Nucleolar behaviour during meiosis in four species of phyllostomid bats (Chiroptera, Mammalia)

We analyzed the behavior of the nucleolus, nucleolar structures and nucleolus organizer regions (NORs) during meiotic division in four species of phyllostomid bats that have different numbers and locations of NORs. Nucleoli began disassembly at leptotene, and the subcomponents released from the nucleolus were dispersed in the nucleoplasm, associated with perichromosomal regions, or they remained associated with NORs throughout division. In Phyllostomus discolor, a delay in nucleolus disassembly was observed; it disassembled by the end of pachytene. The RNA complexes identiied by acridine orange staining were observed dispersed in the nucleoplasm and associated with perichromosomal regions. FISH with rDNA probe revealed the number of NORs of the species: one NOR in Carollia per spicillata, one pair in Platyrrhinus lineatus and P. discolor, and three pairs in Artibeus lituratus. During pachytene, there was a temporary dissociation of the homologous NORs, which returned to pairing at diplotene. The variation in the number (from one to three pairs) and location of NORs (in sex or autosomal chromosomes, at terminal or interstitial regions) did not seem to interfere with the nucleolar behavior of the different species because no variation in nucleolar behavior that could be correlated with the variation in the number and chromosomal location of NORs was detected.

Comparative morphology of the tongue in free-tailed bats (Chiroptera, Molossidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Suitability of DNA extracted from archival specimens of fruit-eating bats of the genus Artibeus (Chiroptera, Phyllostomidae) for polymerase chain reaction and sequencing analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Morphological and morphometric characteristics of the epididymis in the Neotropical bats Eumops glaucinus and Molossus molossus (Chiroptera: Molossidae).

The ability of certain species of bats to store viable spermatozoa in the cauda epididymis, for periods of many months beyond the end of spermatogenesis was first recognized over a century ago. However, information about the bat epididymis is still scarce or absent. Thus, this study aimed to characterize and to compare morphologically and morphometrically the regional histology of the epididymis of Eumops glaucinus and Molossus molossus (Chiroptera: Molossidae). Histologically, the epididymis of both species was subdivided into 4 segments: initial segment, caput, corpus and cauda. In comparing the two species, it was observed that the tubular and luminal diameters and percentage of interstitial tissue showed significant differences in all segments. The epithelial height, in both, is greater in the initial segment with a decrease until the cauda epididymis. In relation to the luminal diameter, both species showed a gradual increase from the initial segment to the cauda. The percentage of epithelium, lumen and interstitial tissue varied between both, sometimes M. molossus showing a significantly higher percentage, and other times, E. glaucinus. In both species, the principal cell was the most abundant (> 77%), followed by basal cells at approximately 13% and apical cells at 4% in all segments. Spermatozoa were observed in greater amounts in corpus and cauda epididymis segments. In summary, ours results show that, despite that the species analyzed belong to different genera and have different breeding cycles, the epididymis exhibits similarities in the two species and morphometric and composition differences compared to the majority of mammals.

The diet of bats from Southeastern Brazil: the relation to echolocation and foraging behaviour

In this study the incidence of moths and beetles was examined from feces samples of bats that use different foraging behaviors. Twenty sites around the Fazenda Intervales, a Field Research Station located in São Paulo State, in southeastern Brazil were sampled. Feces were collected from bats caught in mist nets, Turtle Traps or hand nets and, in one case, from beneath a roost. Feces samples were taken from six species of bats: Micronycteris megalotis (Gray, 1842), Mimon bennettii (Gray, 1838), Furipterus horrens (F. Cuvier, 1828), Myotis riparius Handley, 1960, Myotis ruber (E. Geoffroy, 1806) and Histiotus velalus (I. Geoffroy, 1824). To record and describe the frequencies dominating bat echolocation calls, an Anabat II bat detector coupled with an Anabat ZCA interfaces and DOS laptop computers were used. The data show that Furipterus horrens feeds extensively on moths, as predicted from the features of its echolocation calls. Gleaning bats, whose echolocation calls are much less conspicuous to moths take a wide range of insect (and other) prey.

Bats from Fazenda Intervales, Southeastern Brazil: species account and comparison between different sampling methods

Assessing the composition of an area's bat fauna is typically accomplished by using captures or by monitoring echolocation calls with bat detectors. The two methods may not provide the same data regarding species composition. Mist nets and harp traps may be biased towards sampling low flying species, and bat detectors biased towards detecting high intensity echolocators. A comparison of the bat fauna of Fazenda Intervales, southeastern Brazil, as revealed by mist nets and harp trap captures, checking roosts and by monitoring echolocation calls of flying bats illustrates this point. A total of 17 species of bats was sampled. Fourteen bat species were captured and the echolocation calls of 12 species were recorded, three of them not revealed by mist nets or harp traps. The different sampling methods provided different pictures of the bat fauna. Phyllostomid bats dominated the catches in mist nets, but in the field their echolocation calls were never detected. No single sampling approach provided a complete assessment of the bat fauna in the study area. In general, bats producing low intensity echolocation calls, such as phyllostomids, are more easily assessed by netting, and bats producing high intensity echolocation calls are better surveyed by bat detectors. The results demonstrate that a combined and varied approach to sampling is required for a complete assessment of the bat fauna of an area.

Karyotypic patterns of seven species of molossid bats (Molossidae, Chiroptera)

G- and C- banding patterns of seven species of the bat family Molossidae, Eumops glaucinus, E. perotis; Molossops abrasus, M. remminckii, Molossus ater, M. molossus, and Nyctinomops laticaudatus, were identified. Comparisons among the karyotypes of these species showed extensive homologies between E. perotis, M. ater, M. molossus, M. abrasus, and N. laticaudatus, demonstrating inter- and intrageneric conservatism, and a lesser degree of homologies in M. temminckii and glaucinus, reflecting intrageneric variation, Chromosomal variation was due to inversions, Robertsonian rearrangements, translocations, and variations in the location of constitutive heterochromatin and nucleolus organizer regions. The chromosome corresponding to No. 5 in the M. ater karyotype is discussed. We suggest that the Nyctinomops and Molossops karyotypes represent the primitive condition and that Molossus and Eumops have derived karyotypes.

Genetic variability in species of bats revealed by RAPD analysis

Random amplified polymorphic DNA molecular marker was utilized as a means of analyzing genetic variability in seven bat species: Molossus molossus, M. rufus, Eumops glaucinus, E. perotis, Myotis nigricans, Eptesicus furinalis, and Artibeus planirostris. The determination of genetic diversity was based on 741 bands produced by a 20-random primer set. Only eight bands were considered monomorphic to one species. The greatest number of bands and the most polymorphic condition were exhibited by M. molossus, followed by M. nigricans, A. planirostris, E. furinalis, E. glaucinus, M. rufus, and E. perotis. Nei's genetic diversity index in the seven species considering the 20 primers was not greater than 0.22, but some primers were capable of detecting values between 0.39 and 0.49. Nei's unbiased genetic distance values and the UPGMA clustering pattern show that M. molossus and M. rufus have a close genetic relationship, unlike that observed between E. perotis and E. glaucinus. The latter was clustered with A. planirostris and E. furinalis. The low values for genetic diversity and distance observed indicate a genetic conservatism in the seven species. The fluorescent in situ hybridization experiments did not confirm a monomorphic condition for the eight bands identified, demonstrating that the monomorphic bands obtained by random amplified polymorphic DNA are insufficient for the identification of bat species.

Potential force of infection of human rabies transmitted by vampire bats in the Amazonian region of Brazil

Human rabies tansmitted by bats has acquired greater epidemiologic relevance in various Latin American countries, just when cases transmitted by dogs have decreased. Concern has been heightened by reports of increased rates of bats biting humans in villlages in the Amazonian region of Brazil. The aim of the present work was to estimate the potential force of infection (per capita rate at which susceptible individuals acquire infection) of human rabies transmitted by the common vampire bat if the rabies virus were to be introduced to a colony of bats close to a village with a high rate of human bites. The potential force of infection could be then used to anticipate the size of a rabies outbreak in control programs. We present an estimator of potential incidence, adapted from models for malaria. To obtain some of the parameters for the equation, a cross-sectional survey was conducted in Mina Nova, a village of gold prospectors in the Amazonian region of Brazil with high rates of bates biting humans. Bats were captured near dwellings and sent to the Rabies Diagnostic Laboratory at the Center for Control of Zoonoses (São Paulo, Brazil) to be examined. To estimate the force of infection, a hypothetical rabies outbreak among bats was simulated using the actual data obtained in the study area. of 129 people interviewed, 23.33% had been attacked by a vampire bat during the year prior to the study, with an average of 2.8 bites per attacked person. Males (29.41%) were attacked more often than females (11.36%); also, adults (29.35%) were attacked more often than children (8.33%). None of the 12 bats captured in Mina Nova tested positive for rabies, but the force of infection for a hypothetical outbreak was estimated to be 0.0096 per person per year. This risk represents 0.96 cases per 100 area residents, giving an incidence of 1.54 cases of bat-transimtted buman rabies per year in the village of Mina Nova (160 inhabitants). The estimated risk is comparable with what has been observed in similar Brazilian villages.