National Repository of Grey Literature 34 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Genetic consequences of bottlenecks and population admixture in Eurasian beaver (Castor fiber)
Náhlovský, Jan ; Munclinger, Pavel (advisor) ; Hulva, Pavel (referee)
In the last few centuries beavers passed through dramatic declining of the population size followed by expansion supported by reintroductions. The genetical variability is much decreased due to this bottleneck. Current beavers possess 31 known recent mitochondrial haplotypes, among which some were described independently several times. The haplotypes form two clusters, which serve as a base for dividing beaver populations into the west and east ESU. While microsatellite loci show moderate variability, the diversity of Y chromosome loci is very low. There are only ten described alleles of the DRB second exon, which belong to the MHC loci. No mitochondrial haplotype or MHC allele is shared between relict populations. This is not noticeable in samples from the time before the bottleneck. Described subspecies are therefore only the artefact of the recent bottleneck. Newly established populations comprise in many cases beavers of various origin and are more or less admixed. It seems, that the admixed populations have higher viability and conversely in some relict populations it is possible to find the evidence of the inbreeding depression. Thus, for reintroductions it is advantageous to use individuals from several source relict populations or to use beavers from admixed populations. Several species passed...
The use of conserved microsatellite locus for the study of the population structure of afromontain birds
Franková, Martina ; Munclinger, Pavel (advisor) ; Bartáková, Veronika (referee)
The Sky islands are alpine habitats that are geographically separated by the surrounding lowlands. These dynamic systems affect species distribution and population structure. They are also generators of diversity with a high degree of endemism and offer considerable potential to explore how different evolutionary processes lead to species formation. This work was focused on the analysis of the population structure of six species of songbirds living on the Sky islands of the Cameroon volcanic line. Conservative microsatellite loci were used for this analysis. I tested 17 conservative loci, each of them was amplified in at least 4 species. Reduced polymorphism is unlikely affected by genetic distance, but by phenomena such as genetic bottleneck, founder effect, or long-term inbreeding. Despite the higher incidence of null alleles and lower locus variability, I was able to use the data in population studies. Among the populations of endemic species Cyanomitra oritis and Arizelocichla tephrolaema, I detected an increase in genetic differentiation and near- zero gene flow between the sky islands. Conversely, species with wide distribution of Cinnyris reichenowi and Linurgus olivaceus showed extensive gene flow between sky islands. Partial isolation in sky islands was detected in Cryptospiza reichenovii and...
Coevolution of avian ectoparasites in the tropics
Gajdošová, Magdalena ; Munclinger, Pavel (advisor) ; Votýpka, Jan (referee)
Host-parasite associations are born by cospeciations or by host switches. Feather lice have traditionally been used as model parasites for studying these events and underlying ecological factors. By now tens of analyses have addressed comparisons of host and parasite phylogenies to study cospeciations and host switches in lice, however, these analyses are strongly biased towards the temperate zone. Tropical environment could provide new insight into the origin of host-parasite interactions, because it is ecologically unique. This work aims to supplement the knowledge of host-parasite associations in lice using coevolution analyses of two feather lice genera and their passerine hosts in tropical rainforest in Cameroon. It shows that lice in the tropics cospeciate rarely. To assess whether host switches are non-random and occur preferentially between hosts with specific traits, this work also analyses relations between parasite genetic distances and hosts' trait similarities. No effect of host morphology and spatial distribution was found. However, genetic distances of the lice strongly correlate with genetic distances of their hosts.
Avian malaria parasites and their vectors
Synek, Petr ; Munclinger, Pavel (advisor) ; Hypša, Václav (referee) ; Široký, Pavel. (referee)
Parasites causing avian malaria belong to the group Haemosporida, which represents a monophyletic group of dixenic protists within Apicomplexa. Their asexual reproduction takes place in a vertebrate intermediate host, and the formation of gametes and sporogony occur in blood-sucking dipteran insects, which are the definitive hosts of these parasites. Three main genera (​Plasmodium​, Haemoproteus ​and ​Leucocytozoon​) are found mostly in their avian hosts. We focused on the Haemosporida of wild birds and their transmission by insect vectors in natural populations, which had previously been a neglected area. Our results were obtained both by traditional methods (investigation of infections by microscopy of blood smears) and mainly by molecular methods (e.g. nested PCR) centered around work with unique haplotypes of the haemosporid lineages. The aim of our work was to determine the range of possible insect vectors of avian haemosporidians in the territory of the Czech Republic, taking into account the specificity of the parasites within these vectors, and to describe the diversity of haemosporidians in the populations of their bird intermediate hosts. We chose four different species of birds from four orders (Passeriformes, Strigiformes, Accipitriformes, and Galliformes). As potential vectors of avian...
Sequence diversity of mtDNA and genetic structure of eastern part of the African Sahel
Tlačbabová, Klára ; Černý, Viktor (advisor) ; Munclinger, Pavel (referee)
Eastern part of the African Sahel, connecting sub-Saharan Africa with North and East Africa, play an important role as a bidirectional corridor for vertically and horizontally migrations of populations. It is the strategic region to study human genetic diversity due to the presence of ethnically, linguistically, culturally and geographically diversity. This work is focused on the analysis of HVS-I and HVS-II segments of mtDNA. The work provides new information about genetic structure and migration activity of this region by analysis twelve populations belonging to three African linguistic families and different subsistent strategies. Analysis of mtDNA revealed the higher diversity of the populations of east Sudan and Horn of Africa, which is connected with the spreading of populations along the Nile River. It seems, that in this region linguistic factors have bigger impact on genetic diversity then the geografic ones. The opposite situation is observed in populations of Chad, where populations with similiar geografic location and different linguistic affilation revealed low genetic differentiation. The intra-population analysis shows the significant influence of genetic drift on the pastoralists living on the Red Sea Coast - Beja and Rashaida. In Beja is probably due to decrease of size of...
Mosquitoes as hosts and vectors of protozoa transmitted to birds
Fialová, Magdaléna ; Svobodová, Milena (advisor) ; Munclinger, Pavel (referee)
Mosquitoes belong to significant representatives of inscet which are particularly studied due to their ability to transmit pathogens (viruses, bacteria, protozoa, worms) in many cases causing serious illnesses. The hosts of these pathogens can be various animals including birds. In this study I have focused on protozoa (especially Plasmodium and Trypanosoma) transmitted by a mosquito. Concerning trypanosomes the mosquito is one of several possible vectors and up to now there have been named two trypanosomes transmitted by birds, namely Trypanosoma culicavium and Trypanosoma thomasbancrofti. In the case of the genus Plasmodium the mosquito is the only vector and there are many more species of the genus Plasmodium, which mosquito transmits between birds. Key words: vector, mosquito, host, bird, Trypanosoma, Plasmodium, infection
The impact of geography and subsistence on distribution of NRY haplogroups in Europe and Africa
Nováčková, Jana ; Černý, Viktor (advisor) ; Munclinger, Pavel (referee) ; Macholán, Miloš (referee)
Y chromosome is due to its special characteristics the ideal tool of archaeogenetic studies. Its diversity is influenced by several factors and I analysed two of them (geographical location and subsistence). I generated SNPs and STRs data from several loci of samples from Slovakia (156 samples, 5 regions) and sub-Saharan Africa, where I analysed samples of sedentary farmers (481 samples, 18 regions) and nomadic pastorals (405 samples, 16 regions). Slovakia is situated at the meeting point of two migration ways. First of them was spread from the east to the west and is associated with enlargement of haplogroup R1a in Europe. The second came from the Iberian Peninsula eastward and is associated with enlargement of haplogroup R1b. Results of MDS graphs replicate the geographical map of Europe. Slovakia is situated in the middle of Russian, Balkanian and Iberian samples. Correlation between genetics and geographic distances is indicated by hierarchical AMOVA analysis and Mantel tests. Populations in sub-Saharan Africa differ from each other by the subsistence pattern. Different life style influence the diversity of the Y chromosome. Nomadic pastoralists and sedentary farmers share different haplogroups, for example, while haplogroup R1b was detected only in nomadic pastoral groups, sedentary farmers...
Whole-genome analysis of the house mouse hybrid zone
Janoušek, Václav ; Munclinger, Pavel (advisor) ; Choleva, Lukáš (referee) ; Chan, Yingguang Frank (referee)
Hybrid zones provide a valuable opportunity to study the process of speciation in real time. Untested combinations of genes from diverging populations come to the contact here causing a breakdown of genetic interactions and giving rise to reproductive isolation. Two house mouse subspecies (Mus musculus musculus/Mus musculus domesticus) form a narrow zone of secondary contact across Central Europe which is thought to be maintained by a balance between selection against unfit hybrids and dispersion of individuals. During my PhD study my collaborators and I used an array of ~ 1400 SNP markers to study patterns of introgression on a genome-wide scale across two/three house mouse hybrid zone transects. Our aim was to identify the genomic regions putatively harboring genes which are involved in the reproductive isolation between the two subspecies, characterize their distribution in mouse genome and assess genomic features associated with them. We were able to confirm on a genome-wide scale the importance of the X chromosome in the evolution of reproductive isolation. This chromosome exhibited introgression corresponding to strong negative epistasis and the patterns were consistent between transects pointing out to a common basis of reproductive isolation playing a role in two transects. Contrary to the...
Cospeciation of bird ectoparasites
Gajdošová, Magdalena ; Munclinger, Pavel (advisor) ; Votýpka, Jan (referee)
In a case when two taxa are ecologically very closely related, speciation in one of them may induce speciation in the other one. This phenomenon is called cospeciation. Host specific parasites and their hosts are one of the systems where cospeciation has been frequently studied. Birds and their ectoparasites traditionally serve as a model system. Up to now dozens of cospeciation studies have been done on birds and their ectoparasites by comparing their phylogenetic trees. This work reviews the results of these studies and evaluates the possible effect of ecological and other factors. Cospeciation appears to take place often among birds and their permanent ectoparasites. 64% of the performed studies showed significant cospeciation. The rate of cospeciation varies greatly between different taxa. Some ecological aspects seem to play prominent role, especially those that provide dispersal opportunities to parasites.

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