Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “BATS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 1,207 records · Page 67Linked to original sources

Isolation and characterization of 115 street rabies virus isolates from Ethiopia by using monoclonal antibodies: identification of 2 isolates as Mokola and Lagos bat viruses.

There were 115 isolates of rabies viruses recovered by tissue culture technique from 119 animal brains collected in Ethiopia. By using 17 selected antinucleocapsid monoclonal antibodies (MAbs), 113 isolates were classic street rabies viruses (serotype 1). An isolate of feline origin (Eth-16) was a Mokola virus (serotype 3) and another isolate (Eth-58, obtained from a rabid dog) was serotype 2 (Lagos bat virus). None of the 16 antiglycoprotein MAbs used neutralized the Eth-16 isolate, whereas Eth-58 was neutralized by 1 (TERA543). Antirabies vaccines prepared from Pitman-Moore and Pasteur virus strains protected mice against homologous challenge, but neither was protective against the 2 rabies-related virus isolates. The isolation of Mokola and Lagos bat viruses from domestic animals in eastern Africa is of public and veterinary concern mainly due to lack of effective vaccines against these agents and the difficulty of proper diagnosis.

Animals↗

Bats with hATs: evidence for recent DNA transposon activity in genus Myotis.

Transposable elements make up a significant fraction of many eukaryotic genomes. Although both classes of transposable elements, the DNA transposons and the retrotransposons, show substantial expansion in plants and invertebrates, the DNA transposons are thought to have become inactive in mammalian genomes long ago. Here, we report the first evidence for recent activity of DNA transposons in a mammalian lineage, the bat genus Myotis. Six recently active families of nonautonomous hobo/Activator/TAM transposons were identified in the Myotis lucifugus genome using computational tools. Low sequence divergence among the individual sequences and between individual sequences and their respective consensus sequences suggest their recent expansion in the M. lucifugus genome. Furthermore, amplification and sequencing of polymorphic insertion loci in a related taxon, M. austroriparius, confirms their recent activity. Myotis is one of the largest mammalian genera with 103 species. The discovery of DNA transposon activity in this genus may therefore influence our understanding of genome evolution and diversification in bats and in mammals in general. Furthermore, the identification of a likely autonomous element may lead to new approaches for mammalian genetic manipulation.

Animals↗

Mitochondrial DNA polymorphism in three Antillean island populations of the fruit bat, Artibeus jamaicensis.

The Neotropical fruit bat, Artibeus jamaicensis, occurs throughout Latin America and on many islands in the Caribbean. Populations from Jamaica (in the Greater Antilles) to Barbados (in the Lesser Antilles) have been classified as a subspecies (A.j. jamaicensis) separate from that on the Lesser Antillean island of St. Vincent (A.j. schwartzi). Mitochondrial DNA (mtDNA) was isolated from 54 individuals collected on these islands, analyzed by digestion with restriction endonucleases, and the restriction sites were mapped. Three different mtDNA genotypes (16,000 +/- 200 bp) were identified: J-1 (16 animals from Jamaica, one from St. Vincent, 15 from Barbados), J-2 (two animals from Jamaica), and SV-1 (18 animals from St. Vincent, two from Barbados). The J-1 and J-2 genotypes were estimated to differ from each other by only 0.4%, but the SV-1 genotype differed from J-1 and J-2 by 8.1%-10.5%. The estimated sequence divergence between SV-1 and J-1 is unusually large for mammals that are regarded as conspecific. Restriction mapping showed that the differences among the genotypes (presence or absence of particular restriction sites) were located throughout the genome. The presence of the J-1 mtDNA genotype on Jamaica and on St. Vincent and Barbados (1,400 km away) demonstrates that maternal lineages in these bats are not necessarily confined to single islands or limited geographic regions. The presence of the J-1 mtDNA genotype within the A. j. schwartzi population on St. Vincent and the presence of the SV-1 genotype in two specimens of A. j. jamaicensis from Barbados document genetic exchange between subspecific populations on these islands, which are separated by 180 km of open water.

Animals↗

Identification of androgen metabolic pathways in the brain of little brown bats (Myotis lucifugus): sex and seasonal differences.

During the reproductive cycle of the little brown bat (Myotis lucifugus), the display of sexual behavior is out of synchrony with maximal gonadal development, suggesting that changes in plasma hormone levels per se are not the primary determinants of neural responsiveness. In the present study, we investigated pathways of androgen metabolism in the brain of the bat and compared brain aromatase activity in spring and in autumn. Tissue homogenates were incubated with [3H] androstenedione in the presence of an NADH/NADPH-generating system, and radiolabeled products isolated and their authenticity verified by recrystallization to constant specific activity. Aromatase was identified in preoptic/hypothalamic and adjacent limbic areas, and 5 alpha-reductase was detected in all major brain divisions. No gender-based differences in brain aromatase were seen in spring just prior to emergence from hibernation; however, activity was greater in males than in females when measured during maximal breeding activity in autumn. In addition, seasonal changes were evident in the preoptic/hypothalamic regions of both sexes (spring greater than autumn), although estrone yields from limbic tissues remained constant. Thus, in seasonally breeding species, the rate at which circulating androgen is converted to estrogen or other biologically active metabolites in the brain itself may be an important determinant of behavioral or feedback responsiveness.

Androgens↗

Audio-vocal learning in a non-human mammal: the lesser spear-nosed bat Phyllostomus discolor.

In the course of development, pups of the neotropical bat Phyllostomus discolor seem to adapt their isolation calls to the vocal signature of their mother's directive calls. Under controlled experimental conditions however, audio-vocal learning so far has not been demonstrated in any terrestrial mammal except man. In the present study one group of bat pups was hand-reared in the absence of conspecific vocalizations, whereas an unvarying, digitally stored maternal directive call was repeatedly presented to the juveniles of a second group prior to each feeding. In contrast to the unstimulated controls, the animals of the playback group adapted their isolation call structure to this external acoustic reference signal.

Acoustic Stimulation↗

Facilitative responses to species-specific calls in cortical FM-FM neurons of the mustached bat.

FM-FM neurons in the auditory cortex of the mustached bat are highly specialized for echolocation, responding facilitatively to the combination of frequency modulated (FM) components of biosonar pulse and its echo. Here we propose they are also specialized for processing bat communication calls. FM-FM neurons respond facilitatively to natural call syllable pairs, and exhibit inter-syllable interval tuning to the natural range of intervals. Our results support a role for 'combination-sensitive' neurons in communication, and suggest that cortical neurons can possess multiple distinct specialized modes of response.

Animal Communication↗

Baseball bat assault injuries.

The baseball bat, according to Baltimore City police crime statistics, is a commonly used weapon. To assess the severity of injuries inflicted by this modern-day club, we retrospectively reviewed 75 charts of patients treated at the University of Maryland Medical Systems Hospital for baseball bat injuries from January 1990 through July 1991. Multisystem trauma was documented, with craniocerebral injury being the most frequent and the most frequent cause of death. Of the victims struck on the head, 26% sustained an intracranial hemorrhage. In our series, the history of loss of consciousness and the Glasgow Coma Scale score failed to reliably identify the patients with serious injuries. Seventeen percent of our patients with intracranial hemorrhages had both a negative or uncertain history of loss of consciousness and a normal Glasgow Coma Scale score on arrival.

Adolescent↗

Prophylaxis against rabies in children exposed to bats.

Rabies has become a disease of increasing concern. One reason is that bat variant rabies is a more common cause of human disease, with 1-2 deaths per year in the United States. Bat bites are much more difficult to document than bites from larger animals. Deaths from rabies encephalitis have remained undiagnosed until postmortem examination. Prophylaxis includes a series of 5 vaccinations during 28 days. Vaccine efficacy has been documented, even in young children.

Animals↗

Low-frequency echolocation enables the bat Tadarida teniotis to feed on tympanate insects.

The European free-tailed bat, Tadarida teniotis, forages in uncluttered airspace by using intense narrow-band echolocation calls with low frequency (11-12 kHz), and feeds on relatively large flying insects, mainly (90% by volume) of the tympanate orders Lepidoptera and Neuroptera. The use of low-frequency echolocation calls without strong harmonics appears to be a specialization for long-range detection of large, tympanate insects, which are less well represented in the diet of most other aerial-hawking bats. The results provide evidence in support of the allotonic frequency hypothesis, i.e. that use of echolocation calls with frequencies above or below the best hearing of tympanate insects is an adaptation to increase the availability of these insects.

Animals↗

Extreme population structuring in the threatened ghost bat, Macroderma gigas: evidence from mitochondrial DNA.

The ghost bat, Macroderma gigas, has undergone a major range contraction and is currently restricted around a few, highly disjunct maternity sites. The amount and distribution of mitochondrial DNA (mtDNA) variation within extant populations has been used to assess levels of current and historical maternal gene flow between these populations. An approximately 330 base pair fragment spanning a hypervariable area of the mtDNA control region was amplified and sequenced by using 22 individuals from four current ghost bat populations. The mean sequence diversity of 4.5% between populations was six times higher than that within populations (0.68%), and alleles within populations were monophyletic. Restriction enzyme analysis of amplified products from an additional 100 individuals revealed fixed allelic differences in the distribution of control region genotypes between the four populations. It is suggested that this extreme genetic subdivision is a consequence of long-term female philopatry. For the purposes of management each population should be treated as an independent entity. The depth of the genetic structuring suggests that the isolation of extant populations preceded the historical range contraction.

Alleles↗

Sperm competition in bats.

Sperm competition is a widespread phenomenon influencing the evolution of male anatomy, physiology and behaviour. Bats are an ideal group for studying sperm competition. Females store fertile sperm for up to 200 days and the size of social groups varies from single animals to groups of hundreds of thousands. This study examines the relationship between social group size and investment in spermatogenesis across 31 species of microchiropteran bat using new and published data on testis mass and sperm length. In addition to male competition, I examined the effects of female reproductive biology on characteristics of spermatogenesis. Comparative studies indicate that relative testis mass is positively related to sperm competition risk in a wide range of taxa. Social group size may also influence the level of sperm competition, and one of the costs of living in groups may be decreased confidence of paternity. I used comparative analysis of independent contrast (CAIC) to control for phylogeny. Using two possible phylogenies and two measures of social group size, I found a significant positive relationship between social group size and testis mass. There was no relationship between testis mass and the dimension of the female reproductive tract or oestrus duration. Sperm length was not significantly related to body mass or group size, nor was it related to oestrus duration.

Animals↗

Male dispersal in the noctule bat (Nyctalus noctula): where are the limits?

Studying the dispersal behaviour of small, volant, and nocturnal animals such as microchiropterans with direct methods (banding--recapture, telemetry) is a very difficult task. The development of easily scorable and highly variable genetic markers nowadays allows us to study some aspects of dispersal indirectly, using population genetics. Here, we applied these indirect methods to characterize male dispersal behaviour in a European bat species. The eight microsatellite loci analysed were highly variable in all the nursing colonies assessed (h = 0.63-0.93). Contrary to what we found in the mtDNA, an AMOVA and F-statistics showed that the overall European population structure of the noctule bat was very weak, indicating a high male dispersal rate. Nevertheless, the population was not totally panmictic (theta = 0.006, p < 0.001), and neither isolation by distance, nor influence of migration could account for this result. Rather, an analysis of pairwise theta-values showed that the population structure might be explained partly by a geographical barrier to gene flow (the Alps), and partly by the fact that there is some limit to the distance the males can disperse.

Animals↗

Parentage, reproductive success and breeding behaviour in the greater horseshoe bat (Rhinolophus ferrumequinum).

Female greater horseshoe bats form maternity colonies each summer in order to give birth and raise young. During the mating period, females visit males occupying territorial sites, copulation takes place and sperm are stored until ovulation occurs, normally in April. Using microsatellite markers and a likelihood method of parentage analysis, we studied breeding behaviour and male reproductive success over a five-year period in a population of bats in south-west Britain. Paternity was assigned with 80% confidence to 44% of young born in five successive cohorts. While a small annual skew in male reproductive success was detected, the variance increased over five years due to the repeated success of a few individuals. Mating was polygynous, although some females gave birth to offspring sired by the same male in separate years. Such repeated partnerships probably result from fidelity for either mating sites or individuals or from sperm competition. Females mated with males born both within and outside their own natal colony; however, relatedness between parents was no less than the average recorded for male female pairs. Gene flow between colonies is likely to be primarily mediated by both female and male dispersal during the mating period rather than more permanent movements.

Animals↗

Flexibility in assessment of prey cues: frog-eating bats and frog calls.

Predators use cues associated with their prey to assess prey quality and to avoid consuming poisonous prey. Considerable attention has been given to predators' use of aposematic cues to assess prey quality, but little is known about predators that eavesdrop on prey cues that are not intended for them. Here we investigate the prey-cue/prey-quality associations of a predator that eavesdrops on the sexual advertisement signals of its prey. Stability is expected in prey-cue/prey-quality associations when mistakes in prey assessment are lethal. Conversely, flexibility is possible when mistakes are less costly. Predators that must respond to temporal and spatial fluctuations in prey availability should be more flexible in their assessment of prey quality. Given these predictions, we examined flexibility in the ability of wild-caught bats to reverse prey-cue/prey-quality associations for a preferred prey and a poisonous one. We found that the predatory bat, Trachops cirrhosus, has a heretofore undescribed ability to reverse its evaluations of the cues that signal preferred prey.

Adaptation, Biological↗

Coprophagy in a cave-adapted salamander; the importance of bat guano examined through nutritional and stable isotope analyses.

During a two year population ecology study in a cave environment, 15 Eurycea (= Typhlotriton) spelaea were observed ingesting bat guano. Furthermore, E. spelaea capture numbers increased significantly during the time that grey bats (Myotis grisescens) deposited fresh guano. We investigated the hypothesis that this behaviour was not incidental to the capture of invertebrate prey, but a diet switch to an energy-rich detritus in an oligotrophic environment. Stable isotope assays determined that guano may be assimilated into salamander muscle tissue, and nutritional analyses revealed that guano is a comparable food source to potential invertebrate prey items. This is the first report of coprophagy in a salamander and in any amphibian for reasons other than intestinal inoculation. Because many temperate subterranean environments are often energy poor and this limitation is thought to select for increased diet breadth, we predict that coprophagy may be common in subterranean vertebrates where it is not currently recognized.

Animals↗

Mating system and brain size in bats.

The contribution of sexual selection to brain evolution has been little investigated. Through comparative analyses of bats, we show that multiple mating by males, in the absence of multiple mating by females, has no evolutionary impact on relative brain dimension. In contrast, bat species with promiscuous females have relatively smaller brains than do species with females exhibiting mate fidelity. This pattern may be a consequence of the demonstrated negative evolutionary relationship between investment in testes and investment in brains, both metabolically expensive tissues. These results have implications for understanding the correlated evolution of brains, behaviour and extravagant sexually selected traits.

Animals↗

Evolution of European bat lyssaviruses.

Forty-seven European bat lyssaviruses (EBL) and two African insectivorous bat lyssaviruses (Duvenhage viruses) were selected for a comparison to be made of their evolutionary relationships. Studies were based on direct sequencing of the PCR-amplified products of the 400 nucleotides coding for the amino terminus of the nucleoprotein. Phylogenetic relationships were analysed after bootstrap resampling using the maximum parsimony and the neighbour-joining methods. Analyses of both the nucleotide and amino acid sequences placed these viruses in three separate clusters, namely genotype 4 (Duvenhage), genotype 5 (EBL1) and genotype 6 (EBL2). Evolutionary analysis of the nucleoprotein gene of EBL1 and EBL2 indicated low intrinsic heterogeneity mainly due to synonymous substitutions. In addition, both EBL1 and EBL2 evolved into at least two genetically distinguishable lineages (a and b) following geographical drifting. We can speculate that subsequently the lineages EBL1a and EBL1b were introduced into parts of northern Europe from two different geographical directions; EBL1b was probably introduced most recently and was from North Africa. Eptesicus serotinus appears to be the principal reservoir for EBL1 and Myotis dasycneme and M. daubentonii the reservoirs for EBL2.

Amino Acid Sequence↗

Genome sequence analysis of Tamana bat virus and its relationship with the genus Flavivirus.

Tamana bat virus (TABV, isolated from the bat Pteronotus parnellii) is currently classified as a tentative species in the genus FLAVIVIRUS: We report here the determination and analysis of its complete coding sequence. Low but significant similarity scores between TABV and member-viruses of the genus Flavivirus were identified in the amino acid sequences of the structural, NS3 and NS5 genes. A series of cysteines located in the envelope protein and the most important enzymatic domains of the virus helicase/NTPase, methyltransferase and RNA-dependent RNA polymerase were found to be highly conserved. In the serine-protease domain, the catalytic sites were conserved, but variations in sequence were found in the putative substrate-binding sites, implying possible differences in the protease specificity. In accordance with this finding, the putative cleavage sites of the TABV polyprotein by the virus protease are substantially different from those of flaviviruses. The phylogenetic position of TABV could not be determined precisely, probably due to the extremely significant genetic divergence from other member-viruses of the family FLAVIVIRIDAE: However, analysis based on both genetic distances and maximum-likelihood confirmed that TABV is more closely related to the flaviviruses than to the other genera. These findings have implications for the evolutionary history and taxonomic classification of the family as a whole: (i) the possibility that flaviviruses were derived from viruses infecting mammals rather than from mosquito viruses cannot be excluded; (ii) using the current criteria for the definition of genera in the family Flaviviridae, TABV should be assigned to a new genus.

Amino Acid Sequence↗