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Reproductive isolation barriers in the hybrid zone of the house mouse (Mus musculus)
Albrechtová, Jana ; Piálek, Jaroslav (advisor) ; Sedláček, František (referee) ; Reifová, Radka (referee)
Reproductive isolation occurring at the gamete level is called gametic isolation and almost always prevents gene flow between unrelated species and (to some extent) between closely related species or subspecies. The hybrid zone of the house mouse (HMHZ), which was formed by contact and interbreeding of two subspecies, the Western European house mouse (M. m. domesticus) and the Eastern European house mouse (M. m. musculus) provides a usefull model for the study of speciation processes involving gametic isolation. The probability of sperm competition within the female reproductive tract is high in the house mouse because high levels of sexual promiscuity (in 20˗40 % of all reproductive cycles) have been observed in this species. Thus, the reproductive isolation at gametic level may be determined both by the phenotypic characteristics of sperm (the ability to outcompete heterospecific sperm in the process of sperm- sperm competition) and by the preference of the sperm of conspecific males in the female reproductive tract (cryptic female choice). In my Ph.D. thesis I tested the degree of affinity of male and female gametes reciprocally between the both subspecies of M. musculus and the phylogenetically more distant species M. spretus, which is characterized by a higher degree of promiscuity. Although a...
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Phylogenetic relationships and evolution of the genus Acomys (Rodentia: Muridae)
Palupčíková, Klára ; Frynta, Daniel (advisor) ; Sedláček, František (referee) ; Mazoch, Vladimír (referee)
The geographical distribution and phylogeny of the spiny mice of the genus Acomys Geoffroy I., 1838 remains a controversial and open topic. This doctoral thesis deals with the intraspecific structure and geographical distribution of the genus Acomys from the northern, eastern, central and southern parts of Africa, the Mediterranean islands of Cyprus and Crete, the Turkish coast, the Arabian and Sinai Peninsula and Iran, using molecular analyzes. Molecular analyzes were based on both the mitochondrial gene sequences of the D-loop genes (publication I.) and cytochrome b, as well as the nuclear sequences of the Intraretinal Binding Protein gene (IRBP) (publication IV) and recombinant activation gene 1 (RAG1) (publication II.). Furthermore, the data were subjected to phylogenetic analyzes using the Maximum Probability, Bayesian, Maximum Parsimony, and Minimum Evolution analysis. The results of mentioned analyses confirmed that the Afro-Mediterranean Acomys cahirinus and Asian Acomys dimidiatus are clearly separated. The large similarity between the haplotypes of continental Africa and the northern Mediterranean (A. cahirinus sensu stricto) supports the hypothesis that the ancestors of A. nesiotes, A. cilicicus and A. minous are very likely to spread as commensal populations, thereby challenging their...
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Preferences and characteristics of movement in a horizontal and vertical dimension in the black rat (Rattus rattus)
Skalíková, Hana ; Frynta, Daniel (advisor) ; Sedláček, František (referee)
The black rat (Rattus rattus) has been one of the most widespread and economically important rodent pests for centuries. Yet, it is a neglected species in research, so we still do not know much about its ecology and behaviour. The aim of this thesis is to characterize the exploratory behavior of the black rat in a three-dimensional environment. The results of this thesis showed that the black rat, when presented with a choice between vertical and horizontal space, prefers to stay in vertical space at one of the upper height levels. We are thus inclined to think of the rat as a semi-arboreal species with a strong willingness to climb. Also, four exploratory strategies were identified in this work, some of which can be compared to fast and slow exploratory strategies. This work also proposed and tested an experimental design that is suitable for testing the exploration of a vertically active species such as the black rat. Keywords: the black rat, three-dimensional environment, preferences, exploration, exploratory strategies
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Factors affecting behaviour of avian predators to hoverflies (Syrphidae) and their models (Aculeata)
Truhlářová, Marie ; Exnerová, Alice (advisor) ; Sedláček, František (referee)
Batesian mimicry is an antipredator strategy used by harmless species to mimic dangerous models by their appearance. The so-called imperfect mimics are a phenomenon within Batesian mimicry. It would be expected that Batesian mimics are selected to resemble the model as perfectly as possible. However, in some species the resemblance is very poor. The aim of this study was to test reaction of predators towards a textbook example of Batesian mimics with imperfect mimicry, i.e., hoverflies (Syrphidae) and to verify some of the hypotheses describing imperfect mimicry. We conducted two experiments in which the model predators were great tits (Parus major). The topic of the first experiment was the effect of diversity of models on categorization and generalization of hoverflies. Birds were divided into two groups, with the first group receiving high diversity of models (10 species of Hymenoptera) and second group receiving low diversity of models (2 species of Hymenoptera). There were two parts of this experiment. Categorization training when great tits learn to discriminate between two categories of prey, palatable and unpalatable and generalization test, when great tits generalized their experience from categorization training to novel prey. Palatable prey was represented by non-mimetic flies (Diptera),...
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Lachrymal secretion in tenrecs: physiological, behavioral and phylogenetic contexts (Tenrecinae, Afrosoricida)
Bálek, Jiří ; Horáček, Ivan (advisor) ; Sedláček, František (referee)
The secretion of white liquid around the eyes and nose with a spiny tenrecs Echinops telfairi and Setifer setosus mentions for the first time Poduschka in 1974, but until now this phenomenon in these species no one paid any detail. Similar secretion was described in Mountain beaver or by shrews. The impetus for shedding the excitement caused by the presence of an individual female or another male or its odor. Males secretions also used for marking territory. A total of 70 samples of eye secretions from ten male Echinops telfairi during the entire active season (from March to October) have been collected within this study. For protein detection method was used two-dimensional polyacrylamide gel electrophoresis (2D PAGE) and subsequent identification by mass spectrometry. An autopsy of the eye area was performed for representatives of all four genera of the subfamily Tenrecinae (Tenrec, Setifer, Echinops, Hemicentetes), died in Pilsen Zoo. It was found that a) species of pinholes that produce ocular secretions are significantly higher tear and Harder's gland, b) secretions contain lipocalins - proteins with the ability to transmit pheromones and other hydrophobic molecules, c) secretions of the orbital region having a different composition than the secretions from the nasal area (significantly lower protein...
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A test of "object permanence" in Paridae and effect of neophobia and individual explorative strategies on success in solving object permanence tasks
Marhounová, Lucie ; Landová, Eva (advisor) ; Sedláček, František (referee)
Object permanence (OP) is a cognitive ability that enables animals to mentally represent the existence of hidden objects even if they can not be perceived by senses. In humans, OP develops during six qualitative stages, in which the understanding of relationships between objects in space and time changes. Current research shows that primates, some carnivores and several species of birds also acquire various degrees of this ability depending on their social life and foraging strategies. Many studies of OP have focused on food-storing birds but yet only in the Corvidae family. Therefore we decided to test this ability in two species of the Paridae family, food-storing coal tit (Periparus ater, N=23) and non-storing great tit (Parus major, N=24) to find out which stage they can achieve and whether there is a difference between these species in relation to their caching ability. Our results suggest that food-storing coal tits search for completely hidden objects significantly better than great tits. Most of the great tits were not able to solve this task. However, the upper limit for both species is probably Stage 4 because coal tits probably solved OP tasks with more screens randomly or used alternative strategies rather than mental representation. Substantial interindividual variability in the...
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Contribution of social dominance on performance in spatial cognitive tasks in pigeons
Janská, Iveta ; Landová, Eva (advisor) ; Sedláček, František (referee)
Diploma thesis generally compares individual success pigeons in spatial tasks of varying complexity (in a role that requires abstraction of visual stimuli representing spatial relationships on the touch screen using two different strategies and spatial search task the middle plate of a series of plates with different variants of location) with hierarchical status of males and group females. Specifically thesis compares individual success pigeons in spatial tasks of varying complexity. The hardest task requires a certain level of abstraction of visual stimuli representing spatial relationships using experimentally induced two strategies: mapping strategy or specific symbol association with a position in space. The role tests on the touch screen with the help of operant conditionings. Difficulty in various stages of growing, the last stage role does manage only some individuals. Conversely easier task in real space with a bird tasked with finding the midpoint between objects in different variants locations within the arena. The difficulty of the task is not growing, and it can solve some individuals who have not learned operant conditioning if the previous job. Performance in cognitive tasks could be affected by the hierarchical status of the animal in the group. Pigeons position in the hierarchy has...
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Optimization of litter size in rodents
Cingelová, Alexandra ; Dušek, Adam (advisor) ; Sedláček, František (referee)
Optimization of litter size can be defined as adjustment of litter size according to actual environmental conditions or condition of mother to reach a compromise between the maximum number of offspring and their individual fitness. Rodents are an ideal taxon to study this topic because of their enormous interspecific variability in life strategies across the whole order. The variation in litter size among rodent species was influenced by countless ecological and social factors during their evolution. These include the geographical location of the breeding populations, various life and reproductive strategies such as r-/K-strategy, the presence of altricial or precocious offspring, various ways of life, the presence of water in the environment, predation rate, hibernation, and sociality. Litter size can be adjusted already before fertilization, for example by choosing a partner, by timing reproduction, condition, age and social status of the mother. Genetic factors affecting litter size are, for example, MHC glycoprotein polymorphism and t-haplotype. Reduction of the litter size may occur before insemination by influencing the ovulation rate, female reproductive hormone levels and exposure to the stressors, during implantation by selective abortion, and postpartum by infanticide, siblicide, and...
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