National Repository of Grey Literature 61 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Melanism in free living vertebrates
Slavíková, Ema ; Munclinger, Pavel (advisor) ; Exnerová, Alice (referee)
Melanism is an over-development of melanin in the skin and its cover that is described in a large number of species in vertebrates. Increasing number of studies observing melanistic traits in animal species tends to reveal genetical, physiological and behavioural characteristics associated with dark pigmentation. This bachelor thesis briefly summarizes knowledge about occurrence and characteristics of melanistic animals associated with their specific pigmentation. Presented are rules and theories associated with melanism in vertebrates, e.g., melanocortin theory, thermal hypothesis and Gloger's rule.
Evolution of endemism of mountain animal species
Švihálková, Tereza ; Munclinger, Pavel (advisor) ; Hořák, David (referee)
The mountain islands, isolated habitats surrounded by a distinct lowland environment, are home to a variety of endemic animal species. These hot-spots of biodiversity and endemism can be found mainly in tropical areas. Thus, the occurrence of endemics partially corresponds to the general macro-ecological rules of biogeography. For a more specific explanation of the origin and evolution of mountain animal species, we usually proceed from two theories - vicariate and dispersion. The validity of these theories varies in relation to taxon, locality, and evolutionary past, so it is difficult to generalize them globally. This bachelor thesis summarizes the prerequisites for the occurrence of endemic species and knowledge from some world- important mountain localities with a large number of endemic animals.
B2 insertions in mouse population genetics
Kubešová, Lenka ; Munclinger, Pavel (advisor) ; Macholán, Miloš (referee)
1. Prolog Nejvíce zkoumaným savcem (s výjimkou člověka) je drobný živočich, všemi velice dobře známý a provázející člověka odnepaměti. Je to domácí myš. Narozdíl od obrovského množství poznatků o inbredních kmenech myší kupodivu doposud stále víme poměrně málo o jejich blízkých příbuzných - volně žijících domácích myších. Zvláště chybí data o genetické struktuře populací na vyšší škále (na úrovni celých kontinentů). Na této škále se v současné době pro studium populační genetiky využívá převážně mitochondriální DNA (mtDNA) díky svým unikátním vlastnostem (jednoduše izolovatelná, nerekombinující, až na vzácné vyjímky uniparetálně děděná a u obratlovců rychle se vyvíjející). Pro zjevné limitace mtDNA jako markeru (jedná se jen o maličký kus genomu navíc vypovídající jen o mateřském původu) a nejednoznačným výsledkům vyvstává potřeba nalézt pro studium populační genetiky myší vhodné markery z jiných částí genomu. Nejvhodnější možností se jeví být markery založené na SINE elementech. SINE (short interspersed elements) jsou úseky DNA, které se nacházejí v genomech obratlovců (běžně se vyskytující u savců, zejména primátů, hlodavců a kopytníků) ve vysokém počtu navzájem si podobných kopií rozmístěných na různých místech genomu. SINE elementy mají jako markery pro populační genetiku několik výhod. Jejich hlavními...
Recently active L1 and B1 retrotransposons in the mouse genome
Janoušek, Václav ; Munclinger, Pavel (advisor) ; Bryja, Josef (referee)
The work focuses on two recently active retrotransposon families in the house mouse genome. They are L1 and B1 retrotransposons. The aim of the work was to find polymorphic retrotransposon insertions caused by their recent activity. Two genomes of mouse inbred strains derived from the different house mouse subspecies were compared. The BACends from MSM/Ms derived from M. m. molossinus were compared with the reference genome of C57BL/6J derived mostly from M. m. domesticus. The set of output insertions was classified into several subfamilies of B1 a L1 families. The presence/absence of these insertions was tested using PCR in all three house mouse subspecies and also in two sister species (M. spretus and M. macedonicus). The particular subfamilies differed with regard to presence in latter species. Despite the supposed lack of activity of older L1 families (F2 and F3) they persist in house mouse population as an ancestral polymorphism. Unlike L1 subfamilies, B1 subfamilies appear to be active in house mouse genome for longer period of time. Also the difference between the whole families L1 and B1was observed. Thus, according to my data L1 family seems to be recently more active than B1 family.
Genetic conflicts and speciation
Kropáčková, Lucie ; Reifová, Radka (advisor) ; Munclinger, Pavel (referee)
In this thesis I'll examine the role of genetic conflicts in the origin of new species. Genetic conflicts can lead to an origin of reproductive barrier between the emerging species, especially postzygotic reproductive isolation. An example of such conflict could be meiotic drive on sex chromosomes, which distort sex ratio and seems to act a role in a hybrid male sterility. Another example may be genomic imprinting causing an abnormal placenta and embryo development in interspecies hybrids. Coevolution between cytoplasmic and nuclear genes can cause sterility of pollen in hybrids from plants. Similarly, the intracellular bacterium Wolbachia induces cytoplasmic incompatibility in animals. Mobilization of transposons may also lead to hybrid dysgenesis.
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...
Y chromosome in the mouse hybrid zone
Rubík, Pavel ; Munclinger, Pavel (advisor) ; Zemanová, Barbora (referee)
The contact zone between subspecies of house mouse Mus musculus musculus and Mus musculus domesticus is one of the most intensively studied hybrid zones. It is also due to extensive introgression of the Y chromosome of M. m. musculus subspecies to the genetic background of M. m. domesticus. One theory of the origin of the introgression explains it by intragenomic conflict between the sexes. With a set of variable microsatellite markers on the Y chromosome, I have examined the validity of this theory by simple approaches revealing the history of the introgression area. It turned out that overly big variability of our markers makes the revelation of this theory impossible. Our markers have been found suitable for use in the analysis of population structure of house mouse. Thanks to them, we can identify migrants between localities and estimate the level of closeness of the population structure in relation to migrants from the neighborhood. Populations in our analysis proved to be relatively closed and resistant to the influx of migrants. Despite the conclusions of previous research where the dispersion of males ran up to one kilometer, I have discovered a relatively large number of migrations to a distance of thirty kilometers. Keywords Mus musculus musculus, Mus musculus domesticus, Y chromosome,...
Genomic imprinting and evolution of sexually dimorphic traits
Farkačová, Klára ; Kratochvíl, Lukáš (advisor) ; Munclinger, Pavel (referee)
Genomic imprinting is a process whereby expression of an allele differs depending upon its parent of origin. It can be found on autosomes and also on sex chromosomes. Basic hypothesis for the evolution of genomic imprinting is the hypothesis based on the existence of sexual conflict. It can be classified into interlocus sexual conflict and intralocus sexual conflict hypotheses. Under interlocus sexual conflict hypothesis we can diffferentiate parental conflict hypothesis and parent-offspring conflict hypothesis. These theories were historically proposed for the first two taxonomical groups, where genomic imprinting was discovered, namely for angiosperms and placental mammals. Theory of parental conflict proposes that genomic imprinting evolved because the paternally inherited alleles are more selfish to mothers than are the maternally inherited alleles. Parent-offspring conflict hypothesis proposes that genomic imprinting evolved because maternal genes try to regulate demands of paternally inherited alleles in embryos. More recently, genomic imprinting has been found also in other taxons and in alleles, which do not bring any advantage during embryonic development. The intralocus sexual conflict hypothesis is applicable for every trait under sexually-specific selection. It provides potential...

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