|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
|
Molecular aspects of interspecific hybridization of sturgeons related to polyploidy and in situ conservation
HAVELKA, Miloš
Sturgeons (Chondrostei: Acipenseriformes) display markedly disjunct distributions with a wide occurrence in the northern hemisphere. Their unique benthic specializations, conserved morphology, evolutionary age, the variation in their basic diadromous life history, and the large public interest due to their near extinction or critically endangered status make sturgeons and paddlefishes one of the most interesting group of vertebrates. In addition to that, ploidy diversity of Acipenseriformes possessing three ploidy groups having ~ 120 chromosomes, ~ 240 ? 270 chromosomes and ~ 360 chromosomes provides unique model for investigation of evolutionary processes which were going through the genome duplication events. Sturgeons are also notoriously known for their strong propensity to interspecific and intergeneric hybridization which can result in hybrids with various ploidy levels. All these facts make sturgeon genetics and cytogenetics a thriving but also complicated area for research. In the present work, the role of genome duplication and functional reduction evens in evolution of sturgeon species as well as sturgeons? ploidy levels and ploidy relationships among Acipenseriformes were investigated using molecular markers. In addition to that, clarification of origin of abnormal ploidy levels and observation of segregation pattern of microsatellite alleles in the course of hybridization of polyploid sturgeon species were included into this study. With regard to the all considerations and observations provided by this study we concluded that evolution of sturgeon species is still widely dynamic and ongoing process which might goes through the allopolyplodization as well as autopolyplidization events.
|
|
|
Genetic diversity of European greyling (Thymallus thymallus) in the Czech Republic based on mitochondrial DNA variation
HAVELKA, Miloš
Goal of this Thesis is the comparison of the Grayling˘s genetic diversity. The complete mitochondrial DNA (mtDNA) control region (1083 base pairs) and gene for cytochrom B (1076 base pairs) were sequenced in 147 European grayling (Thymallus thymallus), from 21 populations in Czech Republic, Slovakia and Bosnia. In samples, 17 haplotypes were detected with average haplotype diversity Hd = 0,5480 and genic differentiation (FST) from 0,001 to the 0.9341. The most common haplotype TH1 was detected in 92 samples. An inferred intraspecific phylogenetic tree revealed three well-separated clades. One clade was represented by Danubian haplotypes from Slovakia. Second highly divergent clade contained individuals from river Vrbas in Bosnia, and the last biggest clade included haplotypes of all three sea basins from Czech Republic. We suppose that the gained results will be later utilized to the choice of suitable conservation measures that will lead to stabilization of the state of ancestral population of this ever more rare species in our region.
|
|
| |
guest ::
RSS feed.