National Repository of Grey Literature 72 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
Sexual dimorphism in the mouse olfactory system
Kuntová, Barbora ; Stopka, Pavel (advisor) ; Havlíček, Jan (referee) ; Žídek, Lukáš (referee)
Sexually dimorphic behaviour of the house mouse (Mus musculus musculus) relies on various physical and chemical cues, however, chemical signals are the most essential cues for individual recognition and in causing various priming effects on reproductive behaviour of the receiver. House mice belong to macrosmatic mammals, and thus, their sense of smell is highly developed and is able to recognize a wide spectrum of ligands from other individuals and from their surrounding environment. Volatile signals belong to organic compounds that are produced by most tissues, and may have harmfull effects on cells, and thus they are transported out of the body with lipocalin transporters where some of them may function as signals. These volatile signals are able to stimulate chemosensory neuronal receptors, and thus, yield particular responses in neural circuits. The ligand sensing has a differential effect upon males and females, however, it has not been shown yet in wild mice whether these differences are also caused by the variation in receptors and neural processing, or rather by differential expression of signals typical for each sex. The aim of this thesis was to perform comparative analysis of orofacial mucosal tissues to determine the specificity of expression of particular lipocalins. For the first time...
Evolution of olfactory receptors
Klempt, Petr ; Stopka, Pavel (advisor) ; Vinkler, Michal (referee)
This bachelor thesis deals with the largest gene family of mammals which encode olfactory receptors. Olfactory receptors fall in rhodopsin-like GPCRs subfamily, approximately 600 - 800 millions of years old. At least from this time, olfactory receptors play, as a part of one of the oldest senses (smell), fundamental role in detection of chemical cues from water or air. This work summarizes large repertoire of olfactory receptors and its changes during the evolution of important animal taxons with emphasis on number and fraction of functional and nonfunctional olfactory receptor genes. Those values are part of criteria used for olfactory ability of animals. Olfactory receptors are typically placed on surface of sensory neuron placed in olfactory epithelium, where they bind various odorants and triggers signal cascade which leads to neuron's membrane depolarization. Therefore, about one half of this work summarizes knowledge of olfactory receptor's molecular biology like their structure, main parts of signal cascade (Gαolf, ACIII, CNG channel, Ca2+ dependent Cl- channel) just as parts needed for steady-state establishment. Expression of olfactory receptors detected in amount of non-olfactory tissues (mussels, sperm, brain etc.), indicate possibly important biomedical roles of this receptors.
Sperm acrosomal reactien in selected species of mammals
Frolíková, Michaela ; Stopka, Pavel (advisor) ; Jonáková, Věra (referee) ; Petr, Jaroslav (referee)
Mammalian sperm must undergo the process of capacitation - series of physiological and biochemical modifications prior fertilization. In last stage of capacitation sperm undergoes acrosome reaction (AR). During AR the cell membrane of the sperm fuses with the outer acrosomal membrane and the contents of acrosomal vesicle are released into extracellular space. Sperm which did not undergo AR or sperm missing acrosome at all are unable to fertilize. AR results into dramatical changes in the sperm head. Most of the proteins present in plasmatic and outer acrosomal membrane are reorganized or lost. There are also significant changes in cytoskeletal and intraacrosomal proteins are released to extracellular space uncovering new surface domains. Some sperms undergo AR even without presence of inductor of AR during capacitation in vitro. This event is called spontaneous (accelerated) AR. The latest research indicates that spontaneous AR is natural part of the process of fertilization. Field mice (Apodemus) show high level of promiscuity leading to significant risk of sperm competition. Unique reproduction strategy where the sperms form so-called sperm trains was evolved in field mice. Spontaneous AR is probably enabling the dissociation of sperms from the sperm train. The spontaneous AR rate is dependent on...
The role of Toxoplasma gondii on the expression of Major Urinary Proteins in the house mouse
Hladovcová, Denisa ; Stopka, Pavel (advisor) ; Hrdý, Ivan (referee)
Major Urinary Proteins (MUP) are pheromonal transmitters involved in chemical communication in rodents. Complexes of MUPs and ligands mediate information about genetical background of an individual and co-create individual scent profile. They play a significant role in kinship determination, the crucial factor in the choice of a mating partner. It is assumed that the MUP production is energetically demanding due to the pressure of sexual selection, and the transmitted signal is thus supposed to be honest. This theory hasn't yet been experimentally tested, neither was proven the effect of another intense selection pressure- a parasitic infection. In my thesis, I describe the effect of an infection of a parasite Toxoplasma gondii on MUP production. The results suggest that the production is altered in both sexes, the production decreasing in males to the level of male castrates (or the female level). Considering the results of more detailed analysis of the infection we assume that the energetical demands of the MUP production doesn't allow the production of ordinary amounts if MUPs during the first phase of the infection as the energy is primarily devoted to the infection control. The increased production in latter phase can be attributed to the importance of scent communication. Decreased levels of...
Social communication in the house mouse (Mus musculus)
Černá, Zuzana ; Stopka, Pavel (advisor) ; Havlíček, Jan (referee)
Chemical communication is the most important way of communication in the house mouse. Traditionally, the urine of the house mouse was the most studied source of signals. Typical way of scent marking, relatively simple way of collection and analysis was the main reason. The analysis of physical interaction of two mouse conspecifics has shown that there are several other very important sources of chemical signals. My ethological analysis has revealed that during the first interaction of two individuals of opposite sex, the most investigated body part is the orofacial region, and that the oral contact with salivary exchange is very frequent. At the same time, the results of this research have demonstrated the significant influence of reproductive status on behavioural patterns in individuals of both sex. One of these important sources of chemical signals is the saliva. During the interaction between two individuals, saliva is actively investigated by sniffing and physically exchanged. Gas chromatography and mass spectrometry (GC-MS) was used for chemical analysis of saliva. It has revealed that saliva is a sexually dimorphic signal, which may represent individual odour profiles. Uniqueness of this odour is not based on the presence of special substances typical just for one sex, unique is the blend,...
Deciphering the biological role of Ddi1-like protein family
Sivá, Monika ; Grantz Šašková, Klára (advisor) ; Bařinka, Cyril (referee) ; Stopka, Pavel (referee)
Ddi1-like protein family has been recently raised into the spotlight by the scientific community due to its important roles in cellular homeostasis maintenance. It represents a specific group among shuttling proteins of the ubiquitin-proteasome system. When compared to other shuttles, Ddi1-like protein family members harbor a unique retroviral-protease like domain besides the conventional ubiquitin-like (UBL) domain and domains interacting with ubiquitin. In addition, a helical domain of Ddi (HDD) has been recently found in most of the orthologs. In this thesis, I focus on characterization of several members of Ddi1-like protein family, both on molecular level using NMR and in model mouse strains via a variety of biological methods. Solution structure of the UBL domain of Ddi1p of S. cerevisiae was solved and its characteristics were compared to those of the UBL domain of its human ortholog. Furthermore, we show that human DDI2 specifically binds to ubiquitin with its terminal domains, both the UBL and the UIM; however, with very low affinity in contrast to binding properties of its yeast counterpart. Our study also show that hDDI2 does not form a head-to-tail homodimer. Based on our structural studies, we hypothesize that human DDI2 might have evolved a different function compared to its yeast...
Generation and analysis of mutant mouse models to study pathophysiological roles of KLK5 and KLK7 in epidermis
Kašpárek, Petr ; Sedláček, Radislav (advisor) ; Stopka, Pavel (referee) ; Machoň, Ondřej (referee)
Kallikrein-related peptidases (KLKs) constitute a family of closely related serine proteases encoded by genes clustered in one chromosomal locus. KLKs are widely expressed in a variety of tissues and numerous in vitro experiments suggest their important roles in many physiological and pathological processes. However, the biological roles of KLKs in vivo are often obscured mainly due to unavailability of suitable animal models. Although gene deficient mouse models were generated for several KLK genes, they had limited use for understanding the roles of individual proteases in the complex environment in vivo. One of the main obstacles which hampers in vivo analysis is partial functional overlap between some KLKs. This makes traditional single-gene deficient animal models an inadequate tool to address the biological impact of the gene deficiency as compensatory mechanisms often result in a lack of phenotype. In this work, we used the transcription activator-like effector nuclease (TALEN) technology to generate several novel mutant mouse models to study the complex KLK proteolytic pathways and their roles in healthy organism and in disease. We prepared a novel mouse model for Netherton syndrome (NS), an autosomal recessive skin disorder caused by mutation in the gene SPINK5, which encodes the KLK-inhibitor...

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