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Chemical signals and reproductive processes of the house mouse (Mus musculus)
Černá, Martina
The aim of my thesis was to identify proteins involved in chemical communication and especially those that are involved in sexual signalling. Volatile chemical signals are transported with lipocalins in their beta-barrel structure to present their ligands to receptors or out of the body. Thus, I focused on the identification of these proteins in saliva and vaginal secretion of the house mouse using proteomic and transcriptomic approaches. Due to a cyclic manner of reproduction and its hormonal control, I have also focused on the role of estradiol on sperm phenotype in the laboratory mouse. We have identified an elevated sexual dimorphism in several lipocalins (i.e. 10 out of 20) in the saliva proteome where they may play a role in sexual signalling (i.e. similar to their described roles in the mouse urine). Interestingly, vaginal secretion also contains lipocalins and they rise from proestrus to estrus and remain steady during metestrus. Such variation provides evidence that they serve sexual signalling, however, due to their elevated levels during metestrus it is most likely that their ligands function as signals and not the proteins themselves. On the level of sperm phenotype, we have provided evidence, that experimental concentrations of estradiol have differential effects on sperm. This is due...
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Chemical signals and reproductive processes of the house mouse (Mus musculus)
Černá, Martina ; Stopka, Pavel (advisor) ; Petr, Jaroslav (referee) ; Sedláček, Radislav (referee)
The aim of my thesis was to identify proteins involved in chemical communication and especially those that are involved in sexual signalling. Volatile chemical signals are transported with lipocalins in their beta-barrel structure to present their ligands to receptors or out of the body. Thus, I focused on the identification of these proteins in saliva and vaginal secretion of the house mouse using proteomic and transcriptomic approaches. Due to a cyclic manner of reproduction and its hormonal control, I have also focused on the role of estradiol on sperm phenotype in the laboratory mouse. We have identified an elevated sexual dimorphism in several lipocalins (i.e. 10 out of 20) in the saliva proteome where they may play a role in sexual signalling (i.e. similar to their described roles in the mouse urine). Interestingly, vaginal secretion also contains lipocalins and they rise from proestrus to estrus and remain steady during metestrus. Such variation provides evidence that they serve sexual signalling, however, due to their elevated levels during metestrus it is most likely that their ligands function as signals and not the proteins themselves. On the level of sperm phenotype, we have provided evidence, that experimental concentrations of estradiol have differential effects on sperm. This is due...
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The influence of estrogens on mouse sperm capacitation and acrosome reaction in vitro
Tejnická, Magda ; Komrsková, Kateřina (advisor) ; Linhart, Otomar (referee)
There are an increasing amount of compounds in the environment that can have a negative effect on reproductive parameters in both male and female organism. There has been a worldwide decline of sperm quality during past decades and this fact lead to an increase of unnatural ways of conception through assisted reproduction techniques in the specialised centres. Natural estrogens are one of these compounds and they get into waste water after being excluded from the body by the urine. They get back into the human body from drinking water or from the food, and they can interfere with function of endogenous hormones in very low concentrations. For these reasons it is up to date to deal with the influence of these compounds on mammalian sperm. For many years, estrogens have been considered typically female sex hormones. It is now certain that they are also very important in the regulation of male reproduction. Endogenous estrogens in mammalian males are an important part of the endocrine system. Estrogens play an important role in the development of germ cells, spermatogenesis and processes leading to successful egg fertilization such as a capacitation or acrosomal reaction. Tyrosine phosphorylation is one of the essential steps for the properly ongoing process of capacitation in sperm followed by a...
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Dynamics of acrosome reaction during intra-specific sperm competition in rodents.
Veselá, Kateřina ; Hortová, Kateřina (advisor) ; Pěknicová, Jana (referee)
Dynamics of acrosome reaction during intra-specific sperm competition in rodents Sperm acrosome integrity is disturbed in promiscuous species field mice (Apodemus) and more than half of the spermatozoa undergoing spontaneous acrosome reaction (AR) before binding to the zona pellucida. In Muridae it is documented a generally high rate of spontaneous AR, and the percentage increases in promiscuous species up to 60 % in 60 min capacitation in vitro. The acrosome integrity positively corellates with presence of CD46 protein which absence in wood mouse is fenotypicaly same as in CD46 knock-out mouse leading to accelerated spontaneous AR. It is necessary to clarify whether for mouse sperm it is essential the primary binding of intact sperm to zona pellucida of the egg or whether it is preferred secondary sperm binding after spontaneous AR. In this context, the question is whether there is a relocalization of the key fusion protein IZUMO in sperm during spontaneous AR. IZUMO relocalization was monitored by immunofluorescence at specific times of capacitation in vitro during spontaneous and induced AR. IZUMO relocalization as closely connected to actin cytoskeleton, and β1 integrins. Dynamics and localization of β1 integrin during spontaneous and induced AR was also detected by immunofluorescence. Our results...
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