Full Text Available Calomys callosus, Rengger 1830 (Rodentia, Cricetidae, a wild rodent found in Central Brazil, was studied to investigate its susceptibility to Toxoplasma gondii experimental infection and its humoral immune response against this protozoa. The electrophoretic profile of the serum proteins of C. callosus showed that IgG, which shows no affinity to Protein A, has higher cross reactivity with rat IgG than with IgG from other rodents. The susceptibility assay was performed by inoculation groups of animals with various suspensions of T. gondii tachyzoites from 102 to 106 parasites. All animals died between 3 and 9 days after infection and the kinetics of antibody synthesis was determined. Basically, they recognized predominantly the immunodominant antigen SAG-1 (P30. The immunohistochemistry assays revealed that the liver was the most heavily infected organ, followed by the spleen, lungs, intestine, brain and kidneys. It can be concluded that C. callosus is an excellent experimental model for acute phase of Toxoplasma infection
Modulation of parasitemia and antibody responce to Trypanosoma cruzy by cyclophosphamide in Calomys callosus (Rodentia, Cricetidae Modulação da parasitemia e da resposta de anticorpos ao Trypanosoma cruzi pela ciclofosfamida em Calomys callosus (Rodentia, Cricetidae
Monamaris Marques Borges
Full Text Available Calomys callosus a wild rodent, previously described as harboring Trypanosoma cruzi, has a low susceptibility to infection by this protozoan. Experiments were designed to evaluate the contribution of the immune response to the resistance to T. cruzi infection exhibited by C. calossus. Animals were submitted to injections of high (200 mg/kg body weight and low (20 mg/kg body weight doses of cyclophosphamide on days -1 or -1 and +5, and inoculated with 4 x 10³ T. cruzi on day O. Parasitemia, mortality and antibody response as measured by direct agglutination of trypomastigotes were observed. Two hundred mg doses of cyclophosphamide resulted in higher parasitemia and mortality as well as in suppression of the antibody response. A single dose of 20 mg enhanced antibody levels on the 20th day after infection, while an additional dose did not further increase antibody production. Parasitemia levels were not depressed, but rather increased in both these groups as compared to untreated controls. Passive transfer of hyperimmune C. callosus anti-T. cruzi serum to cyclophosphamide immunosuppressed animals resulted in lower parasitemia and mortality rates. These results indicate that the immune response plays an important role in the resistance of C. callossus to T. cruzi.Calomys-callosus, roedor silvestre, que já foi encontrado naturalmente infectado pelo Trypanosoma cruzi, tem baixa suscetibilidade à infecção experimental por este protozoário. Foram feitos experimentos para avaliar a contribuição da resposta imune a essa baixa suscetibilidade. Animais foram submetidos a injeção de doses altas (200 mg/kg peso corporal ou doses baixas (20 mg/kg peso corporal de ciclofosfamida nos dias -1 ou -1 e +5, e inoculados com 4 x 10³ T. cruzi no dia O. Observou-se a curva de parasitemia, mortalidade e resposta de anticorpos medida por aglutinação direta de tripomastigotas. Doses de 200 mg resultaram em parasitemia e mortalidade mais elevada e supress
Neste trabalho foram estudados exemplares do roedor, Calomys callosus, nascidos em laboratório, a infecções experimentais com quatro parasitos: Plasmodium berghei, Leishmania mexicana amazonensis, Schistosoma mansoni e Hymenolepsis nana. A positividade das infecções foi de 80% para os três primeiros parasitos e 0 para H. nana. C. callosus é um roedor de excelente adaptação em laboratório e de fácil manuseio. Acredita-se que, de acordo com os resultados obtidos neste trabalho, este animal pode...
Dalva A. Mello
Full Text Available Neste trabalho foram estudados exemplares do roedor, Calomys callosus, nascidos em laboratório, a infecções experimentais com quatro parasitos: Plasmodium berghei, Leishmania mexicana amazonensis, Schistosoma mansoni e Hymenolepsis nana. A positividade das infecções foi de 80% para os três primeiros parasitos e 0 para H. nana. C. callosus é um roedor de excelente adaptação em laboratório e de fácil manuseio. Acredita-se que, de acordo com os resultados obtidos neste trabalho, este animal poderia ser um bom modelo experimental de laboratório para certos agentes patogênicos.
Mirian A. Boim; Nestor Schor
A função renal do roedor Calomys callosus, envolvido no ciclo de transmissão de diversos agentes patogênicos para o homem foi avaliada no animal intacto, através da técnica de depuração e micropunção renal. Os resultados mostraram que este roedor apresenta níveis pressóricos, hematócrito e proteinas plasmáticas semelhantes aos dos ratos submetidos ao mesmo procedimento experimental. Os pesos corporal e renal, bem como a filtração glomerular global e por nefro assemelham-se aos do camundongo. ...
Lenzi Jane A
Full Text Available Calomys callosus Rengger, 1830 (Rodentia: Cricetidae is a mouse-like South American wild rodent, which is permissive to Schistosoma mansoni infection. In this paper we studied the effect of schistosomal infection in C. callosus mesenteric and omental milky spots (MS, subsidiary foci of coelom-associated lymphomyeloid tissue (CALT, during the acute, transitional (acute to chronic, and chronic phases of the infection. MS were morphologically analyzed by histological methods, using brigthfield and confocal laser scanning microscopies. The MS of infected animals were mainly of lymphomyelocytic (42 to 90 days and lymphoplasmacytic (160 days of infection types and showed frequent presence of lymphoid follicles with germinal centers, plasmacytogenesis and plasmacytosis, mastocytosis, megakaryopoiesis, erythropoiesis and less pronounced eosinopoiesis. These results indicate that MS are a preferential site of germinal-center-dependent and independent plasmacytogenesis, and a bone marrow-like organ, committed with various cellular lineages. The consequence of C. callosus MS reactivity for schistosomal infection is still unknown and is under investigation.
Mirian A. Boim
Full Text Available A função renal do roedor Calomys callosus, envolvido no ciclo de transmissão de diversos agentes patogênicos para o homem foi avaliada no animal intacto, através da técnica de depuração e micropunção renal. Os resultados mostraram que este roedor apresenta níveis pressóricos, hematócrito e proteinas plasmáticas semelhantes aos dos ratos submetidos ao mesmo procedimento experimental. Os pesos corporal e renal, bem como a filtração glomerular global e por nefro assemelham-se aos do camundongo. Surpreendentemente estes roedores apresentaram significante número de glomérulos superficiais por rim, permitindo a avaliação da hemodinàmica glomerular. Apesar da pressão arterial semelhante à dos ratos Munich-Wistar (MW, a pressão hidráulica intraglomerular no Calomys callosus foi inferior. Esta redução foi conseqüente à menor resistência pós-glomerular quando comparada à dos ratos MW. O fluxo plasmático glomerular atingiu valor bastante elevado em relação à filtração glomerular por nefro, fato que não só compensaria a reduzida pressão intraglomerular, como também seria suficiente para elevar a filtração (por g/rim a níveis superiores neste roedor, pois o coeficiente de ultrafiltração glomerular (Kj foi semelhante ao do rato MW. O presente trabalho sugere que apesar das dificuldades técnicas que este animal impõe devido ao seu reduzido tamanho, o estudo da função renal global bem como da hemodinàmica glomerular é factível, podendo portanto ser utilizado como modelo para estudo da função renal em doenças tropicais.Renal function was characterized in Calomys callosus, a rodent which can participate in the transmission of several human diseases. The results showed that the pressures levels, hematocrit and plasmatic proteins were similar to rats submitted to the same experimental maneuvers. The corporal and renal weights, whole and single nephron glomerular filtration rates were similar to the mouse
Mirian A. Boim
Full Text Available A função renal do roedor Calomys callosus, envolvido no ciclo de transmissão de diversos agentes patogênicos para o homem foi avaliada no animal intacto, através da técnica de depuração e micropunção renal. Os resultados mostraram que este roedor apresenta níveis pressóricos, hematócrito e proteinas plasmáticas semelhantes aos dos ratos submetidos ao mesmo procedimento experimental. Os pesos corporal e renal, bem como a filtração glomerular global e por nefro assemelham-se aos do camundongo. Surpreendentemente estes roedores apresentaram significante número de glomérulos superficiais por rim, permitindo a avaliação da hemodinàmica glomerular. Apesar da pressão arterial semelhante à dos ratos Munich-Wistar (MW, a pressão hidráulica intraglomerular no Calomys callosus foi inferior. Esta redução foi conseqüente à menor resistência pós-glomerular quando comparada à dos ratos MW. O fluxo plasmático glomerular atingiu valor bastante elevado em relação à filtração glomerular por nefro, fato que não só compensaria a reduzida pressão intraglomerular, como também seria suficiente para elevar a filtração (por g/rim a níveis superiores neste roedor, pois o coeficiente de ultrafiltração glomerular (Kj foi semelhante ao do rato MW. O presente trabalho sugere que apesar das dificuldades técnicas que este animal impõe devido ao seu reduzido tamanho, o estudo da função renal global bem como da hemodinàmica glomerular é factível, podendo portanto ser utilizado como modelo para estudo da função renal em doenças tropicais.
Cibele R. Bonvicino
Full Text Available A new Brazilian Calomys Waterhouse, 1837 species is described based on morphologic and karyologic data. This species is endemic to the Cerrado of Central Brazil and allopatric with all other species of the genus Calomys. Its chromosome complement (2n = 46, AN = 66 is different from those described in other Calomys species. Morphometric analysis significantly distinguished this new species from other Calomys of the Brazilian fauna like C. callosus (Renger, 1830, C. expulsus (Lund, 1841 and C. tener (Winge, 1887 and placed it among the large-sized Calomys.
Full Text Available The myenteric plexus of the digestive tract of the wild mouse Calomys callosus was examined using a histochemical method that selectively stains nerve cells, and the acetylcholinesterase (AChE histochemical technique in whole-mount preparations. Neuronal density was 1,500 ± 116 neurons/cm2 (mean ± SEM in the esophagus, 8,900 ± 1,518 in the stomach, 9,000 ± 711 in the jejunum and 13,100 ± 2,089 in the colon. The difference in neuronal density between the esophagus and other regions was statistically significant. The neuron profile area ranged from 45 to 1,100 µm2. The difference in nerve cell size between the jejunum and other regions was statistically significant. AChE-positive nerve fibers were distributed within the myenteric plexus which is formed by a primary meshwork of large nerve bundles and a secondary meshwork of finer nerve bundles. Most of the nerve cells displayed AChE activity in the cytoplasm of different reaction intensities. These results are important in order to understand the changes occurring in the myenteric plexus in experimental Chagas' disease
Vieira, Andreia Espíndola
Full Text Available As células animais estocam carboidratos na forma de glicogênio como fonte de energia. Esses depósitos ocorrem amplamente nos tecidos embrionários para disponibilização rápida de energia, principalmente durante a diferenciação e o desenvolvimento das células. O presente trabalho avaliou a distribuição de depósitos de glicogênio durante a odontogênese intra-uterina em Calomys callosus utilizando fetos com 12 a 20 dias, sendo 5 fetos de cada dia. As cabeças dos fetos foram removidas e fixadas em formaldeído 10% em PBS. Os espécimes foram processados para inclusão em glicol metacrilato (Leica Historesin, sendo aqueles com mais de 15 dias previamente descalcificados em EDTA. Para cada dia de desenvolvimento obteve-se cortes semi-seriados com 3 μm de espessura. As lâminas foram divididas em 2 grupos, sendo um grupo submetido à reação P. A. S. e o outro submetido à amilase salivar e em seguida à reação P. A. S. (grupo controle. Ao microscópio de luz foi observada, nas fases iniciais da odontogênese (12-15 dias, reação P. A. S. mais evidente nas células ectomesenquimais e aos 16-17 dias a reação predominou na região do folículo dental. Aos 18-19 dias a reação intensificou-se no retículo estrelado e aos 20 dias nas células do epitélio interno e na papila dental. De acordo com a metodologia empregada e com os resultados obtidos, concluímos que ocorre variação dos depósitos de glicogênio nas diferentes regiões do germe dental ao longo da odontogênese e que o Calomys callosus representa um modelo biológico para estudos da odontogênese.
Sonia G. Andrade
Full Text Available Calomys callosus a wild rodent, is a natural host of Trypanosoma cruzi. Twelve C. callosus were infected with 10(5 trypomastigotes of the F strain (a myotropic strain of T. cruzi. Parasitemia decreased on the 21 st day becoming negative around the 40th day of infection. All animals survived but had positive parasitological tests, until the end of the experiment. The infected animals developed severe inflammation in the myocardium and skeletal muscle. This process was pronounced from the 26 th to the 30th day and gradually subsided from the 50 th day becoming absent or residual on the 64 th day after infection. Collagen was identified by the picro Sirius red method. Fibrogenesis developed early, but regression of fibrosis occurred between the 50th and 64th day. Ultrastructural study disclosed a predominance of macrophages and fibroblasts in the inflammatory infiltrates, with small numbers of lymphocytes. Macrophages had active phagocytosis and showed points of contact with altered muscle cells. Different degrees of matrix expansion were present, with granular and fibrilar deposits and collagen bundles. These alterations subsided by the 64th days. Macrophages seem to be the main immune effector cell in the C. callosus model of infection with T. cruzi. The mechanisms involved in the rapid fibrogenesis and its regression deserve further investigation.
Herrera, Elba Juliana Rojas; Miño, Mariela Haydée; Notarnicola, Juliana; Robles, María del Rosario
A new oxyurid nematode Syphacia hodarae n. sp. is described from the cecum and rectum of the cricetid rodent Calomys laucha Fischer, 1814 (Sigmodontinae, Phyllotini), captured in an agroecosystem of central Argentina. The new species is distinguished from other members of the genus mainly by the shape of the cephalic plate, presence of cervical alae in females, absence of lateral alae, and absence of deirids. Some characters are shared with Syphacia carlitosi, a parasite of Akodon azarae from the wetlands in Argentina. However, S. hodarae can be differentiated from this species by the absence of ornamentation on the accessory hook of the gubernaculum, length of spicule and gubernaculum, size of the eggs, and distance to the vulva from the anterior end. This is the first record of a Syphacia species from the tribe Phyllotini in Argentina, and the first time a Syphacia species is reported from C. laucha . PMID:21506826
Rupali Vitthal Sarpate
Full Text Available Context: Strobilanthus callosus Nees and Strobilanthus ixiocephala Benth belongs to family Acanthaceae. The plants have been the subject of scientific research which confirms its use in folk medicine as anti-inflammatory drugs showing potent anti-rheumatic effects. Previous research claims the anti-inflammatory and anti-arthritic activities of Lupeol and 19α-H Lupeol isolated from Strobilanthus callosus and Strobilanthus ixiocephala roots. Based on the literature cited, the unexplored parts stems and leaves of the two species were selected for the present study. Aim: The present study is designed to isolate steroidal and alkaloidal components from the two species Strobilanthus callosus and Strobilanthus ixiocephala using the unexplored parts viz. stems and leaves and to investigate its anti-inflammatory effect. Settings and Design: The anti-inflammatory effect was investigated employing subacute anti-inflammatory models namely cotton pellet granuloma and carrageenan-induced rat paw edema. Materials and Methods: Anti-inflammatory activity was carried out using isolated test components RVS-A (Lupeol, RVS-C (Doctriacantone and standard drug Diclofenac sodium (10 mg/kg. Results: The present study has dealt up with isolation of two phytoconstituents Lupeol and Dotriacontane which gave marked anti-inflammatory activity at the dose 20 mg/kg in both the models Carrageenan induced rat paw edema and Cotton pellet granuloma. Conclusion: The results confirm that the mechanism of the anti-inflammatory effect of RVS-A (Lupeol and RVS-C (Doctriacantone involves reduction of prostaglandins through inhibition of cyclooxygenase and suppression of proliferative phase of sub acute inflammation. Thus the steroidal and alkaloidal components Lupeol and Doctriacantone isolated from Strobilanthus callosus Nees and Strobilanthus ixiocephala Benth shows marked anti-inflammatory activity.
Fresh dried and old (6-12 months) dried kachri (Cucumis callosus) were treated with 0, 2.5, 5 and 7 kGy of gamma radiation in a Cobalt 60 gamma cell (GC-1200). The irradiated samples of kachri were stored at room temperature (28±2 °C). Total bacterial count and nutrient composition were evaluated immediately after irradiation and at regular intervals of 1 month during 3 months of storage. Results indicated that gamma radiation reduced the total bacterial counts of dried samples of both fresh and old dried kachri. Dose of 5.0 kGy was sufficient to eliminate total bacterial count and there was no microbial growth in 5.0 kGy irradiated samples during the storage period. No significant differences were observed in the proximate composition of both types of kachri at all irradiation doses. It was concluded that irradiation treatments of kachri improves keeping quality of both freshly dried and old dried Kachri. (author)
Sommaro, Lucía V.; Steinmann, Andrea R.; Chiappero, Marina B.; Priotto, José W.
We studied the short term spacing behavioural responses of corn mice ( Calomys musculinus) with regard to population density in four 0.25 ha enclosures (two control and two experimental) in the 2007 breeding season. The goal of this research was to test the hypothesis that spacing behaviour only operates among C. musculinus adult females. We estimated 207 home ranges to study: 1) the home range size and the overlap degree of adult males and females in relation to population density; 2) the settlement distances of juveniles to the centre of activity of their mothers and the home range overlap proportion between them and their mothers in relation to population density. We found that home range size and overlap degree in C. musculinus adults were determined by sex and density. At high population density males had significant smaller and more exclusive home ranges, and this might reflect induced territoriality derived from social restrictions. Female home range sizes remained similar irrespective of population density, and they kept exclusive home ranges in both control and experimental enclosures. Thus, females maintained their territories independent of the population density values. The settlement distances of juveniles from their mothers and the overlap proportion between them and their mothers were independent of population density. We conclude that spacing behaviour only operates among C. musculinus adult females and it could have a role in regulating population abundances limiting the number of females that acquire breeding spaces.
Reis, Francineto S; Barros, Maria Claudene; Fraga, Elmary Da C; Da Penha, Tatiane A; Teixeira, Whaubytfran C; Dos Santos, Ana Clara G; Guerra, Rita De Maria S N De C
During fauna studies, thirty-six wild mammals were collected in adjacent areas of Itapecuru River and Environmental Preservation area of Inhamum, state of Maranhão, Brazil. They were sampled for ectoparasites. The following specimens of the order Rodentia and its respective ectoparasites were identified: Akodon sp. (Androlaelaps sp. and Laelaps sp.), Oecomys sp. (Androlaelaps sp. and Amblyomma cajennense), Oligoryzomys sp. (Androlaelaps sp. Laelaps sp. and Amblyomma sp.) e Oryzomys megacephalus (A. cajennense). In Calomys callosus no ectoparasite was found. It was observed infestation in the order Didelphimorphia as follows: Didelphis marsupialis (Androlaelaps sp., Laelaps sp. and larvae of Diptera Cyclorrhapha); Gracilinanus sp. (Laelaps sp. and larvae of Diptera Cyclorrhapha), Monodelphis domestica (Poplygenis (Polygenis)), Cummingsia sp., Amblyomma sp. and Androlaelaps sp.). Marmosa sp. e Thylamis sp. had no ectoparasites. From the captured hosts 56% were infested, 82% and 44% rodents and marsupials, respectively. Mites from the family Laelapidae presented the great diversity of hosts and genus. PMID:20059819
Felipe Bortolotto Peters
Full Text Available Studies on the richness of small mammals in the Brazilian South Region are recent and point out the need for using varied methods. This way, this paper contributes to knowledge on the fauna of small sigmodontinae rodents in Santa Catarina, including Holochilus brasiliensis and Calomys laucha in the list of species with confirmed occurrence in this state. The records of H. brasiliensis refer to Laguna (n = 2 and Timbe do Sul (n = 1. In turn, C. laucha presents 23 records from Capinzal. The entire material is represented by skull fragments from owl pellets samples collected from nests and feeding perches of the Tyto alba.
Fuentes, M. V.; Sáez, S.; Trelis, M.; Muñoz-Antoli, C.; Esteban, J. G.
Comunidad helmintiana de Apodemus sylvaticus (Rodentia, Muridae) en la Sierra de Gredos (España).— Como parte de los estudios helmintofaunísiticos que sobre pequeños mamíferos se están llevando a cabo en la península ibérica, la sierra española de Gredos fue estudiada. La comunidad helmintiana del ratón de campo, Apdoemus sylvaticus (Rodentia, Muridae), fue analizada. Cualitativamente, 13 especies de helmintos fueron detectadas: Plagiorchis sp. I y Plagiorchis sp. II (Trematoda...
Horáček, I.; Knitlová, M.; Wagner, Jan; Kordos, L.; Nadachowski, A.
Roč. 8, č. 5 (2013), e62498. E-ISSN 1932-6203 R&D Projects: GA ČR GA205/09/0184 Institutional support: RVO:67985831 Keywords : Mammalia * Rodentia * Genus Micromys * Late Cenozoic Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.534, year: 2013
María C.PROVENSAL; Jaime J.POLOP
自1984年4月至1999年8月,我们沿铁路轨道检测了农田中暮鼠(Calomys venustus)的多度,研究了种群密度、越冬种群结构和繁殖期长度之间的关系,发现种群具有增长、高数量和下降年份.将动物按照同生群(种群内在相同时间内出生的一些个体)分开,利用2×2列联表卡方检验对不同性别的越冬种群结构与数量(高数量和种群下降)间的关联性进行了分析. 就高密度与种群密度下降年份中的同生群组成而言,不同密度的年份显示种群结构有显著差异.在数量增长和高密度的年份里,在繁殖季节的起始期,前一年秋季出生的个体比同年夏季出生的个体在数量上要占优势,而在同生群数量下降年份则相反,特别是雌性.高密度年份具有繁殖期缩短的特征,而种群增长年份繁殖期延长.结果表明,这些变化不能只归结于繁殖期长或繁殖率引起密度变化.我们的结论是:解释C.venustus种群消长不能仅考虑动物同生群本身,需要考虑其社会和环境因子的作用.%We examined the relationship between population density and overwintering population structure and length of the breeding periods ofCalomys venustus. Abundance ofC.venustus was monitored from April 1984 to August 1999 on railway banks in a rural area. Years of increasing density, high, and declining density were recognized. An index of population change from spring to autumn in each year was calculated. Animals were assigned to a cohort and a 2×2 contingency table by a Chi-square statistic was calculated to test for dependence between the overwintering population structure and density years (high and decline) by sex. Years of different density showed significant difference in population structure, in respect to composition of the overwintering cohort during high density and declining density years. At the onset of breeding periods, during increase and high density years, animals born the previous autumn
López-Antoñanzas, Raquel; Gutkin, Vitaly; Rabinovich, Rivka; Calvo, Ran; Grossman, Aryeh
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
Alberico Michael; González M. Alonso
Comparative data about movements, density, home range, and reproductive activity of Proechimys semispinosus and Hoplomys gymnurus (Rodentia: Echimyidae) were obtained by means of an eight-month capture-recapture study in the Bajo Calima region of the pacific coast of Colombia. In addition, intra and interespecific behavioral interactions were studied in captivity. Hoplomys gymnurus had a higher density than Proechimys semispinosus in the primary forest habitat, while the reverse situation was...
Full Text Available Riassunto Sulla tassonomia sottospecifica di Microtus savii (Rodentia, Arvicolidae Viene riveduta e riassunta la situazione tassonomica sottospecifica di Microtus (Terricola savii, anche tramite la descrizione di due nuovi taxa: Microtus (Terricola savii tolfetanus, dei Monti della Tolfa e Microtus (Terricola savii niethammericus, del Gargano.
Gilbert, Avery Nelson
Litter size and mammary number in the mammalian order Rodentia show a significant positive correlation. Mean litter size is typically one-half the number of available mammaries, while maximum litter size approximates mammary number. Similar relationships are found in the families Muridae, Cricetidae, and Sciuridae. The relationship of litter size to mammary number is significantly different between the arboreal and terrestrial squirrels, and between the hystricomorph and nonhystricomorph rode...
Yüksel Coskun; Servet Ulutürk; Alaettin Kaya
Cariotipi di Nannospalax (Palmer 1903) (Rodentia, Spalacidae) dell’Anatolia centro-orientale, Turchia
Sono stati analizzati i cariotipi di 20 (11 maschi e 9 femmine) Nannospalax catturati, nel periodo 2006-2009, in 11 località dell’Anatolia centro-orientale (Turchia). Sono state individuate sei diverse forme cromosomiche (2n=49; 2...
André Filipe Testoni; Sérgio Luiz Althoff; André Paulo Nascimento; Francisco Steiner-Souza; Ives José Sbalqueiro
Rhagomys rufescens (Rodentia: Sigmodontinae) is an endemic species of the Atlantic forest from Southern and Southeastern Brazil. Some authors consider Rhagomys as part of the tribe Thomasomyini; but its phylogenetic relationships remain unclear. Chromosomal studies on eight specimens of Rhagomys rufescens revealed a diploid number of 2n = 36 and a number of autosome arms FN = 50. GTG, CBG and Ag-NOR banding and CMA3 /DAPI staining were performed on metaphase chromosomes. Eight biarmed and nin...
Franco, N. H.; Olosson, A.; J.B. Santos; Brosseron, F.; Pinto, A.; Ricardo, E.
p. 275-279 O Projecto Rodentia, implementado no ano 2006/2007, visa promover a cultura científica em alunos do 1º ciclo do Ensino Básico, familiarizando-os com o Método Científico e desenvolvendo competências conceptuais, processuais e atitudinais, com base na Etologia Aplicada e na reflexão ética sobre o bem-estar animal. Foram instalados em três salas de aula habitats especialmente desenhados, contendo cada um dois ratos de laboratório. Inicialmente orien...
Full Text Available Hystricognathi represent a monophyletic taxon within Rodentia. Since phylogenetically analyzed morphological systems are essential for revealing evolutionary processes, this study identifies evolutionary character transformations on the stem lineage of Hystricognathi as derived from the author's own work and the literature. Data so far indicate that evolutionary transformations in the rostral head region, the loss of tactile ability in the outer nasal skin and the mobile arrangement of the associated cartilage, were allied with a switch from omnivorous to herbivorous and fiber-rich nutrition. Additional character transformations in the skull assist in digesting such food. Structures associated with reproduction and placentation show a remarkable pro portion of derived character conditions: the chorioallantoic placenta has a ring-shaped organization and growth structure which optimizes the capacity for passive diffusion, a subplacenta occurred as a specialized region responsible for placental invasion and the inverted yolk sac facilitates substance exchange with the main placenta. Finally, precocial newborns evolved as a derived condition within Rodentia. All things considered, a mode of reproduction is indicated, which does not demand excessive additional energy intake by the mother and is in accordance with her low energetic diet. Hystricognathi possess major character transformations that represent prerequisites for their successful radiation at the time when more open ecosystems and grasslands evolved during Earth history. The analysis resulted in the reconstruction of a life-near picture of the hystricognath stem species pattern with high explanatory power in terms of changes in space and time and their interdependence with biodiversity.
Lamotheoxyuris ackerti n. gen., n. comb. (Nematoda: Heteroxynematidae) parasite of Neotoma spp. (Rodentia: Muridae) Lamotheoxyuris ackerti n. gen., n. comb. (Nematoda: Heteroxynematidae) parásito de Neotoma spp. (Rodentia: Muridae)
JORGE FALCÓN-ORDAZ; Jesús A. Fernández; LUIS GARCÍA-PRIETO
On the basis of the revision of the type material of Aspiculuris ackerti Kruidenier & Mehra, 1959, and new specimens collected from Neotoma nelsoni Goldman, 1905 (Rodentia: Cricetidae), in Veracruz, Mexico, we herein to which A. ackerti is transferred as Lamotheoxyuris ackerti This new genus differs from all other genera included in 1) mouth surrounded by six lips; 2) extension of lateral alae describe a new genus (Lamotheoxyuris n. gen.), (Kruidener & Mehra, 1959) n. gen., n. comb. Heteroxyn...
Luo, Guangjie; Liao, Jicheng
Meriones meridianus belongs to the genus Meriones in Gerbillinae. Total length of complete mitochondrial genome of M. meridianus is 16,376 bp and the heavy strand contains 32.8% A, 13.1% G, 25.3% C and 28.8% T. Sequences of protein-coding genes are 11,341 bp in length, accounting for 69.25%, approximately. Results of phylogenetic analysis shown that M. meridianus and Meriones unguiculatus were clustered in a single branch. This conclusion would be an important data for relevant studies about the genus Meriones, and mitochondrial genome would be an important supplement for the gene pool of Rodentia. It would play a pivotal role in researches about phylogeography and proteomics involving M. meridianus as well. PMID:26075483
Luo, Guangjie; Liao, Jicheng
Meriones libycus belongs to the genus Meriones in Gerbillinae, its complete mitochondrial genome is 16,341 bp in length. The heavy strand contains 32.8% A, 13.1% G, 25.3% C, 28.8% T, protein-coding genes approximately accounting for 69.54%. Results of phylogenetic analysis showed that M. libycus and Meriones unguiculatus were clustered together, and it was consistent with that of primary morphological taxonomy. This study verifies the evolutionary status of M. libycus in Meriones at the molecular level. The mitochondrial genome would be a significant supplement for the gene pool of Rodentia and the conclusion of phylogenetic analysis could be an important molecular evidence for the classification of Gerbillinae. PMID:26017047
Diego A. Caraballo; Paola C. Jablonski; Pablo J. Rebagliati; María Susana Rossi
Diversidad cromosómica en tuco-tucos (Ctenomys, Rodentia) de los humedales del noreste argentino. La diversidad cromosómica es clave para entender la evolución de las especies de mamíferos. Los roedores, el taxón más diversificado de los mamíferos, presentan una gran diversidad cromosómica; el estudio de sus cariomorfos ha contribuido mucho a la comprensión de su evolución. Los roedores subterráneos del género Ctenomys (tuco-tucos) son uno de los géneros de mamíferos con mayor número de espec...
Full Text Available Faunistical data regarding small mammal fauna from the south-western part of Romania are very poor and not to date. The only serious studies were made between 1966 and 1971 along the Danube River by the researchers: A. Popescu, Pr. Barbu, M. Hamar, M. Şutova. In our collection campaign we captured 6 species of Insectivora: Erinaceus concolor, Talpa europaea, Sorex araneus, Neomys fodiens, Neomys anomalus and Crocidura leucodon. Also we caught 9 species of rodents (Rodentia: Muscardinius avellanarius, Mus musculus, Mus spicilegus, Micromys minutus, Pitymis subterraneus, Apodemus flavicollis, Apodemus sylvaticus, Apodemus agrarius, and Microtus arvalis. Our study brings new faunistical data regarding distribution of some small species of mammals in this part of Romania. Also we confirm the presence of Apodemus agrarius kahmanni in the Banat.
Fadda, Carlo; Leirs, Herwig
The present study investigated growth patterns under three different environmental conditions in a single population of the rodent Mastomys natalensis (Rodentia, Muridae) in Morogoro, Tanzania. The study aimed to test whether and how post-weaning ontogenetic processes are affected by different...... second half of the year in years when the November/December rains were very poor. The second group (beta generation) grew under conditions when these rains were abundant. Finally, the gamma generation, consisted of animals that were born in the middle of the rainy season in years when there was a...
Full Text Available The karyotypes of 85 specimens of Oligoryzomys nigripes (Rodentia, Sigmodontinae collected in the Cerrado and Atlantic Forest of seven states of Brazil were analyzed. Eighty four specimens presented a karyotype with 2n = 62 and one individual had 2n = 61 due to a monosomy of the X chromosome. High levels of intra- and inter-population karyotypic variability, due to sex chromosomes heteromorphisms and pericentric inversions in four autosomes (pairs 2, 3, 4 and 8, led to a variation of the autosomal arm numbers (fundamental number, FN from 78 to 82. Synaptonemal complex analyses revealed normal meiosis in males heterozygous for pericentric inversions. We found 39 different cytotypes, 27 of which are herein described for the first time. A literature survey revealed 46 described karyotypes for O. nigripes. We tested the hypothesis that chromosomal variants frequencies are dependent on geographical distribution and we propose a model for the karyotypical evolution of Oligoryzomys nigripes with 2n = 62/FN = 78-82.
André Filipe Testoni
Full Text Available Rhagomys rufescens (Rodentia: Sigmodontinae is an endemic species of the Atlantic forest from Southern and Southeastern Brazil. Some authors consider Rhagomys as part of the tribe Thomasomyini; but its phylogenetic relationships remain unclear. Chromosomal studies on eight specimens of Rhagomys rufescens revealed a diploid number of 2n = 36 and a number of autosome arms FN = 50. GTG, CBG and Ag-NOR banding and CMA3/DAPI staining were performed on metaphase chromosomes. Eight biarmed and nine acrocentric pairs were found in the karyotype of this species. The X and Y chromosomes were both acrocentric. Most of the autosomes and the sex chromosomes showed positive C-bands in the pericentromeric region. The X chromosome showed an additional heterochromatic block in the proximal region of the long arm. Nucleolus organizer regions (NORs were located in the pericentromeric region of three biarmed autosomes (pairs 4, 6 and 8 and in the telomeric region of the short arm of three acrocentrics (pairs 10, 12 and 17. CMA3/DAPI staining produced fluorescent signals in many autosomes, especially in pairs 4, 6, and 8. This study presents cytogenetic data of Rhagomys rufescens for the first time.
Elsy Nalleli Loría-Cervera
Full Text Available 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 10 2 and 2.5 x 10 6 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.
Lamotheoxyuris ackerti n. gen., n. comb. (Nematoda: Heteroxynematidae parasite of Neotoma spp. (Rodentia: Muridae Lamotheoxyuris ackerti n. gen., n. comb. (Nematoda: Heteroxynematidae parásito de Neotoma spp. (Rodentia: Muridae
Full Text Available On the basis of the revision of the type material of Aspiculuris ackerti Kruidenier & Mehra, 1959, and new specimens collected from Neotoma nelsoni Goldman, 1905 (Rodentia: Cricetidae, in Veracruz, Mexico, we herein to which A. ackerti is transferred as Lamotheoxyuris ackerti This new genus differs from all other genera included in 1 mouth surrounded by six lips; 2 extension of lateral alae describe a new genus (Lamotheoxyuris n. gen., (Kruidener & Mehra, 1959 n. gen., n. comb. Heteroxynematinae by the following main traits: reduced; and 3 lack of caudal alae.Con base en la revisión del material tipo de Aspiculuris ackerti Kruidenier y Mehra, 1959 y de nuevos ejemplares recolectados en Neotoma nelsoni Goldman, 1905 (Rodentia: Cricetidae, en Veracruz, México, se describe un nuevo género (Lamotheoxyuris n. gen., al que A. ackerti es transferido como Lamotheoxyuris ackerti (Kruidener y Mehra, 1959 n. gen., n. comb. Este nuevo género se distingue de todos los demás géneros incluidos en Heteroxynematinae por las siguientes características: 1 presencia de seis labios rodeando la boca; 2 extensión reducida del ala lateral; y 3 carencia de ala caudal.
Full Text Available African mole-rats (Bathyergidae, Rodentia contain several social, cooperatively breeding species with low extrinsic mortality and unusually high longevity. All social bathyergids live in multigenerational families where reproduction is skewed towards a few breeding individuals. Most of their offspring remain as reproductively inactive "helpers" in their natal families, often for several years. This "reproductive subdivision" of mole-rat societies might be of interest for ageing research, as in at least one social bathyergid (Ansell's mole-rats Fukomys anselli, breeders have been shown to age significantly slower than non-breeders. These animals thus provide excellent conditions for studying the epigenetics of senescence by comparing divergent longevities within the same genotypes without the inescapable short-comings of inter-species comparisons. It has been claimed that many if not all social mole-rat species may have evolved similar ageing patterns, too. However, this remains unclear on account of the scarcity of reliable datasets on the subject. We therefore analyzed a 20-year breeding record of Giant mole-rats Fukomys mechowii, another social bathyergid species. We found that breeders indeed lived significantly longer than helpers (ca. 1.5-2.2fold depending on the sex, irrespective of social rank or other potentially confounding factors. Considering the phylogenetic positions of F. mechowii and F. anselli and unpublished data on a third Fukomys-species (F. damarensis showing essentially the same pattern, it seems probable that the reversal of the classic trade-off between somatic maintenance and sexual reproduction is characteristic of the whole genus and hence of the vast majority of social mole-rats.
Apanaskevich, Dmitry A
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
Edgardo M. Rengifo
Full Text Available Se describe el nido de Scolomys melanops (Rodentia: Cricetidae, encontrado en el Nororiente de Perú en un hábitat de Colinas bajas. Se identificó tres estructuras en el nido: a Orificio de acceso y salida; b Túnel y c Dormidero, en este último se encontraron restos de frutos, fibras del pedúnculo y tallos de Lepidocaryum tenue (Arecales: Arecaceae “Irapay”. Se sugiere en base al material vegetal encontrado en el nido, la existencia de una relación de depredación entre el roedor Scolomys melanops y la palmera Lepidocaryum tenue.
Estrutura da comunidade de pequenos mamíferos (Mammalia, Rodentia da Estação Ecológica de Águas Emendadas, Planaltina, Distrito Federal, Brasil Community structure of small mammals (Mammalia, Rodentia from Estação Ecológica de Águas Emendadas, Planaltina, Distrito Federal, Brazil
Full Text Available Foram investigadas, no presente estudo a composição de espécies e a abundância de uma comunidade de pequenos mamíferos presentes nos campos de murundus, um tipo fitofisionômico característico da região central dos Cerrados brasileiros. Duas grades de armadilhas do tipo Sherman foram montadas e oito espécies de roedores foram capturadas. Não foi registrada a presença de nenhum marsupial na região. As espécies mais abundantes foram Bolomys lasiurus (Lund, 1841, Thalpomys lasiotis Thomas, 1916 e Calomys tener (Winge, 1888. Durante a estação chuvosa, B. lasiurus foi a espécie mais abundante, ao contrário de T. lasiotis que apresentou maior número de indivíduos durante o período seco. Esta distinção com relação à abundância dos indivíduos dessas duas espécies pode ser um mecanismo de adaptação que permite a coexistência nos mesmos habitats.In the present study we investigated the species composition and abundance of a small mammal community from a "campo de murundus", a characteristic vegetational type of Central Brazilian Cerrados. Two grids of Sherman traps were set and eight species of rodents was recorded. No marsupials were found in this habitat. The most abundant species were Bolomys lasiurus (Lund, 1841, Thalpomys lasiotis Thomas, 1916 and Calomys tener (Winge, 1888. Bolomys lasiurus was the most abundant species during the rainy season and T. lasiotis was more common in dry season. This may be a mechanism allowing their coexistence in the same habitats.
Naiff, Roberto Daibes; Barrett, Toby Vincent
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
Fisher, Robert D.; Ludwig, Craig A.
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.
Cooney, Joseph C; Burgdorfer, Willy; Painter, Martin K; Russell, Cynthia L
Studies were conducted over a four-county area of northwest Alabama to determine the association of eastern cottontail rabbits with Dermacentor variabilis, the eastern United States vector of Rocky Mountain spotted fever. A secondary objective was to compare infestations of this tick on rabbits with infestations on commonly encountered rodent species as a means of determining the relative importance of each in the disease transmission cycle. These epidemiologic surveys were conducted in response to reported fatal cases of Rocky Mountain Spotted Fever in two counties of the study area. From 202 eastern cottontail rabbits, 3,956 ticks were collected. Of this total, 79.87% were Haemphysalis leporispalustris, 9.15% Amblyomma americanum, 8.22% Ixodes dentatus, and 2.76% D. variabilis. Only immature stages of D. variabilis were collected from cottontail rabbits. Ticks were collected on rabbits in all months except November, and only one specimen was taken in January. Based on the average number of ticks per host collected in each month, April was the peak month for D. variabilis and I. dentatus. High values for H. leporispalustris also occurred at this time, but even higher values occurred in October and December. The heaviest infestation of A. americanum occurred during the month ofAugust and coincides with the activity period for the larvae of this species. Two hundred sixty-nine of the smaller Rodentia, comprising 13 species, yielded 264 ticks, all D. variabilis, and all but two were immature stages. Five rodent species, Microtus ochragaster Orozomys palustris, Peromyscus gossypinus, Peromyscus leucopus, and Sigmodon hispidus accounted for 95.83% of the ticks collected, and appeared to be preferred hosts for D. variabilis; all five had higher infestation levels per host than did the eastern cottontail rabbit. Data on host relationships in association with seasonal activity are presented. PMID:16599149
Teta, Pablo Vicente
La tribu Abrotrichini (Rodentia, Cricetidae) es uno de los clados de Sigmodontinae más recientemente diagnosticados. Su distribución es fundamentalmente andino-patagónica, con mayor diversidad de especies en el sur de Argentina y Chile. En esta tesis se evaluaron las relaciones filogenéticas entre sus integrantes, utilizando 21 taxones terminales (20 vivientes y uno fósil) y un grupo externo (Wiedomys). Se realizó un análisis cladístico a través de búsquedas exactas y heurísticas de 99 caract...
Fisher, Robert D.; Ludwig, Craig A.
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.
Fisher, Robert D.; Ludwig, Craig A.
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.
Cristina V. Cademartori
Full Text Available Reproductive Biology of Delomys dorsalis (HENSEL, 1872 -Rodentia, Sigmodontinae- in an area of mixed forest with conifers, at Rio Grande do Sul, Brasil. Delomys dorsalis is restricted to the wet tropical and subtropical forests of southern and southeastern Brazil and northeastern Argentina. The reproductive cycle of this species was studied by the histological examination of the reproductive tracts of animals caught in an area of mixed forest with conifers (29º 23´ S, 50º 23´ W, in southern Brazil, and from observations on a laboratory group of individuals. Fourteen expeditions were carried out from February 1997 to April 1998, during approximately 3 nights, using 140 live traps set on the ground and on branches between 1.5 and 2.0 m high. Reproductively active individuals were observed year round, although winter was marked by a reduction in breeding activity resulting from recruitment. Females showed a post-partum oestrus and a gestation time between 21 and 22 days. The litter size in captivity ranged from two to four, though pregnant females collected from the field had even five embryos. External reproductive features, frequently used as indicatives of the reproductive status of small mammals in ecological studies, were not accurate and underestimated the number of active animals in the population. Some individuals showed a remarkable scansorial ability that should be considered in future studies about population dynamics.
La presencia de Ixodes luciae en el noroeste argentino y nuevos huéspedes para Ixodes pararicinus y algunas especies de Amblyomma (Acari: Ixodidae Presence of Ixodes luciae in Argentina northwest and new hosts for Ixodes pararicinus and some species of Amblyomma (Acari: Ixodidae
Analía G. Autino
Full Text Available El análisis de una colección de garrapatas de mamíferos del noroeste argentino, depositados en la Colección de Anexos de la Colección Mamíferos Lillo (CML de la Universidad Nacional de Tucumán, permitió ampliar el área de distribución de Ixodes luciae Sénevet, a las provincias de Salta y Tucumán e incrementar su rango de huéspedes al roedor sigmodontino Calomys callosus (Rengger y a los marsupiales de la familia Didelphidae Micoureus constantiae (Thomas, Thylamys cinderella Thomas y Thylamys venustus (Thomas. Se registró a C . callosus y Oligoryzomys destructor (Tschudi como nuevos huéspedes de Ixodes pararicinus Keirans & Clifford, y a los Carnivora Lycalopex gymnocercus (Fischer y Oncifelis geoffroyi (d´Orbigny & Gervais como nuevos huéspedes de Amblyomma neumanni Ribaga y Amblyomma parvum Aragão, respectivamente. Adicionalmente, se observó la infestación de Lutreolina crassicaudata (Desmarest (Didelphidae por I. luciae y la presencia de Amblyomma tigrinum Koch, sobre L. gymnocercus . Ninfas de Amblyomma sp . se obtuvieron de Akodon Meyen (Sigmodontinae.The analysis of a tick collection of mammals from northwestern Argentina deposited in the Annexes (ACML of Colección Mamíferos Lillo (CML National University of Tucumán, amplified the distribution of Ixodes luciae Sénevet, to Salta and Tucumán provinces and increased the host range to the sigmodontinae rodent Calomys callosus (Rengger and the Didelphidae Micoureus constantiae (Thomas, Thylamys cinderella Thomas and Thylamys venustus (Thomas. Calomys callosus and Oligoryzomys destructor (Tschudi were registered as new hosts of Ixodes pararicinus Keirans & Clifford, and the Carnivora Lycalopex gymnocercus (Fischer and Oncifelis geoffroyi (d´Orbigny & Gervais as new hosts of Amblyomma neumanni Ribaga, and Amblyomma parvum Aragão, respectively . Lutreolina crassicaudata (Desmarest (Didelphidae was also found infested with I. luciae while Amblyomma tigrinum Koch was
Leishmaniose cutânea na Amazônia: isolamento de Leishmania (Viannia lainsoni do roedor Agouti paca (Rodentia: Dasyproctidae, no estado do Pará, Brasil Cutaneous leishmaniasis in the Amazon Region: isolation of Leishmania (Viannia lainsoni from the rodent Agouti paca (Rodentia: Dasyproctidae in Pará State, Brazil
Fernando T. Silveira
Full Text Available Fez-se o registro, pela primeira vez, do isolamento de Leishmania (V. lainsoni de um mamífero silvestre, o roedor Agouti paca (Rodentia: Dasyproctidae, no Estado do Pará, Brasil. As amostras do parasita foram isoladas da pele, aparentemente íntegra, de 3 espécimes desse roedor, capturados no município de Tucuruí (ilha de Tocantins, em área que seria inundada pela formação do lago da hidrelétrica construída naquele município. Nenhum isolamento foi obtido de vísceras de qualquer dos animais. A identificação das amostras de L. (V. lainsoni baseou-se na morfologia de amastigotas e promastigotas, no comportamento da infecção em "hamsters", na análise bioquímica de isoenzimas e, ainda, através de testes com anticorpos monoclonais. A natureza inaparente da infecção nos animais faz supor que o mamífero em questão possa representar um hospedeiro definitivo do parasita na região Amazônica.The isolation of Leishmania (V. lainsoni is recorded for the first time from a wild animal, the rodent Agouti paca (Rodentia: Dasyproctidae, from Pará State, north Brazil. Isolates of the parasite were made from apparently normal skin of 3 specimens of this rodent captured on the Island of Tocantins, in the municipality of Tucuruí, an area subsequently flooded in the formation of the lake associated with the Tucuruí hydroeletric dam. No isolations were made from the viscera. Identification of the parasite was in each case based on morphology of the amastigotes and promastigotes, behavior of the organism in hamsters, isoenzymes profiles and the use of monoclonal antibodies. The inapparent nature of the infection leads us to suggest that the "paca", Agouti paca, represents a primitive host of L. (V. lainsoni in the Amazon Region.
Redelsperger, François; Cornelis, Guillaume; Vernochet, Cécile; Tennant, Bud C; Catzeflis, François; Mulot, Baptiste; Heidmann, Odile; Heidmann, Thierry; Dupressoir, Anne
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
Range expansion of Oligoryzomys longicaudatus (Rodentia, Sigmodontinae in Patagonian Chile, and first record of Hantavirus in the region Ampliación del rango de distribución de Oligoryzomys longicaudatus (Rodentia, Sigmodontinae en la Patagonia de Chile y primer registro de Hantavirus en la región
Full Text Available At present, 20 species of Oligoryzomys (Rodentia, Sigmodontinae are recognized in the Neotropical region, most of them distinguished by their karyotypes, which fluctuates between 46-70 chromosomes. Two species are currently recognized in Chile, Oligoryzomys longicaudatus (Bennet, 1832; "colilargo" or the long-tailed pygmy rice rat; 2n = 56, which ranges from 27° to approximately 51° S, and O. magellanicus (Bennet, 1836; Magellanic pygmy rice rat; 2n = 54, south of 51° S in the Patagonian region of Chile and Argentina. As part of an ongoing research on the southern Patagonia of Chile, we report the results of small mammal samplings in six localities. We karyotyped 28 specimens and we also sequenced the hypervariable mtDNA region I in 22 individuals, aligning these sequences with an under development phylogeny of O. longicaudatus. We also evaluated the serology and viral charge in all captured specimens to detect the presence of antibodies to Andes virus (ANDV through Strip Immunoblot Assay (SIA, and of viral genome by RT-PCR. The results consistently showed that the karyotype of southern Patagonia specimens was 2n = 56, equal to that of O. longicaudatus, and that individuals from this area do not differentiate phylogenetically from those of the northern range of distribution. In addition, the serology showed the presence of antibodies IgG anti-ANDV and of viral genome in heart, kidney, spleen, and lungs of a single specimen of Oligoryzomys from the locality of Fuerte Bulnes in the Magallanes region. We conclude that all specimens trapped south of 51° S correspond to Oligoryzomys longicaudatus, thus expanding the distribution of this specie! from 51° to at least 55° S. The results also extended the disiribution of the Andes strain of Hantavirus to southernmost Patagonia.Actualmente se reconocen 20 especies de Oligoryzomys (Rodentia, Sigmodontinae en la región Neotropical, la mayoría de ellas distinguidas por sus cariotipos, los que fluct
Schumaker, T T; Labruna, M B; Abel, I dos S; Clerici, P T
The life cycle of Ixodes (Ixodes) loricatus Neumann, reared in the laboratory, is described. Engorged females collected from opossums trapped in the states of Minas Gerais and São Paulo, Brazil, which were used to start the laboratory colonies, were designated as BMG and CSP, respectively. Larval and nymphal ticks from both colonies fed separately on Rattus norvergicus Berkenhout or Calomys callosus Rengger, whereas Didelphis marsupialis L and Didelphis albiventris Lund were used as hosts for BMG and CSP adults, respectively. Biological and developmental data obtained from ticks of both the BMG and CSP colonies that were reared separately for two consecutive generations were compared. The percentage of fed or molted ticks reared on C. callosus was higher than that recorded for ticks fed on R. norvergicus in the majority of the observations. Despite significant differences among several of the biological parameters, the pattern of the life cycles of the two tick colonies was similar. Results indicated that the mean life cycle duration of I. (I.) loricatus was approximately 7 mo from parental oviposition to the occurrence of F1 eggs, regardless of geographic origin or host species. PMID:11004783
Bianchi, Rita De Cassia; Mendes, Sérgio Lucena
This study demonstrates that ocelots (Leopardus pardalis) extensively use primates as a food resource at the Caratinga Biological Station (CBS) in Southeast Brazil. Analysis of 60 fecal samples collected over 4 years revealed predation upon the brown howler monkey (Alouatta guariba), the muriqui (Brachyteles hypoxanthus), and the brown capuchin monkey (Cebus apella). The most frequent items found in the fecal samples analyzed were Calomys (n=16) and non-identified Aves (n=15), followed by A. guariba (n=12). Although Rodentia was the most common group consumed (n=52) Primates were found in 27% of total fecal samples and were the third most consumed group in relation to the total items. Particularly, predation of A. guariba by ocelots (20% of the total fecal samples) was not an isolated event; our results showed that this species was preyed on across several months. Predation on primates was far higher at CBS than at other sites where comparable studies have been carried out. PMID:17330310
Badenhorst, Daleen; Dobigny, Gauthier; Adega, Filomena; Chaves, Raquel; O’Brien, Patricia C. M.; Ferguson-Smith, Malcolm A; Waters, Paul D.; Robinson, Terence J
The Rattini (Muridae, Murinae) includes the biologically important model species Rattus norvegicus (RNO) and represents a group of rodents that are of clinical, agricultural and epidemiological importance. We present a comparative molecular cytogenetic investigation of ten Rattini species representative of the genera Maxomys, Leopoldamys, Niviventer, Berylmys, Bandicota and Rattus using chromosome banding, cross-species painting (Zoo-fluorescent in situ hybridization or FISH) and BAC-FISH map...
Julieta Machado Paçô
Full Text Available A total of 25 specimens of Cavia porcellus (guinea pig, 5 Dasyprocta agouti (agouti, and 22 Calomys callosus (vesper mice were inoculated with infective eggs of Lagochilascaris minor. The inoculum was prepared with embryonated eggs and orally administered to each individual animal through an esophagus probe. In parallel, 100 specimens of Felis catus domesticus were individually fed with 55-70 nodules containing 3rd-stage larvae encysted in tissues of infected rodents. Animals were examined and necropsied at different time intervals. The migration and encystment of L3 larva was observed in viscera, skeletal muscle, adipose and subcutaneous tissues from all rodents. Adult worms localized at abscesses in the cervical region, rhino, and oropharynx were recovered from domestic cats inoculated with infected rodent tissues. Through this study we can conclude that: (1 wild rodents act as intermediate hosts, characterizing this ascarid heteroxenic cycle; (2 in natural conditions rodents could possibly act as either intermediate hosts or paratenic hosts of Lagochilascaris minor; (3 despite the occurrence of an auto-infecting cycle, in prime-infection of felines (definite hosts the cycle is only completed when intermediate hosts are provided; and (4 in the wild, rodents could serve as a source of infection for humans as they are frequently used as food in regions with the highest incidence of human lagochilascariasis.
Vitaliano, S N; Mineo, T W P; André, M R; Machado, R Z; Mineo, J R; Werther, K
Toxoplasma gondii affects mainly warm-blooded animals, including birds. Even though previous experimental data indicate that raptors are resistant to clinical infection, there is no information regarding the susceptibility of Brazilian birds of prey to T. gondii. The present study aimed to observe how the crested caracara, a common raptor in Brazil, interacts with T. gondii using an experimental model. Seven crested caracaras, seronegative for T. gondii, were separated into infected (n=5) and control groups (n=2). Birds from the infected group were fed T. gondii-infected Calomys callosus, a rodent present in Brazilian savanna and described as highly susceptible to infection by the parasite, for three consecutive days, while control animals were fed non-infected rodents. All infected birds produced T. gondii-specific IgG antibodies that were firstly detected at day 7 post-infection, with peak production detected between 15 and 30dpi. No significant alterations in clinical and hematological parameters were observed throughout the experimental period, and parasites were sparsely found in muscular tissues after the birds were euthanized. In conclusion, our results demonstrated that crested caracaras are resistant to oral infection with T. gondii, suggesting that the host-parasite relationship between both species has reached a remarkable equilibrium. PMID:20451327
Wolf, Rafael William; Aragona, Mônica; Muñoz-Leal, Sebastián; Pinto, Leticia Borges; Melo, Andréia Lima Tomé; Braga, Isis Assis; Dos Santos Costa, Jackeliny; Martins, Thiago Fernandes; Marcili, Arlei; de Campos Pacheco, Richard; Labruna, Marcelo B; Aguiar, Daniel Moura
Taking into account the diversity of small terrestrial mammals of the Pantanal, the present study aimed to verify the occurrence of infection by Ehrlichia spp., Anaplasma spp., Rickettsia spp., Hepatozoon spp., Babesia spp. and parasitism by ticks in non-volant small mammals collected in the Brazilian Pantanal. Samples of blood, liver and spleen were collected from 64 captured animals, 22 marsupials and 42 rodents. Pathogen detection was performed by the use of genus-specific Polymerase Chain Reaction (PCR) assays. Ticks collected from the animals consisted of Amblyomma sculptum and Amblyomma triste nymphs, and Ornithodoros guaporensis larvae. None of the vertebrate samples (blood, liver, or spleen) yielded detectable DNA of Rickettsia spp. or Ehrlichia spp. The blood of the rodent Hylaeamys megacephalus yielded an Anaplasma sp. genotype (partial 16S rRNA gene) 99% similar to multiple Anaplasma spp. genotypes around the world. The blood of three rodents of the species Calomys callosus were positive for a novel Hepatozoon sp. agent, phylogenetically related (18S rDNA gene) to distinct Hepatozoon genotypes that have been detected in rodents from different parts of the world. One marsupial (Monodelphis domestica) and three rodents (Thrichomys pachyurus) were positive to novel piroplasmid genotypes, phylogenetically (18S rDNA gene) related to Theileria bicornis, Cytauxzoon manul, and Cytauxzoon felis. The present study provides the first molecular detection of Hepatozoon sp. and piroplasmids in small mammals in Brazil. Additionally, we expanded the distribution of O. guaporensis to Brazil, since this tick species was previously known to occur only in Bolivia. PMID:26782931
Krawczak, Felipe S; Agostinho, Washington C; Polo, Gina; Moraes-Filho, Jonas; Labruna, Marcelo B
In 2010, a novel spotted fever group rickettsiosis was reported in the Atlantic rainforest coast of Brazil. The etiological agent was identified as Rickettsia sp. strain Atlantic rainforest, and the tick Amblyomma ovale was incriminated as the presumed vector. The present study evaluated under laboratory conditions four colonies of A. ovale: two started from engorged females that were naturally infected by Rickettsia sp. strain Atlantic rainforest (designated as infected groups); the two others started from noninfected females (designated as control groups). All colonies were reared in parallel from F0 engorged female to F2 unfed nymphs. Tick-naïve vesper mice (Calomys callosus) or domestic rabbits were used for feeding of each tick stage. Rickettsia sp. strain Atlantic rainforest was preserved by transstadial maintenance and transovarial transmission in A. ovale ticks for at least 2 generations (from F0 females to F2 nymphs), because nearly 100% of the tested larvae, nymphs, and adults from the infected groups were shown by PCR to contain rickettsial DNA. All vesper mice and rabbits infested by larvae and nymphs, and 50% of the rabbits infested by adults from the infected groups seroconverted, indicating that these tick stages were vector competent for Rickettsia sp. strain Atlantic rainforest. Expressive differences in mortality rates and reproductive performance were observed between engorged females from the infected and control groups, as indicated by 75.0% and 97.1% oviposition success, respectively, and significantly lower egg mass weight, conversion efficiency index, and percentage of egg hatching for the infected groups. Our results indicate that A. ovale can act as a natural reservoir for Rickettsia sp. strain Atlantic rainforest. However, due to deleterious effect caused by this rickettsial agent on engorged females, amplifier vertebrate hosts might be necessary for persistent perpetuation of Rickettsia sp. strain Atlantic rainforest in A. ovale under
Ferreira, Thais M F; Olivares, Adriana Itati; Kerber, Leonardo; Dutra, Rodrigo P; Avilla, Leonardo S
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
Fonseca, Maria Joao; Franco, Nuno H.; Brosseron, Francis; Tavares, Fernando; Olsson, I. Anna S.; Borlido-Santos, Julio
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…
Arslan, A.; Zima, Jan
Roč. 64, č. 4 (2012), s. 421-426. ISSN 0324-0770 Institutional support: RVO:68081766 Keywords : karyotype * C-banding * Ag-NOR staining * Caucasian squirrel * Turkey Subject RIV: EG - Zoology Impact factor: 0.309, year: 2012 http://www.acta- zoologica -bulgarica.eu/downloads/acta- zoologica -bulgarica/2012/64-4-421-426.pdf
Ana Rosa Gómez Cano; Manuel Hernández Fernández; M Ángeles Alvarez-Sierra
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 base...
Ana Rosa Gómez Cano
Full Text Available 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.
Reports about albinism in rodents are common. In the family Echimyidae, however, albinism is very rare. This is the second case of coat color variation reported within Echimyidae and the first for the genus Thrichomys. The pelages of Thrichomys pachyurus individuals with normal and variant coat color were observed under a fluorescent artificial light and were examined with a stereoscopic microscope. The descriptions of pelage color were based on the book "Color Standards and Color Nomenclatur...
Antonio Carlos da S.A. Neves
Full Text Available Reports about albinism in rodents are common. In the family Echimyidae, however, albinism is very rare. This is the second case of coat color variation reported within Echimyidae and the first for the genus Thrichomys. The pelages of Thrichomys pachyurus individuals with normal and variant coat color were observed under a fluorescent artificial light and were examined with a stereoscopic microscope. The descriptions of pelage color were based on the book "Color Standards and Color Nomenclature". The predominantly white pattern of coat color in individuals of T. pachyurus suggests a partial albinism caused by delay in migration time of melanoblasts from neural crest to epidermis. The habitat of T. pachyurus has a heavy vegetative cover, which offers natural protection against predators and high-quality nutrition.
Robertsonian chromosome polymorphism of Akodon molinae (Rodentia: Sigmodontinae: analysis of trivalents in meiotic prophase Polimorfismo cromosómico Robertsoniano de Akodon molinae (Rodentia: Sigmodontinae
Full Text Available Akodon molinae (with 2n = 42-43-44 and an FN = 44 shows a remarkable polymorphism of chromosome 1 in natural and laboratory populations. Specimens 2n = 42, named single homozygotes (SH, have a chromosome pair 1 formed by two large metacentric chromosomes. Specimens 2n = 3, heterozygotes (Ht, have one chromosome 1 and two medium-sized subtelocentric chromosomes, 1a and 1b, which are homologous with the long and short arms of chromosome 1 respectively. Specimens 2n = 44 are double homozygotes (DH, with just two pairs of medium-sized subtelocentric chromosomes, 1a and 1b. Analysis of meiotic metaphases I and II showed that anomalous segregation occurs more frequently in spermatocytes carrying the 1a and 1b chromosomes. This would disturb gametogenesis and other reproductive and developmental processes, producing a marked decrease in viability of DH individuals. There is, as yet, no satisfactory explanation for these phenomena. To investigate structural elements which might explain such segregational anomalies, we have studied bivalent and trivalent synapsis in pachytene spermatocytes from SH, Ht and DH specimens. Of a total of 80 spermatocyte nuclei microspreads, the following results were obtained: of 16 microspreads from two SH individuals, 20 autosomic bivalents plus the XY bivalent were observed; of 48 microspreads from three Ht individuals, 19 autosomic bivalents, 1 trivalent and an XY bivalent were seen; and of the 16 microspreads from two DH individuals, 21 autosomic bivalents plus the XY bivalent were found. Trivalents analysed showed complete pairing between the short arms of 1a and 1b, and having an apparently normal synaptonemal complex (SC with lengths of 1 and 2.8 µm. The trivalent SC showed three telomeric ends, corresponding to arms: q1 and q1a; p1 and q1b; and p1a and p1b, with attachment plates to the nuclear envelope of normal organisation. None of the trivalents showed asynapsis or desynapsis between p1a and p1b, nor an association with the XY bivalent. In 70 % of spermatocytes studied, the XY bivalent showed complete pairing between X and Y, with SC formation along the whole length of the Y chromosome. The remaining 30 % showed partial pairing, with an SC length which varied from the common end. Based on these findings and those of previous studies, we discuss: 1.- that the obliged configuration of the trivalent, with SC formation between the short arms of 1a and 1b, helps to assure a quasi normal segregation between 1, 1a and 1b in anaphase I of Ht meiosis; and 2.- that co-existence in trivalents of chromosomes 1, 1a and 1b in Ht individuals, breaks down the structural and functional integrity of the short arms of 1a and 1b, producing an accumulative damage which would also explain the decreased viability of individuals bearing these chromosomesAkodon molinae con 2n = 42-43-44 y FN = 44 presenta un notable polimorfismo en el cromosoma 1 en poblaciones naturales y de laboratorio, los individuos 2n = 42 tienen un par 1 formado por dos cromosomas metacéntricos grandes y son denominados homocigotos simples (SH; los individuos 2n = 43, heterocigotos (Ht, presentan un cromosoma 1 y dos cromosomas subtelocéntricos de tamaño medio 1a and 1b, que son homólogos con los brazos largo y corto del 1, respectivamente; y los individuos 2n = 44 que son los doble homocigotos (DH y presentan dos pares de cromosomas subtelocéntricos 1a y 1b. Análisis de la metafases I y II meióticas han demostrado que se producen segregaciones anómalas con una alta frecuencia en los espermatocitos portadores de los cromosomas 1a and 1b. Ello alteraría a otros procesos, como la gametogénesis, la reproducción y el desarrollo, disminuyendo la viabilidad individual y poblacional de los DH. No ha habido una explicación satisfactoria para estos fenómenos. Para investigar elementos estructurales que pudiesen explicar tales alteraciones segregacionales, se estudió la sinapsis de bivalentes y trivalentes en espermatocitos en paquiteno de ejemplares SH, Ht y DH. De un total de 80 microesparcidos de núcleos de espermatocitos: en 16 núcleos de ejemplares SH se observaron 20 bivalentes autosómicos más el bivalente XY; en 48 núcleos de Ht se observaron 19 bivalentes autosómicos, 1 trivalente y un bivalente XY; y en 16 núcleos de DH se observaron 21 bivalentes autosómicos más el bivalente XY. Los trivalentes analizados mostraron apareamiento completo entre los brazos cortos de 1a y 1b conformándose un complejo sinaptonémico (CS aparentemente normal con una longitud entre 1 µm y 2,8 µm. El CS de los trivalentes presentó tres extremos teloméricos correspondientes a los brazos: q1 y q1a, p1 y q1b y p1a y p1b, con placas de inserción a la envoltura nuclear de organización normal. En ninguno de los trivalentes se observó asinapsis o desinapsis entre p1a y p1b, ni asociaciones con el bivalente XY. En el 70 % de los espermatocitos estudiados el bivalente XY mostró apareamiento completo entre X e Y, con formación de CS en toda la longitud del cromosoma Y. El 30 % restante presentó apareamiento parcial con un CS de longitud variable a partir del extremo común. Sobre la base de los resultados de este trabajo y los antecedentes existentes, se discute: 1.- que la configuración obligada del trivalente con formación de CS entre los brazos cortos de 1a y 1b, contribuye a asegurar la segregación cuasi normal entre 1, 1a y 1b en la I anafase de la meiosis de los Ht; y 2.- que la coexistencia en los trivalentes de los cromosomas 1, 1a y 1b en los Ht, erosiona la integridad estructural y funcional de los brazos cortos de 1a y 1b, daño que sería acumulativo y que explicaría la viabilidad disminuída de los individuos portadores de estos cromosomas
Maria Claudene Barros
Full Text Available A new molecular phylogeny for akodontine rodents from Brazil was proposed. The phylogenetic tree was enriched with the area of occurrence and with information on the karyotype of the samples. Based on this enriched tree, and with a described methodology, hypotheses were proposed on the karyotype and area of occurrence of the ancestors of each Clade. Thus it was possible to discuss hypotheses on chromosome evolution of the group, and on dispersion events from the "area of original differentiation" of akodontines in the Andes. Chromosome evolution started with high diploid numbers (2n=52 and showed a tendency to reduction (until 2n=14 in more recent clades. Independent side-branches of the tree showed 2n reduction and in one case the 2n increased. At least four dispersion events from the Andes down to South-eastern Brazil were proposed. The results should suggest the direction of new studies on comparative karyology.Uma nova filogenia molecular para roedores akodontinos do Brasil é proposta. A árvore filogenética foi enriquecida com a área de ocorrência e com informações sobre o cariótipo das amostras. Baseado nisto, e com a metodologia descrita, foram propostas hipóteses sobre as características do cariótipo e sobre a área de ocorrência dos ancestrais de cada clado. Assim, foi possível discutir hipóteses sobre evolução cromossômica do grupo, e sobre eventos de dispersão a partir da área de diferenciação original dos akodontinos nos Andes. A evolução cromossômica começou com números diplóides altos (2n=52 e mostrou uma tendência a redução (até 2n=14 em clados mais recentes. Ramos independentes da árvore mostraram redução do 2n e num caso aumentou o numero diplóide. Foram propostos pelo menos quatro eventos de dispersão dos Andes até o Brasil Sul-Oriental. Os resultados indicam a direção de novos estudos em cariologia comparada.
Full Text Available Siete ejemplares de Sciurus granatensis (ardilla colombiana de diferentes fenotipos según color, rescatadas del tráfico ilegal de fauna silvestre de Colombia fueron estudiadas. Mediante técnicas convencionales de bandeo cromosómico G, C, Q, R y NOR se estableció su cariotipo 2n=42. Se encontraron tres cariomorfos de acuerdo al Número Fundamental (NF y características propias de cada uno de los complementos ocasionadas por distintos rearreglos cromosómicos, lo cual sugiere que S. granatensis es un complejo de especies. No se observó relación entre cariotipo y fenotipo. La variación en el color del pelaje se debe probablemente a las condiciones ambientales.Seven specimens of Sciurus granatensis (redtailed squirrel rescued from illegal fauna traffic in Colombia were studied; they had different phenotypes according to colour. G, C, Q, R and NOR chromosome banding was used, being found a 2n=42 diploid number for the Sciurus granatensis Colombian squirrels. There were 3 karyomorphs according to fundamental number (FN and different chromosomal characteristics caused by rearregement, suggesting that S. granatensis represents a complex of species. Relationships between karyotype and phenotype were not observed. The variation in the colour of sqirrels’ fur was probably due to environmental conditions.
Chacón Marcos Nicolás
Full Text Available Siete ejemplares de Sciurus granatensis (ardilla colombiana de diferentes fenotipos según color, rescatadas del tráfico ilegal de fauna silvestre de Colombia fueron estudiadas. Mediante técnicas convencionales de bandeo cromosómico G, C, Q, R y NOR se estableció su cariotipo 2n=42. Se encontraron tres cariomorfos de acuerdo al Número Fundamental (NF y características propias de cada uno de los complementos ocasionadas por distintos rearreglos cromosómicos, lo cual sugiere que S. granatensis es un complejo de especies. No se observó relación entre cariotipo y fenotipo. La variación en el color del pelaje se debe probablemente a las condiciones ambientales.Seven specimens of Sciurus granatensis (redtailed squirrel rescued from illegal fauna traffic in Colombia were studied; they had different phenotypes according to colour. G, C, Q, R and NOR chromosome banding was used, being found a 2n=42 diploid number for the Sciurus granatensis Colombian squirrels. There were 3 karyomorphs according to fundamental number (FN and different chromosomal characteristics caused by rearregement, suggesting that S. granatensis represents a complex of species. Relationships between karyotype and phenotype were not observed. The variation in the colour of sqirrels' fur was probably due to environmental conditions.
MOIRA S. SOMBRA; ANTONIO M MANGIONE
The diet of mara (Dolichotis patagonum, Zimmeraman 1780) within the limits of Sierra de las Quijadas National Park (San Luis, Argentina) is described. Other studies regarding mara’s diet showed that mara, feeds on different species of grasses and shrubs. However, there is controversy regarding the proportions of these items in the diet or whether this proportion varies seasonally. Considering mara’s body size, anatomical features and physiology, we suggest that mara feeds on grasses in a grea...
MOIRA S. SOMBRA
Full Text Available The diet of mara (Dolichotis patagonum, Zimmeraman 1780 within the limits of Sierra de las Quijadas National Park (San Luis, Argentina is described. Other studies regarding mara’s diet showed that mara, feeds on different species of grasses and shrubs. However, there is controversy regarding the proportions of these items in the diet or whether this proportion varies seasonally. Considering mara’s body size, anatomical features and physiology, we suggest that mara feeds on grasses in a greater proportion than shrubs and forbs. Moreover, giving that in this region precipitation varies considerably between seasons; it is also expected to find a correlation between the diet of mara and seasons. Fecal pellets of mara were collected during four periods including two dry, and two wet seasons. Relative frequency of each item in scats was determined by microhistological analysis. Results support the hypothesis that mara shows preference for grasses, despite they are less available than shrubs and forbs and that this preference remains constant through seasons regardless of the precipitation regime. The characteristics of mara’s diet and the ecological implications of these findings are discussedEn este trabajo se describe la dieta de mara (Dolichotis patagonum Zimmeraman 1780 en el Parque Nacional Sierra de las Quijadas (San Luis, Argentina. Los estudios realizados sobre su dieta indican que se alimenta de varias especies de gramíneas y arbustos. Sin embargo, existe cierta controversia acerca de la proporción en que se presentan estos ítemes, y si las mismas varían estacionalmente. En base al tamaño corporal de mara, y a sus características anatómicas y fisiológicas se propone que, mara consume una mayor proporción de gramíneas que de otras hierbas no graminiformes y dicotiledóneas en general. Además esperamos una variación estacional de la dieta, correlacionada a una posible variación estacional en los recursos alimentarios asociada a las precipitaciones. Se colectaron muestras de heces correspondientes a cuatro estaciones en el parque, dos estaciones secas y dos lluviosas. Mediante análisis microhistológico se determinó la proporción de cada ítem medido como frecuencia de aparición en las heces. Los resultados apoyan la hipótesis de un consumo preferencial de gramíneas por parte de mara. Las gramíneas aparecen en mayor proporción en la dieta a pesar de estar en menor disponibilidad en el hábitat y sin que el régimen de precipitación tenga algún efecto Se discuten las características de la dieta de mara y las implicancias ecológicas relacionadas con esta especie
C. DANIEL ANTINUCHI
Full Text Available In this work, we evaluated the energetic status, activity daily metabolic rate, thermoregulatory capacity and the existence of torpor in Akodon azarae (Fisher 1829. Basal metabolic rate (BMR was similar to the expected value from Kleiber´s, and also according to the BMR of phylogenetically related species. No statistical difference in BMR between sexes was detected. For both males and females, activity daily metabolic rate was 235 % of BMR. Body temperature was not statistically different, neither at different ambient temperatures nor between sexes. In the thermoneutral zone, body temperature was 36.1 ± 1.5 °C. Thermal conductance was lower than the expected for mammals whereas thermoregulatory capacity was 136 % of the expected. Akodon azarae did not show evidence of torporEn este trabajo fueron evaluadas, para Akodon azarae (Fisher 1829, la tasa metabólica basal (BMR y de actividad diaria así como la capacidad termorregulatoria y la posible existencia de torpor. La BMR no presentó diferencias estadísticas con la esperada por la ecuación de Kleiber así como con la esperada para especies filogenéticamente relacionadas. Tampoco fueron detectadas diferencias significativas en la BMR entre sexos. La tasa metabólica de actividad diaria para ambos sexos fue el 235 % de la BMR. La temperatura corporal no presentó variaciones entre individuos mantenidos a diferentes temperaturas ambiente ni tampoco entre sexos y en termoneutralidad fue de 36,1 ± 1,5 °C. Por otra parte, la conductancia térmica fue menor a la esperada mientras que la capacidad termorregulatoria fue el 136% de la esperada. Akodon azarae no presenta sopor
Full Text Available 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.
Full Text Available It has been shown that the local extinction of large-bodied frugivores may cause cascading consequences for plant recruitment and overall plant diversity. However, to what extent the resilient mammals can compensate the role of seed dispersal in defaunated sites is poorly understood. Caviomorph rodents, especially Dasyprocta spp., are usually resilient frugivores in hunted forests and their seed caching behavior may be important for many plant species which lack primary dispersers. We compared the effect of the variation in seed mass of six vertebrate-dispersed plant species on the caching decision by the red-rumped agoutis Dasyprocta leporina Linnaeus, 1758 in a land-bridge island of the Atlantic forest, Brazil. We found a strong positive effect of seed mass on seed fate and dispersal distance, but there was a great variation between species. Agoutis never cached seeds smaller than 0.9 g and larger seeds were dispersed for longer distances. Therefore, agoutis can be important seed dispersers of large-seeded species in defaunated forests.
Fabiana de Oliveira Lara-Silva
Full Text Available 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.
Full Text Available Notocotylus loeiensis n. sp. (Trematoda: Notocotylidae is described from the cecum of the lesser rice field rat (Rattus losea, from Loei Province in Thailand with a prevalence of 9.1% (eight of 88 rats infected. The new species differs from previously described Notocotylus species mainly by the extreme prebifurcal position of the genital pore and the number of ventral papillae. This is the first description at the species level of Notocotylus from mammals in Southeast Asia.
Chaisiri K.; Morand S.; Ribas A.
Notocotylus loeiensis n. sp. (Trematoda: Notocotylidae) is described from the cecum of the lesser rice field rat (Rattus losea), from Loei Province in Thailand with a prevalence of 9.1% (eight of 88 rats infected). The new species differs from previously described Notocotylus species mainly by the extreme prebifurcal position of the genital pore and the number of ventral papillae. This is the first description at the species level of Notocotylus from mammals in Southeast Asia.
Full Text Available 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.
Thomas, H. G.; Scantlebury, M.; Swanepoel, D.; Bateman, P. W.; Bennett, N. C.
Sociality in mole rats has been suggested to have evolved as a response to the widely dispersed food resources and the limited burrowing opportunities that result from sporadic rainfall events. In the most arid regions, individual foraging efficiency is reduced, and energetic constraints increase. In this study, we investigate seasonal differences in burrow architecture of the social Cryptomys hottentotus hottentotus in a mesic region. We describe burrow geometry in response to seasonal weather conditions for two seasons (wet and dry). Interactions occurred between seasons and colony size for the size of the burrow systems, but not the shape of the burrow systems. The fractal dimension values of the burrow systems did not differ between seasons. Thus, the burrow complexity was dependent upon the number of mole rats present in the social group.
Matulová, Petra; Witter, K.; Míšek, Ivan
Roč. 43, 2/3 (2002), s. 138-142. ISSN 0300-8207 R&D Projects: GA AV ČR IAA7039901; GA ČR GP304/01/P021; GA MŠk OC B8.20; GA AV ČR KSK6005114 Keywords : dentition * odontogenesis * proliferation marker Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.646, year: 2002
José Geraldo Pereira da Cruz
Full Text Available In the wild, animals are exposed to an ever-changing array of sensory stimuli. The captive environment, by contrast, is generally much more impoverished in terms of the cues it offers the animals housed within. In a bid to remedy this, and promote better welfare, mice (Mus musculus were exposed to two conditions: no auditory stimulation, and stimulation with classical music. In all experiments, a battery of behavior tests was used. The results demonstrated significantly decreased immobility in the forced swim, increased enclosed arm entries in the plus-maze, and decreased immobility in the open-field, in animals that had been pre-exposed to music 24h earlier, suggesting that changes in mouse motor activity were caused by classical music. This study led to the conclusion that environmental enrichment may have profound effects on the behavior of mice in behavioral tests, and that classical music can be a relatively simple method of contributing to the well-being of captive mice, but it can affect the results of experiments such as forced swimming.
José Geraldo Pereira da Cruz; Débora Delwing Dal Magro; Júlia Niehues da Cruz
In the wild, animals are exposed to an ever-changing array of sensory stimuli. The captive environment, by contrast, is generally much more impoverished in terms of the cues it offers the animals housed within. In a bid to remedy this, and promote better welfare, mice (Mus musculus) were exposed to two conditions: no auditory stimulation, and stimulation with classical music. In all experiments, a battery of behavior tests was used. The results demonstrated significantly decreased immobility ...
Carter, Anthony Michael; Enders, A C; Jones, C J P; Keovichit, P K; Hugot, J P
. There was a single fetus that very likely would be precocial at birth. DISCUSSION: A lobulated labyrinth and the presence of a subplacenta and a fibrovascular ring emerged as synapomorphies for Hystricognathi. Laonastes, Ctenodactylus and stem Hystricognathi all had precocial young, whereas altriciality...
Markowski, D.; Ginsberg, H.S.; Hyland, K.E.; Hu, R.
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.
William Burgos-Paz; Mario Cerón-Muñoz; Carlos Solarte-Portilla
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 differen...
Arslan, A.; Zima, Jan; Yorulmaz, T.; Gözütok, S.; Toyran, K.
Roč. 61, 1-2 (2013), s. 47-51. ISSN 0015-5497 Institutional support: RVO:68081766 Keywords : AgNOR staining * Anatolia * C-banding * Glis glis * Myodes glareorus Subject RIV: EG - Zoology Impact factor: 0.478, year: 2013
Juana Luis; Lorena Ramírez; Agustín Carmona; Guadalupe Ortiz; Jesús Delgado; René Cárdenas
Aunque inicialmente se pensaba que la testosterona inhibía el despliegue de conducta paterna en los machos de roedores, en algunas especies se ha demostrado que son necesarios niveles altos de testosterona para la exhibición de cuidados paternos. En cautiverio, los machos del ratón mexicano de los volcanes (Neotomodon alstoni), proporcionan a sus crías los mismos cuidados que la madre, con la excepción del amamantamiento. En este estudio se midieron los niveles plasmáticos de testosterona: en...
New records of three rare rodent species from SE Bulgaria are reported, as follows: European Snow Vole (Chionomys nivalis) – Madzharovo Town, Eastern Rhodope Mountains (UTM MG01); Gray Dwarf Hamster (Cricetulus migratorius) –Matochina Village (UTM MG 63); and Roach's Mouse-tailed Dormouse (Myomimus roachi) –Malki Voden Village, Eastern Rhodope Mountains (UTM MG11). All three species were found in the food remains of two owl species: the Barn Owl (Tyto alba) and the Tawny Owl (Strix aluco), an...
Kim, Eun Bae; Lee, Sang-Goo
The complete mitochondrial genome of the Mongolian gerbil, Meriones unguiculatus, was sequenced. The 16,360 bp long genome has 37 genes typical for rodent mitogenomes, including 22 tRNA genes, 2 rRNA genes, and 13 protein-coding genes. The total GC content of the mitochondrial genome is 36.96% with the base composition of 32.61% A, 23.71% C, 13.24% G, and 30.44% T. Translational terminators of three genes (cytb, cox3, and nad4) were generated by the addition of 3' A residues to the mRNA. This novel rodent mitochondrial genome will provide comparable information for understanding the rodent mitochondrial evolution. PMID:25185794
Abiadh, Awatef; Chetoui, M'barek; Lamine-Cheniti, Taher; Capanna, Ernesto; Colangelo, Paolo
Although gerbils forms an important component of the mammalian fauna of arid and semi-arid area, the taxonomic and phylogenetic relationship within the species of the genus Gerbillus are still ambiguous. The present paper introduces findings based on the whole cytochrome b (1140 bp) mitochondrial genes of seven species (Gerbillus campestris, G. latastei, G. nanus, G. tarabuli, G. gerbillus, G. simoni and G. nigeriae) six of which are present in Tunisia. Our results show that all the Gerbillus species are monophyletic. Moreover, molecular phylogeny rejects the genus rank for the taxon Dipodillus. Gebillus nanus, a species belonging to the subgenus Hendecapleura, early diverged from the other species which are divided into two clades: the subgenus Dipodillus, including G. campestris and G. simoni and the subgenus Gerbillus including G. gerbillus, G. nigeriae, G. tarabuli and G. latastei. These results are congruent with morphological and karyological evidences. According to molecular clock, the appearance of the genus Gerbillus coincides with the Miocene-Pliocene expansion of African arid biomes. Extensive intraspecific chromosomal changes evolved in a relatively narrow lapse of time, like in the case of G. latastei, allowing the fixations of different chromosomal variants due to pericentric inversion. PMID:20412863
Cleber J.R. Alho
Full Text Available (1 The Pantanal is the central portion of a sunken flat plain bordering the upper Paraguay river, with an area of 140,000 km². Seasonal floods begin in January and end in April. From May to October the land dries out and campos (grassland formations and scattered pools appear. (2 Typical capybara habitat in the Pantanal is composed of three components: the water, a patch of forest, and a grass field for foraging. Highest densities of capybaras (14 individuals/km² were found during the rainy season when the available space for capybaras was reduced due to the flooding. Areas without ponds or creeks presented low densities (from 0.38 to 0.84 capybaras/km². Group sizes ranged from 2 to 49 individuals (x = 9.48. (3 Reproduction occurred year-round and young of different ages were seen throughout the year. However, the principal recruitment of young to the population was observed in July-August. While the females took turns in caring for young of different ages, probably the offspring of mothers who are sisters in the same social groups, the males competed intensively with each other for access to breeding females. The male's reproductive success appears to be limited to the number of breeding females that males have access to in the social group.
A. L. Cherubini; T. H. Barrella; R. J. DA SILVA
The objective of this paper is to report the death of a Boa constrictor amarali after ingestion of a tree porcupine. The animal was donated to the Center for the Study of Venoms and Venomous Animals (CEVAP/UNESP) - and died in captivity. At necropsy, spine-like structures were observed in the stomach serosa and vicinity, and the stomach mucosa showed an intense reddish area, suggesting inflammation. The analysis of the spine-like structure revealed that they were tree porcupine spines. The fe...
Full Text Available Parasitic investigations of the subspecies Mus mayori pococki were carried out in four rainforests that included two man and biosphere reserves and two forest reserves of Sri Lanka from October 2006 to August 2007. Rodents were live-trapped using Shermans traps. Of the 117 individuals of M. m. pococki captured 73% were infested with four types of ectoparasites mites of the genus Echinolaelaps, a louse Polyplax serrata, a larval stage of hard tick Ixodes and pseudoscorpions of the genus Megachernes. Mites were the most abundant ectoparasite of this rodent host. Faecal examination revealed the presence of a nematode larva of the Order Strongylida and five types of parasitic ova; three nematode ova types i.e. strongyle, strongyloides, ascarid types, and cestode and mite ova. In comparison to the non-infested hosts, those infested did not show a significant difference in body weight and size. Both sexes had an equal probability of being exposed to ectoparasites. The present study on the parasitic investigations of M. m. pococki reports four new host-ectoparasite and six new endoparasitic records for the Sri Lankan rodent host.
Leirs, Herwig; Verheyen, Walter; Verhagen, Ron
We investigated habitat preference, dispersal and movement patterns of Mastomys natalensis in fallow land and maize fields in Tanzania. During periods of low densities, the animals seemed to avoid open spaces and were concentrated in areas with rich vegetation cover. A high turn-over rate, even in...
Philip G. Cox
Full Text Available 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.
Bueno Angulo Marta Lucía
Full Text Available Debido a la poca información ecológica, taxonómica o genética sobre las ardillas colombianas, existen problemas
sistemáticos aun no resueltos (Emmons LH, 1990, lo cual dificulta la reubicación y/o liberación de ejemplares sin procedencia, provenientes del tráfico ilegal de fauna silvestre. Estudios cariológicos sirven para detectar variaciones intra e interespecíficas por lo que en este trabajo se busco detectar diferencias cariotípicas entre varios fenotipos Sciurus granatensis. La diferenciación genética en conservación, puede ser una herramienta
útil en la toma de decisiones en los procesos de liberación de ejemplares capturados, dado que la introducción
de individuos con genomas diferentes en un población puede originar un proceso de depresión por exogamia o introgresión genética (pérdida de alelos adaptativos locales, procesos nocivos para la población receptora. Se estudiaron siete especímenes (cinco hembras y dos machos de S. granatensis procedentes del tráfico ilegal. Los cariotipos fueron obtenidos a partir de cultivos de linfocitos de sangre periférica. Las metafases con bandas G, R, C, Q y NOR, se analizaron al microscopio y se ordenaron en el programa Lucia Karyotyping®. Los individuos estudiados corresponden a los tres fenotipos reportados por Emmons LH, 1990, pero con una gran variación cariológica. Solo uno de los machos no corresponde a los fenotipos descritos, y además presenta varios rearreglos cromosómicos que lo diferencian notablemente de los demás, por lo cual posiblemente se trate de un híbrido estéril originado de dos poblaciones diferenciadas cariológicamente. El número de cromosomas fue constante (2n=42, con variación en el número fundamental (NF=80; 81, por lo cual se reportan tres cariomorfos para Sciurus granatensis, según NF y los rearreglos cromosómicos encontrados. Se observó variación en los pares 9, 16 y una translocación universal entre autosomas dentro de uno de los ejemplares. El cromosoma X es submetacéntrico mediano. El cromosoma Y es acrocéntrico, coincidente con lo descrito para Sciurus. No se registró una relación cariotipo-fenotipo. Por lo tanto se puede sugerir que Sciurus granatensis, es un complejo de especies con diferencias cariológicas y morfológicas que no ha sido estudiado a profundidad teniendo en cuenta su amplia distribución geográfica.
Suárez, Pablo; Nagamachi, Cleusa Yoshiko; Lanzone, Cecilia; Malleret, Matias Maximiliano; O'Brien, Patricia Caroline Mary; Ferguson-Smith, Malcolm Andrew; Pieczarka, Julio Cesar
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
Colombian Squirrels cytogenetic showed a great variability which has renewed the interest in evolutionary aspects within the group. Many chromosome banding tools must be analyzed carefully in addition to the classical G-banding G technique. These techniques include other differential bands like Q and R banding and no differential banding (C and NOR). In this article the use of each of these supplements in the cytogenetic analysis of species and cytotypes observations for the Colombian squirrels is explained.
Carlos Eduardo Faresin e Silva
Full Text Available The aim was to characterize the karyotype of rodents of the genus Proechimys from three localities in the central Brazilian Amazon, in the search for new markers that might shed light on our understanding of the taxonomy and evolutionary history of this taxon. Two karyotypes were found, viz., 2n = 28, FN = 46 in individuals from the NRSP (Cuieiras River and REMAN (Manaus, and 2n = 46, FN = 50 in individuals from the Balbina Hydroelectric Plant. While individuals with the karyotype with 2n = 28 chromosomes were morphologically associated with Proechimys cuvieri, their karyotype shared similarities with those of the same diploid number in two other regions. Although three karyotypes are described for Proechimys cuvieri, no geographic distribution pattern that defined a cline could be identified. Based on the morphological examination of voucher specimens and additional results from molecular analysis, the karyotype with 2n = 46 and FN = 50 could be associated with P. guyannensis.
A. L. Cherubini
Full Text Available The objective of this paper is to report the death of a Boa constrictor amarali after ingestion of a tree porcupine. The animal was donated to the Center for the Study of Venoms and Venomous Animals (CEVAP/UNESP - and died in captivity. At necropsy, spine-like structures were observed in the stomach serosa and vicinity, and the stomach mucosa showed an intense reddish area, suggesting inflammation. The analysis of the spine-like structure revealed that they were tree porcupine spines. The feeding habits and inexperience of this Boa constrictor amarali in selecting its prey may have been be responsible for its death.
Carolina Alicia Labaroni
Full Text Available 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.
Luo, Guangjie; Ding, Li; Liao, Jicheng
Stylodipus telum belongs to the genus Stylodipus in the subfamily of Dipodinae. We got its complete genome first and it is 16,696 bp in length, the heavy strand contains 31.0% A, 13.8% G, 27.3% C, 27.9% T. Among them, protein-coding genes take up approximately 67.90% of the complete sequence. Trees constructed through phylogenetic analysis showed S. telum and Jaculus jaculus were clustered in one branch belonging to the family Dipodinae. This conclusion was identical to the former result by the methods of morphological taxonomy, and it would be convenient for further research on S. telum and other jerboa. PMID:26024139
Tarcísio de Souza Duarte
Full Text Available ABSTRACT The cuticle is the outermost of the three cellular layers of the mammalian hair. It comprises numerous keratinized scales, whose morphology, combined with other microscopic characteristics of the hair, confers characteristic signature traits to various different species. This study aimed to analyze whether the cuticular patterns of the aristiform hair had any signature implications for the two species of the genus Abrawayaomys Cunha & Cruz, 1979. We identified the cuticular profiles of A. ruschi and A. chebezi. Both species have similar hair pattern. The base of the hair shows "irregular waved" scales with smooth and continuous edges, and the apex showed "transversal waved" small-sized scales with continuous and ornamented edges. The middle portion of the hair exhibits different cuticular patterns on different sides of a single hair follicle: "transversal waved" on the dorsal side and "narrow losangled" on the ventral side. This distribution pattern of the cuticular scales is an unprecedented record for any mammal, and it is an important generic feature that allows the identification of single samples, such as those found in predators' gastrointestinal contents. The species in question are considered rare due to the restricted number of specimens deposited in scientific collections. Our findings may contribute to expanding the species' geographic range by making it possible to identify it in various situations. These results highlight the relevance of studies pertaining the identification of the micromorphology of the aristiform hair, which can be used as a tool to accurately identify rodents.
Tarcísio de Souza Duarte; Gisele Lessa
ABSTRACT The cuticle is the outermost of the three cellular layers of the mammalian hair. It comprises numerous keratinized scales, whose morphology, combined with other microscopic characteristics of the hair, confers characteristic signature traits to various different species. This study aimed to analyze whether the cuticular patterns of the aristiform hair had any signature implications for the two species of the genus Abrawayaomys Cunha & Cruz, 1979. We identified the cuticular profiles ...
Hernández Fernández, M.; Peláez-Campomanes, Pablo
[EN] In order to make inferences on the climatic range of extinct rodent genera, cluster analysis using dental morphological variables is performed. The goal of this study is to obtain rodent groupings which relate extinct an extant rodent genera on the basis of the ecomorphology of the dentition. The method is applied to two rodent groups, Murinae and hypsodont “Cricetidae” from the Iberian Plio- Pleistocene. The results show that dental morphology of the Plio-Pleistocene Murinae fr...
Hernández Fernández, Manuel; Peláez-Campomanes de Labra, Pablo
In order to make inferences on the climatic range of extinct rodent genera, cluster analysis using dental morphological variables is performed. The goal of this study is to obtain rodent groupings which relate extinct an extant rodent genera on the basis of the ecomorphology of the dentition. The method is applied to two rodent groups, Murinae and hypsodont “Cricetidae” from the Iberian Plio- Pleistocene. The results show that dental morphology of the Plio-Pleistocene Murinae from the Iber...
Tenora, F.; Baruš, Vlastimil; Prokeš, Miroslav; Šumbera, R.; Koubková, B.
Roč. 40, č. 3 (2003), s. 153-160. ISSN 0440-6605 R&D Projects: GA AV ČR IAA6093104; GA ČR GA206/00/1699 Institutional research plan: CEZ:AV0Z6093917 Keywords : Bathyergidae * helminth s * Malawi Subject RIV: EG - Zoology Impact factor: 0.474, year: 2003
G de Graaff
Full Text Available Aspects of the ecology and distribution of the Damara mole-rat (Cryptomys hottentotus damarensis are discussed relative to its life in the arid Kalahari Gemsbok National Park. The value of coat colour as a taxonomic criterion for the subspecies is discussed. Notes are also presented on reproduction, aspects of behaviour such as: habitat, nests, orientation, activity, locomotion, voice, food, feeding and social life, symbiosis, commensalism, parasites and predators.
Full Text Available Spiny rats of the genus Proechimys are morphologically diverse, widely distributed and have diploid numbers ranging from 2n = 14-16 to 2n = 62. In this paper we present cytogenetical data and brief comments on morphological and biogeographical issues related to spiny rats. In our sample of 42 spiny rats collected from 12 Brazilian Amazonian tropical rainforest and the Cerrado (Brazilian savanna sites we detected nine karyological entities: four different karyomorphs with 2n = 30, three with 2n = 28, one with 2n = 15 and one with 2n = 44. Based on qualitative morphological characters these karyomorphs can be allocated to five species within the goeldii, guyannensis and longicaudatus species groups.
Pereira, Daniella L; Walters, Jacklynn; Bennett, Nigel C; Alagaili, Abdulaziz N; Mohammed, Osama B; Kotzé, Sanet H
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
Bendová, Karolína; Marková, Silvia; Searle, J. B.; Kotlík, Petr
Roč. 27, č. 1 (2016), s. 111-112. ISSN 1940-1736 R&D Projects: GA ČR GAP506/11/1872; GA AV ČR IAA600450901 Institutional support: RVO:67985904 Keywords : mtDNA capture * Myodes glareolus * phylogeography Subject RIV: EG - Zoology Impact factor: 1.209, year: 2014
Šumbera, R.; Baruš, Vlastimil; Tenora, F.
Roč. 52, č. 2 (2003), s. 149-153. ISSN 0139-7893 R&D Projects: GA ČR GA206/00/1699; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6093917 Keywords : heavy metals * rodents * bioaccumulation Subject RIV: EG - Zoology Impact factor: 0.494, year: 2003 http://www.ivb.cz/folia/52/2/149-153.pdf
Buchtová, M.; Matulová, Petra; Witter, K.; Tichý, F.
Roč. 74, č. 3 (2005), s. 319-327. ISSN 0001-7213 R&D Projects: GA MŠk OC B23.001 Institutional research plan: CEZ:AV0Z50450515 Keywords : oral cavity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.353, year: 2005
Weers, van D.J.; Shaohua, Zheng
Early to Middle Pleistocene Hystrix material in the collections of the IVPP in Beijing, has been biometrically studied and compared with other fossil and extant species. The specimens are from Zhoukoudian (Beijing), the Liucheng Gigantopithecus cave (Guangxi) and other caves in that province, the Wa
Svobodová, Petra; Pejčoch, M.; Heroldová, Marta; Pavlíček, T.; Nevo, E.; Šumbera, R.; Hubálek, Zdeněk
Roč. 61, č. 1 (2009), s. 99-106. ISSN 1211-0981 Institutional research plan: CEZ:AV0Z60930519 Keywords : Emmonsia * adiaspiromycosis * adiasporomycosis * lung tissue Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology http://web.natur.cuni.cz/cvsm/CM61106.pdf
Suchomel, J.; Heroldová, Marta
Roč. 53, č. 4 (2007), s. 185-191. ISSN 1212-4834 Grant ostatní: GA ČR(CZ) GP526/03/P051 Institutional research plan: CEZ:AV0Z60930519 Keywords : pheasantry * diversity * small terrestrial mammals Subject RIV: EH - Ecology, Behaviour http://journals.uzpi.cz:8050/uniqueFiles/00162.pdf/
Nuri YIĞIT; ÇOLAK, Ercüment; GATTERMANN, Rolf; Neumann, Karsten; ÖZKURT, Şakir
Currently, 4 species, Mesocricetus auratus, Mesocricetus raddei, Mesocricetus newtoni, and Mesocricetus brandti of the genus Mesocricetus are accepted as the valid taxa based on karyotype and morphologic features. A potential fifth species, Mesocricetus nigriculus, is under dispute and is currently listed as a subspecies of M. raddei, along with Mesocricetus raddei raddei and Mesocricetus raddei avaricus. UPGMA cluster analyses performed with biometrical measures confirm, only partially, the ...
Martínková, Natália; Moravec, J.
Roč. 61, 3-4 (2012), s. 254-267. ISSN 0139-7893 R&D Projects: GA AV ČR IAA600930609 Institutional support: RVO:68081766 Keywords : divergence * evolutionary history * supertree * supermatrix * phylogenetic tree terrace * Microtus * Arvicolinae Subject RIV: EG - Zoology Impact factor: 0.494, year: 2012
Pečnerová, P.; Martínková, Natália
Roč. 41, č. 3 (2012), s. 211-219. ISSN 0300-3256 Institutional research plan: CEZ:AV0Z60930519 Keywords : phylogeny * Sciurus * biogeography * colonisation Subject RIV: EG - Zoology Impact factor: 2.793, year: 2012
Ndiaye, A.; Ba, K.; Aniskin, V. M.; Benazzou, T.; Chevret, P.; Konečný, Adam; Sembene, M.; Tatard, C.; Kergoat, G. J.; Granjon, L.
Roč. 41, č. 1 (2012), s. 11-28. ISSN 0300-3256 R&D Projects: GA AV ČR IAA6093404 Institutional research plan: CEZ:AV0Z60930519 Keywords : geometric morphometrics * Middle Pleistocene * African gerbils * West Africa * taxonomy Subject RIV: EG - Zoology Impact factor: 2.793, year: 2012
Mikula, Ondřej; Šumbera, R.; Aghová, Tatiana; Mbau, J. S.; Katakweba, A. S.; Sabuni, C. A.; Bryja, Josef
(2016). ISSN 0300-3256 R&D Projects: GA ČR GAP506/10/0983; GA ČR GA15-20229S Institutional support: RVO:68081766 Keywords : Saccostomus * phylogeny * phylogeography * Plio-Pleistocene climate changes * taxonomic revision * Nesomyidae * Cricetomyinae Subject RIV: EG - Zoology Impact factor: 3.224, year: 2014
Wei, Haixue; Jia, Qiang; Li, Fengjun; Liu, Yongcheng; Chen, Shunde; Yong, Bin
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
Malé, P.-J, G.; Martin, J.-F.; Galan, M.; Deffontaine, V.; Bryja, Josef; Cosson, J.-F.; Michaux, J.; Charbonnel, N.
Roč. 105, č. 4 (2012), s. 881-899. ISSN 0024-4066 Grant ostatní: 6th Framework Programme(XE) GOCE-2003-010284 EDEN Source of funding: R - rámcový projekt EK Keywords : balancing selection * bank voles * diversity * immunogenetics * molecular epidemiology * Puumala hantavirus * zoonoses Subject RIV: EG - Zoology Impact factor: 2.413, year: 2012
Douzery Emmanuel JP
Full Text Available Abstract 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.
Mahmoud I. Shoulkamy
Full Text Available The karyotype and C-banding pattern of the unstriped grass rat Arvicanthis niloticus from four localities in Egypt are presented. All individuals karyotyped, as a rule, have the same diploid number of 2n = 62 and autosomal Fundamental Number of aFN = 62. In addition, all chromosomes have a large centromeric block of fairly uniform size. However, an additional interstitial or telomeric small C-band is scored in some chromosomes. Nevertheless, frequent heteromorphism in the morphology and heterochromatin content of both the homologous chromosomes of the pair No. 1 and the X chromosome are scored in some individuals from the four localities and led to an aFN = 63. Accordingly, four forms or cytotypes, namely ANI-1a, ANI-1b, ANI-1c and ANI-1d, are recognized based on this variation, which is mostly attributed either to addition or deletion of a heterochromatic segment as a result of pericentric inversions. Of these four forms, the ANI-1a is considered ancestral for A. niloticus in Egypt and is closely similar to that of the Ethiopian A. dembeensis, regardless the contradiction concerned with nomenclature of the X chromosome, while the karyotypes of the other forms are synapomorphy of the form ANI-1a and showed as well a relative resemblance to those of the Ethiopian A. abyssinicus and A. blicki. Therefore, it is concluded that the genus Arvicanthis would be represented by an Egyptian-Ethiopian radiation (A. niloticus, A. dembeensis, A. abyssinicus and A. blicki and by a Central-Western African one, including the karyotypes described as A. centralis and A. solatus. Moreover, A. niloticus should be regarded no longer as a single species but as a cluster of several proper species.
ARSLAN, Atilla; AKAN, Şükrüye
The present study reports the banding patterns (G- and C-banding) of chromosomes of Cricetulus migratorius from Central Anatolia. Karyotype of C. migratorius comprised (2n) 22 chromosomes. The number of chromosomal arms (FN) was 44 and the number of autosomal arms (FNa) was 40. Subtelocentric X and Y chromosomes were very similar in size, but they differed on G- and C-banding patterns. Most autosomes in this species were C-negative. Pair no. 4 had very small centromeric C-bands, autosome no. ...
The community structure of small mammals living in the within-dike zone indicates that the species typical for the ecosystems survive there up to present. The conditions in the monitored area remain still within the limits of ecological tolerance of the studied species. The number of individuals of the species occurring in the monitored localities varied within the limits of the amplitude of their population fluctuation cycles. With regard to the rather wide amplitude of fluctuation cycles of the small mammal populations and their length taking usually 4-6 years, the significant data concerning the influence of the changed hydrological regime on the small mammals in this area can be obtained not earlier than after 10-15 years. (authors). 1 tabs., 2 figs., 2 refs
Blake, B H
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
Jaffar Ud Din
Full Text Available The Woolly Gliding Squirrel Eupetaurus cinereus is an extremely rare, localized, and endangered mammal and may constitute one of the endemic species of Pakistan. The species was rediscovered in northern Pakistan in the mid-1990s after a 70-year absence of records. All the previous information regarding this giant squirrel was limited to museum specimens, collected mostly from areas presently in northern Pakistan in the late 1800s. Sighting of the species is extremely challenging owing to its nocturnal behavior, low densities and the inhospitable terrain it is reported from. Here we report detailed information about the species collected during the rescue of a young male individual from Gilgit City followed by its successful release in its natural habitat. We report that the species is still facing human-induced threats and may disappear from the mountains of northern Pakistan if informed management measures are not taken. Moreover, the occurrence of the species outside its core distribution range, i.e., districts Gilgit and Diamer, still remains questionable; therefore, it is recommended that further in-depth research studies be undertaken to determine the status of the species across the entire reported range.
Gomes Rodrigues, Helder; Merceron, Gildas; Viriot, Laurent
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.
Flavio M.R. Da Silva Júnior; RITA I. MONARCA; DEODÁLIA DIAS; MARIA G. RAMALHINHO; MARIA L. MATHIAS; Ana L. Muccillo-Baisch
Small mammals have been used to predict ecotoxicological damage caused by metals in field studies and laboratory exposure. In natural ecosystems, rodents play an important role either as seed dispersers or food providers for various predators since they represent intermediate links in the food chain. Several studies have already focused on the effects of metals on wild rodents, but data provided on the effects of organic contaminants, such as crude oil, are scarce. Among the possible biologic...
André Luiz Quagliatto Santos
Full Text Available This paper describes the morphology of the tongue, its extrinsic muscles, and the characteristics of lingual papillae in Cuniculus paca. We used fifteen specimens from the Wild Animals Sector of Universidade Estadual Paulista (UNESP. In this species, the tongue is divided into three regions: root, body, and apex. The latter is delimited by the lingual frenum, which has the aspect of fibrous membrane. We also identified a median groove and a prominence on its dorsal surface. The extrinsic tongue muscles are the styloglossus, hyoglossus, genioglossus, geniohyoid, and milohyoid, the latter two are inserted into the hyoid apparatus. As for the presence of lingual papillae, we observed five papillae types in all specimens: filiform, fungiform, vallate, foliate, and conic. The filiform papillae are distributed throughout the apex surface and tongue body. They are caudally inclined throughout the body, until they are modified in the root region and form the conic papillae. The fungiform papillae are distributed in a large amount on the lingual apex, between the filiform papillae. This papilla type has a mushroom-like shape. Only two vallate papillae are located in the caudal portion of the lingual root, and they have an oval shape and are surrounded by a deep groove. The foliate papillae are observed in parallel grooves or slots located in the lateral portion of the tongue, between the vallate papillae and half of the intermolar prominence. In the tongue root, body, and apex we observed keratinized squamous stratified epithelium lining both the lingual papillae and the surface between them.
Impacto del castor (Castor canadensis, Rodentia) en bosques de lenga (Nothofagus pumilio) de Tierra del Fuego, Chile Impact of american beaver (Castor canadensis, Rodentia) in lenga (Nothofagus pumilio) forests of Tierra del Fuego, Chile
Aida Baldini U; Juan Oltremari A; Mauricio Ramírez
Castor canadensis es un roedor de Norteamérica introducido a la porción argentina de Tierra del Fuego en el año 1946, invadiendo territorios chilenos del mismo sector. En esta zona los castores construyen diques y se alimentan de material arbóreo extraído principalmente de Nothofagus pumilio. En el estudio se intentó probar que los castores provocan daño en la biomasa y volumen de los bosques de N. pumilio. Los objetivos del estudio fueron identificar los tipos de daños y cuantificar las pérd...
Temporal dynamics of milk composition of the precocial caviomorph Octodon degus (Rodentia: Octodontidae Dinámica temporal de la composición de la leche del caviomorfo precocial Octodon degus (Rodentia: Octodentidae
Full Text Available During lactation, both the nutritional and energetic requirements of suckling change gradually. These changes normally are accompanied by modifications in chemical composition of the milk. We investigated the temporal course of milk composition during lactation in a precocial caviomorph rodent, the "degu" (Octodon degus under laboratory condition. Female degus were kept in laboratory during gestation and lactation and fed with commercial food pellets. Milk was collected at three stages of lactation: early (days 5-8, n = 12, middle (days 15-21, n = 7 and late (days 26-40, n = 6, and analyzed for protein, carbohydrates, lipids, ash, total solids and energy. On average, carbohydrates decreased from 3.1 ± 0.3 % (early to 1.1 ± 0.3 % (late during lactation; lipids, protein, ash, total solids and energy remained about the same. Lipids, the main component of the milk, were 17.3 % and protein remained near 4.4 %. Over lactation, total energy concentration of milk remained near 4.0 kJ mL-1. The maintenance of milk composition during lactation may be related to the initially high energetic and nutritional requirements associated with a precocial reproductive modeDurante la lactancia, tanto los requerimientos energéticos como nutricionales de las crías cambian gradualmente. Estos cambios normalmente van acompañados por modificaciones en la composición química de la leche. Se investigaron los cambios temporales de la composición de la leche durante la lactancia en el roedor caviomorfo precocial "degu" (Octodon degus bajo condiciones de laboratorio. Las hembras de degu fueron mantenidas en el laboratorio durante preñez y lactancia, y fueron alimentadas con alimento comercial de conejo. La leche fue colectada en tres estados de lactancia: temprana (días 5-8, n = 12, media (días 15-21, n = 7 y tardía (días 26-40, n = 6, y analizadas para proteínas, hidratos de carbono, lípidos, ceniza, sólidos totales y energía. En promedio, los hidratos de carbono disminuyen desde 3,1 ± 0,3 % (temprana hasta 1,1 ± 0,3 % (tardía durante la lactancia; mientras que, los lípidos, las proteínas, la ceniza, los sólidos totales y la energía se mantienen relativamente constantes. Los lípidos, el principal constituyente de la leche fue de 17,3 % y las proteínas correspondieron al 4,4 %. Durante la lactancia, la concentración de energía total de la leche permaneció cerca de los 4,0 kJ mL-1. La mantención de la composición de la leche durante la lactancia puede estar relacionada con los altos requerimientos energéticos y nutricionales asociados al modo reproductivo precocial
Habitat use and relative abundance of the Spotted Paca Cuniculus paca (Linnaeus, 1766 (Rodentia: Cuniculidae and the Red-rumped Agouti Dasyprocta leporina (Linnaeus, 1758 (Rodentia: Dasyproctidae in Guatopo National Park, Venezuela
Full Text Available The Spotted Paca Cuniculus paca and the Red-rumped Agouti Dasyprocta leporina are affected by habitat loss and hunting. In Venezuela, their conservation status is unknown, even within protected areas. The objective of this study was to estimate the relative abundance, activity patterns, habitat use, and effect of human activities on these species in Venezuela. To achieve this, 26 camera-trap stations (20.8km2 were established in Guatopo National Park between February and April 2011, characterization of the habitat was undertaken and occupancy models were created. The relative abundance of the Spotted Paca was 1.62 captures/100trap-nights, with a fully nocturnal activity pattern. The relative abundance of the Red-rumped Agouti was 2.32 captures/100trap-nights, with a pronounced diurnal activity pattern. The occupation probability of the Red-rumped Agouti (0.61 SE 0.02 was higher than that of the Spotted Paca (0.27 SE 0.02. Spotted Pacas were mainly found in areas with mature forest and high tree density, whereas the Red-rumped Agoutis were most frequently found in valleys with little disturbed forest. A positive correlation was found between illegal hunting activities and areas occupied by the Spotted Paca. It is important to strengthen the park control measurements to reduce illegal hunting of Spotted Pacas.
Dietas de Abrothrix andinus, Phyllotis xanthopygus (Rodentia y Lepus europaeus (Lagomorpha en un ambiente altoandino de Chile Feeding habits of Abrothrix andinus, Phyllotis xanthopygus (Rodentia and Lepus europaeus (Lagomorpha in an Andean environment of Chile
Full Text Available Los roedores nativos Abrothrix andinus, Phyllotis xanthopygus y el lagomorfo introducido Lepus europaeus, coexisten en ambientes altoandinos del centro-norte de Chile, donde la disponibilidad de alimento es escasa y distribuida heterogéneamente en el paisaje. Propusimos que en estos ambientes las especies en estudio se comportarían como herbívoros generalistas y que existiría una alta sobreposición en la dieta entre la liebre y los roedores nativos. El objetivo de este trabajo fue documentar la composición de la dieta de las tres especies y determinar su amplitud, preferencia y sobreposición en la dieta a partir del análisis microhistológico de heces frescas. Los resultados indican que las tres especies se comportaron como herbívoros-folívoros, siendo la dieta de L. europaeus la de mayor amplitud trófica. Abrothrix andinus seleccionó todos los ítemes que consume, mientras que P. xanthopygus y L. europaeus realizaron un consumo más oportunista. La mayor sobreposición en la dieta se observó entre los roedores nativosThe native rodents Abrothrix andinus, Phyllotis xanthopygus and the introduced lagomorph Lepus europaeus coexist in the highlands of north-central Chile, where food availability is scarce. We hypothesized that in these environments, the studied species would behave as generalist herbivores and where the diet of native rodents would overlap that of hares greatly. The aim of this study was to quantify feeding habits, amplitude, diet preferences and overlap of these three species through microhistological analysis of fresh faeces. While all three species behaved as herbivore-folivores, L. europaeus showed the largest niche breath. Abrothrix andinus selected all consumed items, while P. xanthopygus and L. europaeus exhibited a more opportunistic consumption food items. The highest diet overlap was observed between native rodents
Dieta de Sciurus ingrami Thomas (Rodentia, Sciuridae em um remanescente de Floresta com Araucária, Paraná, Brasil Diet of Sciurus ingrami Thomas (Rodentia, Sciuridae on a Araucauria Pine Forest remnant, Paraná, Brazil
João M. D. Miranda
Full Text Available Este estudo foi realizado entre fevereiro de 2002 e janeiro de 2003, em um remanescente de Floresta com Araucária, localizado no Distrito do Bugre, Município de Balsa Nova, Paraná, Brasil. O objetivo foi conhecer as espécies utilizadas na alimentação por Sciurus ingrami Thomas, 1901 no decorrer de um ano. Foram registradas dez (N = 10 espécies na dieta dos serelepes, pertencentes a sete famílias botânicas. Os serelepes predaram sementes de três espécies e se alimentaram de três espécies exóticas, mostrando adaptabilidade a ambientes alterados.This study was conducted between February, 2002 and January, 2003 in a remnant of Araucaria Pine Forest located in the District of Bugre, Municipality of Balsa Nova, Paraná, Brazil. The goal of this study was to survey the species used as food items by Sciurus ingrami Thomas, 1901 throughout a year. Ten (N = 10 species were recorded in the diet of these squirrels, belonging to seven plant families. Squirrels preyed on seeds of three plant species and fed on three exotic species, indicating good adaptability to disturbed habitats.
MYOCASTOR COYPUS (“COIPO”, RODENTIA, MAMMALIA COMO RECURSO EN LOS HUMEDALES DE LA PAMPA BOANERENSE: PATRONES DE EXPLOTACIÓN/Myocastor coypus (“coipo”, Rodentia, Mammalia as an archaeological resource in the wetlands of Buenos Aires Pampas: exploitation
Full Text Available Myocastor coypus es una de las especies más abundantes en los humedales de la región pampeana, particularmente en las cuencas de los ríos Salado y Paraná. Distintas líneas de evidencia permiten sostener que fue un recurso ampliamente aprovechado siendo central en las estrategias económicas de los cazadores-recolectores-pescadores durante el Holoceno tardío. Se presentan los resultados obtenidos del análisis de restos arqueofaunísticos de esta presa mediano-pequeña, a partir de: análisis cuantitativos, estimación de clases de edad, análisis de huellas, termoalteraciones y fracturas. El objetivo es analizar los patrones de explotación del coipo utilizando información proveniente de los sitios de la localidad La Guillerma (LG1, LG4 y LG5 y San Ramón 7 (SR7 ubicados en el curso inferior del río Salado y del sitio Río Luján (RL y la localidad Cañada Honda (CH localizados en el NE bonaerense. Los resultados permiten sostener que la presión de captura se dio sobre presas adultas, que ingresaron completas a los sitios. Las huellas evidencian la ejecución de una serie de acciones para su aprovechamiento (cuereo, desarticulación y descarne. Abstract Myocastor coypus is one of the most abundant species found in archaeological sites in the Pampean Region wetlands, especially in the Salado and Paraná river basins. On the basis of different lines of evidence, it may be suggested that this animal was an extensively exploited resource, proving to be central in the strategies of hunter-gatherer-fishers that inhabited these regions during the Late Holocene. In this study, data obtained from archaeofaunal analysis are described: quantitative, age-class and butchering evidence analysis (cut marks, burning features and fracture patterns. We aim at analyzing the exploitation patterns of coypu using data found in La Guillerma (LG1, LG4 and LG5 and San Ramón 7 (SR7, pertaining to the lower Río Salado basin, and in Río Luján (RL and Cañada Honda (CH situated in the northeastern province of Buenos Aires. Results show that adult prey capture was practised, where the entire animal bodies had been introduced in the sites. Cut marks also evidence a series of tasks associated to exploitation (skinning, disarticulation and defleshing.
New species of Aspiculuris (Nematoda: Heteroxynematidae, parasite of Mus musculus (Rodentia: Muridae, from Hidalgo, Mexico Una nueva especie de Aspiculuris (Nematoda: Heteroxynematidae, parásito de Mus musculus (Rodentia: Muridae, de Hidalgo, México
Full Text Available Aspiculuris huascaensis n. sp. was found in the intestine of Mus musculus collected from 2 localities in Hidalgo, Mexico, and is described herein. The new species possesses cervical alae abruptly interrupted at mid-length of esophageal bulb form an acute angle, distinguishing it from 5 of the 17 species in the genus. The new species is differentiated from 11 of the remaining species by having cervical alae that form an acute angle and end at mid-length of the esophageal bulb. Aspiculuris huascaensis n. sp. most closely resembles A. tetraptera in the position of the terminal end of the cervical alae. However, the new species can be distinguished from that species by the number of caudal papillae (12 vs. 14, the presence of a sessile precloacal papilla between 2 cuticular folds, and by having a single pedunculate papilla located slightly posterior to the cloaca.Se describe una especie nueva, Aspiculuris huascaensis n. sp., proveniente del intestino de Mus musculus de 2 localidades de Hidalgo, México. Esta especie cuenta con 1 ala cervical interrumpida abruptamente formando un ángulo agudo; con base en este carácter, la especie nueva se distingue de 5 de las 17 especies que contiene el género. De 11 especies más, A. huascaensis n. sp. se diferencia por el ángulo agudo que forma el ala cervical y porque ésta finaliza a la mitad de la longitud del bulbo esofágico. Aspiculuris huascaensis n. sp. se asemeja a A. tetraptera por la terminación del ala cervical. Sin embargo, puede distinguirse de dicha especie por el número de papilas caudales (12 vs. 14, por la presencia de una papila precloacal sésil entre 2 pliegues cuticulares y por una papilla sencilla detrás de la cloaca.
Ana L. Muccillo-Baisch; Patrick F. Silva; Krissia A. De Almeida; Flavio M.R. Da Silva Júnior
The toxicity of petroleum components is well described in the literature, especially with regard to mutagenic and carcinogenic effects. In some groups of animals, such as birds, oil exposure seems to alter blood parameters, while this relationship is poorly understood in rodents. The study aimed to investigate alterations in hematological profile in the wild rodent Calomys laucha exposed to crude oil contaminated soils. In this study, males specimens of Calomys laucha were exposed for 14 days...
Paulo César Simões-Lopes
Full Text Available Santa Catarina Island possesses dozens of archeological sites where the skeletal remains of a great array of animals can be found. The goal of this study was to quantify the skeletal remains of capybaras found at the archeological site SC PRV 02 (1067 to 1735 BP, located in the northern part of the island, along the shores of Lagoa da Conceição, a saltwater lagoon. Thirty-seven skeletal fragments of at least 12 different individuals were identified. The anatomic regions of the capybaras most sought-after by pre-colonial inhabitants were the anterior and posterior limbs. About 40% of the skeletal fragments did not show any epiphyseal fusion with the shaft. Approximately 48% of the fragments found presented evidence of human activity. Our analyses suggest that capybaras played an important role in the diet of these inhabitants and that they were also used for the confection of different functional goods. We diagnosed the manipulation techniques used to obtain these goods, such as percussion and transversal section. The evidence of carbonization and superficial incisions indicates dismembering, preparation, and consumption of capybaras for feeding. Similar techniques were found at other archeological sites of the same age, suggesting that even though pre-colonial inhabitants of the island were considered to be fishermen, capybaras represented a well-appreciated resource.
Gilberto S Gazêta; Marinete Amorim; David EP Bossi; Arício X Linhares; Nicolau M Serra-Freire
From June 1999 to May 2001, small mammals were captured in three areas of the Atlantic Forest in Southeastern Brazil and examined for ectoparasites. Analysis of ectoparasites revealed the presence of a new chigger genus and species, Caamembecaia gratiosus, from Trinomys gratiosus. This is the first record of a chigger from T. gratiosus.
Maurício Eduardo Graipel; Luiz Gustavo Rodrigues Oliveira-Santos; Marilena Altenfelder Arruda Campos; Pâmela Castro Antunes
The population dynamics and reproductive issues of two species of rodents of the family Cricetidae, Rice Rats (Euryoryzomys russatus) and Pygmy Rice Rats (Oligoryzomys nigripes), were studied for 24 months in an Atlantic Forest area in southern Brazil. Euryoryzomys russatus presented density-dependent population fluctuation, and recruitment was positively associated with temperature. Oligoryzomys nigripes displayed the lowest abundance, greatest population fluctuation and shortest permanence ...
Němec, P.; Cveková, P.; Benada, Oldřich; Wielkopolska, E.; Olkowitz, S.; Turlejski, K.; Burda, H.; Bennett, N. C.; Peichl, L.
Roč. 75, 2-4 (2008), s. 356-364. ISSN 0361-9230 Grant ostatní: GA AV ČR(CZ) GA206/06/1469; ZA(ZA) 2069070 Institutional research plan: CEZ:AV0Z50200510 Keywords : microphthalmia * ocular regression * subterranean mammals Subject RIV: EE - Microbiology, Virology Impact factor: 2.281, year: 2008
Full Text Available This study investigated some aspects of the reproductive biology of male and female greater bandicoot rats Bandicota indica in southern Thailand from September 2004 to September 2006. In females, body, uterine and preputial gland weights, occurrences of pregnancies and placental scars, and in males, testicular weights and histology, and sizes of accessory sex glands, were recorded. Pregnancies occurred predominantly, but not exclusively, in the wet season, with a higher incidence pregnancies in the second, than in the first, dry season. Uterine and preputial gland weights tended to be lower in the first, but not the second dry season, with placental scars occurring at all times of year. Males tended to have heavier testes in the wet season but some seminiferous tubules contained sperm even in the dry season. Seminal vesicles, but not prostates and preputial glands, tended to be heavier in animals in the wet season. We conclude that the greater bandicoot rat in southern Thailand shows maximal reproductive activity in the wet season with some reproductive activity, albeit variable from year to year, occurring in the dry season depending upon environmental conditions. This study has also shown that females, as well as males, have large preputial glands, and that males invariably have small testes regardless of the time of year. These observations suggest a similar timing of reproduction, but a different breeding biology and perhaps social organisation, from that of the sympatric ricefield rat, Rattus argentiventer [Current Zoology 55(1: 48–55, 2009].
Panti-May, Jesús Alonso; Robles, María Del Rosario
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
Roč. 270, č. 4 (2006), s. 672-681. ISSN 0952-8369 R&D Projects: GA AV ČR IAA6045307 Institutional research plan: CEZ:AV0Z50450515 Keywords : Mus * geometric morphometrics * thin-plate spline Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.413, year: 2006
YİĞİT, Nuri; ÇOLAK, Ercüment
In this study, seventeen specimens of Meriones tristrami from Kilis were compared with the specimens of Meriones tristrami bodenheimeri along with topotypes of Meriones tristrami lycaon close to those from Kilis. It was determined that the specimens from Kilis were distinguishable from M.t. lycaon by characters such as dorsal coloration, Tx100 / HB (ratio of tail length to head and body), zygomatic breadth, occipitonasal length, basal length, diastema length, occipital width, weight, bacul...
Galiano, Daniel; Bernardo-Silva, Jorge; de Freitas, Thales R. O.
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
C. C. Rosa; T. Flores; J. C. Pieczarka; R. V. Rossi; M. I. C. Sampaio; J. D. Rissino; P. J. S. Amaral; C. Y. Nagamachi
The rodent genus Oecomys (Sigmodontinae) comprises ∼16 species that inhabit tropical and subtropical forests in Central America and South America. In this study specimens of Oecomys paricola Thomas, 1904 from Belém and Marajó island, northern Brazil, were investigated using cytogenetic, molecular and morphological analyses. Three karyotypes were found, two from Belém ($2n = 68$, fundamental number (FN) = 72 and $2n = 70$, FN = 76) and a third from Marajó island ($2n = 70$, FN = 72). No molecular or morphological differences were found between the individuals with differing cytotypes from Belém, but differences were evident between the individuals from Belém and Marajó island. Specimens from Belém city region may represent two cryptic species because two different karyotypes are present in the absence of significant differences in morphology and molecular characteristics. The Marajó island and Belém populations may represent distinct species that have been separated for some time, and are in the process of morphological and molecular differentiation as a consequence of reproductive isolation at the geographic and chromosomal levels. Thus, the results suggest that O. paricola may be a complex of species.
André Luiz Rodrigues Roque
Full Text Available The importance of the genus Thrichomys in the retention of infection and transmission of Leishmania species is supported by previous studies that describe an ancient interaction between caviomorphs and trypanosomatids and report the natural infection of Thrichomys spp. Moreover, these rodents are widely dispersed in Brazil and recognized as important hosts of other tripanosomatids. Our main purpose was to evaluate the putative role of Thrichomys laurentius in the retention of infection and amplification of the transmission cycle of Leishmania infantum and L. braziliensis. Male and female T. laurentius (n = 24 born in captivity were evaluated for the retention of infection with these Leishmania species and followed up by parasitological, serological, hematological, biochemical, histological, and molecular assays for 3, 6, 9, or 12 months post infection (mpi. T. laurentius showed its competence as maintenance host for the two inoculated Leishmania species. Four aspects should be highlighted: (i re-isolation of parasites 12 mpi; (ii the low parasitic burden displayed by T. laurentius tissues; (iii the early onset and maintenance of humoral response, and (iv the similar pattern of infection by the two Leishmania species. Both Leishmania species demonstrated the ability to invade and maintain itself in viscera and skin of T. laurentius, and no rodent displayed any lesion, histological changes, or clinical evidence of infection. We also wish to point out the irrelevance of the adjective dermotropic or viscerotropic to qualify L. braziliensis and L. infantum, respectively, when these species are hosted by nonhuman hosts. Our data suggest that T. laurentius may act at least as a maintenance host of both tested Leishmania species since it maintained long-lasting infections. Moreover, it cannot be discarded that Leishmania spp. infection in free-ranging T. laurentius could result in higher parasite burden due the more stressing conditions in the wild. Therefore the tissular parasitism of the skin, infectiveness to the vector, and amplification of the transmission cycle of both Leishmania species could be expected.
The M'sila region has been recently the theatre of an important outbreak of cutaneous leishmaniasis. The search for the animal reservoir resulted in the discovery of 3 rodents, Psammomys obesus, naturally infected with Leishmania. This is of importance as far as prophylactic measures are concerned. PMID:6347415
G. A. Villegas Guzmán; T. M. Pérez
Se registran 153 ejemplares de once especies de pseudoescorpiones encontradas en 32 nidos de cinco especies del género Neotoma del Altiplano Mexicano. En los nidos de N. albigula se encontró a Tychochernesinflatus, Lustrochernes grossus, Serianus dolosus y Juxtachelifer fructuosus; en los de N. goldmani a T. inflatus;en los de N. micropus a Pachychernes sp. y Chelifer cancroides; en los de N. mexicana a Paraliochthonius sp.,Larca chamberlini, S. dolosus, Illinichernes distinctus y T. inflatus...
Witter, K.; Lesot, H.; Peterka, Miroslav; Vonesch, J. L.; Míšek, Ivan; Peterková, Renata
Roč. 50, - (2005), s. 401-409. ISSN 0003-9969 R&D Projects: GA MŠk OC B23.001; GA ČR GA304/02/0448 Institutional research plan: CEZ:AV0Z50390512 Keywords : tooth development * odontogenesis * embryo Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.288, year: 2005
Nicolas J. Schweigmann
Full Text Available To identify wild hosts of Trypanosoma cruzi, surveys were conducted in the subandean valleys of Jujuy Province, Argentina, between June 1986 and March 1987. Seventy two mammals from 13 different species were examined by xenodiagnosis. Fifty two of them were mostly roedents trapped at the localities of Maimará, León and Tilcara, and the remainder had been kept in captivity at the Estación Biológica Experimental, in Jujuy. Trypanosoma cruzi infection was detected only in 2 Octodontomys gliroides (2 pos./8 exam. 25% from all 72 examined mammals. Isolates were called Octodontomys Argentina 1 and 2 (OA1 and OA2. Both infected animals were caught at the archaelogical ruin of Pucará, at Tilcara. Repeated searches for triatomines in the ruin itself and in neighbour houses rendered negative results. Groups of mice inoculated with either OA1 or OA2 isolates became infected between 7 (OA1 to 12 days (OA2 postinoculation PI. Parasitemia peaks were observed between day 12th - 14th PI. Scarce amastigote nests were found in myocardium and skeletal muscle. Mortality was observed only for mice inoculated with OA1. Isoenzyme patterns of OA1 and OA2 were identical to one found in dogs and slightly different from that of human parasites in Argentina. Bones from Octodontomys sp., were recently found in a cave, dated 10200-8600 BC, in Pumamarca, near Tilcara, Jujuy. There are evidences that O. gliroides cohabited with man in ancient times and was associated to the domestic cycle of T. cruzi transmission, playing a role like that of domestic cavies. in Bolivia.
G de Graaff
Full Text Available The history of classification ofAfrotropical molerats is reviewed and an assessment is made of the supposed taxonomic "isolation" of the molerats (bathyergids by considering morphological features in the skull, post-cranial skeleton, reproductive organs and myology which collectively point to hystricomorph affinities in contrast to a myomorph relationship which is often postulated.
Dawson, Mary R.; Krishtalka, Leonard; Stucky, Richard K.
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.
Rivera, Daniela S; Inestrosa, Nibaldo C; Bozinovic, Francisco
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
Rowe, Kevin C; Achmadi, Anang S; Esselstyn, Jacob A
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
Arslan, A.; Yorulmaz, T.; Toyran, K.; Gözütok, S.; Zima, Jan
Roč. 64, č. 2 (2011), s. 215-222. ISSN 0008-7114 R&D Projects: GA MŠk LC06073 Institutional research plan: CEZ:AV0Z60930519 Keywords : Central Europe * chromosome banding * karyotype differentiation * Turkey Subject RIV: EG - Zoology Impact factor: 0.533, year: 2011
Arslan, A.; Yorulmaz, T.; Toyran, K.; Albayrak, I.; Zima, Jan
Roč. 76, č. 4 (2012), s. 435-439. ISSN 0025-1461 Institutional support: RVO:68081766 Keywords : AgNOR staining * C-banding * cytogenetics * jerboas Subject RIV: EG - Zoology Impact factor: 0.809, year: 2012
Izdebska, Joanna N; Fryderyk, Sławomira; Rolbiecki, Leszek
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
Izdebska, Joanna N; Rolbiecki, Leszek
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
Calebe Pereira Mendes; José Flávio Cândido-Jr
This work describes the foraging techniques, body positions and behavior of free-ranging Ingram's squirrel Guerlinguetus ingrami Thomas, 1901 in a region of the Araucaria moist forest, in the Atlantic Forest of southern Brazil. The animals were observed using the "all occurrence sampling" method with the aid of binoculars and a digital camcorder. All behaviors were described in diagrams and an ethogram. We recorded five basic body positions, 24 behaviors, two food choices, and three feeding s...
Calebe Pereira Mendes
Full Text Available This work describes the foraging techniques, body positions and behavior of free-ranging Ingram's squirrel Guerlinguetus ingrami Thomas, 1901 in a region of the Araucaria moist forest, in the Atlantic Forest of southern Brazil. The animals were observed using the "all occurrence sampling" method with the aid of binoculars and a digital camcorder. All behaviors were described in diagrams and an ethogram. We recorded five basic body positions, 24 behaviors, two food choices, and three feeding strategies utilized to open fruits of Syagrus romanzoffiana (Cham., the main food source of Ingram's squirrels. We also observed a variance in the animals' stance, which is possibly influenced by predation risk, and discuss the causes of some behaviors.
ÇOLAK, Reyhan; Nuri YİĞİT; ÇOLAK, Ercüment
The blood serum proteins of Meriones meridianus, Meriones crassus, Meriones persicus and Meriones tristrami, all found in Turkey, along with domestic Meriones unguiculatus, which originated in Mongolia, were examined for the first time by SDS-PAGE. In the globulin zone, seven to ten bands were identified, one band in the post-albumin and albumin zones and one or two bands in the pre-albumin zone of five species of the genus Meriones. There was no diagnostic difference in the pattern of serum ...
Balakirev, Alexander E; Abramov, Alexei V; Rozhnov, Viatcheslav V
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 Chiromyscuschiropus, 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: Chiromyscuschiropus (the type species of Chiromyscus), Chiromyscuslangbianis (previously regarded as a species of Niviventer), and a new species, described in this paper under the name Chiromyscusthomasi sp. n. PMID:25493050
Full Text Available 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, C. langbianis (previously regarded as a species of Niviventer, and a new species, described in this paper under the name C. thomasi sp. n.
Alexander Balakirev; Alexei Abramov; Viatcheslav Rozhnov
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 a...
Niederschuh, Sandra J; Witte, Hartmut; Schmidt, Manuela
In the stem lineage of therians, a comprehensive reorganization of limb and body mechanics took place to provide dynamic stability for rapid locomotion in a highly structured environment. At what was probably the same time, mammals developed an active sense of touch in the form of movable mystacial vibrissae. The rhythmic movements of the limbs and vibrissae are controlled by central pattern-generating networks which might interact with each other in sensorimotor control. To test this possible interaction, we studied covariation between the two by investigating speed-dependent adjustments in temporal and spatial parameters of forelimb and vibrissal kinematics in the rat. Furthermore, the possible role of carpal vibrissae in connecting the two oscillating systems was explored. We compared locomotion on continuous and discontinuous substrates in the presence and absence of the mystacial or/and carpal vibrissae across a speed range of 0.2-0.5m/s and found that a close coupling of the kinematics of the two oscillating systems appears to be precluded by their differential dependence on the animal's speed. Speed-related changes in forelimb kinematics mainly occur in temporal parameters, whereas vibrissae change their spatial excursion. However, whisking frequency is always high enough that at least one whisk cycle falls into the swing phase of the limb, which is the maximum critical period for sensing the substrate on which the forepaw will be placed. The influence of tactile cues on forelimb positional control is more subtle than expected. Tactile cues appear to affect the degree of parameter variation but not average parameters or the failure rate of limbs during walking on a perforated treadmill. The carpal vibrissae appear to play a role in sensing the animal's speed by measuring the duration of the stance phase. The absence of this cue significantly reduces speed-related variation in stride frequency and vibrissal protraction. PMID:25547567
Full Text Available Abstract Geometric morphometrics was used to investigate the Ethiopian Myomys - Stenocephalemys complex, and to suggest possible explanations for differences in size and shape. The four species of the complex (M. albipes, M. ruppi, S. griseicauda, S. albocaudata and a Kenyan species, M. fumatus, were studied using Procrustes analysis of three dimensional landmarks collected over the skull. All these species occur in very different habitats, from forests at 1000 m up to the Afro Alpine moorlands above 4000 m. There is a substantial contradiction between phylogenetic relationships based on chromosomal rearrangements and allozymes (two distinct lineages corresponding to the two genera, and mtDNA (Stenocephalemys being paraphyletic. Geometric morphometrics supports the former hypothesis. Partial Least-Squares analysis shows a significant relation between variation in size and shape and altitude, which strongly suggests that adaptation is a major causal factor for divergence in the morphology of the skull. Size increases with altitude, paralleling a clinal change in shape, which involves stenocephaly as characterising the highland species. This shape modification allows the rodents to scan the sky efficiently for birds, which represent the main category of predators in the Afro Alpine moorlands.
Dewi, Kartika; Hasegawa, Hideo; Fitriana, Yuli Sulistya; Asakawa, Mitsuhiko
The present report describes Syphacia (Syphacia) maxomyos sp. n. (Nematoda: Oxyuridae) from two species of spiny rats, Maxomys musschenbroekii from Sulawesi and M. whiteheadi from Sumatra. It is characterized by a cephalic plate extending laterally with dorsoventral constriction and stumpy eggs with an operculum rim reaching pole. It is readily distinguishable by the former feature from all of hitherto known representatives of this genus in Indonesia, but it resembles parasites in Murini and Hydromyni rodents in continental Asia and Sahul. This is the first Syphacia species distributed in both the Sunda Shelf and Sulawesi with the exception of Syphacia muris, a cosmopolitan pinworm found in rodents of the of genus Rattus. It is surmised that S. maxomyos is specific to Maxomys and that it was introduced to Sulawesi by dispersal of some Maxomys from the Sunda Shelf. PMID:26062434
Caraballo, Diego A; Abruzzese, Giselle A; Rossi, María Susana
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. PMID:22810419
Moreira, G. J.
Full Text Available The genus Actenomys is registered from Plioceno sediments of Buenos Aires province, Argentina. Anatomy of skull and dentition of the genus is described, giving special emphasis to the origin and insertion points of the masticatory musculature. Actenomys is compared with the extant fossorial rodent of the genus Ctenomys, and the development of the masticatory muscles and their degree of functionality are inferred. It is concluded that Actenomys presents a less robust skull, with a masticatory musculature in agreement and incisives with great procumbency. This evidence could explain a possible adaptation of Actenomys to dig using the incisives and an adaptation to live in habitats of higher humidity than the extant forms.Se describe la anatomía cráneo-dentaria del género Actenomys, registrado en sedimentos del Plioceno de la provincia de Buenos Aires (República Argentina, con especial énfasis los puntos de origen e inserción de la musculatura masticatoria; se lo compara con el roedor fosorial viviente del género Ctenomys, infiriéndose el desarrollo de los músculos masticatorios y su grado de funcionalidad. Se concluye que Actenomys presenta un cráneo menos robusto, con una musculatura masticatoria acorde e incisivos procumbentes, lo que podría explicar una posible adaptación para cavar con los mismos, y que estaría adaptado a vivir en ambientes con un porcentaje de humedad mayor que las formas actuales.
Ventura, Karen; O'Brien, Patricia Caroline Mary; do Nascimento Moreira, Camila; Yonenaga-Yassuda, Yatiyo; Ferguson-Smith, Malcolm Andrew
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
Di-Nizo, Camilla Bruno; Ventura, Karen; Ferguson-Smith, Malcolm Andrew; O'Brien, Patricia Caroline Mary; Yonenaga-Yassuda, Yatiyo; Silva, Maria José de J
Oligoryzomys belongs to the tribe Oryzomyini, and contains about 22 species. Diploid numbers range from 2n = 44 in Oligoryzomys sp. 2 to 2n = 72 in O. utiaritensis and phylogenetic relationships are not well defined. The high morphological convergence leads to misidentification of taxonomic entities and the species are often identified by chromosomal characters. Until now, the genus has been studied only by classical cytogenetic approaches. To understand the chromosomal evolution of Oligoryzomys, we developed chromosome probes from a female of Oligoryzomys moojeni (OMO) with 2n = 70 and hybridized to other five Oligoryzomys species. The probes painted 31 segments on O. fornesi (OFO) with 2n = 62; 32 segments on O. microtis (OMI), 2n = 64; 33 segments on O. nigripes (ONI), 2n = 62 and on O. rupestris (ORU), 2n = 46; and 34 on Oligoryzomys sp. 2 (OSP), 2n = 44. OMO probes 4 and 5 showed a syntenic association in O. fornesi, O. microtis and O. nigripes and were also presented in the same pair, although disrupted, in O. rupestris and Oligoryzomys sp. 2. Concerning O. rupestris and Oligoryzomys sp. 2, species with the lowest diploid numbers of the genus, a total of 8 probes hybridized to 11 segments on the largest pair of ORU 1 and 9 probes hybridized to 12 segments on OSP 1. Also, OMO 6 painted three segments in ORU, corresponding to the proximal segment of ORU 2q, and the whole of ORU 19 and 20. In OSP, the segment corresponding to ORU 20 was homologous to OSP 1p. OMO X showed signals of hybridization in both X and Y chromosomes. Extensive chromosomal rearrangements, that could not be detected by classical cytogenetic techniques, such as pericentric inversions or repositioning of centromeres, Robertsonian rearrangements and tandem fusions/fissions, as well as gain/activation or loss/inactivation of centromeres and telomeric sequences have driven the huge genome reshuffling in these closely related species. PMID:25658766
N.THITIPRAMOTE; J.SUWANJARAT; W.G.BREED
This study investigated some aspects of the reproductive biology of male and female greater bandicoot rats,Bandicota indica,in southern Thailand from September 2004 to September 2006. In females,body,uterine and preputial gland weights,occurrences of pregnancies and placental scars,and in males,testicalar weights and histology,and sizes of accessory sex glands,were recorded. Pregnancies occurred predominantly,but not exclusively,in the wet season,with a higher incidence pregnancies in the second,than in the first,dry season. Uterine and preputial gland weights tended to be lower in the first,but not the second dry season,with placental scars occurring at all times of year. Males tended to have heavier testes in the wet season but some seminiferous tubules contained sperm even in the dry season. Seminal vesicles,but not prostates and preputial glands,tended to be heavier in animals in the wet season. We conclude that the greater bandieoot rat in southern Thailand shows maximal reproductive activity in the wet season with some reproductive activity,albeit variable from year to year,occurring in the dry season depending upon environmental conditions. This study has also shown that females,as well as males,have large preputial glands,and that males invariably have small testes regardless of the time of year. These observations suggest a similar timing of reproduction,but a different breeding biology and perhaps social organisation,from that of the sympatric ricefield rat,Rattus argentiventer.
Ondríková, J.; Miklisová, D.; Ribas, Alexis; Stanko, M.
Brno : Ústav biologie obratlovců AV ČR, 2010 - (Bryja, J.; Zasadil, P.). s. 163 ISBN 978-80-87189-07-8. [Zoologické dny. 11.02.2010-12.02.2010, Praha] Institutional research plan: CEZ:AV0Z60930519 Keywords : helminth s * rodents * Slovakia Subject RIV: EG - Zoology http://zoo.ivb.cz/doc/sborniky/sbornik_2010.pdf
Ana Gabriela da Silva Rocha
Full Text Available Out of the 5 species of Guinea pig registered for Brazil, 4 (Cavia fulgida, C. porcellus, C. aperea, and C. magna have already been reported as hosts of Paraspidodera uncinata. The rodent species C. magna and C. aperea are small-sized mammals, with terrestrial habits, which occur from southern Brazil to eastern Uruguay. Guinea pig specimens donated for research were necropsied for the analysis of endoparasites, and the nematodes found were identified as P. uncinata. The microhabitats of this species were the small and large intestines in C. magna and the large intestine in C. aperea. The prevalence of P. uncinata in the hosts was 60% in C. magna (n = 5 and 14% in C. aperea (n = 7. The record of P. uncinata in different Guinea pig species allows inferring that the foraging mode is similar in the different locations where they occur in southern Brazil, because, perhaps, the infection of hosts has occurred through the ingestion of vegetables contaminated with P. uncinata eggs. This study contributes to knowledge on the helminth fauna of C. magna and C. aperea in southern Brazil.
Nguyen, Dang Xuan; Nguyen, Nghia Xuan; Nguyen, Duy Dinh; Dinh, Tri Huy; Le, Dinh Thuc; Dinh, Duong Hai
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
Nguyen, Dang; Nguyen, Nghia; Nguyen, Duy; Dinh,Tri; Le,Dinh; Duong,Dinh
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, Centra...
Full Text Available 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.
Rajičić Marija; Adnađević Tanja; Stamenković Gorana; Blagojević Jelena; Vujošević Mladen
B chromosomes (Bs) are a very heterogeneous group of extra chromosomes. In various species Bs occur with different nucleotide sequences ranging from repetitive to protein coding. In yellow-necked field mice, Apodemus flavicollis Bs are small euchromatic chromosomes and untill now, only few molecular analyses have been conducted. In this study we examined A. flavicollis individuals with different number of Bs for presence of two genes, C-KIT and 18S rRNA. Th...
Full Text Available B chromosomes (Bs are a very heterogeneous group of extra chromosomes. In various species Bs occur with different nucleotide sequences ranging from repetitive to protein coding. In yellow-necked field mice, Apodemus flavicollis Bs are small euchromatic chromosomes and untill now, only few molecular analyses have been conducted. In this study we examined A. flavicollis individuals with different number of Bs for presence of two genes, C-KIT and 18S rRNA. The C-KIT proto-oncogene was found on Bs in three Canidae species and one Cervidae species. This gene is a coding receptor critical for proliferation and cell differentiation of hematopoietic, melanoblast and primordial germ cells, and is highly conserved within mammals. While using semiquantitative PCR, we did not notice any difference in the C-KIT band intensity among animals with different number of Bs (0-3. The presence of only one copy of C- KIT gene was confirmed using real time-PCR on genomic DNA of A. flavicollis specimens with different number of Bs. rRNA genes in eukaryotes’ genome are organized like units of tandem repeated sequences. The units form distinct clusters on one to several chromosome pairs. rRNA genes were found on Bs in different species including two species of genus Apodemus. One particular sample with 2 Bs showed the number of 18S rRNA gene about three times that of the calibrator 0 B sample. This result can indicate the presence of 18S rRNA gene on Bs, but its confirmation requires the implementation of other methods. Still, we can neither confirm nor deny the existence of pseudogen of tested target genes, or lose of exon 1 of C-KIT protooncogen in Bs of A. flavicollis. Our findings are further discussed. [Projekat Ministarstva nauke Republike Srbije, br. 173003
I studied the relationship between sex and infestation with ectoparasites in the water rat Scapteromys aquaticus from La Plata river marshland, Argentina. The Relative Density's Index (RDI) for males was 3.90% (females 3.60%). A total of 2653 ectoparasites were collected on 33 male hosts, and 1945 on 31 females. Ectoparasite specific richness (S) and diversity (H) were S = 14, H = 1.17 on males, and S = 10, H = 1.52 on females. The similarity between male and female rodents according to their ectoparasites was 75.00%. Although no ectoparasite species showed significant mean abundance (MA) differences between host sexes (p hosts (N = 2.01, p ectoparasite burden and specific richness. This information has epidemiological potential because the closely related Scapteromys tumidus is involved in the transmission of Rickettsia coronii, which causes Marsella fever in humans. PMID:18494333
Andersen, Douglas C.; MacMahon, James A.
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.
Ondríková, J.; Miklisová, D.; Ribas, Alexis; Stanko, M.
Roč. 55, č. 4 (2010), s. 369-378. ISSN 1230-2821 Institutional research plan: CEZ:AV0Z60930519 Keywords : helminth community * rodents * south-eastern Slovakia Subject RIV: EG - Zoology Impact factor: 1.144, year: 2010
Air C. Barretto
Full Text Available Three isolates of Leishmania were recovered from five of 27 specimens of the rodent Proechimys iheringi denigratus Moojen captured near Três Braços in the Atlantic Forest region of Bahia, Brazil. Two of these isolates were recovered from hamsters inoculated with a pooled triturate of liver, spleen and skin tissue from apparently healthy P. i. denigratus. The third isolate was recovered from a triturate of only skin tissue from another. Metastasis was observed in the inoculated hamsters, the parasites grew abundantly in artificial media and a typical suprapylarial pattern of infection in Lutzomyia longipalpis was produced indicating that the parasites belong to the Leishmania mexicana complex. All isolates reacted with Leishmania mexicana mexicana and Leishmania mexicana amazonensis monoclonal antibodies. The isoenzyme analysis differentiated these isolates from standard isolates of L. m. mexicana, L. m. amazonensis, L. m. aristedesi, L. m. pifanoi, L. m. garnhami and L. m. ssp.(Goiás-W. Barbosa. These isolates seem to be a subspecies of L. mexicana very closely related to L. m. amazonensis from which they differ by decreased electrophoretic mobility of GPI, PEP and ALAT. This is the first record of the isolation of a parasite of thegenus Leishmania in a rodent captured in the State of Bahia.Três isolados de Leishmania foram obtidos de cinco entre 27 exemplares do roedor Proechimys iheringi denigratus, capturados na região de Três Braços, na mata atlântica do Estado da Bahia, Brasil. O isolamento desse parasito foi feito através de inoculação de triturado de pele, baço e fígado em patas de hamsters. Em pelo menos um dos casos, (MTB-574, o parasito foi isolado da pele. Metas- tase foi observada nos hamsters inoculados, os parasitos cresceram abundantemente em meios artificiais de cultura e um padrão suprapapilario típico foi obtido em Lutzomyia longipalpis, indicando que o parasito pertence ao complexo L. mexicana. Todos os isolados reagiram positivamente com anticorpos monoclonais de L. m. mexicana e L. m. amazonensis. A análise isoenzimática diferenciou o parasito de isolados padrões de L. m. mexicana. L. m. amazonensis. L. m. aristedesi. L. m. pifanoi. L. m. garnhami e L. m. ssp(Goiás-W. Barbosa. O parasito parece ser uma subespécie de L. mexicana muito próxima à L. m. amazonensis, da qual difere pela menor mobilidade eletroforêtica de GPI, PEP e ALAT. Este e o primeiro registro do isolamento de um parasito do gênero Leishmania em um roedor capturado no Estado da Bahia.
Full Text Available Conventional chromosomal preparations were made of three native mice from Huánuco, Peru: a male and a female of Thomasomys sp., and a male of Akodon orophilus. Thomasomys sp. had a karyotype of 2n = 42, XY (n = 21, meanwhile A. orophilus presented 2n = 22, XY (n = 11. Comparisons between chromosomal pairs from the existent literature indicate that both are new karyotypes. Thomasomys sp. has a distinct sexual Y chromosome, the only metacentric (m reported for the genus. The chromosomes X and Y of A. orophilus are acrocentrics (a; and the length of chromosome Y (2/3 of the length of X distinguishes A. orophilus from other congeneric. Because the structural differences between the sexual chromosomes usually generates mechanism of reproductive isolation at intraspecific level and are bigger still in interspecific crosses, we concluded that the karyotypes reported here support the validity of the species A. orophilus and suggest that Thomasomys sp. represents a new species to science.
Shintaku, Yuta; Motokawa, Masaharu
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
Jeon, Mi Gyung; Kim, Ji Young; Park, Yung Chul
We sequenced and characterized a complete mitogenome (KP671850) of the Chinese Apodemus peninsulae and compared it with a previously published mitogenome of the Korean A. peninsulae (NC016060). The total length of the Chinese A. peninsulae mitogenome is 16,457 bp. The mitogenome consists of 13 protein-coding genes (PCGs), two rRNA (12S rRNA and 16S rRNA) genes, 22 tRNA genes, and one D-loop region. The most common start codon was ATG, used in the nine PCGs for initiation. The mitogenomes of Chinese and Korean A. peninsulae showed 98.9% sequence similarity. The intra-/interspecific phylogeny of the Chinese A. peninsulae revealed that the Chinese A. peninsulae was well grouped with the Korean A. peninsulae. The clade of A. peninsulae was sister to that of Apodemus agrarius, Apodemus chejuensis, and Apodemus chevrieri. PMID:26006285
Richard, Florence; Gerbault-Seureau, Michèle; Douangboupha, Bounneuang; Keovichit, Kham; Hugot, Jean-Pierre; Dutrillaux, Bernard
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. PMID:27193170
YİĞİT, Nuri; ÇOLAK, Ercüment; VERİMLİ, Reyhan
The Habitat, external and cranial morphologies, and karyotype of Turkish specimens of Tatera indica are described for the first time with this study. It was determined that Tatera indica was located in uncultivated arid and semi-arid habitat in southeastern Turkey. Its external and cranial characteristics are consistent with those detailed in published papers. The karyotype of Tatera indica is composed of 2n = 68, NF = 84 and NFa = 80.
Luz V. Carrizo
Full Text Available Se describe el esqueleto postcraneal de dos especies de roedores sigmodontinos Rhipidomys austrinus Thomas, 1921 y Graomys griseoflavus (Waterhouse, 1837. Se detalla cada estructura del esqueleto postcraneal sobre la base de la forma, tamaño, superficie y orientación de cada elemento esqueletal. La anatomía postcraneal de estas dos especies muestra caracteres asociados a patrones morfológicos diferentes, vinculados a su modo de locomoción. Es así que R. austrinus exhibe características en varios elementos del postcráneo consistente con una locomoción arborícola, mientras G. griseoflavus muestra atributos en su esqueleto relacionados a una locomoción de tipo terrestre.
María Eugenia Copa Alvaro; Geovana Shirley Mendieta; Amy L. Deane
Actualmente, la presencia de la chinchilla de cola corta (Chinchilla chinchilla), abundante en la región andina sudamericana durante el siglo pasado, ha sido fehacientemente documentada en pocas localidades del norte de Chile y Argentina; en Bolivia aunque su presencia es altamente probable, los últimos registros confiables datan de 1939. La cacería con fines peleteros disminuyó significativamente la población silvestre de la especie lo que derivó en un estatus de conservación "En Peligro Crí...
Basheva, Ekaterina A; Torgasheva, Anna A; Gomez Fernandez, Maria Jimena; Boston, Emma; Mirol, Patricia; Borodin, Pavel M
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. PMID:24924853
Bueno Martha Lucía; Gómez Laverde Marcela
The presence oftwo chromosomal races is reported in a comparative study of populatlons of Proechimys semlspinosus from the Pacific lowlands of Colombia. These races are differenciated by the constitutive heterochromatin found using the C-band technlque. The population from Nariño locality lacks centromeric heterochromatin and has large blocks of telomeric heterochromatin in several chromosomes while the population from Chocó loca lity has small blocks of centromeric heterochromatin in the maj...
Bueno Martha Lucía
Full Text Available The presence oftwo chromosomal races is reported in a comparative study of populatlons of Proechimys semlspinosus from the Pacific lowlands of Colombia. These races are differenciated by the constitutive heterochromatin found using the C-band technlque. The population from Nariño locality lacks centromeric heterochromatin and has large blocks of telomeric heterochromatin in several chromosomes while the population from Chocó loca lity has small blocks of centromeric heterochromatin in the majority of the chromosomes and small and medium size blocks of telomeric heterochromatin only in three pairs of chromosomes. Thesimilarity between the heterochromatin pattem in the Gorgona island (Gómez-Laverde et al" 1990 and Nariño populations suggests a very close relation ship and supports the affinities ofthe island's biota with the southwestem region of Colombia and northem region of Ecuador previously reported in others biological groups.Mediante un estudio comparativo en poblaciones de Proechimys semispinosus del pacífico colombiano se registra la presencia de dos razas cromosómicas; estas se diferencian por el patrón de heterocromatina constitutiva detectable mediante las técnicas de bandas C. La población de la localidad de Nariño presenta ausencia casi total de heterocromatina centromérica y presencia de bloques grandes de heterocromatina telomérica en varios cromosomas, mientras que la población de la localidad del Chocó presenta bloques muy pequeños de heterocromatina centromérica en la mayoría de los cromosomas y bloques pequeños y medianos teloméricos solo en tres pares cromosómlcos. La similitud del patrón de heterocromatina, entre las poblaciones de la isla Gorgona (Gómez-Laverde et al" 1990 y de Nariño, sugiere una estrecha relación entre ellas; este hecho se suma a las evidencias sobre la afinidad de la biota de la isla con la región su roccidental de Colombia y del norte del Ecuador, reportada en otros grupos biológicos.
Alessandra Queiroga Gonçalves
Full Text Available A new genus and a new species of Heligmonellidae nematodes are described parasiting the stomach of three agoutis (two Dasyprocta fuliginosa and one D. leporina captured in the middle and high Negro river microregion, state of Amazonas, Brazil. The new genus, as well as its type-species, are closely related to the trichostrongylids included in Fuellebornema, particularly on what concerns the pattern of the caudal bursa, but differing from them by the characteristics of the synlophe, that presents a poorly developed carene, when compared to the referred number of body ridges in Freitastrongylus n. gen. and consequently in F. angelae n. sp.,in which the ridges are well developed and the carene at mid-body has a similar size when compared to the ridge situated in front of the right field (ridge no. 5. Caudal bursa is of the type 1-4, with rays 9 shorter than rays 10, with a very long genital cone.
Lorenzo, Consuelo; Sántiz, Eugenia C; Navarrete, Darío A; Bolaños, Jorge
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
du Toit, Nina; van Vuuren, Bettine Jansen; Matthee, Sonja; Matthee, Conrad A
Within southern Africa, a link between past climatic changes and faunal diversification has been hypothesized for a diversity of taxa. To test the hypothesis that evolutionary divergences may be correlated to vegetation changes (induced by changes in climate), we selected the widely distributed four-striped mouse, Rhabdomys, as a model. Two species are currently recognized, the mesic-adapted R. dilectus and arid-adapted R. pumilio. However, the morphology-based taxonomy and the distribution boundaries of previously described subspecies remain poorly defined. The current study, which spans seven biomes, focuses on the spatial genetic structure of the arid-adapted R. pumilio (521 specimens from 31 localities), but also includes limited sampling of the mesic-adapted R. dilectus (33 specimens from 10 localities) to act as a reference for interspecific variation within the genus. The mitochondrial COI gene and four nuclear introns (Eef1a1, MGF, SPTBN1, Bfib7) were used for the construction of gene trees. Mitochondrial DNA analyses indicate that Rhabdomys consists of four reciprocally monophyletic, geographically structured clades, with three distinct lineages present within the arid-adapted R. pumilio. These monophyletic lineages differ by at least 7.9% (±0.3) and these results are partly confirmed by a multilocus network of the combined nuclear intron dataset. Ecological niche modeling in MaxEnt supports a strong correlation between regional biomes and the distribution of distinct evolutionary lineages of Rhabdomys. A Bayesian relaxed molecular clock suggests that the geographic clades diverged between 3.09 and 4.30Ma, supporting the hypothesis that the radiation within the genus coincides with paleoclimatic changes (and the establishment of the biomes) characterizing the Miocene-Pliocene boundary. Marked genetic divergence at the mitochondrial DNA level, coupled with strong nuclear and mtDNA signals of non-monophyly of R. pumilio, support the notion that a taxonomic revision of the genus is needed. PMID:22728170
Matthee, Sonja; Ueckermann, Edward A
Laelaps horaki n. sp. and L. radovskyi n. sp. are described from the pelage of the rodent Rhabdomys pumilio (Sparrman) in the Western Cape Province, South Africa. The formal taxonomic description and illustrations are derived from adults (females and males) and deutonymphs. A key to southern African species of Laelaps Koch, 1836 is given. PMID:19337857
Matthee, Sonja; Ueckermann, Edward A
Androlaelaps rhabdomysi n. sp. is described from the pelage of the endemic rodent Rhabdomys pumilio (Sparrman) in the Western Cape Province, South Africa. The formal taxonomic description and illustrations are derived from adults (female and male) and deutonymphs. The specimens are similar in appearance to two congeneric species A. dasymys (Radford, 1939) and A. fahrenholzi (Berlese, 1911), but differ in the following features: genital shield long and almost parallel-sided; metapodal shield elongate; and anal shield longer than wide. Furthermore, the pilus dentilis on the fixed cheliceral digit of A. rhabdomysi is a rather broad sausage-shape and slightly constricted medially, whereas in the other two species it has an inflated base and is slender distally. PMID:18535789
Y Rassi; Jalali, M.; E. Javadian; MH Moatazedian
This study was carried out in Arsanjan county Fars province, a new focus of ZCL, during 1999-2000. Totally fifty nine Meriones libycus captured by live traps and four out of them (6.8%) were naturally infected with parasites. Parasites were cultured in monophasic medium RPMI 1640 and isolated promastigotes were identified using RAPD-PCR test in Medical Parasitology Unit of Shiraz University of Medical Sciences. The results showed that parasites were L. major, so, Meriones libycus was known th...
Full Text Available This study was carried out in Arsanjan county Fars province, a new focus of ZCL, during 1999-2000. Totally fifty nine Meriones libycus captured by live traps and four out of them (6.8% were naturally infected with parasites. Parasites were cultured in monophasic medium RPMI 1640 and isolated promastigotes were identified using RAPD-PCR test in Medical Parasitology Unit of Shiraz University of Medical Sciences. The results showed that parasites were L. major, so, Meriones libycus was known the principal reservoir of ZCL in the rural region of Arsanjan. Rhombomys opimus and Tatera indica were absent in the study areas.
Full Text Available The Dinagat Bushy-tailed Cloud Rat Crateromys australis belongs to the group of Cloud Rats, arboreal and folivorous nocturnal rodents endemic to the forests of the Philippines. The species, endemic to a small island Dinagat in the Philippines, was discovered and captured in 1975. Since then, despite repeated surveys, no specimen was found until 2012. It is listed as Critically Endangered by IUCN Red List and was even believed to be extinct. Finally, Dinagat Bushy-tailed Cloud Rat was rediscovered in January 2012 and its presence confirmed on Dinagat Island. The rediscovery of this species underlines the local, national and international importance of Dinagat Island (or Dinagat-Siargao cluster of islands, as the most distinct subcentre of species endemism within the Greater Mindanao Faunal Region. Unfortunately, only one locally protected area exists on the whole island and none of the last remaining native forest habitats on Dinagat are currently protected at the national level. Mining and habitat destruction constitute a serious threat to this species. We believe that this rediscovery may provide some important and timely impetus and urgency to the need for a more rational, scientifically-based and island-wide, development program on Dinagat by also incorporating an island/region-wide biodiversity conservation strategy that would help ensure the effective, longer-term protection of the larger majority of the few remaining natural habitats in this region.
Se presenta un índice que permitirá evaluar el hábitat de la "Lapa andiim" o "Tinajo" (Agouti taczanowskii) en zonas de bosque andino nublado. El objetivo fundamental de este índice, es obtener elementos que sirvan para la toma de decisiones en cuanto al diseño de áreas de reserva y planes de manejo sobre esta especie. Este índice se basa en la aplicación de criterios tanto cualitativos como cuantitativos, los cuales son tabulados y computados para sacar un valor de calidad de hábitat para ca...
Svitlana V. Zadyra
Full Text Available The present research dedicates the integral assessment of biochemistry indexes of nature populations of rodents under conditions of environment pollution by heavy metals. The raised content in soils of mobile forms Pb, Cd, Cr, Ni and Co was revealed оn distance of 500 m to the South-West from Tripillya Thermal Power Plant (Kyiv region, Ukraine. That’s considerably (3–5 times exceeds levels for territory of Kaniv Nature Reserve (Cherkassy region, Ukraine. Territory of National Nature Park “Holosiivsky” (Kyiv, Ukraine characterized by rather increased content of active form of researched heavy metals especially Pb. Increase of the concentration of diene conjugates (3–7 times and malonic dialdehyde (2–4 times in yellow-necked mouse liver (Apodemus flavicollis of under pollution by heavy metals has been discovered. Insignificant increasing of content of Schiff basis in liver cells of rodents in region of impact of Tripillya TPP (in 2 times in spring and in summer, in autumn – in 2.5 times was detected. Seasonal dynamics of the maintenance of lipid peroxidation has been revealed. The registered changes of biochemical indicators testify about presence ecological-biochemical stress in an organism of the yellow-necked mouse in the district of influence of Tripillya TPP.
Full Text Available The hypothalamus is a forebrain structure critically involved in the organization of defensive responses to aversive stimuli. Gamma-aminobutyric acid (GABAergic 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.
Biagioni, A.F.; Silva, J.A.; Coimbra, N.C.
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
Full Text Available Trichospirura aethiopica n. sp. is described from unidentified tubular structures (pancreatic ducts? near the stomach of the murid Malacomys longipes Milne-Edwards, 1877 in Gabon. The extremely long and narrow buccal capsule, posterior position of the vulva, unequal spicules and absence of caudal alae readily identified the specimens as belonging to Trichospirura Smith & Chitwood, 1967, but a combination of several characters distinguished them from the described species in this genus. Males of the new species are characterized by the absence of precloacal papillae, the presence of four pairs of postcloacal papillae and a left spicule length of 165–200 μm. With only five nominal and one unnamed species, the host range of Trichospirura extends into the Neotropical, Indo-Malayan and Ethiopian Realms and comprises three classes of vertebrates, Amphibia, Reptilia and Mammalia, suggesting a larger species diversity than that currently recorded. Detection is difficult as predilection sites are often outside the gut lumen. It was noted that, irrespective of their geographic origin, species from mammals share certain characters (shorter left spicule and absence of precloacal papillae that oppose them to those from amphibians and reptiles. A hypothesis for the origin of Trichospirura in mammals through a remote host-switching event in tupaiids in southern Asia, likely facilitated by the intermediate hosts, and for their subsequent migration to the Ethiopian and finally Neotropical Realm is proposed. Regarding the two species from anurans and saurians in the Antilles, one or two host-switching events are considered equally possible, based on morphological characters.
Izdebska, Joanna N; Rolbiecki, Leszek
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
Izdebska, Joanna N; Rolbiecki, Leszek
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
Full Text Available Understanding what influences the activity of organisms is important for both ecological understanding and species conservation. Using data from 2,707 camera trap days distributed across 24 forest sites, we present quantitative analyses of the activity pattern of Cuniculus paca (Linnaeus, 1766 in southern Amazonia. We compared the activity pattern of this species across four designated subsets of the 24-hours diel cycle (dawn, dusk, day and night. Using linear regression models we tested the influence of season, temperature and rainfall on the activity patterns of C. paca (paca. We also evaluated the nocturnal photos of paca (N = 111 as a function of the degree of lunar illumination in order to test the prediction that pacas minimize their activity during moon phase when illumination is brighter. Pacas were not recorded during the day but were active at dawn, dusk and night time. We found differences in the influence of the abiotic variables on the nocturnal activity of pacas in the study area. There was no significant difference between the observed (expressed as the frequency of total counts of independent photos over the five classes of lunar illumination and the expected activity of pacas, based on the frequency of days in the lunar cycle with different classes of lunar illumination, whereas lunar illumination had a weak negative influence on the timing of paca activity (i.e. pacas were active closer to sunset with increasing lunar illumination. However, the timing of nocturnal activity in pacas was not influenced by season, temperature or rainfall. Our findings highlight the ecological plasticity of this Neotropical rodent which has a key function in the maintenance of Neotropical forests.
Bocherens, Herve; Michaux, Jacques; Talavera, Francisco Garcia; Van der Plicht, Johannes
Fossil bone collagen (14)C dating and delta(13)C and delta(15)N isotopic measurements of the rodent Canariomys bravoi from Tenerife (Canary Islands.. Spain) were used to test two different hypotheses about the causes of extinctions of endemic vertebrates on islands. climate versus humans. For the Te
Spotorno, Angel E; Zuleta, Carlos; Walker, Laura I; Manriquez, German; Valladares, Pablo; Marin, Juan C
A small, new species of gerbil rodents of the genus Eligmodontia from the southwestern dunes of the Atacama Desert in northern Chile is described; the genus had not been reported for this western lowland region. Our description is based on cytogenetic and molecular data, as well as cranial and external morphology. In order to support this hypothesis, we studied 27 specimens captured in Playa Los Choros (Coquimbo) and Copiapó (Atacama), comparing them with samples of all the extant species of the genus. Nineteen individuals consistently showed 2N=50, FN=48, with telocentric chromosomes and G-bands identical to those of the geographically northeastern E. hirtipes; these two groups were geographically separated by E. puerulus (2N = 34, FN = 48). The phylogenetic analysis of 56 Eligmodontia cytochrome-b gene sequences yielded a maximum-likelihood phylogenetic tree where the new species formed a divergent and well-supported clade within the genus, which was also confirmed by unweighted parsimony, minimum evolution, and Bayesian analyses. The new species has K2P genetic distances of 12.8% from the geographically distant E. hirtipes, and 10.3% from E. puerulus. Axes 1 and 2 of Principal Component Analysis based on 12 body and skull measurements clearly separated the new species, the latter having a smaller head+body length (70.6 +/- 3.4 mm, n = 17) and lower weight (11.9 +/- 1.9 g, n = 20). We provide strong evidence to recognize a distinct new western lineage within Eligmodontia genus, Eligmodontia dunaris sp. nov., for which we give a complete taxonomic description and a hypothetical biogeographic scenario. The new species should be considered endangered, due to its level of endemism, its low population numbers (which can be occasionally increased after a blooming desert) and its fragile dry habitat patchily distributed near the Atacama Desert. PMID:25250459
Karen Ventura; Maria José de Jesus Silva; Yatiyo Yonenaga-Yassuda
A novel karyotype with 2n = 50, FN = 48, was described for specimens of Thaptomys collected at Una, State of Bahia, Brazil, which are morphologically indistinguishable from Thaptomys nigrita, 2n = 52, FN = 52, found in other localities. It was hence proposed that the 2n = 50 karyotype could belong to a distinct species, cryptic of Thaptomys nigrita, once chromosomal rearrangements observed, along with the geographic distance, might represent a reproductive barrier between both forms. Phylogen...
Omar dos Santos Carvalho
Full Text Available Junto ao Lago da Pampulha, Belo Horizonte, MG, foram capturados (julho/72-novembro/73 28 exemplares de Holochilus brasiliensis, dos quais 11 (39,3% eliminavam nas fezes ovos viáveis de S. mansoni. Miracídios da cepa mencionada ("H" infectaram Biomphalaria glabrata e as cercárias obtidas também infectaram camundongos albinos, recuperando-se, ao final do experimento, 35,3% de vermes adultos. Por outro lado, cercárias de cepa humana ("LE" de S. mansoni infectaram sete exemplares de H. brasiliensis, nascidos em laboratório, recuperando-se no fim de 60 dias, 30,5% de vermes adultos. Estudos anatomapatológicos de H. brasiliensis demonstraram infecção generalizada, encontrando-se granuloma no esôfago, estômago, intestino (delgado e grosso, fígado, baço, pâncreas e linfonodos abdominais. Espessamentos fibrosos da íntima da veia porta, granulomas em espaços porta e fibrose incipiente dos espaços porta e interlobular foram lesões decorrentes da presença de ovos de S. mansoni encontrados no fígado. Em ambiente semi-natural, foi possível fechar o ciclo do S. mansoni sem direta participação humana, utilizando-se B. glabrata experimentalmente infectadas com trematódeos da cepa "LE", H. brasiliensis nascidos em laboratório e B. glabrata nascida no ambiente semi-natural estabelecido. Verificou-se que ambas as cepas ("H" e "LE" comportaram-se de maneira análoga, não sendo verificadas, também, diferenças morfológicas entre os ovos e vermes adultos de ambas. As observações, realizadas no campo e no laboratório demonstraram que o Holochilus brasiliensis é bom hospedeiro de Schistosoma mansoni. Assim, em determinadas áreas e sob certas condições ecológicas, o cricetídeo em questão poderá, efetivamente, integrar-se ao ciclo do trematódeo na natureza, independente ou paralelamente à presença do homem. Assinala-se, finalmente, que o presente trabalho relata o segundo fechamento do ciclo biológico de S. mansoni em condições ditas semi-naturais. Os primeiros estudos, entretanto, de Antunes, Milward de Andrade, Katz & Coelho4,,em 1971 e de Antunes5, em 1971 foram feitos utilizando-se o Nectomys s. squamipes.
Ectoparasite occurrence associated with males and females of wild rodents Oligoryzomys flavescens (Waterhouse) and Akodon azarae (Fischer) (Rodentia: Cricetidae: Sigmodontinae) in the Punta Lara wetlands, Argentina.
The objective of this research was to study infestation parameters and indexes of ectoparasites associated with each sex of the wild rodents Oligoryzomys flavescens (Waterhouse) andAkodon azarae (Fischer) in the Punta Lara wetlands, Argentina. A trend towards higher mean abundance (MA) and ectoparasite specific richness was observed in males of O. flavescens whereas those values were similar for both A. azarae sexes. The prevalence of the following ectoparasites was significantly higher on males (P<0.05): Mysolaelaps microspinosus Fonseca (65.2%) and Hoplopleura travassosi Werneck (73.9%) on O. flavescens, and Ixodes loricatus Neumann (71.4%) on A. azarae. Only H. travassosi mean abundance was significantly higher on males (MA=44.1). Since I. loricatus and Hoplopleura spp. are involved in the transmission of pathogens that cause diseases in animals and humans, and whose reservoirs are rodent hosts, these results are epidemiologically important. PMID:21120393
Ectoparasite occurrence associated with males and females of wild rodents Oligoryzomys flavescens (Waterhouse) and Akodon azarae (Fischer) (Rodentia: Cricetidae: Sigmodontinae) in the Punta Lara Wetlands, Argentina
The objective of this research was to study infestation parameters and indexes of ectoparasites associated with each sex of the wild rodents Oligoryzomys flavescens (Waterhouse) and Akodon azarae (Fischer) in the Punta Lara wetlands, Argentina. A trend towards higher mean abundance (MA) and ectoparasite specific richness was observed in males of O. flavescens whereas those values were similar for both A. azarae sexes. The prevalence of the following ectoparasites was significantly higher on m...
Full Text Available In this study, reproductive biology of Glis glis (Linnaeus, 1766 and weight gaining of pups were studied in four localities by using wooden nestboxes and tattoo pliers method in mixed deciduous forest of Istranca Mountains in Turkish Thrace. By considering morphological peculiarities, body weight gaining and reproductive signs of adults, mating behaviors and breeding times were measured from specimens captured in nestboxes. Results showed that females were mated between June 15 and August 18 and gave a birth between July 14 and September 16. The litter size ranged from 1 to 12 (Mean 6.05, n = 100 and the least weight of newborn is 2 g. Female to male ratio were in the range of 48.2 to 51.8%, respectively (n = 82. Over wintering adult yearlings reached maturity in mid June. Yearlings arising hibernation after May gained weight during September and October and they entered hibernation at the end of November. The litters at bird gained weight daily from 0.83-1.19 g and reached to 25.16-35.7 g at mean within 30 days during August and September.
Bryja, Josef; Granjon, L.; Dobigny, G.; Patzenhauerová, Hana; Konečný, Adam; Duplantier, J.-M.; Gauthier, P.; Colyn, M.; Durnez, L.; Lalis, A.; Nicolas, V.
Roč. 19, č. 21 (2010), s. 4783-4799. ISSN 0962-1083 R&D Projects: GA AV ČR IAA6093404; GA ČR GAP506/10/0983 Institutional research plan: CEZ:AV0Z60930519 Keywords : cytochrome b * microsattelites * mtDNA introgression * Quaternary * rodenta Subject RIV: EG - Zoology Impact factor: 6.457, year: 2010
Li, Yuchun; Wu, Yi; Harada, Masashi; Lin, Liang-Kong; MOTOKAWA, Masaharu
The karyotypes of three rat species from Hainan Island, China, were examined. Niviventer fulvescens (Gray, 1847) had 2n=46 and FN=64, similar to the karyotypes reported for N. fulvescensfrom Southeast Asia, while Niviventer lotipes (Allen, 1926) had 2n=52 and FN=66, which is distinct from the known karyotypes of other Niviventer species. Niviventer lotipes was recently considered conspecific with N. tenaster (Thomas, 1916), but the two were found to have extremely different karyotypes (2n=52 ...
Fatemeh Tabatabaei Yazdi
Full Text Available Jirds (genus Meriones are a diverse group of rodents, with a wide distribution range in Iran. Sundevall’s jird (Meriones crassus Sundevall, 1842 is one such species that shows a disjunct distribution, found on the Iranian Plateau and Western Zagros Mountains. Morphological differences observed between these two populations, however, lack quantitative support. Morphological differences between geographical populations of Meriones crassus were analysed and compared with those of the sympatric M. libycus. Similarities in the cranial morphology of these species were found, e.g. in a relatively large and inflated bulla. A two-dimensional geometric morphometric analysis was done on the skull of 275 M. crassus and 220 M. libycus from more than 70 different localities in their distribution range. Results confirm cranial differences between specimens of M. crassus from the Western Zagros and those from Africa and Arabia, mainly at the level of the relative size of the tympanic bulla, that were significantly correlated with the annual rainfall and elevation. Moreover, the study supports the hypothesis that the Western Zagros specimens are both a geographically and phenotypically distinct group compared to the other Iranian M. crassus specimens, suggesting that the former might be a distinct species.
Gulck, T. van; Stocks, R.; Verhagen, Ron;
placement of perches increased local hunting activity of at least the Black Shouldered Kite but there were no obvious effects on rodent population size or survival. In a single field where avian predation was prevented by covering the field with a net, an increase in survival was observed. The opposite was...
Pablo Valladares F.; Martín Espinosa; Mauricio Torres; Eric Diaz; Nicolai Zeller; Jorge de La Riva; Moisés Grimberg; Ángel Spotorno
Reportamos un nuevo registro de Chinchilla chinchilla para la Región de Atacama, Chile. Se basa en ejemplares fotografiados por cámaras de movimiento en el Parque Nacional Nevado Tres Cruces y sus alrededores y por restos óseos y de fecas encontrados en laderas de cerros, ya sea con pendiente abrupta o con rodados, ambas formaciones con cuevas de mediano tamaño. No existen reportes científicos para esta especie en la Región de Atacama en los últimos cincuenta años. Se analiza el estado de con...
The present study evaluates the parasitological model constituted by the wood mouse (Apodemus sylvaticus) and its intestinal cestode (Skrjabinotaenia lobata) as a potential bioindicator of Cd and Pb in the urban dumping site of Garraf near the city of Barcelona (Spain) and in Begues (reference site). Tissues and respective S. lobata specimens of 38 wood mice captured in Garraf and Begues were analyzed for Cd and Pb by means of ICP-MS. Higher cadmium levels in S. lobata were found only in respect to the muscular levels of their hosts. Nevertheless, lead levels were 8.5-, 53.2- and 81.4-fold higher in S. lobata than kidney, liver and muscle levels of A. sylvaticus from Garraf, respectively. Thus, the proposed model seems to be a promising bioindicator to evaluate environmental lead exposure in terrestrial habitats. In addition, all available data on lead bioaccumulation by cestode parasites of terrestrial mammals are generally discussed. - The parasitological model S. lobata/A. sylvaticus presents suitable features to be used as a bioindicator of lead pollution in terrestrial habitats
Justin K. Williams
Full Text Available There are four extant species of Gerbilliscus, formally classified as Tatera, native to the southern African subregion, each exhibiting varying degrees of environmental tolerance. These species are also routinely reported from many of the palaeontological and archaeological sites in the region. We used a geographic information systems analysis to examine the distribution of modern Gerbilliscus by georeferencing museum specimens. The distribution of Gerbilliscus was then compared to the latest treatment of the vegetation of South Africa, Lesotho and Swaziland in order to quantify the genus’s environmental tolerances and propose a new niche model for this taxon. Palaeoenvironmental reconstructions are made possible by defining the tolerance limits of modern taxa that have persisted relatively unchanged throughout the Plio-Pleistocene. Tolerance limits can then be applied to fossil-bearing localities where these taxa are known to have occurred in the past. Results from our analysis indicated that Gerbilliscus exhibits a wide range of environmental tolerances that must be considered when reconstructing palaeoenvironments.
Full Text Available A few individuals of albino Horay-bellied Squirrels along with normal gray individuals of Callosciurus pygerythrus have been observed in Sibsagar district of Assam, India. One albino female was studied in captivity. This paper presents our observations on the breeding behaviour and the parental care exhibited by the albino squirrel in captivity. The squirrel bred twice in captivity with a normal male of the same species. In both the periods, a single male baby with normal coat colour developed. Oral dose of vitamin E has been found helpful in the breeding of the studied squirrel species. The mother squirrel exhibited parental care by carrying her baby using her mouth, to a safer place during danger. However, the observed phenomenon is unlike that of the cat species. Some of the habitat ecology and feeding habits of the albino squirrels have also been studied, both in natural and in captive conditions.
Quintana Cardona, J.
Full Text Available For the first time, the partial skeleton of the Pliocene Muscardinus cyclopeus is described from Punta Nati-3, located in the northwest of the municipality of Ciutadella de Menorca (Balearic Islands, western Mediterranean. Based on bone parameters it is shown that the size of Muscardinus cyclopeus is on overage 69% higher than that of Muscardinus avellanarius. The main features that distinguish M. cyclopeus from M. avellanarius are, among others: the relatively wider diameter of the proximal epiphysis of the ulna; the relatively shorter olecranon; the less marked concavity in the fovea of the proximal epiphysis of the radius; the relatively shorter ilium; the more symmetrical epicondyles of the distal femoral epiphysis; the relatively higher lateral epicondyle dorsoventrally, with a very flat ventral surface; and the relatively narrower tibia transversely. As a species evolved in an insular context, it is still very difficult to discern which of these characters are primitive and which are derived.Se describe, por primera vez, parte del esqueleto del muscardino gigante del Plioceno de Menorca, procedente del yacimiento 3 de Punta Nati, situado al noroeste del término municipal de Ciutadella de Menorca (Islas Baleares, Mediterráneo occidental. A partir de los parámetros óseos se ha podido constatar que Muscardinus cyclopeus muestra, de media, un tamaño un 69% superior al de Muscardinus avellanarius (Linnaeus, 1758. Entre las principales características óseas que diferencian M. cyclopeus de M. avellanarius cabe destacar, entre otras, el diámetro proporcionalmente más ancho de la epífisis proximal de la ulna, el olecranon proporcionalmente más corto, la fóvea de la epífisis proximal del radio con una concavidad menos marcada, el ilium proporcionalmente más corto, los epicóndilos de la epífisis distal del fémur más simétricos, el epicóndilo lateral proporcionalmente más alto en sentido dorso-ventral, con la superficie ventral muy aplanada y la tibia proporcionalmente más estrecha en sentido transversal. Al tratarse de una especie evolucionada en un contexto insular, resulta difícil dilucidar cuales son caracteres primitivos y caracteres derivados.
Witter, K.; Pavlíková, H.; Matulová, Petra; Míšek, Ivan
Roč. 265, - (2005), s. 264-270. ISSN 0362-2525 R&D Projects: GA ČR GA304/02/0448; GA MŠk OC B23.001 Institutional research plan: CEZ:AV0Z50450515 Keywords : mouth * dentition * tooth Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.421, year: 2005
Omar dos Santos Carvalho
Full Text Available Junto ao Lago da Pampulha, Belo Horizonte, MG, foram capturados (julho/72-novembro/73 28 exemplares de Holochilus brasiliensis, dos quais 11 (39,3% eliminavam nas fezes ovos viáveis de S. mansoni. Miracídios da cepa mencionada ("H" infectaram Biomphalaria glabrata e as cercárias obtidas também infectaram camundongos albinos, recuperando-se, ao final do experimento, 35,3% de vermes adultos. Por outro lado, cercárias de cepa humana ("LE" de S. mansoni infectaram sete exemplares de H. brasiliensis, nascidos em laboratório, recuperando-se no fim de 60 dias, 30,5% de vermes adultos. Estudos anatomapatológicos de H. brasiliensis demonstraram infecção generalizada, encontrando-se granuloma no esôfago, estômago, intestino (delgado e grosso, fígado, baço, pâncreas e linfonodos abdominais. Espessamentos fibrosos da íntima da veia porta, granulomas em espaços porta e fibrose incipiente dos espaços porta e interlobular foram lesões decorrentes da presença de ovos de S. mansoni encontrados no fígado. Em ambiente semi-natural, foi possível fechar o ciclo do S. mansoni sem direta participação humana, utilizando-se B. glabrata experimentalmente infectadas com trematódeos da cepa "LE", H. brasiliensis nascidos em laboratório e B. glabrata nascida no ambiente semi-natural estabelecido. Verificou-se que ambas as cepas ("H" e "LE" comportaram-se de maneira análoga, não sendo verificadas, também, diferenças morfológicas entre os ovos e vermes adultos de ambas. As observações, realizadas no campo e no laboratório demonstraram que o Holochilus brasiliensis é bom hospedeiro de Schistosoma mansoni. Assim, em determinadas áreas e sob certas condições ecológicas, o cricetídeo em questão poderá, efetivamente, integrar-se ao ciclo do trematódeo na natureza, independente ou paralelamente à presença do homem. Assinala-se, finalmente, que o presente trabalho relata o segundo fechamento do ciclo biológico de S. mansoni em condições ditas semi-naturais. Os primeiros estudos, entretanto, de Antunes, Milward de Andrade, Katz & Coelho4,,em 1971 e de Antunes5, em 1971 foram feitos utilizando-se o Nectomys s. squamipes.Close to the Pampulha Lake, Belo Horizonte, MG (Brazil, there were collected (july/72 -November/73 28 specimens of Holochilus brasiliensis, 11 of them (39.3% eliminating S. mansoni viable eggs in their faeces. Miracidia from the strain above ("H" could infected Biomphalaria glabrata, the cercariae shed later being also able to infect albino mice, from whose faeces 35,3% of adult worms were recovered in the end of the experiment. S. mansoni cercariae from human strain ("LE" infected 7 H. brasiliensis laboratory specimens, and 30,5% of adult worms could be recovered in the end of 60 days. Anatomopathological studies of H. brasiliensis demonstrated generalized infection, granulomes being detected in the esophagus, stomach, intestines (small and large, tiver, spleen, pancreas and abdominal lymphnodes. Fibrous thickenning of the portal vein intima, granulomes in portal spaces an incipient fibrosis of portal and interlobular spaces were the lesion triggered by the presence of S. mansoni eggs in the liver. In semi-natural surroundings (Fig. 1, the life cycle of S. mansoni could be completed, with no human interference, by using B. glabrata experimentally infected with trematodes from "LE" strain, laboratory-bred H. brasiliensis and B. glabrata specimens from hat seminatural surroundings. It was observed that both strains ("H" and "LE" displayed similar behaviour, no morphological differences having been detected between their eggs and adult worms. Field and laboratory studies demonstrated Holochilus brasiliensis to be a satisfactory intermediate host of S. mansoni. It is than possible that, under certains ecological conditions, the cricetids under study may eventually be integrated in the trematode natural cycle, independently from or parallely the presence of man. It must finally be pointed out that the present paper reports the second case of lifecycle completion under semi-natural conditions. The former studies4,5, however, were conducted on Nectomys s. squamipes.
Montenegro Díaz, Olga; López Arévalo, Hugo; Cadena, Alberto
Se estudiaron aspectos demográficos de Rhipidomys latimanus de febrero a agosto de 1989, utilizando la técnica de captura-recaptura en una cuadrícula de 1.2 Ha. con vegetación de Bosque altoandino y páramo a una altura superior a los 3.000 msnm en el oriente de Cundinamarca, Colombia. La densidad poblacional se incrementó en los meses de mayor precipitación y la supervivencia se mantuvo entre moderada y alta. La actividad reproductiva fue constante en esta época del año, El área de acción pro...
Kvičerová, Jana; Mikeš, V.; Hypša, Václav
Roč. 138, č. 10 (2011), s. 1217-1223. ISSN 0031-1820 R&D Projects: GA ČR GD206/09/H026 Grant ostatní: GA ČR(CZ) GA206/08/1019; GA AV ČR(CZ) KJB601410816 Institutional research plan: CEZ:AV0Z60220518 Keywords : coccidia * Eimeriidae * Rodents * garden dormouse * 18S rDNA * ORF 470 * oocyst morphology * oocyst residuum * phylogenetic analysis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.961, year: 2011
Vasilieva, N Yu; Khrushchova, A M; Shekarova, N; Rogovin, K A
In this paper we report the results of testosterone manipulation in the blood of male Campbell dwarf hamsters Phodopus campbelli Thomas, 1905 through castration, followed by testosterone treatment. Under these conditions, we studied antibody production rates in response to injection with sheep red blood cells (SRBC). It was shown that castration induced a dramatic decrease in blood testosterone but had no effect on the humoral response to SRBC. Males that received a testosterone compound with a long-lasting action (omnadren) exhibited a poor response to SRBC following re-exposure in the context of elevated testosterone compared to castrated males inoculated with an oil base of the drug. PMID:26349233
Endoparasitos em cobaias (Cavia porcellus (Mammalia, Rodentia, Caviidae provenientes de biotérios de criação e experimentação do município do Rio de Janeiro, Brasil Endoparasites in guinea pigs (Cavia porcellus (Mammalia, Rodentia, Caviidae from breeding and experimentation animal housing of the municipality of Rio de Janeiro, Brazil
Luciana Casartelli Alves
Full Text Available Foi realizado um levantamento sobre a prevalência e intensidade de infecção de endoparasitos em cobaias convencionais de linhagem Short Hair provenientes de biotérios de criação (A e experimentação (B do município do Rio de Janeiro, Brasil, avaliando-se a eficácia das medidas de prevenção entre eles. Para a realização do estudo, utilizou-se exame direto de mucosa e do conteúdo intestinal, a técnica de tricromo de WHEATLEY e exames coproparasitológicos pelas técnicas de Ritchie e Kinyoun. Os parasitos encontrados através da técnica de exame direto da mucosa e do conteúdo intestinal e de tricromo de WHEATLEY com as respectivas prevalências foram: Balantidium sp. (78%, Cyathodinium sp. (68%, Eimeria caviae (38%, Paraspidodera uncinata (34% e Giardia muris (24%. Nos exames de fezes realizados pelas técnicas de Ritchie e Kinyoun, foram encontrados os seguintes parasitos com as respectivas prevalências no biotério A: E. caviae (74%, Balantidium sp. (68%, Cyathodinium sp. (68% e Cryptosporidium sp. (5%. No biotério B, observou-se: E. caviae (58%, Balantidium sp. (42%, Cyathodinium sp. (25% e G. muris (8%. A alta prevalência de endoparasitos nos biotérios sugere a necessidade de se rever a eficácia das barreiras sanitárias adotadas.This paper discusses the prevalence and intensity of infection of endoparasites in conventionally maintained Short Hair guinea pigs colonies from a breeding (A and an experimental (B facilities in Rio de Janeiro, Brazil. It also evaluates the efficacy of the methods of prevention adopted by both facilities. The search of parasites was performed by direct examination of intestinal mucosa and its contents, WHEATLEY's trichrome method and coproparasitological examinations by Ritchie's and Kinyoun's techniques. The prevalences of endoparasites found throught direct examination of intestinal mucosa and its contents were: Balantidium sp. (78%, Cyathodinium sp. (68%, Eimeria caviae (38%, Paraspidodera uncinata (34% and Giardia muris (24%. The prevalences of endoparasites found throught Ritchie's and Kinyoun's techniques in facility A were: E. caviae (74%, Balantidium sp. (68%, Cyathodinium sp. (68% and Cryptosporidium sp. (5%. In facility B: E. caviae (58%, Balantidium sp. (42%, Cyathodinium sp. (25% and G. muris (8% were found. The high prevalences in both facilities suggest that the efficacy of the sanitary barriers adopted in the prevention of parasitic infections should be revised.
Intraspecific differences in metabolic rate of Chroeomys olivaceus (Rodentia: Muridae: the effect of thermal acclimation in arid and mesic habitats Diferencias intraespecíficas en la tasa metabólica de Chroeomys olivaceus (Rodentia: Muridae: efecto de la aclimatación térmica en hábitat áridos y mésicos
F. Fernando Novoa
Full Text Available Studies of metabolic capacities in rodents have been largely studied at an inter-specific levels, but physiological capacities of populations belonging to the same species have received lesser attention. Here we studied the maximum and basal metabolic rates of two populations of the rodent Chroeomys olivaceus dwelling in habitats with contrasting temperature and rainfall regimes, and to test if differences in metabolic capacities are due to local adaptation or acclimatization effect. After four weeks of acclimation to 25 ºC and 10 ºC, the BMR and MMR were determined in individuals from the northern population of Caleta Loa, and the southern population of La Picada. Individuals from ‘La Picada’ population were heavier than those from Caleta Loa. MMR and BMR exhibited higher values in cold acclimated animals compared with warm-acclimated animals. Besides, BMR, but not MMR, was lower in Caleta Loa individuals, in spite of the acclimation treatment. Hence, the differences in the metabolic capacities and the response to acclimation of C. olivaceus populations appear to be an evolutionary response to the environmental cuesLas capacidades metabólicas en roedores han sido ampliamente estudiadas en un nivel ínterespecífico, pero los atributos fisiológicos de las poblaciones que pertenecen a una misma especie, han recibido menos atención. Aquí estudiamos las tasas metabólicas máximas y basales de dos poblaciones del roedor Chroeomys olivaceus que viven en habitats con temperaturas y regímenes de precipitaciones contrastantes y se analiza si las diferencias en las capacidades metabólicas se deben a diferenciación local o a efectos de aclimatación. Después de cuatro semanas de aclimatación a 25 ºC y 10 ºC, el BMR y MMR fueron determinados en individuos de la población norteña de Caleta Loa y en la población sureña de "La Picada". Los individuos de la población "La Picada" presentaron mayor masa corporal que los de Caleta Loa. Los valores de MMR y BMR fueron más altos en animales aclimatados al frío, comparados con los aclimatados a temperaturas más cálidas. Asimismo, sólo BMR y no MMR, fue más bajo en los individuos de Caleta Loa, a pesar del tratamiento de aclimatación. Por lo tanto, las diferencias en las capacidades metabólicas y en la respuesta a la aclimatación de las poblaciones de C. olivaceus, parecen ser una respuesta evolutiva a las claves ambientales
Identificación de los mecanismos subyacentes a la invasión de Castor canadensis (Rodentia) en el archipiélago de Tierra del Fuego, Chile Identifying the mechanisms underlying the invasion of Castor canadensis (Rodentia) into Tierra del Fuego archipelago, Chile
PETRA K WALLEM; Jones, Clive G; Marquet, Pablo A.; Fabián M. Jaksic
Castor canadensis es considerado un ingeniero ecosistémico arquetípico, ya que altera el estado de factores bióticos y abióticos, mediante interacciones no tróficas, modificando sustancialmente los ecosistemas que habita. Esta especie fue introducida en la Isla Grande de Tierra del Fuego en 1946 por el gobierno argentino, con el fin de estimular la industria peletera. Actualmente se encuentra presente en las principales islas del archipiélago, incluyendo Tierra del Fuego, Navarino, Dawson y H...
Infección inducida en el roedor selvático Dasyprocta leporina (Rodentia: Dasyproctidae, con huevos larvados de Lagochilascaris minor (Nematoda: Ascarididae Induced infection in the wild rodent Dasyprocta leporina (Rodentia: Dasyproctidae with larval eggs of Lagochilascaris minor (Nematoda: Ascarididae
Full Text Available Ejemplares de Dasyprocta leporina Linnaeus, 1758 fueron criados alejados de su ambiente natural. A los 3 ó 4 meses de edad, se los inoculó por vía oral con huevos de Lagochilascaris minor Leiper, 1909 obtenidos de una paciente nativa. Los huevos se los incubó por más de 80 dias, para que de ellos fuese posible obtener por compresión mecánica, larvas que se mantuviesen vivas en medio acuoso por 48 horas o más. Sacrificados los animales a los 14 ó 46 dias posteriores a la infección, se hallaron en los músculos esqueléticos larvas ovilladas dentro de nódulos inflamatorios, los cuales no presentaban reacción a cuerpo extraño, abscedación o calcificación. El desarollo de los nódulos no parecía afectar la normalidad de los hospedadores. Las larvas obtenidas eran similares a las descritas por SPRENT como de tercer estadio para estos helmintos. Ratones blancos infectados con material similar, no presentaron nódulos en sus músculos ni se pudo recuperar de sus tejidos larva alguna. Por los hallazgos obtenidos con la infección de estos animales, se postula que el helminto no posee ciclo pulmonar y que su desarrollo requiere de un hospedador intermediario.Specimens of Dasyprocta leporina (Linnaeus, 1758 were raised out their natural environment. At three to four months of age they were orally inoculated with Lagochilascaris minor (Leiper, 1909 eggs obtained from a native patient. The eggs were incubated for more than 80 days so that it was possible to obtain, by mechanical compression, larvae that could be maintained alive in liquid medium for 48 hours or more. The animals were sacrificed 14-46 days after infection and tangled larva in inflammatory nodules were found in skeletal muscle without foreign body reaction, abscess formation or calcification. The development of the nodules did not seem to affect the hosts. The larvae obtained were similar to those described by SPRENT as the third stage of these helminths. When white mice were inoculated with similar material it was not possible to recuperate larva from their tissues nor were nodules found. Based on these results it is postulated that the helminth does not present a pulmonary cycle and that its development requires an intermediary host.
Free and total testosterone levels in field males of Octodon degus (Rodentia, Octodontidae: accuracy of the hormonal regulation of behavior Niveles de testosterona libre y totales en machos silvestres de Octodon degus (Rodentia, Octodontidae: exactitud de la regulación hormonal del comportamiento
MAURICIO SOTO- GAMBOA
Full Text Available Animals exhibit continuous seasonal changes in physiological, morphological and behavioral traits associated to their natural annual cycles. One of the most important changes in the organism occurs at the initiation of breeding season. In males these changes include activation of spermatogenesis, enhance of sexual secondary characters and an increase of aggressiveness. All of theses changes are basically regulated by testosterone, but the physiological basis of this testosterone regulation and the effective hormone proportion that acts in target tissues are unknown. In this work I evaluated the relationship between total testosterone, free testosterone associated to aggressive behavior in wild males of Octodon degus. I compared hormonal levels and aggressive behavior during pre, middle and post breeding periods. Results showed that behavioral aggressiveness was correlated with both total and free testosterone in June, during the beginning of breeding season, but not at other times. Results also indicated a lack of relationship between free and total testosterone in most of breeding period. I discuss the importance of this behavior-hormonal regulation (determined by free testosterone and the physiological importance of this mechanism to the organismLos animales presentan variaciones estacionales continuas que incluyen cambios fisiológicos, morfológicos y conductuales, asociados al ciclo anual. Estos cambios generalmente están activados por factores endógenos o exógenos, pero son regulados por el sistema endocrino de organismo. Uno de los cambios más importantes ocurre en el inicio del periodo reproductivo. Durante este periodo los machos presentan cambios asociados a la producción de esperatozoides, exacerbación de caracteres sexuales secundarios y un aumento de la agresividad. Todos estos cambios son regulados en parte por los niveles de testosterona, sin embargo, los mecanismos fisiológicos de esta regulación son desconocidos. En este trabajo evalué la relación que existe entre los niveles de testosterona libre y totales, y examiné su posible asociación con los niveles de agresividad en machos de una población natural de Octodon degus. Mis resultados indicaron que la agresividad se correlaciona directamente con los niveles de testosterona libre y totales solo durante el mes de junio, al inicio del periodo reproductivo, pero no durante el resto del ciclo reproductivo de esta especie. Esto indicaría que la agresividad solo se correlaciona con los niveles de testosterona libre ya que en el medio y el final del periodo reproductivo los niveles de testosterona se mantienen altos sin que se manifiesten dichas conductas. Finalmente, discuto la importancia de la regulación fina de la conducta determinada por la testosterona libre y la importancia fisiológica de este mecanismo de regulación dentro del organismo
Ectoparásitos Asociados a Machos y Hembras de Oxymycterus rufus (Rodentia: Muridae: Estudio comparativo en la Selva Marginal del río de La Plata, Argentina Ectoparasites Associated with Males and Females of Oxymycterus rufus (Rodentia: Muridae: Comparative Study in La Plata River Marshland, Argentina
Full Text Available El objetivo del presente estudio es comparar parámetros e índices de infestación de los ectoparásitos asociados a cada sexo de Oxymycterus rufus (Fischer. El índice de densidad relativa de los machos fue 4,4% y el de las hembras 5,0%. Se recolectaron 873 ectoparásitos de 38 machos y 1015 de 43 hembras. La riqueza y la diversidad específica de los ectoparásitos fueron 12,0 y 1,2 en los machos, 11,0 y 0,7 en las hembras. La similitud entre machos y hembras de acuerdo a sus ectoparásitos fue del 87%. Los resultados obtenidos muestran que el sexo del huésped influenciaría la prevalencia y abundancia media de aquellas especies ectoparásitas que en estudios previos mostraron preferencia por O. rufus, tales como Androlaelaps fahrenholzi (Berlese (abundancia media = 3,5 y prevalencia = 65,8% en los machos; abundancia media = 1,6 y prevalencia = 50,0% en las hembras, Eutrombicula alfreddugesi (Oudemans (abundancia media = 10,9 y prevalencia = 29,0% en los machos; abundancia media = 18,7 y prevalencia = 32,6% en los machos y Ornithonyssus bacoti (Hirst (abundancia media = 7,8 y prevalencia = 63,0% en los machos; abundancia media = 2,7 y prevalencia = 52,6% en las hembras. Esta información es importante desde un punto de vista epidemiológico.Infestation parameters and indexes of ectoparasites associated with each sex of Oxymycterus rufus (Fischer are compared. Males relative density index = 4.4%, females RDI = 5.0%. A total of 873 ectoparasites were collected on 38 males, and 1015 on 43 females; specific richness = 12.0, specific diversity = 1.2 on males, and S = 11.0 H = 0.7 on females. The similarity between both sexes according to their ectoparasites was of 87.0%. The results obtained show that host sex may influence on the prevalence and mean abundance of those ectoparasites which in previous studies have showed preference for O. rufus, such as Androlaelaps fahrenholzi (Berlese (mean abundance = 3.5 and prevalence = 65.8% in males; mean abundance = 1.6 and prevalence = 50.0% in females, Eutrombicula alfreddugesi (Oudemans (mean abundance = 10.9 and prevalence = 29.0% in males; mean abundance = 18.7 and prevalence = 32.6% in females and Ornithonyssus bacoti (Hirst (mean abundance = 7.8 and prevalence = 63.0% in males; mean abundance = 2.7 and prevalence = 52.6% in females. This information is important since an epidemiological viewpoint.
Ectoparásitos Asociados a Machos y Hembras de Oxymycterus rufus (Rodentia: Muridae): Estudio comparativo en la Selva Marginal del río de La Plata, Argentina Ectoparasites Associated with Males and Females of Oxymycterus rufus (Rodentia: Muridae): Comparative Study in La Plata River Marshland, Argentina
El objetivo del presente estudio es comparar parámetros e índices de infestación de los ectoparásitos asociados a cada sexo de Oxymycterus rufus (Fischer). El índice de densidad relativa de los machos fue 4,4% y el de las hembras 5,0%. Se recolectaron 873 ectoparásitos de 38 machos y 1015 de 43 hembras. La riqueza y la diversidad específica de los ectoparásitos fueron 12,0 y 1,2 en los machos, 11,0 y 0,7 en las hembras. La similitud entre machos y hembras de acuerdo a sus ectoparásitos fue de...
Matějů, J.; Říčanová, Štěpánka; Poláková, S.; Ambros, M.; Kala, B.; Matějů, K.; Kratochvíl, L.
Roč. 58, č. 2 (2012), s. 473-482. ISSN 1612-4642 Institutional support: RVO:68081766 Keywords : Translocation * Endangered species * Rodentia Subject RIV: EH - Ecology, Behaviour Impact factor: 1.355, year: 2012
Gabriel Alberto Villegas Guzman; Griselda Montiel Parra; Margarita Vargas; Polaco, Oscar J.
Se registra por vez primera la presencia de tres ameroseídos, Kleemannia plumigera, Ameroseius sp. y Sertitympanum sp. nov. habitando en un nido de Neotoma mexicana colectado en el estado de Durango, México.Se describe la distribución de los ácaros en los componentes que forman la estructura del nido. Asimismo, sedescribe la especie nueva del género Sertitympanum.
Endogenous development, pathogenicity and host specificity of Eimeria cahirinensis Couch, Blaustein, Duszynski, Shenbrot and Nevo, 1997 (Apicomplexa: Eimeriidae) from Acomys dimidiatus (Cretzschmar 1826) (Rodentia: Muridae) from the Near East
Kvičerová, Jana; Ptáčková, P.; Modrý, David
Roč. 100, č. 2 (2007), s. 219-226. ISSN 0932-0113 R&D Projects: GA ČR GA524/03/1548 Institutional research plan: CEZ:AV0Z60220518 Keywords : Eimeria cahirinensis * Acomys * Near East Subject RIV: EG - Zoology Impact factor: 1.512, year: 2007
Pablo G. Rimoldi
Full Text Available El carpincho (Hydrochoerus hydrochaeris es el roedor actual más grande del mundo y uno de los mamíferos típico de las Provincias Fitogeográficas Pampeana y del Espinal, habitando todo el sector Este de las mismas. Estas regiones han sido categorizadas por la World Wildlife Foundation (WWF como áreas "en peligro crítico/ amenazada", y se les asigna el nivel de máxima prioridad de conservación como consecuencia de la destrucción de hábitat, la sobreexplotación, la contaminación y la introducción de especies exóticas. El carpincho presenta una preferencia marcada por los ambientes con abundancia de cuerpos de agua donde la vegetación palustre le proporciona alimento y refugio. De esta forma, tanto los cuerpos de agua como la vegetación asociada es determinante para la prevalescencia de poblaciones de carpinchos en un ambiente determinado. Para la provincia de Santa Fe los registros no son muy abundantes, registrándose hasta la actualidad unos 33 puntos de colecta/observación, la gran mayoría ubicados en el centro y norte de la provincia. El objetivo de la presente contribución es presentar nuevos registros de presencia de Hydrochoerus hydrochaeris en la cuenca del río Carcarañá (sur de la provincia de Santa Fe, y su asociación con algunas variables climático-ambientales y evaluar la distribución de esta especie. Finalmente, se discute la posible expansión o migración de este especie hacia el oeste de esta provincia y de la provincia de Buenos Aires.
First genotoxicity study of Paraná river water from Argentina using cells from the clam Corbicula fluminea (Veneroida Corbiculidae and Chinese hamster (Cricetulus griseus Rodentia, Cricetidae K1 cells in the comet assay
Jacqueline D. Caffetti
Full Text Available High concentrations of xenobiotics from urban and industrial wastes have contributed to the contamination of many aquatic environments. We used the comet assay to evaluate the genotoxic potential of water collected from the River Paraná, which receives a great deal of waste, at three points (Puerto Piray, Eldorado and Montecarlo in the Misiones Province of Argentina. The in vivo comet assay used 40 freshwater clams (Corbicula fluminea while the in vitro comet assay used Chinese hamster (Cricetulus griseus K1 cell (CHO-K1 cultures with the mutagen ethyl methanesulfonate (EMS as the positive control and phosphate buffered saline (PBS as the negative control. Both assays showed statistically significant differences between the three sampling sites in relation to the negative control, the results of this preliminary study indicating that at these three sites water from the Paraná River presents genotoxic potential.