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Endogenous retroviral elements and their functions in the human genome
Famfulíková, Mirka ; Pačes, Jan (advisor) ; Lichá, Irena (referee)
In addition to the coding sequences, the human genome contains a so noncoding DNA, among which we count transposable elements capable of transposition in the genome. The remnants of the past retrovirus infections - endogenous retroviruses (human endogenous retroviruses - HERVs) belong to the transposable elements, which contain the LTR sequences. Human endogenous retroviruses make up to 8% of the size of the human genome. The retroviruses are not only passive relicts, but they have gained some key functions - too. They increase the plasticity of the human genome and some HERV LTRs can serve as binding sites for transcription factors like. Env protein from the families HERV-W and HERV- FRD were coopted by the human genome and are nowadays expressed as proteins Syncitin-1 and Syncitin-2, which are necessary by the forming of human placenta. Unfortunately, the HERV elements can have a negative health impacts. In the last decades they are subject of a debate in connection with various diseases, such as multiple sclerosis, schizophrenia, HIV proliferation and some types of tumorigenesis. The role of HERVs in the human genome is not completely known yet and it is important to continue with their research. Powered by TCPDF (www.tcpdf.org)
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Endogenous retroviral elements and their functions in the human genome
Famfulíková, Mirka ; Pačes, Jan (advisor) ; Lichá, Irena (referee)
In addition to the coding sequences, the human genome contains a so noncoding DNA, among which we count transposable elements capable of transposition in the genome. The remnants of the past retrovirus infections - endogenous retroviruses (human endogenous retroviruses - HERVs) belong to the transposable elements, which contain the LTR sequences. Human endogenous retroviruses make up to 8% of the size of the human genome. The retroviruses are not only passive relicts, but they have gained some key functions - too. They increase the plasticity of the human genome and some HERV LTRs can serve as binding sites for transcription factors like. Env protein from the families HERV-W and HERV- FRD were coopted by the human genome and are nowadays expressed as proteins Syncitin-1 and Syncitin-2, which are necessary by the forming of human placenta. Unfortunately, the HERV elements can have a negative health impacts. In the last decades they are subject of a debate in connection with various diseases, such as multiple sclerosis, schizophrenia, HIV proliferation and some types of tumorigenesis. The role of HERVs in the human genome is not completely known yet and it is important to continue with their research. Powered by TCPDF (www.tcpdf.org)
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Functional genome analysis using the retroviral integration sites permissive for provirus expression in human cells
Miklík, Dalibor ; Hejnar, Jiří (advisor) ; Španielová, Hana (referee)
The expression of retroviral genes depends on the establishment of the provirus - the DNA copy of retroviral genome integrated into the host genome. The transcriptional state of provirus is then influenced by the environment at the site of integration. The phenomenon of proviral silencing is an obstacle to the usage of retroviral vectors and a barrier to the eradication of human immunodeficiency virus type 1 (HIV-1) from infected individuals. Taking advantage of single cell clones bearing one provirus, this diploma thesis investigates the distribution of (epi)genomic features at the sites occupied by stably expressed proviruses. In total, long-term expression profiles of 245 and 255 clones carrying avian sarcoma-leucosis virus (ASLV) and HIV-1, respectively, were obtained. The database-based analysis of 42 integration sites of ASLV and three integration sites of HIV-1 proviruses shows that proviral stable expression highly correlates with the transcriptional start sites (TSS) at the sites of integration. Histone marks characteristic for the proximity of active TSSs and regulatory elements at the sites of integration of stably expressed proviruses confirm this finding. The results presented in this thesis could inspire other analyses investigating the relationship between the integration site and the...
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