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PubMed1982

The role of wild animals in the ecology of dermatophytes and related fungi.

The problems associated with infections by dermatophytes and related fungi are discussed. Published and unpublished surveys of 1 481 wild animals of the orders Carnivora, Ungulata, Lagomorpha, Rodentia, Insectivora and Chiroptera and of 29 birds proved to be positive for fungi which were classified as potentially pathogenic zoophilic, potentially pathogenic geophilic and normally non-pathogenic geophilic. Trichophyton mentagrophytes var. mentagrophytes was isolated from 11% of rodents; the fungus was also isolated from Insectivora, the hare and the ibex. T. mentagrophytes var. erinacei was reported in the hedgehog. Microsporum canis was reported in rodents from anthropogenic areas. M. gypseum was reported in Ungulata, Lagomorpha and Rodentia; other geophilic fungi were found in all the orders investigated, with the exception of Chiroptera which proved to be constantly negative. The relationship between the presence of animals and the "animalization" of the environment, and the consequent presence of geophilic fungi is discussed. It is concluded that wild animals may play a role as carriers of dermatophytes and related fungi, may create environmental conditions favourable to their growth and may help to monitor the presence of a fungus in a given area.

Animal Population Groups↗
PubMed1997

The binding potential of commercial antibody conjugates with sera of various small terrestrial mammals.

Infectious diseases of wild animals are of increasing importance, both from an economic viewpoint and because several of these diseases are pathogenic to man. However, serosurveys to determine the circulation of infectious organisms in wildlife are complicated by the fact that antibodies to species-specific immunoglobulins are not available for use in serological assays such as enzyme-linked immunosorbent assays (ELISAs) or immunofluorescence assays. To determine the binding potential of four commercially available antibody conjugates with the sera of wild animals, sera from 27 species of small terrestrial mammals were allowed to react with alkaline phosphatase-labelled protein A, anti-rabbit IgG, anti-mouse IgG and anti-human IgG by by the use of an ELISA. It was found that sera from some species of the order Lagomorpha bound optimally to anti-rabbit IgG, while anti-mouse IgG could be used for most species of Rodentia. For all Carnivora, Insectivora, Macroscelidea, Hyracoidea and other Rodentia, staphylococcal protein A demonstrated optimal binding. None of the sera that was tested bound to anti-human IgG. These results demonstrate that commercial conjugates can be used in serological assays in which wild animal sera are used, and should be useful for future serosurveys to determine the circulation of infectious agents in small terrestrial mammals.

Animals↗
PubMed2001

Phylogenetic position of Eulipotyphla inferred from the cDNA sequences of pepsinogens A and C.

Although to date the phylogenetic position of the provisional order Eulipotyphla has been assessed by various molecular markers, it has not been conclusively clarified due to low statistical supporting values and inconsistent results. To clarify the phylogenetic position of Eulipotyphla, we cloned cDNAs for pepsinogens A and C from five mammalian species belonging to four different orders and determined their nucleotide sequences. Molecular phylogenetic analysis based on the 1st and 2nd codon positions of the protein-coding region of cDNA sequences strongly supported the close relationship between Eulipotyphla and Chiroptera. Carnivora was found to be a sister group to these two orders. The monophyly of the order Rodentia and that of the cohort Glires (Rodentia and Lagomorpha) was also shown by the present phylogenetic trees of pepsinogens.

Amino Acid Sequence↗
PubMed1992

Stereo architecture of the connective tissue cores of the lingual papillae in the treeshrew (Tupaia glis).

The stereo architecture of the lingual connective tissue cores (CTC) in the treeshrew (Tupaia glis) (which has the primitive characteristics of primates) was observed by scanning electron microscopy, and compared to that of other animal orders. The tongue of the treeshrew has three vallate papillae which are situated in the posterior part of the tongue, while some macaques have several vallate papillae. Among numerous filiform papillae, fungiform papillae are sporadically distributed. A filiform papilla consists of a bundle of several slender spine-like processes arranged in a circle at the basal margin. After removal of the epithelium, the CTC of the filiform papilla looks like a human hand raised with the palm facing towards the tongue tip. The fungiform CTC in the threeshrew is columnar in shape (rather similar to that of Insectivora and Rodentia) and at the top there are several round depressions for taste buds. In the treeshrew several large rod-shaped processes are derived from the postero-lateral margin of the tongue, as in Carnivora (dogs and cats), where foliate papillae are located in many other animal species. The treeshrew has numerous characteristics similar to those of the crab-eating macaque (Primates), but at the same time it has some characteristics similar to those of Insectivora, Rodentia, Carnivora and Artiodactyla.

Animals↗
PubMed1985

Basal metabolic rates in mammals: taxonomic differences in the allometry of BMR and body mass.

No single equation adequately describes the allometric relation between body mass and BMR for mammals. Least squares regression of log-transformed data for 248 eutherian species results in a line with a slope (-0.30) significantly different from that of Kleiber's line (-0.25). Interordinal comparisons of least squares regressions of log-transformed BMR and mass suggest that the Insectivora have a significantly steeper slope to their allometric relationship than do most other orders, while the non-insectivore orders are statistically homogeneous with respect to slope. With respect to elevation, Edentata have the lowest BMRs; Marsupialia, Primates and Chiroptera are indistinguishable from each other but above the edentates; Primates, Chiroptera, Rodentia, Lagomorpha and Carnivora form the next highest homogeneous grouping; and Artiodactyla have the highest BMRs, significantly greater than all but Lagomorpha and Carnivora. Analysis of intraordinal variation within the Rodentia suggests significant heterogeneity among families in BMR-mass allometry.

Animals↗
PubMedDate not supplied

The molecular taxonomy and evolution of the guinea pig.

On the basis of 18 protein sequences totaling 2,413 aligned amino acid sites, it is suggested that the guinea pigs and the myomorphs (rat-like rodents) are not monophyletic. Rather, the evolutionary lineage leading to the guinea pig seems to have branched off prior to the divergence among myomorphs, lagomorphs, primates, chiropterans, artiodactyls, and carnivores. It is suggested therefore that the Caviomorpha (guinea pig-like rodents) and possibly the Hystricomorpha (porcupine-like rodents) should be elevated in taxonomic rank and conferred an ordinal status distinct from the Rodentia. This suggestion calls for a reevaluation of the morphological evolution of guinea pigs and further molecular studies on the possibility of paraphyly of the order Rodentia. If the monophyly of rodents holds, it must be concluded that the pattern of molecular evolution in many guinea pig genes has been extremely unusual and that the causes for this pattern should be sought. It is also suggested that claims of large differences in the rate of molecular evolution between guinea pigs and myomorphs may have been exaggerated in many cases as a result of an erroneous phylogenetic position for the guinea pig. The average rate of amino acid replacement in the guinea pig seems to be comparable to that in the rat and the mouse. However, the data indicate that myomorph and caviomorph genes evolve, on average, about two times faster than their human counterparts. Finally, our analysis provides evidence against the hypothesis that the gundi (an African rodent) represents the most ancient rodent lineage.

Amino Acid Sequence↗
PubMed1997

Phylogenetic analysis of cystic fibrosis transmembrane conductance regulator gene in mammalian species argues for the development of a rabbit model for cystic fibrosis.

The species-specific pattern of cystic fibrosis transmembrane conductance regulator (CFTR) expression was investigated in order to identify species closely related to man which can be used as potential cystic fibrosis (CF) animal models. To this purpose, the nucleotide sequences of the CFTR promoter region of eight mammalian species representing four different orders (Primates, Artiodactyla, Lagomorpha and Rodentia) were analyzed. Distance matrices and unrooted trees of the CFTR promoter region sequences yielded two deeply separated groups, one including man (Homo sapiens), nonhuman primates (Hylobates lar, Macaca fascicularis, Saimiri sciureus), cow (Bos taurus), and rabbit (Oryctolagus cuniculus) and the other including the rodents (Rattus norvegicus, Mus musculus). Divergences between rodent and nonrodent groups have been observed in putative cis transcriptional regulatory elements and can be involved in the differences of pattern of expression between these two groups. Comparison of the available CFTR cDNA sequences enabled us to root the tree with a noneutherian outgroup and to perform a phylogenetic analysis. This analysis did not detect any base composition bias and supported polyphyletic Glires. Although a long-branch attraction artifact cannot be completely excluded, these findings converge toward the recent statement (Graur, Duret, and Gouy 1996) that Lagomorpha is more closely related to Primates than to Rodentia. In addition, the phenylalanine residue in exon 10 involved in the most common CF mutation in man is conserved in rabbit. These phylogenetic analyses as well as anatomical and developmental data suggest that, once rabbit embryonic stem cells become available, the rabbit will provide a suitable tool for both gene transfer and pharmacological investigations and could lead to a better CF model than the current murine models.

Animals↗
PubMed1985

Evolution of crystallins: expression of lens-specific proteins in the blind mammals mole (Talpa europaea) and mole rat (Spalax ehrenbergi).

The mole (Talpa europaea; Insectivora) and the mole rat (Spalax ehrenbergi; Rodentia) both have degenerated eyes as a convergent adaptation to subterranean life. The rudimentary eye lenses of these blind mammals no longer function in a visual process. The crystallin genes, which display a lens-specific expression pattern, were studied in these blind mammals and in related species with normal eyes by hybridizing their genomic DNAs with probes obtained from cDNA clones for alpha A-, alpha B-, and beta Bp-crystallins from calf and gamma 3-crystallin from the rat. For all crystallin genes examined, the hybridization signals of mole and mole rat genomic DNA were comparable, respectively, with those of shrew and of rat and mouse, normal-vision representatives of the orders Insectivora and Rodentia. The expression of the crystallins at the protein level was tested by using antiserum specific for alpha-crystallin in immunofluorescence reactions on lens sections of mole and mole rat eyes and by using antisera against the beta- and gamma-crystallins on sections of the mole eye. All antisera gave positive fluorescence reactions exclusively with lens tissue of these blind mammals, indicating that the crystallins are still normally expressed despite the fact that these lenses have had no function in a visual process in these mammals for at least many million years. These findings apparently imply that some unknown selective advantage has conserved the crystallin genes and their expression after the loss of normal function of the lenses.

Adaptation, Physiological↗
PubMed1999

Comparative anatomy of the claustrum in selected species: A morphometric analysis.

The morphology of the claustrum was studied by stereological methods in representatives of five mammalian orders (Insectivora, Rodentia, Lagomorpha, Carnivora and Primates). In each species under study, a dorsal and a ventral part of the nucleus can be distinguished. Based on differences in shape and separation from surrounding structures, five morphological types of the claustrum occur. The claustrum of Insectivora and some rodents represents the least complicated morphological type. The nucleus is very poorly separated from the surrounding structures. The human claustrum is morphologically the most complicated, although the two above-mentioned principal divisions are apparent. The ventrally situated paraamygdalar part of the human claustrum may correspond to the endopiriform nucleus or ventral part of the claustrum of other mammals, because of its morphological characteristics and connections with the limbic system. In guinea pigs, traditionally classified as members of the Rodentia, a characteristic morphological type of the claustrum is present. This observation may support arguments questioning the current position of this species in mammalian classification. Based on stereological studies, the increase of the claustral volume that occurs with increase of the hemispheric volume is significantly smaller than the increase of the isocortical volume and larger than the increase of the allocortical volume. The increase of the volume of the dorsal and ventral parts of the claustrum does not differ significantly in the species under study. Neurons of the claustrum represent differentiated morphology. The numerical density of neurons in the dorsal part of the claustrum is significantly higher than in the ventral one. Differences in the morphology and cellular structure of the two parts of the claustrum may suggest differences in function of the two parts of the nucleus, most probably concerned with transfer of information among various cortical regions. Changes in the claustrum, a cortico-related structure, that occur with increased brain volume, may suggest that its development is less dynamic than that of the isocortex.

Animals↗
PubMed2006

Karyotypic evolution of the family Sciuridae: inferences from the genome organizations of ground squirrels.

Cross-species chromosome painting has made a great contribution to our understanding of the evolution of karyotypes and genome organizations of mammals. Several recent papers of comparative painting between tree and flying squirrels have shed some light on the evolution of the family Sciuridae and the order Rodentia. In the present study we have extended the comparative painting to the Himalayan marmot (Marmotahimalayana) and the African ground squirrel (Xerus cf. erythropus), i.e. representative species from another important squirrel group--the ground squirrels--, and have established genome-wide comparative chromosome maps between human, eastern gray squirrel, and these two ground squirrels. The results show that 1) the squirrels so far studied all have conserved karyotypes that resemble the ancestral karyotype of the order Rodentia; 2) the African ground squirrels could have retained the ancestral karyotype of the family Sciuridae. Furthermore, we have mapped the evolutionary rearrangements onto a molecular-based consensus phylogenetic tree of the family Sciuridae.

Animals↗
PubMed1994

Eutherian phylogeny as inferred from mitochondrial DNA sequence data.

The phylogenetic relationships among Primates, Artiodactyla, Cetacea, Carnivora, and Rodentia were estimated from the amino acid sequences of proteins encoded by the mitochondrial genomes, for which entire nucleotide sequence data are available, using Marsupialia, Aves, and Amphibia as outgroups. The overall evidence of the maximum likelihood, as well as maximum parsimony, analyses strongly suggests that Rodentia is an outgroup to the other four eutherian orders, and that Cetacea and Artiodactyla form a clade with Carnivora as a sister taxon, consistently with the molecular phylogenetic studies of previous authors. However, analyses of individual proteins do not necessarily conform to this conclusion, and some of the proteins reject the putatively correct tree with nearly 5% significance. Furthermore, the 12S mitochondrial ribosomal RNA sequences do not give the putatively correct tree irrespective of the alignments and of the phylogenetic methods, although the tree is not rejected with a statistical significance. The 16S ribosomal RNA sequences give the putatively correct tree with our sequence alignment when the ML method is used, but the result depends on the alignment and on the choice of outgroup species. These results illustrate the limitation of the ribosomal RNA data alone in phylogenetic inference, and suggest that we must analyze as many genes as possible and synthesize the results to draw a reliable conclusion.

Amino Acid Sequence↗
PubMed1994

Mammalian phylogeny inferred from multiple protein data.

On the basis of multiple protein data, the phylogenetic relationships among the major clades of eutherian mammals, Primates, Cetacea, Artiodactyla, Carnivora, Lagomorpha, Myomorpha, and Caviomorpha, were analyzed by the maximum likelihood (ML) method, together with the maximum parsimony (MP) method and the neighbor joining (NJ) method. Using nineteen protein data, we first reexamined the hypothesis of rodent polyphyly proposed by Graur et al. (1991) based on the four taxon system, consisting of human, mouse (or rat), guinea-pig and an outgroup. The ML analysis does not support the rodent polyphyly, but strongly favors the traditional view of rodent monophyly representing the Myomorpha-Caviomorpha association. In the second analysis, the phylogenetic position of Lagomorpha were reexamined using three sets of multiple protein data, 13 mitochondrial DNA-coded proteins from rodents, rabbit, human, seals, bovine, whales and opossum, 25 protein data from human, rabbit and rodents and an outgroup, and 20 protein data from human, rabbit, bovine (or pig) and rodents. Our analysis favors the closer affinity of Lagomorpha to Primates than to Rodentia. The branching sequence of seven mammalian groups revealed by the present analyses is as follows: Myomorpha-Caviomorpha clade (Rodentia), rabbit, Primates, Carnivora, and Artiodactyla-Cetacea clade. Judging from the branch lengths measured by the numbers of synonymous substitutions, a series of divergence of these mammals is likely to be bush-like. The rapid rate of rodent evolution was reexamined in the light of the new phylogeny.

Amino Acid Sequence↗
PubMed1997

Induction of canine deciduoma in some reproductive stages with the different condition of corpora lutea.

Bitches were examined to see whether canine deciduoma could be induced at some reproductive stages with the different conditions of corpora lutea by inserting a silk suture into the uterine lumen. The bitches stimulated in the early and middle stages of diestrus or in unilateral pregnancy corresponding to these diestrous stages formed deciduoma at a high induction rate, however, no difference in the strength of decidual reaction between the pregnant and diestrous stages was recognized. On the other hand, no reaction could be seen in bitches in late diestrus, the late stage of unilateral pregnancy or the post partum repair phase in which stromal decidual cells similar to those of the rodentia can be seen. In already implanted uteri, however, no deciduoma was formed in the interplacental areas. Even though the corpora lutea were functional, new additional stimulations were not accepted at the interplacental area in which the uterine horn had already been influenced by fertilized ova. From these results, it was suggested that in the dog as well as the rodentia, the endometrium has to be under the influence of functional corpora lutea in order to form deciduoma.

Animals↗
PubMed1995

Comparative observations on lingual papillae and their connective tissue cores in three primates. A scanning electron microscopic study.

The 3-D structure of the connective tissue cores (CTCs) of the lingual papillae in three primates (treeshrew, crab-eating monkey and man) was observed by scanning electron microscopy. Each filiform papilla has some slender protrusions on the top in the three kinds of primates. After removal of the epithelium, the CTC of the filiform papillae has a columnar primary core with some rod shaped secondary protrusions whose number and size vary among the three species. The number of secondary protrusions on the filiform CTC is generally small in the treeshrew and is the greatest in man. The stereo structure of the filiform CTC is fundamentally similar in all these three species and is different from those of other animal orders (i.e. Insectivora, Rodentia etc.). The fungiform CTC in man as well as in the crab-eating monkey is coralliform in shape and branched several times with small depressions for taste buds on the top of each one, though there were some differences between the two species in stereo structure. On the other hand, the fungiform CTC in the treeshrew was columnar in shape and was rather similar to that of Insectivora and Rodentia. In the treeshrew there are several finger-like processes in the region where foliate papillae are located in man as well as in the crab-eating monkey.

Animals↗
PubMed1990

Descending pathways to the spinal cord, III: Sites of origin of the corticospinal tract.

The somata of corticospinal neurons were labeled with horseradish peroxidase that had been applied to a hemisection of the spinal cord at the C1-C2 junction in 22 species of mammals. After tetramethylbenzidine processing, with and without counterstaining with cresyl violet or neutral red, the labeled cells in systematic sets of sections throughout the cerebral cortex were plotted and counted. Several morphological features of the corticospinal cells were examined including their cell type, number, density, concentration, laminar distribution, and their distribution across the cortical surface. The results show that the labeled corticospinal neurons were invariably layer V pyramidal cells. However, in many mammals they were found to be stacked one above the other within layer V, sometimes many neurons deep. Despite the concentration of corticospinal neurons within layer V, many unlabeled neurons were also present within the layer throughout the extent of the labeled region. The results also indicate that at least two spatially distinct regions of neocortex originate corticospinal fibers in each of the animals in the sample. In addition to these two regions, a third segregated region is present in the cortex of primates and an apparently different third region is present in the cortex of Glires (Rodentia and Lagomorpha). The third region of corticospinal cortex in primates is located on the lateral surface of the cortex in prosimians and New World monkeys and is buried in the caudal bank of the inferior arcuate sulcus in Old World monkeys. The results also show a predominantly contralateral corticospinal tract in all but 4 of the 22 mammals in the sample. Although these 4 mammals are each members of the order Insectivora, a less modified member of the same order possessed the predominantly contralateral projection of most mammals, hence denying the notion that a predominantly ipsilateral tract is a characteristic of Insectivora.

Animals↗
PubMed2002

Genotoxicity biomonitoring in regions exposed to vehicle emissions using the comet assay and the micronucleus test in native rodent Ctenomys minutus.

Exposure to motor vehicle emissions represents an important concern for possible long-term health effects. The present report describes: 1) the application and verification of the alkaline comet assay in Ctenomys minutus to detect the possible genotoxicity of automobile emissions; 2) a comparison of the comet assay results with peripheral blood micronucleus (MN) assay results performed in the same animals; and 3) the identification of agents involved in the responses and in the seasonal variation of the effects. Ctenomys minutus (Octodontidae-Rodentia) were captured in two different fields from both sides of RS/030, a highway on the coastal plain of the Brazilian state of Rio Grande do Sul. Reference animals were obtained from a nearby field that was about 3 km distant from any road. By the end of this study, 123 rodents (73 females and 50 males) were live-trapped. Our results indicate that there was an increase in cells with DNA damage for C. minutus environmentally exposed to automobile emissions, as demonstrated by the alkaline comet assay, but there was no increase in micronucleated cells. The alkaline comet assay showed age and gender differences in the response. The comet assay results suggest that adult females are the principal population affected by air pollutants from vehicle emissions. Chemical data were also collected from areas exposed to automobile exhaust and these indicated that elevated levels of hydrocarbons, metals, and NO(2) were associated with the elevated levels of damaged cells observed in the wild rodent C. minutus. Our results agree with previous data on engine and fuel components, where weak increases in damage for native rodents exposed to emissions have been observed. Other larger, controlled studies are needed to better understand how the metabolism of C. minutus affects its response to emission exposure.

Animals↗
PubMed1995

Incisal biting in the mountain beaver (Aplodontia rufa) and woodchuck (Marmota monax).

Analysis of synchronously recorded cine-radiographs and electromyograms in two rodents (Aplodontia rufa and Marmota monax) demonstrates that jaw movements and muscle activities during incisal functions are distinctly different from those found during mastication. Movements during incisal biting are primarily along the midline, accompanied by symmetrical activity of the jaw adductor muscles. Most biting cycles do not end in contact between upper and lower incisors. When contact does occur, the lower incisors are dragged along the lingual surfaces of the upper incisors. Cropping, or tip-to-tip occlusion of upper and lower incisors, was not observed. Sharpening of the lower incisors, a behavior which may be unique to the Rodentia, was recorded in both A. rufa and M. monax. During sharpening, the lingual surface of the lower incisor is dragged across the tip of the upper incisor producing a lingual wear facet. Like incisal biting, sharpening movements are primarily confined to the midline, although there may be lateral movements in some sharpening cycles. Sharpening cycles are among the most rapid cyclic movements recorded in mammals, as the mean frequencies of sharpening are 11 cycles/s in A. rufa and 8 cycles/s in M. monax.

Animals↗
PubMed1996

Support for interordinal eutherian relationships with an emphasis on primates and their archontan relatives.

Current knowledge about mammalian interordinal relationships is growing rapidly; thus this contribution is an attempt to summarize the past 5 years of this literature. We have focused on the recent controversies in mammalian phylogenetics including hypotheses concerning the monophyly of Archonta, the diphyly of Chiroptera, and the polyphyly of Rodentia. All of these issues have been proposed recently, challenging these phylogenetic hypotheses. We have attempted to include all of the comprehensive analyses of eutherian mammal systematics with an emphasis on morphological and molecular data sets where discrete characters are listed so they could be compiled and used in support of interordinal relationships. Particular attention is given to determining which of the living eutherian orders is the closest relative to primates. In reviewing relationships among the mammals, we have focused on collating all of the available evidence so that one could know where each of the specific data sets is in support of the various relationships.

Animals↗