No description available.

Chaerephon (Dobson, 1874), an Old World genus belonging to the family Molossidae, is part of the suborder Vespertilioniformes. Members of this genus are distributed across mainland Africa (sample sites; Tanzania, Yemen, Kenya, Botswana, South Africa and Swaziland), its offshore islands (Zanzibar, Pemba and Mozambique Island), Madagascar and the surrounding western Indian Ocean islands (Anjouan, Mayotte, Moheli, Grande Comore, Aldabra and La Reunion). A multifaceted approach was used to elucidate the phylogenetic and population genetic relationships at varying levels amongst these different taxa. Working at the subspecific level, I analysed the phylogenetics and phylogeography of Chaerephon leucogaster from Madagascar, based on mitochondrial cytochrome b and control region sequences. Cytochrome b genetic distances among C. leucogaster samples were low (maximum 0.35 %). Genetic distances between C. leucogaster and C. atsinanana ranged from 1.77 % to 2.62 %. Together, phylogenetic and distance analyses supported the classification of C. leucogaster as a separate species. D-loop data for C. leucogaster samples revealed significant but shallow phylogeographic structuring into three latitudinal groups (13º S, 15 - 17º S, 22 - 23º S) showing exclusive haplotypes which correlated with regions of suitable habitat defined by ecological niche modelling. Population genetic analysis of D-loop sequences indicated that populations from Madagascar have been expanding since 5 842 - 11 143 years BP. At the infra-generic level, I carried out analyses of sequences of the mitochondrial cytochrome b gene and control region, and the nuclear RAG2 region, to resolve the evolutionary history and taxonomy of the C. pumilus species complex from Africa and the western Indian Ocean islands. The nominate form comprised C. pumilus from Massawa, Eritrea, and this was genetically distinct from all other forms of Chaerephon. Our molecular evidence does not support that the syntype of C. limbatus and the holotypes of C. elphicki and C. langi and topotype of C. naivashae are specifically distinct from C. pumilus s.s. There is evidence of introgression of both C. pusillus and C. pumilus s.l. (south eastern Africa) mitochondrial haplotypes into C. leucogaster. The C. pumilus species complex has several attributes of a ring species, but appears to differ from this model in some important respects. It occurs on the African mainland and western Indian Ocean Islands, including Madagascar, ringing a potential barrier to gene flow, the Mozambique Channel. The taxa within the species complex form a ring in which the differentiated terminal forms, C. pusillus and C. leucogaster, occur in sympatry on Mayotte (Comoro Islands). Although there is evidence of isolation by distance around the ring, there is also a relatively high degree of genetic structure and limited gene flow. It appears that the island-based component species may have differentiated in allopatry, with some gene flow by over water dispersal, whereas the African mainland species may have differentiated through isolation by distance. A further study was aimed at re-examining the phylogeny of C. pumilus sensu lato from south eastern Africa based on a considerably larger sample set with a wider geographic range; I confirmed the previously-reported phylogenetic structure, and identified an additional strongly-supported control region clade. Discriminant Function Analysis based on four echolocation parameters could not discriminate between these clades. The hypothesised existence of cryptic species with distinct echolocation characteristics was not supported. Indices of diversity and neutrality, combined with a ragged multimodal mismatch distribution, are inconsistent with demographic expansion of a single C. pumilus south eastern African population and suggest that the control region lineages are stable populations at demographic equilibrium that were established during the late Pleistocene between 60 000 and 13 000 years ago. Further, more variable markers (microsatellites) were employed for finer-scale resolution of population genetic structure among the five genetic lineages of C. pumilus sensu lato found in the Durban area of KwaZulu-Natal, and to search for hybridization between these lineages. We recovered strong mitochondrial genetic structure, with 90% of the molecular variance occurring among four phylogenetically-defined groups, and a high significant Fst (0.897). Microsatellite data recovered three admixed populations with 3% of the nuclear variance occurring among populations, and global (Fst=0.037) and pairwise Fst values among populations were low and not significant. This is indicative of little genetic structure among the groups of C. pumilus s.l., which appear to comprise a single interbreeding population. Such high levels of mitochondrial genetic structure in the absence of significant nuclear structure are consistent with social isolation mechanisms such as female philopatry, and may reflect introgression of mitochondrial genes due to past hybridisation events with mitochondrially-distinct forms from outside the sampled area. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2013.

Les chauves-souris (Chiroptera) sont reconnues comme réservoirs naturels de nombreux microorganismes, dont certains pathogènes, responsables de maladies sévères chez l’homme. À ce jour, plus de 1 300 espèces de chauves-souris, aux habitats et comportements sociaux multiples, ont été décrites. Cette grande diversité d’espèces reflète l’importante diversité des caractéristiques biologiques, de l’histoire évolutive et de la capacité d’adaptation de cet ordre. Les études immunobiologiques laissent à penser que ces animaux présentent des stratégies antimicrobiennes plus efficientes que les autres mammifères, influencées par leurs caractéristiques spécifiques et par les contraintes pathogéniques associées aux environnements. L’objectif de cette thèse était de mieux comprendre, en utilisant la diversité virale et la circulation du virus rabique comme proxy, comment les contraintes bioécologiques, liées à la phylogénie de l’hôte et à son environnement, pouvaient impacter la diversité virale des chauves-souris, et subséquemment, induire une adaptation locale des gènes de l’immunité. L’ensemble des résultats obtenus montre que les composantes environnementales sont des facteurs clés des diversités virales et immunitaires. Associées aux caractéristiques spécifiques, elles jouent un rôle dans le maintien de ces diversités et déterminent les capacités d'adaptation des chauves-souris. Les processus démographiques semblent également contribuer au maintien des virus dans un environnement donné. Ce travail apporte des éléments de compréhension des mécanismes de maintien et de mise en place des diversités virales et immunitaires qui influencent l'adaptation locale des chauves-souris. / Bats belong to the order Chiroptera and are the only mammals capable of true flight. They are recognized as excellent biodiversity indicators. Furthermore, these animals have been described as natural reservoirs and source of infection for several microorganisms, including pathogens responsible for severe human diseases. Currently, more than 1,300 different bat species are described with different habitats and sociality, reflecting a high diversity of bioecological features, life histories and adaptation capacity. Immunobiological studies suggest that bats present more effective anti-microbial strategies highly influenced by their biological traits as well as by the environmental-associated pathogen pressures. The aim of this thesis was to better understand, using viral diversity and circulation of the rabies virus as a proxy, how bioecological constraints related to the phylogeny and the environment where they evolve, could impact the diversity of hosted viral communities and subsequently induce a local adaptation of immune genes. Altogether, the results obtained during this thesis showed that environmental components were key factors of both viral and immune diversities. Associated with species characteristics, environment plays a key role in shaping both diversities and determines the adaptation ability of bats. Nevertheless, demographic processes should not be overshadowed as they seem to contribute to the maintenance of viruses in a given environment. This work sheds light on the mechanisms maintaining and shaping both viral and immune diversities and subsequently influencing the local adaptation of bats

Submitted by Mario BC (mario@bc.ufrpe.br) on 2018-05-14T12:33:41Z No. of bitstreams: 1 Maria Juliana Gomes Arandas.pdf: 4922822 bytes, checksum: 148127b0ff232a5523d17669ea5ab23c (MD5) / Made available in DSpace on 2018-05-14T12:33:41Z (GMT). No. of bitstreams: 1 Maria Juliana Gomes Arandas.pdf: 4922822 bytes, checksum: 148127b0ff232a5523d17669ea5ab23c (MD5) Previous issue date: 2018-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Bats have peculiar reproductive aspects that evolved in order to adapt to different environmental and climatic conditions. One of the criteria for the understanding about the reproductive biology in bats is the testicular and epididymal morphophysiology. Molossus molossus and Myotis lavali are insectivorous bats, and studies on the reproductive biology of these species are scarce, especially in the Northeast of Brazil. Therefore, it was analyzed the testicular and epididymal histomorphometry as well as testosterone levels of M. molossus and M. lavali from a fragment of Atlantic Forest located between the cities of Tamandaré and Rio Formoso-PE. In total, 23 adult males of M. molossus were studied, being 10 for dry months and 13 for rainy months. Besides that, 34 adult males of M. lavali were analyzed (22 in dry months and 12 in rainy months). After Anesthesia, blood samples were collected to testosterone dosage. Subsequently, the testicles and epididymides were fixed in 10% buffered formalin, and submitted to the routine histological techniques. For the testicles, the following histomorphometric parameters were evaluated: the tubular and intertubular areas, quantification of spermatocytes, rounded and elongated spermatids, Sertoli cells and Leydig cells, while in the epididymis: the tubular, luminal and epithelial areas from the head, body and tail. The results indicated that M. molossus presented higher averages for the tubular and intertubular areas, rounded and elongated spermatids, Leydig cells and testosterone levels. In the epididymis, the tubular, luminal and epithelial areas were larger in rainy months. On the other hand, M. lavali exhibited increased tubular and intertubular areas, number of elongated spermatids, Sertoli cells, Leydig cells and testosterone levels as well as tubular, luminal and epithelial area of the head and tail of the epididymis during the rainy season. Physiologically, males of both species have a high investment in the final stages of spermatogenesis and in the concentration of testosterone. Furthermore, the two species have a greater capacity to store spermatozoa in the region of the tail of epididymis, which relates to the reproductive strategy developed by bats for storage. Although both species exhibit a continuous spermatogenic cycle, it is noted that they adjust their reproduction for the rainy months. / Os morcegos apresentam aspectos reprodutivos peculiares que evoluíram a fim de se ajustar as diferentes condições ambientais e climáticas, e um dos critérios para o conhecimento da reprodução é a morfofisiologia testicular e epididimária. Molossus molossus e Myotis lavali são espécies de morcegos insetívoros, e os estudos referentes a biologia reprodutiva são escassos, principalmente no Nordeste do Brasil. Assim, analisou-se a histomorfometria testicular e epididimária, assim como os níveis de testosterona de M. molossus e M. lavali em um fragmento de Mata Atlântica localizado entre os Municípios de Tamandaré e Rio Formoso-PE. Um total de 23 machos adultos foi selecionado para M. molossus, sendo 10 em meses secos e 13 para meses chuvosos. Ao passo que foram utilizados 34 machos adultos para M. lavali, sendo 22 em meses secos e 12 em meses chuvosos. Após anestesia, as amostras de sangue foram coletadas para a dosagem de testosterona. Os testículos e epidídimos foram removidos e fixados em formal 10% tamponado, e posteriormente submetidos à técnica histológica de rotina. Para o testículo, os seguintes parâmetros histomorfométricos foram avaliados: a área tubular, área intertubular, quantificação dos espermatócitos, espermátides (arredondadas e alongadas), células de Sertoli e células de Leydig, enquanto que no epidídimo: as áreas tubular, luminal e epitelial da cabeça, corpo e cauda. Os resultados indicaram que M. molossus apresentou maiores médias para a área tubular, intertubular, espermátides (arredondadas e alongadas), células de Leydig e níveis de testosterona. No epidídimo, as áreas tubular, luminal e epitelial foram maiores em meses chuvosos. Ao passo que M. lavali na estação chuvosa exibiu um aumento nas áreas tubular e intertubular, nas espermátides alongadas, células de Sertoli, células de Leydig e nos níveis de testosterona, assim como na área tubular, luminal e epitelial da cabeça e cauda do epidídimo. Fisiologicamente, os machos das duas espécies têm um alto investimento nas etapas finais da espermatogênese e na concentração de testosterona. Atrelado a isso, nota-se uma maior capacidade de comportar os espermatozoides na região da cauda do epidídimo, que se relaciona a estratégia reprodutiva desenvolvida pelos morcegos para a estocagem. Embora as duas espécies apresentem um ciclo espermatogênico contínuo, nota-se que ajustam a reprodução para os meses chuvosos.

This study has focused on genetic variability and structure in Chaerephon atsinanana, a newly-described molossid bat found in the mid to southern region of the eastern watershed of Madagascar. As these bats are strong fliers, and are able to traverse the riverine and mountain barriers within the landscape, it was hypothesized that they would show relatively low levels of intraspecific genetic structure, consistent with patterns shown for other Molossidae on Madagascar (Mormopterus jugularis, Mops midas, Mops leucostigma, and C. lecuogaster. Phylogenetic (neighbor-joining, parsimony and Bayesian inference) and population genetic analyses of maternally-inherited mitochondrial control region sequences revealed the presence of 6 distinct haplotype groups separated by genetic distances of up to 8.14% (mean 4.95%). There were high levels of genetic structure among the haplotype groups (overall FST= 0.994). Thus the hypothesis of low levels of genetic structure was rejected. Bayesian skyline analyses and significantly ragged mismatch distributions were consistent with ancient stable C. atsinanana populations which were of constant size during the last two major Pleistocene glacial periods. This made retreat into and expansion from glacial refugia an unlikely explanation for such high levels of structure. An alternative hypothesis is that C. atsinanana haplotype groups are spatially structured as a result of philopatry. As mitochondria are maternally-inherited, this data is consistent with the existence of female philopatry in C. atsinanana. The second aim of this study was to examine the genetic structure of C. atsinanana with nuclear sequence markers, which are biparentally-inherited, in order to provide information on the male contribution to gene flow and the possible presence of male philopatry in this molossid bat species. The initial objective was to amplify and sequence candidate nuclear markers in order to identify those which were variable among C. atsinanana samples. I attempted to amplify and sequence a set of 12 nuclear markers, identified from the literature, which had been reported to show high levels of variability, or which were untested and showed the potential for high levels of variability. Of these, the intron markers PNPO-3, SLC38A7-8, CARHSP1-1, GAD2-1, OSTA-5 had not previously been used in phylogenetic analyses while FES, GHR, RHO1 CHRNA1, STAT5, PRKC1 and THY had been. I was not able to amplify and/or sequence SLC38A7-8, CARHSP1-1, GAD2-1, OSTA-5, CHRNA1, STAT5 and THY across the range of the C. atsinanana samples. PNPO-3, FES, GHR, RHO1 and PRKC1were successfully amplified and sequenced, but showed no variability and very little polymorphism, and were therefore unsuitable for testing hypotheses related to genetic variability of C. atsinanana populations. These five nuclear sequence markers were further used to investigate phylogenetic relationships among 5 genera (Chaerephon, Mops, Mormopterus, Otomops and Sauromys) and 13 species of Afro-Malagasy molossid bats, and to provide a nuclear phylogenetic perspective on the newly-described C. atsinanana. PNPO-3 is a novel nuclear intron marker, previously unused in phylogenetic studies. This intron provides resolution primarily at the genus level, and is less informative at interspecific level. These five nuclear markers were combined with already existing mitochondrial cytochrome b (Cyt b) and nuclear Rag2 data retrieved from GenBank. This study provides strong support for the monophyly of the Chaerephon and Mops taxa included, with the exception of C. jobimena, which was weakly associated with this group. There was no support for the generic affiliation of C. jobimena or for the monophyly of either of the genera Chaerephon or Mops individually. This leads to the suggestion that Mops and Chaerephon be combined into a single genus, with crown age of 14.82 (6.44-25.54) MYA, or 21.97 (12.16-33.44) MYA if C. jobimena is included. Otomops forms a strongly supported clade consistent with its generic status, comprising two subclades corresponding to the recognised sister species O. martiensseni and O. madagascariensis, which last shared a common ancestor 8.35 (2.87-17.47) MYA. This study provides good nuclear support for the mitochondrially-defined subclades of O. martiensseni, which last shared a common ancestor 4.18 (1.08-9.96) MYA. It would appear appropriate to name the clade from north east Africa and Arabia as a new species of Otomops, as the clade from southern and western Africa includes the type locality. This study provides weak support based on individual gene regions for associations of Sauromys with Otomops and Mormopterus, although these do not stand up in the concatenated datasets which offer better resolving power, indicating that Sauromys is not phylogenetically associated with Chaerephon/Mops, Otomops and Mormopterus. These results provide some support for the membership of Mormopterus in the proposed Old World Molossid tribe, Tadarini, but also support Mormopterus as a basal genus within the Molossidae, consistent with its designation as a separate tribe, Mormopterini. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2013.