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Instytut Biologii Doświadczalnej im. Marcelego Nenckiego PAN
Contributor:Konopka, Witold (1975- ) : Supervisor ; Magalska, Adriana (1976- ) : Assistant supervisor
Publisher:Instytut Biologii Doświadczalnej im. M. Nenckiego PAN
Place of publishing: Date issued/created: Description:[4], 156 pages : illustrations ; 30 cm ; Bibliography ; Summary in English
Degree grantor:Instytut Biologii Doświadczalnej im. Marcelego Nenckiego PAN
Type of object: Abstract:In addition to genetic material and molecular machinery necessary for gene expression,cell nucleus contains multiple auxiliary structures that perform diverse functions. Thesestructures include very dynamic and functionally heterogeneous PML (promyelocyticleukemia) nuclear bodies. Their major and crucial constituent is the PML protein. PML nuclearbodies often co-localize with transcriptionally active chromatin and serve as a reservoir ofmultiple other nuclear proteins. Diverse functions of PML-binding partners place PML proteinand PML nuclear bodies at the crossroads of multiple cellular processes, which may beessential for proper animal brain function. The role of PML protein in the adult mouse brainhowever remains to be elucidated. PML expression varies across mouse brain regions and alsodepends on animal age. In adult mice, a relatively high PML expression is observed inhippocampus, a brain structure implicated in learning and memory formation.The main objective of the study described in this thesis was investigation of the role ofPML protein and PML nuclear bodies in shaping the morphology of nuclei of hippocampalneurons and maintaining cognitive abilities of adult mice. To this end, two transgenic animalmodels were generated and analyzed. The first model, with hippocampal PML overexpression,was obtained by introducing an additional PML gene copy be means of injection of AAVs asa gene-carrying viral vector. The second model, with hippocampal PML ablation (knock-out),was obtained using AAVs, which deployed gRNA for PML in a Cre-dependent CRISPR/Cas9system.To characterize spatial and procedural memory formation, operational memory, andanxiety threshold, several behavioral tests were performed within the IntelliCage system. Itwas demonstrated that hippocampal PML ablation impairs operational memory and lowers theanxiety threshold. It was also shown that neither PML ablation nor its overexpression affectspatial and procedural memory formation. Confocal image analysis revealed significantmorphological alteration of neurons’ nuclei and disrupted chromatin organization in the caseof PML overexpression, but not in the case of PML ablation. Histone post-translationalmodifications indicated that in the model with PML overexpression, transcriptionally activechromatin is more densely packed. Moreover, transcriptionally inactive chromatin displays anincreased share of modifications associated with constitutive gene inactivation at the expenseof decreased share of modifications associated with transient gene inactivation. Modulation ofPML level entails commensurate reduction or increase of the nuclear presence of DAXX,a PML partner involved in transcriptional activation of neuronal immediate early genes
Resource type: Detailed Resource Type: Source: Language: Language of abstract: Digitizing institution:Nencki Institute of Experimental Biology of the Polish Academy of Sciences
Original in:Library of the Nencki Institute of Experimental Biology PAS
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