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Evolution of Host Specialisation, Phylogeography and Taxonomic Revision of Xenidae (Strepsiptera)
Benda, Daniel
Twisted-winged parasites (Strepsiptera: Xenidae) are an excellent group for studying the specialisation of parasites on hosts. Their parasitic lifestyle led to the evolution of numerous morphological, behavioural, physiological, and reproductive adaptations. Moreover, many complex adaptive traits of Strepsiptera have no parallel in other organisms. In contrast, little attention has been paid to the study of strepsipteran molecular phylogeny, phylogeography, species delimitation, and their implications for taxonomic classification. Using the methods of molecular phylogeny, we created the first dated phylogenetic study of the family Xenidae. By investigating historical biogeography and ancestral host groups, we indicate that multiple lineages were exchanged between the New World and the Old World + Australia until Antarctica became completely frozen over. During the late Paleogene and Neogene periods, several lineages spread from the Afrotropics to other Old World regions and Australia. The original hosts of Xenidae were most likely social wasps, and the subsequent host switch from social to solitary wasps was secondary and probably occurred only once. The parallel host switch from solitary wasps to digger wasps (Sphecidae) occurred independently in the New and Old World. The biogeography and...
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Evolution of Host Specialisation, Phylogeography and Taxonomic Revision of Xenidae (Strepsitera)
Benda, Daniel ; Straka, Jakub (advisor) ; Malenovský, Igor (referee) ; Cook, Jerry L. (referee)
Twisted-winged parasites (Strepsiptera: Xenidae) are an excellent group for studying the specialisation of parasites on hosts. Their parasitic lifestyle led to the evolution of numerous morphological, behavioural, physiological, and reproductive adaptations. Moreover, many complex adaptive traits of Strepsiptera have no parallel in other organisms. In contrast, little attention has been paid to the study of strepsipteran molecular phylogeny, phylogeography, species delimitation, and their implications for taxonomic classification. Using the methods of molecular phylogeny, we created the first dated phylogenetic study of the family Xenidae. By investigating historical biogeography and ancestral host groups, we indicate that multiple lineages were exchanged between the New World and the Old World + Australia until Antarctica became completely frozen over. During the late Paleogene and Neogene periods, several lineages spread from the Afrotropics to other Old World regions and Australia. The original hosts of Xenidae were most likely social wasps, and the subsequent host switch from social to solitary wasps was secondary and probably occurred only once. The parallel host switch from solitary wasps to digger wasps (Sphecidae) occurred independently in the New and Old World. The biogeography and...
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Evolution, biogeography and systematics of moss-inhabiting flea beetles (Coleoptera: Chrysomelidae: Galerucinae)
Damaška, Albert ; Fikáček, Martin (advisor) ; Bezděk, Jan (referee)
Flea beetles (Alticini) are a highly diversified group of leaf beetles (Chrysomelidae) with about 8 000 known species from about 560 genera distributed worldwide except Antarctica. The major life strategy of flea beetles is external feeding on vascular plants, similarly to other leaf beetles. However, studies published during last years revealed existence of numerous different flea beetle genera feeding on mosses. Moss-inhabiting flea beetles are usually highly specialized and share similar morphological characteristics, including flightlessness, compact body shape and modified antennae. However, their phylogenetic position remained unknown. In this study, I performed a phylogenetic analysis of 14 known moss- and leaf litter inhabiting flea beetle genera, included into a large dataset of various genera of flea beetles. I sequenced 2 mitochondrial and 2 nuclear genes previously used for phylogenetic analyses of Alticini. I also added numerous Neotropical external feeding alticine genera, because taxon samples from previous studies (Ge et al. 2012; Nie et al. 2017) consisted mainly of Oriental genera. Although deep divergences and phylogenetic positions of several genera were not resolved, the analysis revealed a multiple origin of moss- and leaf litter inhabitance among flea beetles. The morphologically...
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Biologická a molekulární charakteristika Cryptosporidium suis-like
VLNATÁ, Gabriela
Cryptosporidium parvum VF383, more commonly known as Cryptosporidium suis-like, has been reported in humans, domesticated ruminants, and wild rats worldwide and described under several names including Cryptosporidium suis-like, based on its close phylogenetic relationship to C. suis. Unlike C. suis, however, it has never been detected in pigs. In the present work, Cryptosporidium suis-like originating from wild brown rats was not infectious for piglets or calves but was infectious for laboratory brown rats, BALB/c mice, and Mongolian gerbils. The prepatent period was 4-5 days for all rodents. The patent period was longer for rats (>30 days) than other rodents (<20 days). None of the rodents developed clinical signs of infection. In all rodents, life cycle stages were detected in the colon by histology and electron microscopy. Oocysts were morphometrically similar to those of C. parvum and smaller than those of C. suis, measuring 5.20 × 4.94 m. Phylogenetic analyses of SSU, actin, and HSP70 gene sequences revealed Cryptosporidium suis-like to be genetically distinct from, C. suis, and other described species of Cryptosporidium. Morphological, genetic, and biological data support the establishment of Cryptosporidium suis-like as a new species, and we propose the name Cryptosporidium occultus sp. n.
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Origin and genetic diversity of Czech populations of critically endangered Spotted Fritillary
STAŠOVÁ, Petra
In my bachelor thesis I focused on a critically endangered species from the cosmopolitan family of Melitaeinae, the spotted fritillary (Melitaea didyma). In the Czech Republic, this species was considered as extinct from majority of its original distribution sites, but but new populations appeared in some Czech localities. The aim of my work was to find out if these populations are indigenous and to classify the Czech population as a subspecies.
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Molecular phylogeny and evolutionary trends in Hieracium (Asteraceae, Lactuceae)
Krak, Karol ; Fehrer, Judith (advisor) ; Zozomová, Judita (referee) ; Nieto Feliner, Gonzalo (referee)
The hawkweed subgenus Hieracium s. str. is notoriously known for its extreme morphological variability and variation in ploidy levels that is associated with differences in modes of reproduction. Extensive past hybridization is supposed for the subgenus, but recent hybridization was evidenced only in few cases. The subgenus attracts the attention of botanists already for more than a century. Therefore the species diversity is largely examined and the taxonomy of the subgenus is well elaborated, although several contradictory taxonomic concepts exist. However the relationships among the species are unknown and haven't been studied yet. The investigation of these relationships from a phylogenetic perspective using molecular approaches was the main aim of the presented thesis. Basic species (both diploid and polyploid), representing morphologically unique taxa, that are supposed to be the basic evolutionary units of the subgenus were studied. The sequences of two intergenic spacers of the cpDNA (trnT-trnL and trnV-ndhC) and the external transcribed spacer of the nuclear ribosomal DNA (nrDNA ETS) were analyzed. Moreover, three new low-copy nuclear markers with higher variability than nrDNA and cpDNA markers were developed and their suitability for phylogenetic studies in Hieracium s. str. was...
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Polyphasic approach to the taxonomy of selected cyanobacteria
MAREŠ, Jan
The modern taxonomic revision of cyanobacteria is a work in progress, with both theoretical and practical challenges to be addressed. This thesis investigated selected terrestrial cyanobacterial taxa using a polyphasic approach, based on molecular phylogenetic analysis and accompanied by phenotypic characterization and nomenclatural treatment. Diverse methodological approaches were used including optical and transmission electron microscopy, molecular analysis (DNA sequencing) of cyanobacterial strains, single cells and filaments, and phylogenetic analysis of multiple genomic loci. This study provided systematic revisions of individual cyanobacterial genera and the entire phylum, and suggestions for future study projects.
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Crenicichla hu, a new species of cichlid fish (Teleostei: Cichlidae) from the Paraná basin in Misiones, Argentina
PIÁLEK, Lubomír
A new species of Crenicichla Heckel, C. hu, is described from the arroyo Piray-Miní, a left-hand tributary of the río Paraná, Misiones province, Argentina. This new species is easily distinguished from its congeners by the dark coloration, a color pattern consisting of 7 to 9 black irregular blotches on the flank, and 47?54 scales in the E1 row. Adult females have dorsal fin with an irregular color pattern formed by wide black and white longitudinal stripes and blotches.
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