrinsic biological traits that could render a species more sensitive to extinction; here, we focus on extrinsic factors. Recently, the International Union for Conservation of Nature developed a new classification of threat types, including climate change, urbanization, pollution, agriculture and aquaculture, and harvesting/hunting. We have used this new classification to analyze two main factors that could explain the expected future loss of mammalian phylogenetic diversity: 1. differences in the type of threats that affect mammals and 2. differences in the number of major threats that accumulate for a single species. Our results showed that Cetartiodactyla, Diprotodontia, Monotremata, Perissodactyla, Primates, and Proboscidea could lose a high proportion of their current phylogenetic diversity in the coming decades. In contrast, Chiroptera, Didelphimorphia, and Rodentia could lose less phylogenetic diversity than expected if extinctions were random. Some mammalian clades, including Marsupiala, Chiroptera, and a subclade of Primates, are affected by particular threat types, most likely due solely to their geographic locations and associations with particular habitats. However, regardless of the geography, habitat, and taxon considered, it is not the threat type, but the threat diversity that determines the extinction risk for species and clades. Thus, some mammals might be randomly located in areas subjected to a large diversity of threats; they might also accumulate detrimental traits that render them sensitive to different threats, which is a characteristic that could be associated with large body size. Any action reducing threat diversity is expected to have a

  18. Next-Generation Sequencing for Rodent Barcoding: Species Identification from Fresh, Degraded and Environmental Samples

    PubMed Central

    Galan, Maxime; Pagès, Marie; Cosson, Jean-François

    2012-01-01

    Rodentia is the most diverse order among mammals, with more than 2,000 species currently described. Most of the time, species assignation is so difficult based on morphological data solely that identifying rodents at the specific level corresponds to a real challenge. In this study, we compared the applicability of 100 bp mini-barcodes from cytochrome b and cytochrome c oxidase 1 genes to enable rodent species identification. Based on GenBank sequence datasets of 115 rodent species, a 136 bp fragment of cytochrome b was selected as the most discriminatory mini-barcode, and rodent universal primers surrounding this fragment were designed. The efficacy of this new molecular tool was assessed on 946 samples including rodent tissues, feces, museum samples and feces/pellets from predators known to ingest rodents. Utilizing next-generation sequencing technologies able to sequence mixes of DNA, 1,140 amplicons were tagged, multiplexed and sequenced together in one single 454 GS-FLX run. Our method was initially validated on a reference sample set including 265 clearly identified rodent tissues, corresponding to 103 different species. Following validation, 85.6% of 555 rodent samples from Europe, Asia and Africa whose species identity was unknown were able to be identified using the BLASTN program and GenBank reference sequences. In addition, our method proved effective even on degraded rodent DNA samples: 91.8% and 75.9% of samples from feces and museum specimens respectively were correctly identified. Finally, we succeeded in determining the diet of 66.7% of the investigated carnivores from their feces and 81.8% of owls from their pellets. Non-rodent species were also identified, suggesting that our method is sensitive enough to investigate complete predator diets. This study demonstrates how this molecular identification method combined with high-throughput sequencing can open new realms of possibilities in achieving fast, accurate and inexpensive species identification

  19. Nuclear organization and morphology of cholinergic, putative catecholaminergic and serotonergic neurons in the brain of the Cape porcupine (Hystrix africaeaustralis): increased brain size does not lead to increased organizational complexity.

    PubMed

    Limacher, Aude'marie; Bhagwandin, Adhil; Fuxe, Kjell; Manger, Paul R

    2008-09-01

    The distribution, morphology and nuclear organization of the cholinergic, putative catecholaminergic and serotonergic systems within the brain of the Cape porcupine (Hystrix africaeaustralis) were identified following immunohistochemistry for choline acetyltransferase, tyrosine hydroxylase and serotonin. The aim of the present study was to investigate possible differences in the complement of nuclear subdivisions of these systems in the Cape porcupine in comparison with previous studies of these systems in other rodents. The Cape porcupine is the largest rodent in which these systems have been examined and has an adult body mass of 10-24kg and an average brain mass of approximately 37g, around 15 times larger than the laboratory rat. The Cape porcupines were taken from the wild and while these differences, especially that of mass, may lead to the prediction of a significant difference in the nuclear organization or number within these systems, all the nuclei observed in all three systems in the laboratory rat and in other rodents had direct homologues in the brain of the Cape porcupine. Moreover, there were no additional nuclei in the brain of the Cape porcupine that are not found in the laboratory rat or other rodents studied and vice versa. It is noted that the medial septal nucleus of the Cape porcupine appeared qualitatively to have a reduced number of neurons in comparison to the laboratory rat and other rodents. The locus coeruleus of the laboratory rat differs in location to that observed for the Cape porcupine and several other rodent species. The Cape porcupine is distantly related to the laboratory rat, but still a member of the order Rodentia; thus, changes in the organization of these systems appears to demonstrate a form of constraint related to the phylogenetic level of the order. PMID:18472246

  20. Threat Diversity Will Erode Mammalian Phylogenetic Diversity in the Near Future

    PubMed Central

    Jono, Clémentine M. A.; Pavoine, Sandrine

    2012-01-01

    To reduce the accelerating rate of phylogenetic diversity loss, many studies have searched for mechanisms that could explain why certain species are at risk, whereas others are not. In particular, it has been demonstrated that species might be affected by both extrinsic threat factors as well as intrinsic biological traits that could render a species more sensitive to extinction; here, we focus on extrinsic factors. Recently, the International Union for Conservation of Nature developed a new classification of threat types, including climate change, urbanization, pollution, agriculture and aquaculture, and harvesting/hunting. We have used this new classification to analyze two main factors that could explain the expected future loss of mammalian phylogenetic diversity: 1. differences in the type of threats that affect mammals and 2. differences in the number of major threats that accumulate for a single species. Our results showed that Cetartiodactyla, Diprotodontia, Monotremata, Perissodactyla, Primates, and Proboscidea could lose a high proportion of their current phylogenetic diversity in the coming decades. In contrast, Chiroptera, Didelphimorphia, and Rodentia could lose less phylogenetic diversity than expected if extinctions were random. Some mammalian clades, including Marsupiala, Chiroptera, and a subclade of Primates, are affected by particular threat types, most likely due solely to their geographic locations and associations with particular habitats. However, regardless of the geography, habitat, and taxon considered, it is not the threat type, but the threat diversity that determines the extinction risk for species and clades. Thus, some mammals might be randomly located in areas subjected to a large diversity of threats; they might also accumulate detrimental traits that render them sensitive to different threats, which is a characteristic that could be associated with large body size. Any action reducing threat diversity is expected to have a

  1. Cholinergic urethral brush cells are widespread throughout placental mammals.

    PubMed

    Deckmann, Klaus; Krasteva-Christ, Gabriela; Rafiq, Amir; Herden, Christine; Wichmann, Judy; Knauf, Sascha; Nassenstein, Christina; Grevelding, Christoph G; Dorresteijn, Adriaan; Chubanov, Vladimir; Gudermann, Thomas; Bschleipfer, Thomas; Kummer, Wolfgang

    2015-11-01

    We previously identified a population of cholinergic epithelial cells in murine, human and rat urethrae that exhibits a structural marker of brush cells (villin) and expresses components of the canonical taste transduction signaling cascade (α-gustducin, phospholipase Cβ2 (PLCβ2), transient receptor potential cation channel melanostatin 5 (TRPM5)). These cells serve as sentinels, monitoring the chemical composition of the luminal content for potentially hazardous compounds such as bacteria, and initiate protective reflexes counteracting further ingression. In order to elucidate cross-species conservation of the urethral chemosensory pathway we investigated the occurrence and molecular make-up of urethral brush cells in placental mammals. We screened 11 additional species, at least one in each of the five mammalian taxonomic units primates, carnivora, perissodactyla, artiodactyla and rodentia, for immunohistochemical labeling of the acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT), villin, and taste cascade components (α-gustducin, PLCβ2, TRPM5). Corresponding to findings in previously investigated species, urethral epithelial cells with brush cell shape were immunolabeled in all 11 mammals. In 8 species, immunoreactivities against all marker proteins and ChAT were observed, and double-labeling immunofluorescence confirmed the cholinergic nature of villin-positive and chemosensory (TRPM5-positive) cells. In cat and horse, these cells were not labeled by the ChAT antiserum used in this study, and unspecific reactions of the secondary antiserum precluded conclusions about ChAT-expression in the bovine epithelium. These data indicate that urethral brush cells are widespread throughout the mammalian kingdom and evolved not later than about 64.5millionyears ago. PMID:26044348

  2. Faster speciation and reduced extinction in the tropics contribute to the Mammalian latitudinal diversity gradient.

    PubMed

    Rolland, Jonathan; Condamine, Fabien L; Jiguet, Frederic; Morlon, Hélène

    2014-01-01

    The increase in species richness from the poles to the tropics, referred to as the latitudinal diversity gradient, is one of the most ubiquitous biodiversity patterns in the natural world. Although understanding how rates of speciation and extinction vary with latitude is central to explaining this pattern, such analyses have been impeded by the difficulty of estimating diversification rates associated with specific geographic locations. Here, we use a powerful phylogenetic approach and a nearly complete phylogeny of mammals to estimate speciation, extinction, and dispersal rates associated with the tropical and temperate biomes. Overall, speciation rates are higher, and extinction rates lower, in the tropics than in temperate regions. The diversity of the eight most species-rich mammalian orders (covering 92% of all mammals) peaks in the tropics, except that of the Lagomorpha (hares, rabbits, and pikas) reaching a maxima in northern-temperate regions. Latitudinal patterns in diversification rates are strikingly consistent with these diversity patterns, with peaks in species richness associated with low extinction rates (Primates and Lagomorpha), high speciation rates (Diprotodontia, Artiodactyla, and Soricomorpha), or both (Chiroptera and Rodentia). Rates of range expansion were typically higher from the tropics to the temperate regions than in the other direction, supporting the "out of the tropics" hypothesis whereby species originate in the tropics and disperse into higher latitudes. Overall, these results suggest that differences in diversification rates have played a major role in shaping the modern latitudinal diversity gradient in mammals, and illustrate the usefulness of recently developed phylogenetic approaches for understanding this famous yet mysterious pattern.

  3. Ecological Niche Modeling of main reservoir hosts of zoonotic cutaneous leishmaniasis in Iran.

    PubMed

    Gholamrezaei, Mostafa; Mohebali, Mehdi; Hanafi-Bojd, Ahmad Ali; Sedaghat, Mohammad Mehdi; Shirzadi, Mohammad Reza

    2016-08-01

    Zoonotic cutaneous leishmaniasis (ZCL), caused by Leishmania major, is a common zoonotic vector-borne disease in Iran. Close contact with infected reservoir hosts increases the probability of transmission of Leishmania parasite infections to susceptible humans. Four gerbil species (Rodentia: Gerbillidae) serve as the main reservoir hosts for ZCL in different endemic foci of Iran. These species include Rhombomys opimus, Meriones libycus, Meriones hurrianae and Tatera indica; while notable infection has been reported in Nesokia indica as well. The purpose of this study is to model the distribution of these reservoirs to identify the risk areas of ZCL. A data bank was developed including all published data during the period of 1970-2015. Maximum entropy model was used to find the most appropriate ecological niches for each species. The areas under curve obtained were 0.961, 0.927, 0.922, 0.997 and 0.899, instead of 1, for training test in R. opimus, M. libycus, T. indica, M. hurrianae and N. indica, respectively. The environmental variable with the highest gain when used in isolation was slope for R. opimus and N. indica, annual mean temperature for M. libycus, and seasonal precipitation for T. indica and M. hurrianae. Summation of presence probabilities for three main species, i.e., R. opimus, M. libycus and T. indica revealed favorable ecological niches in wide areas of 16 provinces. This is the first study to predict the distribution of ZCL reservoir hosts in Iran. Climatology and topography variables had high contributions toward the prediction of potential distribution of the main reservoir species; therefore, as climate changes, the models should be updated periodically with novel data, and the results should be used in disease-monitoring programs.

  4. TRANEXAMIC ACID ACTION ON LIVER REGENERATION AFTER PARTIAL HEPATECTOMY: EXPERIMENTAL MODEL IN RATS

    PubMed Central

    SOBRAL, Felipe Antonio; DAGA, Henrique; RASERA, Henrique Nogueira; PINHEIRO, Matheus da Rocha; CELLA, Igor Furlan; MORAIS, Igor Henrique; MARQUES, Luciana de Oliveira; COLLAÇO, Luiz Martins

    2016-01-01

    ABSTRACT Background: Different lesions may affect the liver resulting in harmful stimuli. Some therapeutic procedures to treat those injuries depend on liver regeneration to increase functional capacity of this organ. Aim: Evaluate the effects of tranexamic acid on liver regeneration after partial hepatectomy in rats. Method: 40 rats (Rattus norvegicus albinus, Rodentia mammalia) of Wistar-UP lineage were randomly divided into two groups named control (CT) and tranexamic acid (ATX), with 20 rats in each. Both groups were subdivided, according to liver regeneration time of 32 h or seven days after the rats had been operated. The organ regeneration was evaluated through weight and histology, stained with HE and PCNA. Results: The average animal weight of ATX and CT 7 days groups before surgery were 411.2 g and 432.7 g, and 371.3 g and 392.9 g after the regeneration time, respectively. The average number of mitotic cells stained with HE for the ATX and CT 7 days groups were 33.7 and 32.6 mitosis, and 14.5 and 14.9 for the ATX and CT 32 h groups, respectively. When stained with proliferating cell nuclear antigen, the numbers of mitotic cells counted were 849.7 for the ATX 7 days, 301.8 for the CT 7 days groups, 814.2 for the ATX 32 hand 848.1 for the CT 32 h groups. Conclusion: Tranexamic acid was effective in liver regeneration, but in longer period after partial hepatectomy. PMID:27438036

  5. Collagen Fingerprinting: A New Screening Technique for Radiocarbon Dating Ancient Bone.

    PubMed

    Harvey, Virginia L; Egerton, Victoria M; Chamberlain, Andrew T; Manning, Phillip L; Buckley, Michael

    2016-01-01

    Collagen is the dominant organic component of bone and is intimately locked within the hydroxyapatite structure of this ubiquitous biomaterial that dominates archaeological and palaeontological assemblages. Radiocarbon analysis of extracted collagen is one of the most common approaches to dating bone from late Pleistocene or Holocene deposits, but dating is relatively expensive compared to other biochemical techniques. Numerous analytical methods have previously been investigated for the purpose of screening out samples that are unlikely to yield reliable dates including histological analysis, UV-stimulated fluorescence and, most commonly, the measurement of percentage nitrogen (%N) and ratio of carbon to nitrogen (C:N). Here we propose the use of collagen fingerprinting (also known as Zooarchaeology by Mass Spectrometry, or ZooMS, when applied to species identification) as an alternative screening method for radiocarbon dating, due to its ability to provide information on collagen presence and quality, alongside species identification. The method was tested on a series of sub-fossil bone specimens from cave systems on Cayman Brac (Cayman Islands), chosen due to the observable range in diagenetic alteration, and in particular, the extent of mineralisation. Six (14)C dates, of 18 initial attempts, were obtained from remains of extinct hutia, Capromys sp. (Rodentia; Capromyidae), recovered from five distinct caves on Cayman Brac, and ranging from 393 ± 25 to 1588 ± 26 radiocarbon years before present (yr BP). All of the bone samples that yielded radiocarbon dates generated excellent collagen fingerprints, and conversely those that gave poor fingerprints also failed dating. Additionally, two successfully fingerprinted bone samples were screened out from a set of 81. Both subsequently generated (14)C dates, demonstrating successful utilisation of ZooMS as an alternative screening mechanism to identify bone samples that are suitable for 1(4)C analysis. PMID:26938469

  6. Complete mitochondrial genome of the Eurasian flying squirrel Pteromys volans (Sciuromorpha, Sciuridae) and revision of rodent phylogeny.

    PubMed

    Ryu, Shi Hyun; Kwak, Min Jung; Hwang, Ui Wook

    2013-02-01

    In this study, the complete mitochondrial genome of the Eurasian flying squirrel Pteromys volans (Rodentia, Sciuromorpha, Sciuridae) was sequenced and characterized in detail. The entire mitochondrial genome of P. volans consisted of 16,513 bp and contained 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and two non-coding regions. Its gene arrangement pattern was consistent with the mammalian ground pattern. The overall base composition and AT contents were similar to those of other rodent mitochondrial genomes. The light-strand origin generally identified between tRNA ( Asn ) and tRNA ( Cys ) consisted of a secondary structure with an 11-bp stem and an 11-bp loop. The large control region was constructed of three characteristic domains, ETAS, CD, and CSB without any repeat sequences. Each domain contained ETAS1, subsequences A, B, and C, and CSB1, respectively. In order to examine phylogenetic contentious issues of the monophyly of rodents and phylogenetic relationships among five rodent suborders, here, phylogenetic analyses based on nucleotide sequence data of the 35 rodent and 3 lagomorph mitochondrial genomes were performed using the Bayesian inference and maximum likelihood method. The result strongly supported the rodent monophyly with high node confidence values (BP 100 % in ML and BPP 1.00 in BI) and also monophylies of four rodent suborders (BP 85-100 % in ML and BPP 1.00 in BI), except for Anomalumorpha in which only one species was examined here. Also, phylogenetic relationships among the five rodent suborders were suggested and discussed in detail.

  7. Cholinergic urethral brush cells are widespread throughout placental mammals.

    PubMed

    Deckmann, Klaus; Krasteva-Christ, Gabriela; Rafiq, Amir; Herden, Christine; Wichmann, Judy; Knauf, Sascha; Nassenstein, Christina; Grevelding, Christoph G; Dorresteijn, Adriaan; Chubanov, Vladimir; Gudermann, Thomas; Bschleipfer, Thomas; Kummer, Wolfgang

    2015-11-01

    We previously identified a population of cholinergic epithelial cells in murine, human and rat urethrae that exhibits a structural marker of brush cells (villin) and expresses components of the canonical taste transduction signaling cascade (α-gustducin, phospholipase Cβ2 (PLCβ2), transient receptor potential cation channel melanostatin 5 (TRPM5)). These cells serve as sentinels, monitoring the chemical composition of the luminal content for potentially hazardous compounds such as bacteria, and initiate protective reflexes counteracting further ingression. In order to elucidate cross-species conservation of the urethral chemosensory pathway we investigated the occurrence and molecular make-up of urethral brush cells in placental mammals. We screened 11 additional species, at least one in each of the five mammalian taxonomic units primates, carnivora, perissodactyla, artiodactyla and rodentia, for immunohistochemical labeling of the acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT), villin, and taste cascade components (α-gustducin, PLCβ2, TRPM5). Corresponding to findings in previously investigated species, urethral epithelial cells with brush cell shape were immunolabeled in all 11 mammals. In 8 species, immunoreactivities against all marker proteins and ChAT were observed, and double-labeling immunofluorescence confirmed the cholinergic nature of villin-positive and chemosensory (TRPM5-positive) cells. In cat and horse, these cells were not labeled by the ChAT antiserum used in this study, and unspecific reactions of the secondary antiserum precluded conclusions about ChAT-expression in the bovine epithelium. These data indicate that urethral brush cells are widespread throughout the mammalian kingdom and evolved not later than about 64.5millionyears ago.

  8. A First Generation Comparative Chromosome Map between Guinea Pig (Cavia porcellus) and Humans.

    PubMed

    Romanenko, Svetlana A; Perelman, Polina L; Trifonov, Vladimir A; Serdyukova, Natalia A; Li, Tangliang; Fu, Beiyuan; O'Brien, Patricia C M; Ng, Bee L; Nie, Wenhui; Liehr, Thomas; Stanyon, Roscoe; Graphodatsky, Alexander S; Yang, Fengtang

    2015-01-01

    The domesticated guinea pig, Cavia porcellus (Hystricomorpha, Rodentia), is an important laboratory species and a model for a number of human diseases. Nevertheless, genomic tools for this species are lacking; even its karyotype is poorly characterized. The guinea pig belongs to Hystricomorpha, a widespread and important group of rodents; so far the chromosomes of guinea pigs have not been compared with that of other hystricomorph species or with any other mammals. We generated full sets of chromosome-specific painting probes for the guinea pig by flow sorting and microdissection, and for the first time, mapped the chromosomal homologies between guinea pig and human by reciprocal chromosome painting. Our data demonstrate that the guinea pig karyotype has undergone extensive rearrangements: 78 synteny-conserved human autosomal segments were delimited in the guinea pig genome. The high rate of genome evolution in the guinea pig may explain why the HSA7/16 and HSA16/19 associations presumed ancestral for eutherians and the three syntenic associations (HSA1/10, 3/19, and 9/11) considered ancestral for rodents were not found in C. porcellus. The comparative chromosome map presented here is a starting point for further development of physical and genetic maps of the guinea pig as well as an aid for genome assembly assignment to specific chromosomes. Furthermore, the comparative mapping will allow a transfer of gene map data from other species. The probes developed here provide a genomic toolkit, which will make the guinea pig a key species to unravel the evolutionary biology of the Hystricomorph rodents.

  9. Highly Diverse Morbillivirus-Related Paramyxoviruses in Wild Fauna of the Southwestern Indian Ocean Islands: Evidence of Exchange between Introduced and Endemic Small Mammals

    PubMed Central

    Mélade, Julien; Dietrich, Muriel; Ramasindrazana, Beza; Soarimalala, Voahangy; Lagadec, Erwan; le Minter, Gildas; Tortosa, Pablo; Heraud, Jean-Michel; de Lamballerie, Xavier; Goodman, Steven M.; Dellagi, Koussay

    2014-01-01

    ABSTRACT The Paramyxoviridae form an increasingly diverse viral family, infecting a wide variety of different hosts. In recent years, they have been linked to disease emergence in many different animal populations and in humans. Bats and rodents have been identified as major animal populations capable of harboring paramyxoviruses, and host shifting between these animals is likely to be an important driving factor in the underlying evolutionary processes that eventually lead to disease emergence. Here, we have studied paramyxovirus circulation within populations of endemic and introduced wild small mammals of the southwestern Indian Ocean region and belonging to four taxonomic orders: Rodentia, Afrosoricida, Soricomorpha, and Chiroptera. We report elevated infection levels as well as widespread paramyxovirus dispersal and frequent host exchange of a newly emerging genus of the Paramyxoviridae, currently referred to as the unclassified morbillivirus-related viruses (UMRVs). In contrast to other genera of the Paramyxoviridae, where bats have been shown to be a key host species, we show that rodents (and, in particular, Rattus rattus) are significant spreaders of UMRVs. We predict that the ecological particularities of the southwestern Indian Ocean, where small mammal species often live in densely packed, multispecies communities, in combination with the increasing invasion of R. rattus and perturbations of endemic animal communities by active anthropological development, will have a major influence on the dynamics of UMRV infection. IMPORTANCE Identification of the infectious agents that circulate within wild animal reservoirs is essential for several reasons: (i) infectious disease outbreaks often originate from wild fauna; (ii) anthropological expansion increases the risk of contact between human and animal populations and, as a result, the risk of disease emergence; (iii) evaluation of pathogen reservoirs helps in elaborating preventive measures to limit the risk

  10. Hantaan virus surveillance targeting small mammals at nightmare range, a high elevation military training area, Gyeonggi Province, Republic of Korea.

    PubMed

    Klein, Terry A; Kim, Heung-Chul; Chong, Sung-Tae; Kim, Jeong-Ah; Lee, Sook-Young; Kim, Won-Keun; Nunn, Peter V; Song, Jin-Won

    2015-01-01

    Rodent-borne disease surveillance was conducted at Nightmare Range (NM-R), near the demilitarized zone in northeast Gyeonggi Province, Republic of Korea, to identify hemorrhagic fever with renal syndrome (HFRS) risks for a mountainous high-elevation (500 m) military training site. Monthly surveys were conducted from January 2008-December 2009. A total of 1,720 small mammals were captured belonging to the Orders Rodentia [Families, Sciuridae (1 species) and Muridae (7 species)] and Soricomorpha [Family, Soricidae (1species)]. Apodemus agrarius, the primary reservoir for Hantaan virus (HTNV), accounted for 89.9% (1,546) of all small mammals captured, followed by Myodes regulus (4.0%), Crocidura lasiura (3.9%), Micromys minutus (1.4%), Mus musculus (0.3%), Microtus fortis (0.2%), Apodemus peninsulae (0.2%), Tamias sibiricus (0.1%), and Rattus norvegicus (<0.1%). Three species were antibody-positive (Ab+) for hantaviruses: A. agrarius (8.2%), M. minutus (4.2%), and C. lasiura (1.5%). HTNV specific RNA was detected in 93/127 Ab+ A. agrarius, while Imjin virus specific RNA was detected in 1/1 Ab+ C. lasiura. Overall, hantavirus Ab+ rates for A. agrarius increased with weight (age) and were significantly higher among males (10.9%) than females (5.1%) (P<0.0001). High A. agrarius gravid rates during the fall (August-September) were associated with peak numbers of HFRS cases in Korea that followed high gravid rates. From 79 RT-PCR positive A. agrarius, 12 HTNV RNA samples were sequenced and compared phylogenetically based on a 320 nt sequence from the GC glycoprotein-encoding M segment. These results demonstrate that the HTNV isolates from NM-R are distinctly separated from HTNV isolated from the People's Republic of China. These studies provide for improved disease risk assessments that identify military activities, rodent HTNV rates, and other factors associated with the transmission of hantaviruses during field training exercises.

  11. The Late Pleistocene Duoi U'Oi cave in northern Vietnam: palaeontology, sedimentology, taphonomy and palaeoenvironments

    NASA Astrophysics Data System (ADS)

    Bacon, Anne-Marie; Demeter, F.; Duringer, P.; Helm, C.; Bano, M.; Vu, The Long; Kim Thuy, Nguyen Thi; Antoine, P.-O.; Thi Mai, Bui; Huong, Nguyen Thi Mai; Dodo, Y.; Chabaux, F.; Rihs, S.

    2008-08-01

    This paper describes new fossil materials recovered at the Duoi U'Oi site, in December 2003, by a Vietnamese-French-Japanese team. The Duoi U'Oi cave is located in Man Duc village, 25 km of Hoà Binh city in northern Vietnam. It belongs to a karstic network developed in a dark grey micritic marine limestone dated from the Lower to the Middle Triassic. The sedimentary fill produced a rich mammalian fauna, essentially composed of isolated teeth of middle- to large-sized mammals (Artiodactyla, Perissodactyla, Proboscidea, Carnivora, Rodentia, Primates), and characteristic of Late Pleistocene. The results of the Duoi U'Oi fieldwork are of great interest for the following reasons: (1) the biochronological age of the fauna is consistent with 230Th/ 234U/ 238U dating from the calcitic floors (66±3 ka). The Duoi U'Oi fauna is thus the oldest well-dated modern fauna known for the Southeast Asian mainland; (2) in terms of sedimentology, the analysis of the formation of the fossiliferous breccia and that of the processes of deposits shows a close relation between the karstic deposits inside the cave and the deposits in the alluvial terraces. The observation of three levels of alluvial terraces associated with three caves situated at 62, 10 and 3 m above the present alluvial plain suggests that exokarstic and endokarstic sediments evolved together; (3) in terms of palaeobiogeography, Duoi U'Oi is the continental fauna showing the strongest resemblance with the Late Pleistocene faunas from Indonesian islands (Punung, Gunung Dawung, Lida Ajer, Sibrambang and Djambu caves); this implies that, at the time of Duoi U'Oi, ca 70 ka, the Sundaland was mainly characterised by faunas of modern aspect; (4) the analysis of major taphonomic factors that led to the mammal assemblage reveals a combination of selective agents (selective role of predators and porcupines, selective destruction of age classes for some species, selective preservation of fossils due to the deposition processes in

  12. The evolutionary radiation of Arvicolinae rodents (voles and lemmings): relative contribution of nuclear and mitochondrial DNA phylogenies

    PubMed Central

    Galewski, Thomas; Tilak, Marie-ka; Sanchez, Sophie; Chevret, Pascale; Paradis, Emmanuel; Douzery, Emmanuel JP

    2006-01-01

    Background Mitochondrial and nuclear genes have generally been employed for different purposes in molecular systematics, the former to resolve relationships within recently evolved groups and the latter to investigate phylogenies at a deeper level. In the case of rapid and recent evolutionary radiations, mitochondrial genes like cytochrome b (CYB) are often inefficient for resolving phylogenetic relationships. One of the best examples is illustrated by Arvicolinae rodents (Rodentia; Muridae), the most impressive mammalian radiation of the Northern Hemisphere which produced voles, lemmings and muskrats. Here, we compare the relative contribution of a nuclear marker – the exon 10 of the growth hormone receptor (GHR) gene – to the one of the mitochondrial CYB for inferring phylogenetic relationships among the major lineages of arvicoline rodents. Results The analysis of GHR sequences improves the overall resolution of the Arvicolinae phylogeny. Our results show that the Caucasian long-clawed vole (Prometheomys schaposnikowi) is one of the basalmost arvicolines, and confirm that true lemmings (Lemmus) and collared lemmings (Dicrostonyx) are not closely related as suggested by morphology. Red-backed voles (Myodini) are found as the sister-group of a clade encompassing water vole (Arvicola), snow vole (Chionomys), and meadow voles (Microtus and allies). Within the latter, no support is recovered for the generic recognition of Blanfordimys, Lasiopodomys, Neodon, and Phaiomys as suggested by morphology. Comparisons of parameter estimates for branch lengths, base composition, among sites rate heterogeneity, and GTR relative substitution rates indicate that CYB sequences consistently exhibit more heterogeneity among codon positions than GHR. By analyzing the contribution of each codon position to node resolution, we show that the apparent higher efficiency of GHR is due to their third positions. Although we focus on speciation events spanning the last 10 million years

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

    PubMed

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

    1994-08-01

    to vary markedly between the different members, in other orders (e.g. Primates, Rodentia and Marsupialia) it fluctuated widely between the different species. Phylogenetic analysis indicates that the subcellular distribution of AGT1 has changed radically on numerous occasions during the evolution of mammals. The new observations presented in this paper are compatible with our previous demonstration of a relationship between AGT1 subcellular distribution and either present or putative ancestral dietary habit, and our previous suggestion that the molecular evolution of the AGT gene has been markedly influenced by dietary selection pressure. PMID:7813517

  14. Rabbits, if anything, are likely Glires.

    PubMed

    Douzery, Emmanuel J P; Huchon, Dorothée

    2004-12-01

    Rodentia (e.g., mice, rats, dormice, squirrels, and guinea pigs) and Lagomorpha (e.g., rabbits, hares, and pikas) are usually grouped into the Glires. Status of this controversial superorder has been evaluated using morphology, paleontology, and mitochondrial plus nuclear DNA sequences. This growing corpus of data has been favoring the monophyly of Glires. Recently, Misawa and Janke [Mol. Phylogenet. Evol. 28 (2003) 320] analyzed the 6441 amino acids of 20 nuclear proteins for six placental mammals (rat, mouse, rabbit, human, cattle, and dog) and two outgroups (chicken and xenopus), and observed a basal position of the two murine rodents among the former. They concluded that "the Glires hypothesis was rejected." We here reanalyzed [loc. cit.] data set under maximum likelihood and Bayesian tree-building approaches, using phylogenetic models that take into account among-site variation in evolutionary rates and branch-length variation among proteins. Our observations support both the association of rodents and lagomorphs and the monophyly of Euarchontoglires (=Supraprimates) as the most likely explanation of the protein alignments. We conducted simulation studies to evaluate the appropriateness of lissamphibian and avian outgroups to root the placental tree. When the outgroup-to-ingroup evolutionary distance increases, maximum parsimony roots the topology along the long Mus-Rattus branch. Maximum likelihood, in contrast, roots the topology along different branches as a function of their length. Maximum likelihood appears less sensitive to the "long-branch attraction artifact" than is parsimony. Our phylogenetic conclusions were confirmed by the analysis of a different protein data set using a similar sample of species but different outgroups. We also tested the effect of the addition of afrotherian and xenarthran taxa. Using the linearized tree method, [loc. cit.] estimated that mice and rats diverged about 35 million years ago. Molecular dating based on the Bayesian

  15. Evidence for the use of reflected self-generated seismic waves for spatial orientation in a blind subterranean mammal.

    PubMed

    Kimchi, Tali; Reshef, Moshe; Terkel, Joseph

    2005-02-01

    Subterranean mammals like the blind mole-rat (Rodentia: Spalax ehrenbergi) are functionally blind and possess poor auditory sensitivity, limited to low-frequency sounds. Nevertheless, the mole-rat demonstrates extremely efficient ability to orient spatially. A previous field study has revealed that the mole-rat can assess the location, size and density of an underground obstacle, and accordingly excavates the most efficient bypass tunnel to detour around the obstacles. In the present study we used a multidisciplinary approach to examine the possibility that the mole-rat estimates the location and physical properties of underground obstacles using reflected self-generated seismic waves (seismic 'echolocation'). Our field observations revealed that all the monitored mole-rats produced low-frequency seismic waves (250-300 Hz) at intervals of 8+/-5 s (range: 1-13 s) between head drums while digging a bypass to detour an obstacle. Using a computerized simulation model we demonstrated that it is possible for the mole-rat to determine its distance from an obstacle boundary (open ditch or stone) by evaluating the amplitude (intensity) of the seismic wave reflected back to it from the obstacle interface. By evaluating the polarity of the reflected wave the mole-rat could distinguish between air space and solid obstacles. Further, the model showed that the diffracted waves from the obstacle's corners could give the mole-rat precise information on the obstacle size and its relative spatial position. In a behavioural experiment using a special T-maze setup, we tested whether the mole-rat can perceive seismic waves through the somatosensory system and localize the source. The results revealed that the mole-rat is able to detect low frequency seismic waves using only its paws, and in most cases the mole-rats determined accurately the direction of the vibratory source. In a histological examination of the glabrous skin of the mole-rat's paws we identified lamellate corpuscle

  16. Hantaan Virus Surveillance Targeting Small Mammals at Nightmare Range, a High Elevation Military Training Area, Gyeonggi Province, Republic of Korea

    PubMed Central

    Klein, Terry A.; Kim, Heung-Chul; Chong, Sung-Tae; Kim, Jeong-Ah; Lee, Sook-Young; Kim, Won-Keun; Nunn, Peter V.; Song, Jin-Won

    2015-01-01

    Rodent-borne disease surveillance was conducted at Nightmare Range (NM-R), near the demilitarized zone in northeast Gyeonggi Province, Republic of Korea, to identify hemorrhagic fever with renal syndrome (HFRS) risks for a mountainous high-elevation (500 m) military training site. Monthly surveys were conducted from January 2008-December 2009. A total of 1,720 small mammals were captured belonging to the Orders Rodentia [Families, Sciuridae (1 species) and Muridae (7 species)] and Soricomorpha [Family, Soricidae (1species)]. Apodemus agrarius, the primary reservoir for Hantaan virus (HTNV), accounted for 89.9% (1,546) of all small mammals captured, followed by Myodes regulus (4.0%), Crocidura lasiura (3.9%), Micromys minutus (1.4%), Mus musculus (0.3%), Microtus fortis (0.2%), Apodemus peninsulae (0.2%), Tamias sibiricus (0.1%), and Rattus norvegicus (<0.1%). Three species were antibody-positive (Ab+) for hantaviruses: A. agrarius (8.2%), M. minutus (4.2%), and C. lasiura (1.5%). HTNV specific RNA was detected in 93/127 Ab+ A. agrarius, while Imjin virus specific RNA was detected in 1/1 Ab+ C. lasiura. Overall, hantavirus Ab+ rates for A. agrarius increased with weight (age) and were significantly higher among males (10.9%) than females (5.1%) (P<0.0001). High A. agrarius gravid rates during the fall (August-September) were associated with peak numbers of HFRS cases in Korea that followed high gravid rates. From 79 RT-PCR positive A. agrarius, 12 HTNV RNA samples were sequenced and compared phylogenetically based on a 320 nt sequence from the GC glycoprotein-encoding M segment. These results demonstrate that the HTNV isolates from NM-R are distinctly separated from HTNV isolated from the People’s Republic of China. These studies provide for improved disease risk assessments that identify military activities, rodent HTNV rates, and other factors associated with the transmission of hantaviruses during field training exercises. PMID:25874643

  17. Landscape ecology of Trypanosoma cruzi in the southern Yucatan Peninsula.

    PubMed

    López-Cancino, Sury Antonio; Tun-Ku, Ezequiel; De la Cruz-Felix, Himmler Keynes; Ibarra-Cerdeña, Carlos Napoleón; Izeta-Alberdi, Amaia; Pech-May, Angélica; Mazariegos-Hidalgo, Carlos Jesús; Valdez-Tah, Alba; Ramsey, Janine M

    2015-11-01

    Landscape interactions of Trypanosoma cruzi (Tc) with Triatoma dimidiata (Td) depend on the presence and relative abundance of mammal hosts. This study analyzed a landscape adjacent to the Calakmul Biosphere Reserve, composed of conserved areas, crop and farming areas, and the human community of Zoh Laguna with reported Chagas disease cases. Sylvatic mammals of the Chiroptera, Rodentia, and Marsupialia orders were captured, and livestock and pets were sampled along with T. dimidiata in all habitats. Infection by T. cruzi was analyzed using mtDNA markers, while lineage and DTU was analyzed using the mini-exon. 303 sylvatic specimens were collected, corresponding to 19 species during the rainy season and 114 specimens of 18 species during dry season. Five bats Artibeus jamaicensis, Artibeus lituratus, Sturnira lilium, Sturnira ludovici, Dermanura phaeotis (Dp) and one rodent Heteromys gaumeri were collected in the three habitats. All but Dp, and including Carollia brevicauda and Myotis keaysi, were infected with predominately TcI in the sylvatic habitat and TcII in the ecotone. Sigmodon hispidus was the rodent with the highest prevalence of infection by T. cruzi I and II in ecotone and domestic habitats. Didelphis viginiana was infected only with TcI in both domestic and sylvatic habitats; the only two genotyped human cases were TcII. Two main clades of T. cruzi, lineages I (DTU Ia) and II (DTU VI), were found to be sympatric (all habitats and seasons) in the Zoh-Laguna landscape, suggesting that no species-specific interactions occur between the parasite and any mammal host, in any habitat. We have also found mixed infections of the two principal T. cruzi clades in individuals across modified habitats, particularly in livestock and pets, and in both haplogroups of T. dimidiata. Results are contradictory to the dilution hypothesis, although we did find that most resilient species had an important role as T. cruzi hosts. Our study detected some complex trends in

  18. Temperature preferences of African mole-rats (family Bathyergidae).

    PubMed

    Begall, Sabine; Berendes, Meike; Schielke, Charlotte K M; Henning, Yoshiyuki; Laghanke, Marzena; Scharff, Andreas; van Daele, Paul; Burda, Hynek

    2015-10-01

    Many animals are able to detect small temperature differences and show strong temperature preferences during periods of rest and activity. Mammals inhabiting the subterranean ecotope can adapt their digging and foraging activity in shallow tunnels temporarily to periods with favourable ambient air and soil temperatures. Moreover, subterranean mammals have the unique opportunity to select for their nests in soil depths with certain, daily and seasonally constant temperatures. Our knowledge on nest temperatures in several species of subterranean mammals is based on measurements of temperatures in empty nests. We can expect, however, that the temperature in an occupied nest is higher (due to the "igloo effect"). We performed two experiments regarding the temperature preference in five species of African mole-rats (Bathyergidae, Rodentia: Fukomys anselli, F. mechowii, F. micklemi, Heliophobius argenteocinereus, and Heterocephalus glaber). In a first experiment, the animals were tested pairwise (except for the solitary silvery mole-rats, H. argenteocinereus, that were tested singly) in an apparatus consisting of seven chambers with a temperature gradient ranging between 16 and 37°C (air temperature). While the smaller species (<110g; F. anselli, F. micklemi, H. glaber) chose chambers with average air temperatures around 29°C, the larger mole-rats rested preferably at lower temperatures of approximately 25.6°C (F. mechowii) and 27.7°C (H. argenteocinereus). A strong negative correlation between body mass and preferred air temperature was detected across species. Thus, the results comply with the surface-volume-rule. Contrary to expectations, temperature preference of naked mole-rats (H. glaber) did not deviate from those of furred small mole-rats, but followed the general trend with smaller species preferring higher temperatures. In a second experiment, Ansell's mole-rats (F. anselli) were tested in groups of four, six and nine animals and the preferred temperatures

  19. Landscape ecology of Trypanosoma cruzi in the southern Yucatan Peninsula.

    PubMed

    López-Cancino, Sury Antonio; Tun-Ku, Ezequiel; De la Cruz-Felix, Himmler Keynes; Ibarra-Cerdeña, Carlos Napoleón; Izeta-Alberdi, Amaia; Pech-May, Angélica; Mazariegos-Hidalgo, Carlos Jesús; Valdez-Tah, Alba; Ramsey, Janine M

    2015-11-01

    Landscape interactions of Trypanosoma cruzi (Tc) with Triatoma dimidiata (Td) depend on the presence and relative abundance of mammal hosts. This study analyzed a landscape adjacent to the Calakmul Biosphere Reserve, composed of conserved areas, crop and farming areas, and the human community of Zoh Laguna with reported Chagas disease cases. Sylvatic mammals of the Chiroptera, Rodentia, and Marsupialia orders were captured, and livestock and pets were sampled along with T. dimidiata in all habitats. Infection by T. cruzi was analyzed using mtDNA markers, while lineage and DTU was analyzed using the mini-exon. 303 sylvatic specimens were collected, corresponding to 19 species during the rainy season and 114 specimens of 18 species during dry season. Five bats Artibeus jamaicensis, Artibeus lituratus, Sturnira lilium, Sturnira ludovici, Dermanura phaeotis (Dp) and one rodent Heteromys gaumeri were collected in the three habitats. All but Dp, and including Carollia brevicauda and Myotis keaysi, were infected with predominately TcI in the sylvatic habitat and TcII in the ecotone. Sigmodon hispidus was the rodent with the highest prevalence of infection by T. cruzi I and II in ecotone and domestic habitats. Didelphis viginiana was infected only with TcI in both domestic and sylvatic habitats; the only two genotyped human cases were TcII. Two main clades of T. cruzi, lineages I (DTU Ia) and II (DTU VI), were found to be sympatric (all habitats and seasons) in the Zoh-Laguna landscape, suggesting that no species-specific interactions occur between the parasite and any mammal host, in any habitat. We have also found mixed infections of the two principal T. cruzi clades in individuals across modified habitats, particularly in livestock and pets, and in both haplogroups of T. dimidiata. Results are contradictory to the dilution hypothesis, although we did find that most resilient species had an important role as T. cruzi hosts. Our study detected some complex trends in

  20. Comparative sacral morphology and the reconstructed tail lengths of five extinct primates: Proconsul heseloni, Epipliopithecus vindobonensis, Archaeolemur edwardsi, Megaladapis grandidieri, and Palaeopropithecus kelyus.

    PubMed

    Russo, Gabrielle A

    2016-01-01

    This study evaluated the relationship between the morphology of the sacrum-the sole bony link between the tail or coccyx and the rest of the body-and tail length (including presence/absence) and function using a comparative sample of extant mammals spanning six orders (Primates, Carnivora, Rodentia, Diprotodontia, Pilosa, Scandentia; N = 472). Phylogenetically-informed regression methods were used to assess how tail length varied with respect to 11 external and internal (i.e., trabecular) bony sacral variables with known or suspected biomechanical significance across all mammals, only primates, and only non-primates. Sacral variables were also evaluated for primates assigned to tail categories ('tailless,' 'nonprehensile short-tailed,' 'nonprehensile long-tailed,' and 'prehensile-tailed'). Compared to primates with reduced tail lengths, primates with longer tails generally exhibited sacra having larger caudal neural openings than cranial neural openings, and last sacral vertebrae with more mediolaterally-expanded caudal articular surfaces than cranial articular surfaces, more laterally-expanded transverse processes, more dorsally-projecting spinous processes, and larger caudal articular surface areas. Observations were corroborated by the comparative sample, which showed that shorter-tailed (e.g., Lynx rufus [bobcat]) and longer-tailed (e.g., Acinonyx jubatus [cheetah]) non-primate mammals morphologically converge with shorter-tailed (e.g., Macaca nemestrina) and longer-tailed (e.g., Macaca fascicularis) primates, respectively. 'Prehensile-tailed' primates exhibited last sacral vertebrae with more laterally-expanded transverse processes and greater caudal articular surface areas than 'nonprehensile long-tailed' primates. Internal sacral variables performed poorly compared to external sacral variables in analyses of extant primates, and were thus deemed less useful for making inferences concerning tail length and function in extinct primates. The tails lengths of

  1. Chagas disease: control, elimination and eradication. Is it possible?

    PubMed

    Coura, José Rodrigues

    2013-12-01

    From an epidemiological point of view, Chagas disease and its reservoirs and vectors can present the following characteristics: (i) enzooty, maintained by wild animals and vectors, with broad occurrence from southern United States of America (USA) to southern Argentina and Chile (42ºN 49ºS), (ii) anthropozoonosis, when man invades the wild ecotope and becomes infected with Trypanosoma cruzi from wild animals or vectors or when the vectors and wild animals, especially marsupials, invade the human domicile and infect man, (iii) zoonosis-amphixenosis and exchanged infection between animals and humans by domestic vectors in endemic areas and (iv) zooanthroponosis, infection that is transmitted from man to animals, by means of domestic vectors, which is the rarest situation in areas endemic for Chagas disease. The characteristics of Chagas disease as an enzooty of wild animals and as an anthropozoonosis are seen most frequently in the Brazilian Amazon and in the Pan-Amazon region as a whole, where there are 33 species of six genera of wild animals: Marsupialia, Chiroptera, Rodentia, Edentata (Xenarthra), Carnivora and Primata and 27 species of triatomines, most of which infected with T. cruzi . These conditions place the resident populations of this area or its visitors - tourists, hunters, fishermen and especially the people whose livelihood involves plant extraction - at risk of being affected by Chagas disease. On the other hand, there has been an exponential increase in the acute cases of Chagas disease in that region through oral transmission of T. cruzi , causing outbreaks of the disease. In four seroepidemiological surveys that were carried out in areas of the microregion of the Negro River, state of Amazonas, in 1991, 1993, 1997 and 2010, we found large numbers of people who were serologically positive for T. cruzi infection. The majority of them and/or their relatives worked in piassava extraction and had come into contact with and were stung by wild

  2. Chagas disease: control, elimination and eradication. Is it possible?

    PubMed Central

    Coura, José Rodrigues

    2013-01-01

    From an epidemiological point of view, Chagas disease and its reservoirs and vectors can present the following characteristics: (i) enzooty, maintained by wild animals and vectors, with broad occurrence from southern United States of America (USA) to southern Argentina and Chile (42ºN 49ºS), (ii) anthropozoonosis, when man invades the wild ecotope and becomes infected with Trypanosoma cruzi from wild animals or vectors or when the vectors and wild animals, especially marsupials, invade the human domicile and infect man, (iii) zoonosis-amphixenosis and exchanged infection between animals and humans by domestic vectors in endemic areas and (iv) zooanthroponosis, infection that is transmitted from man to animals, by means of domestic vectors, which is the rarest situation in areas endemic for Chagas disease. The characteristics of Chagas disease as an enzooty of wild animals and as an anthropozoonosis are seen most frequently in the Brazilian Amazon and in the Pan-Amazon region as a whole, where there are 33 species of six genera of wild animals: Marsupialia, Chiroptera, Rodentia, Edentata (Xenarthra), Carnivora and Primata and 27 species of triatomines, most of which infected with T. cruzi . These conditions place the resident populations of this area or its visitors - tourists, hunters, fishermen and especially the people whose livelihood involves plant extraction - at risk of being affected by Chagas disease. On the other hand, there has been an exponential increase in the acute cases of Chagas disease in that region through oral transmission of T. cruzi , causing outbreaks of the disease. In four seroepidemiological surveys that were carried out in areas of the microregion of the Negro River, state of Amazonas, in 1991, 1993, 1997 and 2010, we found large numbers of people who were serologically positive for T. cruzi infection. The majority of them and/or their relatives worked in piassava extraction and had come into contact with and were stung by wild