PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Rodentia”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

DNA of Akodon (Rodentia, Cricetidae). I. Biophysical characterization.

Buoyant density in CsCl, melting temperature, and G + C base content of the DNA from four species of Akodon (Rodentia, Cricetidae) were determined. The buoyant density values of 1.699-1.701 g/cm3 were in accordance with the data reported for other cricetids. No satellite bands were seen in neutral CsCl. The Tm values determined in 1 x SSC ranged from 86.2 to 87.0 C, which corresponds to G + C contents of 41.2-43.2%. There was good agreement in DNA base composition of the four species, although values were slightly higher in A. obscurus, suggesting a certain degree of interspecies variability.

Animals↗
PubMed1992

The biochemical phylogeny of guinea-pigs and gundis, and the paraphyly of the order rodentia.

1. Molecular data indicate that caviomorphs (guinea-pig-like rodents) and myomorphs (rat-like rodents) are not monophyletic. 2. Rather, the evolutionary lineage leading to the guinea-pig may have branched off prior to the divergence among myomorphs, lagomorphs, primates, chiropterans, artiodactyls, and carnivores. 3. Thus, the guinea-pig lineage probably represents an ancient eutherian lineage, and should be conferred an independent ordinal status. 4. The gundis (Ctenodactylidae) also seem to have branched off before the divergence among myomorphs, primates, and artiodactyls, but after the divergence of the guinea-pig. 5. Therefore, the order Rodentia as defined at the present time is in all probability a paraphyletic group devoid of taxonomic validity. 6. Previous claims pertaining to large differences in the rate of molecular evolution between guinea-pigs and myomorphs may have been exaggerated in many cases as a result of the erroneous phylogenetic position attributed to the guinea-pig. 7. The average rate of amino acid replacement in the guinea-pig is comparable to that in the rat and the mouse. 8. Protein-coding genes of myomorphs and caviomorphs evole, on average, about two times faster than their counterparts in gundis and humans.

Amino Acid Sequence↗
PubMedDate not supplied

[Pseudophysaloptera kahmanni n. sp. (Nematoda: Physalopteridae), a parasite of the stomach of the dormouse Eliomys quercinus ophiusae Thomas, 1925 (Rodentia: Gliridae) in Formentera (Balearic Islands) (author's transl)].

A new Nematode Physalopteridae, Pseudophysaloptera kahmanni n. sp., parasitizing the stomach of the dormouse Eliomys quercinus ophiusae Thomas, 1925 (Rodentia: Gliridae) in Formentera (Balearic Islands, Spain) is described. It is the first and only species of the genus Pseudophysaloptera Baylis, 1934 to be known parasitizing Rodents in the nature.

Animals↗
PubMed1977

Similarity of satilite DNA properties in the order Rodentia.

We have characterized satellite DNAs from 9 species of kangaroo rat (Dipodomys) and have shown that the HS-alpha and HS-beta satellites, where present, are nearly identical in all species as to melting transition midpoint (Tm), and density in neutral CsCl, alkaline CsCl, and Cs(2)SO(4)-Ag(+) gradients. However, the MS satellites exist in two internally similar classes. The satellite DNAs from three other rodents were characterized (densities listed are in neutral CsCl). The pocket gopher, Thomomysbottae, contains Th-alpha (1.713 g/ml) and Th-beta (1.703 g/ml). The guinea pig (Caviaporcellus) contains Ca-alpha, Ca-beta and Ca-gamma at densities of 1.706 g/ml, 1.704 g/ml and 1.704 g/ml, respectively. The antelope ground squirrel (Ammospermophilusharrisi) contains Am-alpha, 1.708 g/ml, Am-beta, 1.717 g/ml, and Am-gamma, 1.707 g/ml. The physical and chemical properties of the alpha-satellites from the above four rodents representing four different families in two suborders of Rodentia were compared. They show nearly identical Tm, nucleoside composition of single strands, and single strand densities in alkaline CsCl. Similar comparisons on the second or third satellite DNAs from these rodents also indicate a close relationship to each other. Thus the high degree of similarity of satellite sequences found in such a diverse group of rodents suggests a cellular function that is subject to natural selection, and implies that these sequences have been conserved over a considerable span of evolutionary time since the divergence of these rodents about 50 million years ago.

Animals↗
PubMed1992

An intriguing Y chromosome in Heteromys anomalus (Rodentia, Heteromyidae).

The mitotic chromosomes of the pocket mouse Heteromys anomalus (Rodentia, Heteromyidae) from Venezuela were analyzed by means of conventional staining and various banding techniques. The karyotype of this species is distinguished by a Y chromosome with exceptional banding properties. The very large heterochromatic Y long arm shows a remarkable bright quinacrine fluorescence, but only moderate or dull fluorescence when labeled with other AT base pair-specific fluorochromes. The implications of these findings are discussed.

Animals↗
PubMedDate not supplied

[Cutaneous leishmaniasis in Amazonia: isolation of Leishmania (Viannia) lainsoni from the rodent Agouti paca (Rodentia: Dasyproctidae), in the state of Pará, Brazil].

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 hydroelectric 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.

Animals↗
PubMedDate not supplied

[Gallegostronglyus ibicensis n. gen., n. sp. (Nematoda: Metastrongylidae), a lung parasite of Mus musculus Linnaeus, 1758 (Rodentia: Muridale) in Ibiza (Balearic Islands) (author's transl)].

Description of Gallegostrongylus ibicensis n. gen., n. sp., a Metastrongyle parasitizing the lungs of Mus musculus Linnaeus, 1758 (Rodentia: Muridae) in Ibiza (Balearic Islands). Gallegostrongylus n. gen. is proposed to include in the Angiostrongylinae the parasites of the lungs of Rodents, with bursal rays of reduced or middle size, dorsal ray consisting of two branches completely separated and located wide apart from each other, and spicules imbricated, arched and winged.

Animals↗
PubMed1991

Helminthfauna of Microtus (Microtus) cabrerae (Thomas, 1906) (Rodentia: Arvicolidae) in the Iberian peninsula: faunistic and ecological considerations.

Faunistic and ecological study of parasitic helminths of Microtus (Microtus) cabrerae (Thomas, 1906) (Rodentia: Arvicolidae) in the Iberian Peninsula. 70 specimens have been dissected, coming from 8 enclaves located in three Spanish provinces; 6 species of helminths have been detected (1 Digenetic Trematode, 4 Cestodes and 1 Nematode). Structure of helminthfauna of M. (M.) cabrerae in relation to remaining Iberian Arvicolids and the most conditioning ecological factors of the helminthfauna of the Rodent are analyzed.

Animals↗
PubMed1992

The complement system of Calomys callosus, Rengger, 1830 (Rodentia, Cricetidae).

The complement system (C) of Calomys callosus, Rengger, 1830 (Rodentia, Cricetidae), a wild reservoir for several infectious agents in Latin America, was characterized. Sera from normal adult animals lysed sheep erythrocytes (Es) previously sensitized with rabbit serum anti-Es (Ar) in the presence of veronal-buffered saline containing 0.15 mM CaCl2 and 0.5 mM MgCl2, pH 7.4, or unsensitized rabbit erythrocytes (Er) in the presence of one-half isotonic strength veronal-buffered-saline containing 2.5% glucose, 2 mM MgCl2 and 10 mM EGTA, pH 7.4. Both hemolytic curves were sigmoidal in shape, with CH50 values of 30-40 for females and 20-30 for males. C5, determined hemolytically using the intermediate cells EsArClm4m2m3m, was approximately 4.5 x 10(8)/ml and 4.0 x 10(8)/ml for females and males, respectively. Immunochemical serum analyses by double immunodiffusion or by immunoblotting using polyclonal antisera against human C1s, C1q, C2, C3, C4, C5, C8 and factors B, I and H indicated that C. callosus C components factor B, C4 and C3 cross-reacted with the corresponding human C components. Thus, C. callosus was found to contain effective classical and alternative pathways (CP, AP) and common pathways, reasonable amounts of C5 and common epitopes in the key C components, factor B, C4 and C3, which were preserved during evolution.

Animals↗
PubMed1992

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

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.

Animals↗
PubMed1992

The ear in subterranean insectivora and rodentia in comparison with ground-dwelling representatives. I. Sound conducting system of the middle ear.

Compared to acoustically unspecialized mammals (soricids and murids), the middle ear of subterranean insectivores and rodents (twelve species of six families examined) was clearly distinguished and characterized by many common features: rather round and relatively larger eardrum without a pars flaccida; reduced gonial; loose or no connection between the malleus and the tympanic bone; reduced and straightened transversal part of the malleus; enlarged incus; increased and rather flat incudo-mallear joint; rather parallel position of the mallear manubrium and incudal crus longum in some species (and their fusion in bathyergids); reduced or even missing middle ear muscles. Convergent occurrence of these structural features in taxa of different origin and their generally derived character suggest that they cannot be categorized as degenerative. The form of the stapes can be considered as a non-adaptive trait; it was taxon specific yet remarkably polymorphous in some species and exhibited no convergent features among subterranean mammals. Structural retrogression resulting in a columella-like stapes was observed in some species lacking the stapedial artery. The stapedial base was relatively larger than in unspecialized mammals. The subterranean mammals did not exhibit conspicuously enlarged eardrums as would be required for sensitive tuning to low frequencies. It is, however, argued that while selective pressures in the subterranean ecotope promoted hearing of low frequencies, hearing sensitivity did not have to be enhanced.

Animals↗
PubMed1977

Sex chromosome polymorphism in Oryzomys longicaudatus philippii (Rodentia, Cricetidae).

Oryzomys longicaudatus philippii has a diploid number 2N = 56 (N.F. = 70). A polymorphism of X-chromosomes is described and a duplication as causal mechanism is postulated. The degree of chromosomal differences among the 4 karyological forms of O. longicaudatus and between those forms with O. l. philippii, enable us to postulate the level of full species for all of them.

Animals↗
PubMed1978

Protein variation and systematics in Malayan rats of the subgenus Lenothrix (Rodentia: Muridae, genus Rattus Fischer).

1. Electrophoretic variations of 9 erythrocyte proteins, coded by a separate gene locus each, were analysed in and among the 5 Malayan species of Rattus belonging to the subgenus Lenothrix. 2. The average proportion of loci heterozygous per individual for the taxa analysed is 0.037. 3. The results obtained confirm the specific status of the 5 taxa studied. With respect to the relative affinities among the species studied, the present results could resolve the discrepancies between conclusions based on morphological evidence and those based on cytological evidence. 4. The 5 species of Rattus studied may be assigned to 4 groups and comparative data suggest that these groups are relatively distantly related to one another.

Animals↗
PubMed1978

Studies on Rift Valley fever in some African murids (Rodentia: Muridae).

Brains, spleens and livers of 2214 murids, 27 shrews and 7 dormice, trapped at 7 sites in Rhodesia, were tested in 277 pools for the presence of Rift Valley Fever virus. There were no isolations of Rift Valley Fever, but 69 isolations of an unidentified virus were obtained. Sixteen out of 867 sera had low-titre haemagglutination-inhibition activity against Rift Valley Fever antigen, but only one out of 1260 sera had neutralizing antibody. The evidence suggests that murids fail to encounter infection in nature and are unlikely to play a role in circulation and dissemination of Rift Valley Fever virus. Four out of seven widely distributed species of muried, Rhabdomys pumilio, Saccostomys campestris, Aethomys chrysophilus and Lemniscomys griselda, were shown to be capable of circulating amounts of virus likely to be infective for mosquitoes.

Animals↗
PubMedDate not supplied

[Gongylonema pithyusensis n. sp. (Nematoda: Spiruridae), a parasite of the oesophagus of the dormouse Eliomys quercinus ophiusae Thomas, 1925 (Rodentia: Gliridae) in Formentera (Balearic Islands) (author's transl)].

A new Nematode, Gongylonema pithyusensis n. sp., parasitizing the oesophagus mucosa of the dormouse Eliomys quercinus ophiusae Thomas, 1925 in the balearic island of Formentera (Spain) is described. The male of the new species is characterized by the size of spicules and gubernaculum; the female by the morphology of the tail, the posteriour situation of the vulva and the dimensions of the eggs. It is the only Gongylonema species to be known parasitizing Rodents of the family Gliridae.

Animals↗