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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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The significance of the parental origin of the affected chromosome in the development of microdeletion syndromes
Rašpličková, Tereza ; Šolc, Roman (advisor) ; Novotná, Drahuše (referee)
Microdeletion syndromes are complex diseases caused by loss of genetic information resulting from cryptic deletions which are smaller than 5 Mb. They are cause a large number of phenotypic features. Most common are developmental and mental retardations, various physical defects and abnormalities or behavior problems. It has been shown, that in some cases plays a role parental origin of affected chromosome in microdeletion syndrome. In Angelman, Prader-Willi and Beckwith-Wiedemann syndromes is unequal disability of chromosomes caused by genomic imprinting. The reasons for dominance disability of one parental chromosome in Cri du chat syndrome, monosomy 1p36 and Phelan-McDermid syndrome are different and the effect of genomic imprinting has not been confirmed. Key words: microdeletion, microdeletion syndromes, methylation, genomic imprinting
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Epigenetics mechanisms
Šornová, Veronika ; Černá, Marie (advisor) ; Koc, Michal (referee)
Epigenetics is the study of heritable changes in gene activities that are not caused by changes in the DNA sequence. Epigenetic mechanisms can be employed at many levels, from transcription to translation. They include DNA methylation, histone modification, and with it connected chromatin modification, and RNA interference. The result is the change of chromatin conformation leading to decrease or increase of certain gene expression, X-chromosome inactivation or gene imprinting. Epigenetic regulation plays important role in etiopatogenesis of multifactorial diseases. Genetic predisposing factors (in autoimmune diseases there are genes of major histocompatibility complex) and environmental factors, which affect our genome just through epigenetic modifications, are involved in their manifestation. Key words: Epigenetic mechanisms, DNA methylation, histone modification, RNA interference, genomic imprinting, X-chromosome inactivation, multifactorial disease.
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The significance of the parental origin of the affected chromosome in the development of microdeletion syndromes
Rašpličková, Tereza ; Šolc, Roman (advisor) ; Novotná, Drahuše (referee)
Microdeletion syndromes are complex diseases caused by loss of genetic information resulting from cryptic deletions which are smaller than 5 Mb. They are cause a large number of phenotypic features. Most common are developmental and mental retardations, various physical defects and abnormalities or behavior problems. It has been shown, that in some cases plays a role parental origin of affected chromosome in microdeletion syndrome. In Angelman, Prader-Willi and Beckwith-Wiedemann syndromes is unequal disability of chromosomes caused by genomic imprinting. The reasons for dominance disability of one parental chromosome in Cri du chat syndrome, monosomy 1p36 and Phelan-McDermid syndrome are different and the effect of genomic imprinting has not been confirmed. Key words: microdeletion, microdeletion syndromes, methylation, genomic imprinting
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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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Genomic imprinting
Vyskot, Boris
Genomic imprinting represents an epigenetic marking of genes that results in their monoallelic expression, namely in mammals and flowering plants. Here, I also summarize our recent experiments describing the role of DNA methylation and histone H4 acetylation in plant reproductive development.
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