Genetická struktura perlooček druhového komplexu Daphnia longispina v evropských horských jezerech

I studied the genetic structure of cladocerans from the Daphnia longispina complex in several European mountain ranges. The population genetic structure of the D. longispina complex was studied using mitochondrial (mtDNA; partial sequencing of the 12S rRNA gene) and nuclear markers (nine microsatellite loci). Major part of the work was done in the Tatra Mountains; the genetic structure of populations of the Daphnia longispina complex from two parts of this range (the West and the High Tatras) was compared. The pattern of mtDNA confirmed multiple colonization of lakes from different source populations, detected haplotype diversity was high and haplotype sharing only within the West or the High Tatras was observed. The observed genetic differentiation indicates low level of gene flow and persistent founder effect, consistent with the monopolization hypothesis. The alternation of asexual and sexual reproduction in the life cycle of Daphnia, cyclical parthenogenesis, may affect genetic structure of their populations. This was the topic of a study described in the first chapter. A detailed analysis of population structure of two closely related Daphnia species (D. galeata and D. longispina) living in similar habitats (permanent dimictic mountain lakes) in the Tatra Mountains revealed that populations...(in Czech) Genetická struktura perlooček druhového komplexu Daphnia longispina v evropských horských jezerech Ve své práci jsem se zabývala genetickou strukturou populací perlooček z druhového komplexu Daphnia longispina v horských jezerech. Populace perlooček D. longispina a D. galeata byly analyzovány mitochondriálními (část genu pro 12S rRNA) a jadernými markery (devět mikrosatelitových lokusů). Většina práce byla provedena v Tatrách, kde jsem porovnávala genetickou strukturu populací komplexu D. longispina, a to mezi dvěma částmi pohoří: Západními a Vysokými Tatrami. Dle variability mitochondriální DNA byla jezera kolonizována z různých zdrojových populací, zjištěná haplotypová diverzita byla vysoká a sdílení haplotypů bylo pouze v rámci Západních nebo Vysokých Tater. Tato pozorovaná genetická odlišnost mezi dvěma částmi pohoří naznačuje nízký genový tok a přetrvávající efekt zakladatele, což je v souladu s monopolizační hypotézou vysvětlující zdánlivý rozpor mezi značnou schopností disperze, ale zároveň značnými genetickými odlišnostmi mezi populacemi planktonních živočichů. Cyklická partenogeneze, tj. střídání pohlavního a nepohlavního rozmnožování během životního cyklu perlooček, může ovlivnit genetickou strukturu jejich populací. V první kapitole je popsán vliv strategie rozmnožování během...Department of EcologyKatedra ekologieFaculty of SciencePřírodovědecká fakult

Strong differences in the clonal variation of two Daphnia species from mountain lakes affected by overwintering strategy

<p>Abstract</p> <p>Background</p> <p>The population structure of cyclical parthenogens such as water fleas is strongly influenced by the frequency of alternations between sexual and asexual (parthenogenetic) reproduction, which may differ among populations and species. We studied genetic variation within six populations of two closely related species of water fleas of the genus <it>Daphnia </it>(Crustacea, Cladocera). <it>D. galeata </it>and <it>D. longispina </it>both occur in lakes in the Tatra Mountains (Central Europe), but their populations show distinct life history strategies in that region. In three studied lakes inhabited by <it>D. galeata</it>, daphnids overwinter under the ice as adult females. In contrast, in lakes inhabited by <it>D. longispina</it>, populations apparently disappear from the water column and overwinter as dormant eggs in lake sediments. We investigated to what extent these different strategies lead to differences in the clonal composition of late summer populations.</p> <p>Results</p> <p>Analysis of genetic variation at nine microsatellite loci revealed that clonal richness (expressed as the proportion of different multilocus genotypes, MLGs, in the whole analysed sample) consistently differed between the two studied species. In the three <it>D. longispina </it>populations, very high clonal richness was found (MLG/N ranging from 0.97 to 1.00), whereas in <it>D. galeata </it>it was much lower (0.05 to 0.50). The dominant MLGs in all <it>D. galeata </it>populations were heterozygous at five or more loci, suggesting that such individuals all represented the same clonal lineages rather than insufficiently resolved groups of different clones.</p> <p>Conclusions</p> <p>The low clonal diversities and significant deviations from Hardy-Weinberg equilibrium in <it>D. galeata </it>populations were likely a consequence of strong clonal erosion over extended periods of time (several years or even decades) and the limited influence of sexual reproduction. Our data reveal that populations of closely related <it>Daphnia </it>species living in relatively similar habitats (permanent, oligotrophic mountain lakes) within the same region may show strikingly different genetic structures, which most likely depend on their reproductive strategy during unfavourable periods. We assume that similar impacts of life history on population structures are also relevant for other cyclical parthenogen groups. In extreme cases, prolonged clonal erosion may result in the dominance of a single clone within a population, which might limit its microevolutionary potential if selection pressures suddenly change.</p

Genetic structure of the Daphnia longispina complex in European mountain lakes

I studied the genetic structure of cladocerans from the Daphnia longispina complex in several European mountain ranges. The population genetic structure of the D. longispina complex was studied using mitochondrial (mtDNA; partial sequencing of the 12S rRNA gene) and nuclear markers (nine microsatellite loci). Major part of the work was done in the Tatra Mountains; the genetic structure of populations of the Daphnia longispina complex from two parts of this range (the West and the High Tatras) was compared. The pattern of mtDNA confirmed multiple colonization of lakes from different source populations, detected haplotype diversity was high and haplotype sharing only within the West or the High Tatras was observed. The observed genetic differentiation indicates low level of gene flow and persistent founder effect, consistent with the monopolization hypothesis. The alternation of asexual and sexual reproduction in the life cycle of Daphnia, cyclical parthenogenesis, may affect genetic structure of their populations. This was the topic of a study described in the first chapter. A detailed analysis of population structure of two closely related Daphnia species (D. galeata and D. longispina) living in similar habitats (permanent dimictic mountain lakes) in the Tatra Mountains revealed that populations..

Ecological performance of two invasive cladocerans Daphnia ambigua and Daphnia parvula

Katedra ekologieDepartment of EcologyPřírodovědecká fakultaFaculty of Scienc

Valuation of company in a meat industry company

Tato diplomová práce se zabývá oceněním vybraného podniku. Cílem práce je vhodně zvolenými metodami zjistit tržní hodnotu podniku k datu 31. 12. 2018. Teoretická část vymezuje základní postupy při oceňování a metody používané k ocenění podniku. Praktická část je aplikována na společnost Krahulík-MASOZÁVOD Krahulčí, a.s., která se zabývá zpracováním masa a výrobou masných výrobků. V úvodu jsou popsány základní charakteristiky podniku, následně je provedena strategická a finanční analýza. Výsledky předchozích analýz jsou využity k sestavení finančního plánu, který je klíčový pro stanovení hodnoty metodou EVA. Výstupem práce je hodnota podniku zjištěná metodou EVA entity k 31. 12. 2018, která je porovnána s účetní hodnotou a hodnotou stanovenou za pomoci odvětvových multiplikátorů.This master´s thesis deals with the valuation of a selected company. The aim of the thesis is to determine the market value of the company by appropriately chosen methods as of 31 December 2018. The theoretical part defines the basic valuation procedures and methods used to value the company. The practical part is applied to the company Krahulík-MASOZÁVOD Krahulčí, a.s., which deals with meat processing and production of meat products. The introduction describes the basic characteristics of the company, then a strategic and financial analysis is carried out. The results of previous analyzes are used to compile a financial plan, which is key to determining the company value using the EVA method. The output of the thesis is the value of the company determined by the EVA entity method as of 31 December 2018, which is compared with the accounting value and the valuation using multiplies by industry sector

Genetic structure of the Daphnia longispina complex in European mountain lakes

I studied the genetic structure of cladocerans from the Daphnia longispina complex in several European mountain ranges. The population genetic structure of the D. longispina complex was studied using mitochondrial (mtDNA; partial sequencing of the 12S rRNA gene) and nuclear markers (nine microsatellite loci). Major part of the work was done in the Tatra Mountains; the genetic structure of populations of the Daphnia longispina complex from two parts of this range (the West and the High Tatras) was compared. The pattern of mtDNA confirmed multiple colonization of lakes from different source populations, detected haplotype diversity was high and haplotype sharing only within the West or the High Tatras was observed. The observed genetic differentiation indicates low level of gene flow and persistent founder effect, consistent with the monopolization hypothesis. The alternation of asexual and sexual reproduction in the life cycle of Daphnia, cyclical parthenogenesis, may affect genetic structure of their populations. This was the topic of a study described in the first chapter. A detailed analysis of population structure of two closely related Daphnia species (D. galeata and D. longispina) living in similar habitats (permanent dimictic mountain lakes) in the Tatra Mountains revealed that populations..

Data from: Local and regional founder effects in lake zooplankton persist after thousands of years despite high dispersal potential

We reconstructed the genetic structure of a planktonic crustacean Daphnia longispina living in high mountain lakes and ponds in the Pyrenees to investigate whether it was shaped by persistent founder effects originating shortly after the last glacial maximum or by ongoing dispersal and effective migration (gene flow). We found that the genetic structure can largely be explained by a single colonization event following gradual deglaciation of the Pyrenees c. 10-15 000 years ago. Nuclear genetic diversity declined steeply from southeast to northwest, suggestive of serial colonization of available habitats with advancing deglaciation. The spatial genetic structure suggests that founder effects were major determinants of the present-day diversity, both at the catchment level and at the level of individual water bodies, further supporting extremely low effective migration rates. This study reveals a prime example of a founder effect that is both long-lasting and maintained at small spatial scales. Our data suggest a process of isolation by colonisation as a result of strong priority effects and monopolisation. We found evidence for the spread of haplotypes with Pyrenean ancestry across the Palearctic over distances up to 5500 km, although the local genetic structure after colonization was hardly influenced by contemporary dispersal. Finally, our data also suggest that mitochondrial mutation rates in the studied populations were seven times higher than typically assumed. Overall, we show that founder effects can persist for centuries even at small spatial scales at which the potential for dispersal is high

Ventura et al - Pyrenees- New Haplotypes

fasta file showing the alignment of the partial sequence of the 12S mtDNA gene. Individual ID and correspondent GenBank accession number are show

Ventura-Microsats-Pyrenees

Microsatellite genotyping results. Twenty five populations distributed at regional scale in the Eastern Pyrenees (Catalonia) were used for this analysis. Individual ID and sample location are shown