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At least 19 recordsLinked to original sources
PubMed2003

Molecular evolution inferred from immunological cross-reactivity of immunoglobulin G among Chiroptera and closely related species.

We examined the relationships between Megachiroptera and Microchiroptera, and between Chiroptera and other closely related species by the cross-reactivity of immunoglobulin epitopes. Rabbit polyclonal antibody to bat IgG was used for determining the cross-reactivity by a competitive ELISA method. Megachiroptera and Microchiroptera showed high cross-reactivity, over 95.3%, with each other. However, primates and insectivores showed very low cross-reactivity, 8.6 to 20.2% and 5.3 to 12.7%, respectively. These results suggest that suborders of Chiroptera are monophyletic and Chiroptera have a relatively closer relationship to primates than to insectivores.

Animals↗
PubMed1977

[Carpal bones of the Chiroptera in the comparative-anatomical and functional aspects].

Data on investigation of hand sceletal bones carried out in eight genera of three families of bats were subjected to comparative-anatomical and functional analysis. Quantitatively, the hand sceletal bones of Chiroptera preserve constructive pattern general for the hand of terrestrial mammalians Pentadactilus. It has rudiments of the prefirst (Pp) and the seventh (Pm) rays. The latter is situated on the volar surface of the base Mc5. Scaphoid, semilunar and central carnal bones of Chiroptera, like those of Mototremata, some Marsupialia, Insectivorona and Carnivora merge together into one large bone--os lunatum. At the same time, the hand of Chiropter is a highly specialized structure, that is evident from the presence of articular restricotrs of anterior sagging of the wrist, crests and grooves directing movements in a strictly definite plane, from fan-like spreading and bringing together the rays, from very long metacarpal bones and proximal phalanges, from reduction of distal phalangs of the 3d and 5th fingers. Thus, the hand of Chiroptera is a unique example of combination of primitive, initial for pentadactule plantigrades wrist with signs of narrow specialization resembling, to some extent, those of Ungulata; only in Ungulata those signs developed on the base of digitigrades wrist.

Anatomy, Comparative↗
PubMed1978

Mercury content in museum and recent specimens of chiroptera in Japan.

The mercury content of insectivorous Chiroptera caught in 1890, when mercurial pesticides had not yet been in use, and preserved in a museum in alcohol were compared with those caught in 1965--1967 or 1970--1975, during and after the use of mercurial pesticides, and kept frozen. The mercury content of the Chiroptera caught in 1890 was lower than that of those caught during or after the use of mercurial pesticides. Difference in mercury content between bats caught during and after use was not significant.

Animals↗
PubMed2000

Monophyletic origin of the order chiroptera and its phylogenetic position among mammalia, as inferred from the complete sequence of the mitochondrial DNA of a Japanese megabat, the Ryukyu flying fox (Pteropus dasymallus).

Complete sequences of mitochondrial DNA (mtDNA) are useful for the reconstruction of phylogenetic trees of mammals and, in particular, for inferring higher-order relationships in mammals. In this study, we determined the complete sequence (16,705 bp) of the mtDNA of a Japanese megabat, the Ryukyu flying fox (Pteropus dasymallus). We analyzed this sequence phylogenetically by comparing it with the complete sequence of mtDNAs of 35 mammals in an effort to reevaluate the enigmatic relationship between Megachiroptera and Microchiroptera and the relationships between them and other mammals. Maximum-likelihood analysis of 12 concatenated mitochondrial proteins from 36 mammals strongly suggested the monophyly of the order Chiroptera and its close relationship to Fereuungulata (Carnivora + Perissodactyla + Cetartiodactyla). We estimated that megabats and microbats diverged approximately 58 MyrBP and discussed the origin and early evolution of Chiroptera based on our findings.

Animals↗
PubMed1998

The size of sebaceous glands in relation to the size of hair follicles on the heads of some small mammals (Insectivora, Chiroptera, Rodentia).

Many large sebaceous glands have been described, and functions such as scent production suggested, but gland size has seldom been studied in relation to the surface area of their hair follicles. However, investigating this relationship is essential for establishing whether glands produce more sebum than would be required for lubricating associated hair alone. Here, the relationship between sebaceous gland size and the surface area of the associated hair follicles has been studied. Glands on the heads of 20 species from three orders were compared with those associated with fur hairs. In all species, the fur hairs had small hair follicles with small sebaceous glands, as had the mystacial and submandibular hairs of Rodentia. Medium-sized glands and hairs were found in the mystacial and submandibular region in Insectivora, and in the circumoral region in Chiroptera and Rodentia. Large glands and hairs were found on a pad in the corner of the mouth in Rodentia. Although the size of glands was not directly proportional to hair size, some gross trends were noted. Vibrissae had either no or very small sebaceous glands. It is likely that sebum has to be provided from elsewhere to lubricate their surfaces. The glands on the snout of Insectivora and Chiroptera are clearly enlarged and could probably produce more sebum than would be required for grooming vibrissae alone. In Rodentia, vibrissae were surrounded by small hair and glands, and the nearest glands large enough to provide sebum were the glands on the pad in the mouth corner.

Animals↗
PubMedDate not supplied

[Chiroptera viruses transmitted or not transmitted by arthropods].

The authors make a review of literature on viruses isolated from chiroptera's tissues. They study especially two of these viruses: a true arbovirus, the Japanese B encephalitis virus and a virus of the same genus but not arthropod-borne, the Rio Bravo virus. They consider successively for each virus: isolations from bats, serosurveys in bat and in man, and experimental studies with these viruses, allowing to estimate the role of chiroptera in the diffusion and the maintenance of some arboviruses. They also report some personal results of serosurveys in bats from Tunisia and Spain.

Animals↗
PubMed1984

[The fine structure of spermatozoa from Chiroptera].

The fine structure of hibernating bat spermatozoa (Vesperugo savi and Rinolophus f.e.) has been studied by SEM and TEM, during their prolonged storage in female reproductive tract. The main morphological aspects of sperm portions: head, neck, middle piece, principal piece and terminal piece have been described. The Author besides comparisons with other mammalian species and Chiroptera, suggests some typical ultrastructural features of these Chiroptera, as the complete absence of vacuoles in the nuclear chromatin and corrugated structures in the post-acrosomal zone. Moreover electron-dense material in the subacrosomal space and three mitochondria in the neck were observed. Two areas of fusion between outer dense fibers 3 and 8 and the inner ends of the respective longitudinal columns of the fibrous sheath and asymmetrical arrangement of the outer dense fibers of the principal piece were found.

Animals↗
PubMed1978

[Fine structure or retina in Chiroptera (author's transl)].

The retina of Chiroptera, studied during the various seasons of the year, appears well developed, and provided with morphological and structural characters very near to the humans and other mammalians. The retina of Chiroptera it is composed of five layers: 1) it is composed exclusively by rods: his morphological behaviour has been yet described in other night life birds and mammalians (e.g. mice and guinea pigs (Hollenberg e Bernstein), 2) plexiform layer, composed by rod's prolongations and by bipolar cells that there form conventional synapsis and mainly ribbon synapsis, 3) horizontal and amacrine bipolar cells and the middle portion of Müller's cells, 4) inner plexiform layer with conventional type synapsis, 5) layer of the ganglionar cells and of the enlarged prolongations of the inner portion of Müller's cell. The prolongations are separated from the vitreous body by basement membrane. After a detailed description of the elements constituent the different retina's layer, the Author asserts that remarkable qualitative, quantitative and season variations were not found. The inner granular layer as well as the middle part of the Müller's cells, is composed by three different types of cells: horizontal, amacrine, bipolar, which have all the characters of a typical nervous cell. Granules found in pigmented cells how a structural range of variations linked more with the different stages of maturation than with the variety of species investigated. Citoplasmatic polarity of the granules and mytochondria concentration were not noticed as, on the contrary, in other mammalians. The Author emphasizes pynocitosis phenomena both a level of the inner and outer surface of pigmented cells, and at the level of the most outer prolongations of Müller's cell: those cytologic aspects seem to witness a possible transfer of liquids, salts and metabolites from capillaries of the choroid to photoreceptors. Moreover the total absense of blood capillaries in all five layers of the retina is emphasized.he

Animals↗
PubMed1977

[Eco-ethological significance of the allometric development of the two visual systems in chiroptera].

Volumes of the rostral colliculus and the nuclei of the geniculate body were examined in 19 species of Chiroptera belonging to 8 families characterized by different eco-ethological adaptations. These volumes were compared to those of Basal Insectivores using the allometry formula. The data were expressed in terms of progression indices which estimate how many times a given brain center is greater than that of a Basal Insectivore of the same body weight. According to the progression indices of the rostral colliculus, Chiroptera separate into two groups: the Megachiroptera which have a mean index of 331 and the Microchiroptera with a mean index of 188. On the other hand, mean indices of the lateral geniculate body distinguish between three groups : the Megachiroptera (mean 869); the frugivorous and nectarivorous Microchiroptera (mean 293); the insect-eating, blood sucking, and fish eating Microchiroptera (mean 135). The results indicate that the two anatomically and structurally distinct elements belong to two functionally different visual systems which have evolved somewhat independently. The relation between allometric development of these visual centers and the eco-ethological adaptations of the species examined reveals, to a certain extent, the relative importance of the different functional aspects of vision.

Adaptation, Biological↗
PubMed1994

Further characterization of the pituitary-adrenocortical responses to stress in Chiroptera.

Previous studies on bats from this laboratory have revealed the presence of exceptionally high circulating levels of glucocorticoids in two species of the sub-order Megachiroptera. In the present study, the following questions were asked: (1) what effect does the routine handling and examination of captive bats have on the activity of their hypothalamic-pituitary-adrenocortical (HPA) axis?; (2) are the unusually high plasma levels of cortisol and corticosterone found in Pteropus hypomelanus associated with high levels of circulating adrenocorticotropic hormone (ACTH)?; (3) are there diurnal changes in stress responsivity in this species?; and (4) how do levels of glucocorticoids in P. hypomelanus compare with those found in other species of Chiroptera (both micro and megachiropteran species)? Of five species examined, P. hypomelanus had slightly higher total glucocorticoid levels than P. pumulis, but approximately 8-fold higher levels than in three species of Microchiroptera (Artibeus jamaicensis, Carollia perspicillata, and Myotis lucifigus). There was a pronounced diurnal rhythm in glucocorticoid levels in one species (M. lucifigus) for which this was determined. A 1-h period of restraint stress increased glucose and glucocorticoid levels in P. pumulis, and also increased ACTH and glucocorticoids in P. hypomelanus. Fifteen minutes of routine handling (weighting, measuring, etc.) elicited a significant rise in plasma glucocorticoids in P. hypomelanus to combined peak (cortisol plus corticosterone) levels of over 1,000 ng/ml (100 micrograms%). There was no significant difference in the response to handling in bats tested in the morning or evening. Basal ACTH levels as detected by radioimmunoassay were low in P. hypomelanus, in spite of high steroid levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Low levels of calpain activity in Chiroptera brain: implications for mechanisms of aging.

Calcium-dependent neutral proteases ("calpains") have been implicated in degenerative processes in muscles and neurons, suggesting that they might also play a role in age-related brain pathologies and perhaps in brain aging itself. Because Chiroptera exhibit an unusual maximum life span, relative to other mammalian orders, we investigated the activity of these enzymes in the brain of two species of bats. As in other mammals, brain calpain degrades many proteins associated with the cell cytoskeleton. However, enzyme activity is 5-7 fold lower in bat's brain than in a similar-sized mammal, such as the mouse. Moreover, the maximal life span of bats predicted from the equation relating calpain activity and maximal life span across a wide range of mammals is close to the observed values. These results strengthen the hypothesis that calpain activity is somehow linked to the rate at which brains age.

Aging↗
PubMed2004

Evaluation of DNA damage in a population of bats (Chiroptera) residing in an abandoned monazite mine.

Ionising radiation has the ability to induce DNA damage. While the effects of high doses of radiation of short duration have been well documented, the biological effects of long-term exposure to low doses are poorly understood. This study evaluated the clastogenic effects of low dose ionising radiation on a population of bats (Chiroptera) residing in an abandoned monazite mine. Bats were sampled from two chambers in the mine, where external radiation levels measured around 20 microSv/h (low dose) and 100 microSv/h (higher dose), respectively. A control group of bats was sampled from a cave with no detectable radiation above normal background levels. The micronucleus assay was used to evaluate residual radiation damage in binucleated lymphocytes and showed that the micronucleus frequency per 500 binucleated lymphocytes was increased in the lower radiation-exposed group (17.7) and the higher radiation-exposed group (27.1) compared to the control group (5.3). This study also showed that bats exposed to radiation presented with an increased number of micronuclei per one thousand reticulocytes (2.88 and 10.75 in the lower and high radiation-exposed groups respectively) when compared to the control group (1.7). The single-cell gel electrophoresis (comet) assay was used as a means of evaluating clastogenecity of exposure to radiation at the level of individual cells. Bats exposed to radiation demonstrated increased DNA damage as shown by the length of the comet tails and showed an increase in cumulative damage. The results of the micronucleus and the comet assays indicated not only a statistically significant difference between test and control groups (P<0.001), but also a dose-dependent increase in DNA damage (P<0.001). These assays may thus be useful in evaluating the potential clastogenecity of exposure to continuous low doses of ionising radiation.

Animals↗
PubMed2002

A phylogenetic supertree of the bats (Mammalia: Chiroptera).

We present the first estimate of the phylogenetic relationships among all 916 extant and nine recently extinct species of bats Mammalia: Chiroptera), a group that accounts for almost one-quarter of extant mammalian diversity. This phylogeny was derived by combining 105 estimates of bat phylogenetic relationships published since 1970 using the supertree construction technique of Matrix Representation with Parsimony (MRP). Despite the explosive growth in the number of phylogenetic studies of bats since 1990, phylogenetic relationships in the order have been studied non-randomly. For example, over one-third of all bat systematic studies to date have locused on relationships within Phyllostomidae, whereas relationships within clades such as Kerivoulinae and Murinae have never been studied using cladistic methods. Resolution in the supertree similarly differs among clades: overall resolution is poor (46.4%, of a fully bifurcating solution) but reaches 100% in some groups (e.g. relationships within Mormoopidae). The supertree analysis does not support a recent proposal that Microchiroptera is paraphyletic with respect to Megachiroptera, as the majority of source topologies support microbat monophyly. Although it is not a substitute for comprehensive phylogenetic analyses of primary molecular and morphological data, the bat supertree provides a useful tool for future phylogenetic comparative and macroevolutionary studies. Additionally, it identifies clades that have been little studied, highlights groups within which relationships are controversial, and like all phylogenetic studies, provides preliminary hypotheses that can form starting points for future phylogenetic studies of bats.

Animals↗
PubMed2001

An architectonic comparison of the ventrobasal complex of two megachiropteran and one microchiropteran bat: implications for the evolution of Chiroptera.

The architectonic features of the thalamic ventrobasal complex (Vb) of two species of Megachiropteran (Grey-headed flying fox, Pteropus poliocephalus, and the Eastern tube-nosed bat, Nyctimene robinsoni) are compared with those of a Microchiropteran (Australian ghost bat, Macroderma gigas). The somatosensory system was chosen for comparison as it represents a sensory system that has undergone analogous modifications in both Chiropteran lineages (the evolution of the wing). The components of Vb were examined as there are taxon-specific features in this region of the brain. Within the Megachiropteran Vb, four subnuclei were recognized: the ventral posterior medial (VPM), the ventral posterior lateral (VPL), the ventral posterior inferior (VPI), and the basal ventral medial (VMb). In the ghost bat only VPM and VPL were identified with certainty. No VPI was evident in the ghost bat, however a putative VMb was observed. Vb of the ghost bat also lacked the arcuate lamina, which distinguishes VPM from VPL in the Megachiropterans and many other mammals. These taxon-specific differences lend support to the proposal that the order Chiroptera has a diphyletic origin.

Animals↗
PubMed2001

Host switching in Lyssavirus history from the Chiroptera to the Carnivora orders.

Lyssaviruses are unsegmented RNA viruses causing rabies. Their vectors belong to the Carnivora and Chiroptera orders. We studied 36 carnivoran and 17 chiropteran lyssaviruses representing the main genotypes and variants. We compared their genes encoding the surface glycoprotein, which is responsible for receptor recognition and membrane fusion. The glycoprotein is the main protecting antigen and bears virulence determinants. Point mutation is the main force in lyssavirus evolution, as Sawyer's test and phylogenetic analysis showed no evidence of recombination. Tests of neutrality indicated a neutral model of evolution, also supported by globally high ratios of synonymous substitutions (d(S)) to nonsynonymous substitutions (d(N)) (>7). Relative-rate tests suggested similar rates of evolution for all lyssavirus lineages. Therefore, the absence of recombination and similar evolutionary rates make phylogeny-based conclusions reliable. Phylogenetic reconstruction strongly supported the hypothesis that host switching occurred in the history of lyssaviruses. Indeed, lyssaviruses evolved in chiropters long before the emergence of carnivoran rabies, very likely following spillovers from bats. Using dated isolates, the average rate of evolution was estimated to be roughly 4.3 x 10(-4) d(S)/site/year. Consequently, the emergence of carnivoran rabies from chiropteran lyssaviruses was determined to have occurred 888 to 1,459 years ago. Glycoprotein segments accumulating more d(N) than d(S) were distinctly detected in carnivoran and chiropteran lyssaviruses. They may have contributed to the adaptation of the virus to the two distinct mammal orders. In carnivoran lyssaviruses they overlapped the main antigenic sites, II and III, whereas in chiropteran lyssaviruses they were located in regions of unknown functions.

Adaptation, Physiological↗
PubMed2002

A comparative analysis of brain size in relation to foraging ecology and phylogeny in the Chiroptera.

Variations in total brain mass and in the mass of three brain regions (main olfactory bulb, hippocampus, auditory nuclei) were examined using a data set for 63 species of bats (Chiroptera). Using both conventional and phylogenetically based analysis of covariance (log body mass as covariate), we tested several hypotheses that relate total brain mass or the size of the components to variation in foraging ecology, categorized as phytophagous, gleaner, and aerial insectivore. In some analyses, the category phytophagous was split into phytophagous pteropodid and phytophagous phyllostomid to examine differences between two distinct clades of bats. Because the Megachiroptera orient primarily by vision and olfaction, whereas all other bats rely on laryngeal echolocation to locate their prey, we hypothesized that the former would differ in size of the main olfactory bulb, as compared with all other bats. This hypothesis was supported by our analyses. Our more general prediction was that insectivorous bats, which rely heavily on echolocation for the pursuit and capture of their prey, would have larger auditory nuclei than do phytophagous species. This, too, was supported. We also compared phytophagous (fruit or nectar consuming) bats in two families, the Pteropodidae and the Phyllostomidae. We hypothesized that the phyllostomids, which use echolocation while foraging, would have larger auditory nuclei. Although statistical power is low in phylogenetically informed comparisons of the two clades, we did find weak evidence in support of this hypothesis. We conclude that bat brains show evidence of adaptation to foraging ecology.

Adaptation, Physiological↗
PubMed1982

Correlations between major brain regions in Chiroptera.

Unlike small homogeneous nuclei, progression indices of large heterogeneous brain regions show no negative correlations and give no evidence of compensatory effects, presumably because the evolutionary progressions and regressions of multiple neighboring functions mask each other. The diencephalon and various parts of the telencephalon show large positive correlations, apparently reflecting the general increase in size of the brain, relatively to body weight, from presumably primitive to advanced forms. The neocortex is strongly correlated with the striatum, a putative precursor, and with the diencephalon, but less strongly correlated with the cerebellum in Chiroptera than in Primates. The mesencephalon is moderately correlated with the medulla oblongata and cerebellum, but uncorrelated with all parts of the telencephalon except the paleocortex. The bulbus olfactorius is correlated with the septum, schizocortex and hippocampus, but these correlations may be due mostly to the progression of these four structures in Megachiroptera and their regression in insectivorous Microchiroptera, and may not imply major direct functional relationships.

Animals↗