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Earlier evolutionary dead-ends, now the creators of a reproductive strategy: the origin and reproduction of the all-male water frog lineage Pelophylax esculentus
Doležálková, Marie ; Choleva, Lukáš (advisor) ; Mikulíček, Peter (referee) ; Kratochvíl, Lukáš (referee)
Asexual modes of reproduction are usually based on the principle of copying (cloning) DNA from the female and passing it on to the offspring. For most asexually reproducing vertebrates the progeny develop from an unreduced and often unfertilised egg. This is driven by the mechanisms of parthenogenetic and gynogenetic reproduction. While in the former the clonal germ cell develops spontaneously and separately, in the latter a sexual partner is needed to activate the cleavage of the ovum, although without the fusion of the sperm and egg. Therefore in both cases there is no fertilization and the clonal progeny consist solely of daughters, hence the majority of previous studies have only focused on asexual female lineages. However, on rare occasions asexual clonal males can arise when the right fertilization occurs. Whilst these offspring are usually infertile, fertile diploid asexual males have been discovered in just three genera of hybrid origin in vertebrates. One of these unique cases is the European water frog complex of the genus Pelophylax, whose distribution includes the Czech Republic. In areas around the upper Odra River populations of hybrid males were recently discovered who form stable all-male lineages, similar to those formed by asexual females. The results of this study show that males produce...
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Study of influence of 17β-estradiol and 17α-ethynylestradiol on capacitation of mouse sperm in vitro.
Adamusová, Hana ; Bosáková, Zuzana (advisor) ; Pacáková, Věra (referee)
Environmental estrogens (natural and synthetic) belong to a group of contaminants called endocrine disrupting chemicals (EDCs). These compounds interfere with a function of endocrine system. They can bind to natural estrogen receptors or block synthesis of endogenous hormones. 17β-Estradiol (BE2) is a natural endocrine disruptor produced more by women than men. Also a synthetic 17α-ethynylestradiol (EE2) belongs to EDCs. It is used as a main part of birth control pills. Together with other endocrine disruptors EE2 is probably responsible for feminization of male animals living in effluents of waste water treatment plants. The aim of this thesis was to develop a method for determining free 17β-estradiol and 17α-ethynylestradiol available to capacitating sperm. In order to determine a status of BE2 during mouse sperm capacitation in vitro, a high performance liquid chromatography (HPLC) method with tandem mass spectrometry (MS/MS) detection was used. A reversed-phase separation mode using a SunFire C18 column with a simple mobile phase composed of acetonitrile and water at the ratio 40/60 (v/v) containing 0,1% formic acid in both components was applied. Under the optimized separation conditions, calibration curves for 17β-estradiol and 17α-ethynylestradiol were measured in the concentration range of 1-250...
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Functions of repertoire size in passerines
Kinštová, Anna ; Petrusková, Tereza (advisor) ; Musilová, Zuzana (referee)
5 Abstract Songbirds use visual and vocal signals to communicate. Visual signals have several disadvantages, for example they are more difficult to detect in darkness or poor light. On the contrary vocal signals, the most typical and advanced way of communication in passerines, can be noticeable even in these conditions. Vocalizations can be divided into songs and calls. The two main functions of a song, especially in songbirds living in temperate zone, are to defend a territory and to attract a mate. The songbirds have a considerable variety in songs among particular species. Moreover, the individual of the same species can differ greatly in their repertoire size. This means they have different number of song types or syllables. Currently we assume that repertoires have arisen in response to widespread female preference for mates with larger repertoires. The evolution of repertoire complexity was driven by a sexual selection of females preferences. In this case the repertoire size is considered to be a phenotypic trait which should work as an honest indicator of male quality. Therefore females could obtain direct and indirect benefits. I study the functions of repertoire size in passerines in my bachelor thesis. I focus in particular on possible benefits that females could gain from pairing with males with...
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The influence of estrogens on mouse sperm capacitation and acrosome reaction in vitro.
Tejnická, Magda ; Komrsková, Kateřina (advisor) ; Maňásková, Pavla (referee)
- 7 - Abstract 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...
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Hybrid sterility genes in mice: mapping of epistatic interactions
John, Václav ; Forejt, Jiří (advisor) ; Kuthan, Martin (referee)
MOUSE HYBRID STERILITY GENES: A MAPPING OF EPISTATIC INTERACTIONS Hybrid sterility is an important postmeiotic reproductive isolation barrier. The phenotype of mouse hybrid sterility includes decreased testes weight and an absence of sperm. It occurs only in F1 males from PWD/Ph (PWD; Mus musculus domesticus) x C57BL/6J (B6, M. m. musculus) cross but not reciprocal B6 x PWD F1 males (FOREJT & IVÁNYI, 1974; FOREJT et al., 1991). Nowadays we know that the phenotype of hybrid sterility is controlled by the PWD/B6 allelic combination on chromosome 17 at Prdm9 locus is needed and by the PWD allele on chromosome X at Hstx2 locus. This combination of two loci is necessary but not sufficient obtain full sterility (MIHOLA et al., 2008; FOREJT, JIŘÍ, pers. comm.), so another genes must play role. In this experimental work I prepared the F2 cross from B6 and PWD mouse strains and I genotyped the males of F2 crosses and I carried out the QTL analysis. Extended QTL analysis was carried out with all animals carrying Prdm9PWD/B6 - Hstx2PWD allelic combination. The results showed unexpectedly low number of sterile males in F2 generation (1.90 %), and significant QTLs on chromosomes 17 (in Prdm9 loci) and X (different from Hstx2) in sperm, no other significant peak on any chromosome was found. These results indicate a more...
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Phenotypic Analyses of the HD transgenic Minipig Model
Motlík, Jan ; Ellederová, Zdeňka
The transgenic model of Huntington’s disease in minipig (TgHD) was created in 2009 and information coding the sequence of N-terminal part of human mutated huntingtin was transferred to subsequent generations from both female and male sides. In each litter, transgenic (TgHD) and wild-type (WT) piglets were born in approximately equal ratio. At present, the Laboratory of Cell Regeneration and Plasticity keeps sets of animals in F2 and F3 generations with identical genetic background and bred in identical conditions of feeding and housing. The present research project was focused on a complex of non-invasive and invasive approaches to WT and TgHD minipigs to achieve the entire phenotypic analysis of HD progression in this large animal model.
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Phenotypic plasticity of Daphnia cucullata in two lowland ponds
Volemanová, Eva ; Petrusek, Adam (advisor) ; Pichlová, Radka (referee)
4 ABSTRACT Characteristic high helmets in Daphnia cucullata, which increase resistance of Daphnia against various invertebrate predators, can be induced by chemical cues released by these invertebrates but also by small-scale turbulence. I evaluated the response of D. cucullata to both factors in several clones originating from two riverine pools differing in their predator regime. In a large pool, the dominant invertebrate predator is the cladoceran Leptodora kindtii, and the Daphnia population there shows a typical cyclomorphosis. In the second (small) pool, Daphnia do not produce helmets, despite the presence of the phantom midge larvae Chaoborus flavicans. I compared phenotypic changes of Daphnia cucullata clones from these pools to Chaoborus kairomones and to a small-scale turbulence in laboratory experiments. Kairomones induced significantly longer helmets in clones from both pools; however, only clones form the large pool reacted also to turbulence. As all daphnids in the experiments responded to chemical cues from Chaoborus, I assume that either the kairomone dose under natural conditions in the small pool is too low to induce helmets or the phenotypic response of the local population is mediated by other factors. On the other hand, the variation of response to small-scale turbulence suggests that...
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EVALUATE THE PERFORMANCE PARAMETERS OF THE BREEDS OF COMMON CARP AND ITS CROSSBREDS
KŘÍŽ, Michal
The aim of the thesis was to evaluate the performance parameters of the breeds of common carp and its crossbreds by using the top-crossing. On the maternal position the Hungarian synthetic mirror carp line (HSM) was used. On this line, males of HSM, Telč mirror carp (TeL), Northern mirror carp (M72) and Amur mirror carp (AL) were crossed and a hybrid of Ropsha carp (ROP) and Tata carp (TAT) was used as their control group. Rearing of the tested groups was monitored from larval stage until their market size in ponds with a semi-intensive way of management in three localities (2 organisations). In the first year, each tested group was bred individually with internal control group of a different scaly covering phenotype in order to correct the influence of the environment on the weight achieved. In the second and the third year, all the groups were group-labelled and bred together in triplicate (three ponds) localities. In the individual stages of testing, the weight and the survival rate were recorded. Moreover, in the market size stage the biometric measurement and slaughtering value were evaluated. In the overall assessment of the results from all the localities carried out by the ANCOVA procedure, the highest weight at the K3 age was achieved by the hybrid HSM x AL (1413 {$\pm$} 31.5 g; Last square means {$\pm$} S.E.), whose weight was statistically comparable to the other hybrids (HSM x M72 a HSM x TeL). However, it was the only noticeably higher weight in comparison with the HSM (1257 {$\pm$} 31.5 g) with its ordinary heterosis effect of growth on the level of 12.4%. During the third year of testing, the survival ranged from 69.0 % in HSM x Tel to 73.4% in HSM x AL and the values were statistically comparable. The yield parameters (the proportion of the processed body, the proportion of filets with skin and the skinless ones) were similar in all the groups. In the previous periods of testing the results reflected the situation in the market size. As a result, it is concluded that preferably the hybrid HSM x AL could be exploitable in commercial breeding.
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The Influence of eco-toxicological factors on spermatogenesis, morphology and function of mammalian sperm
Vašinová, Jitka ; Pěknicová, Jana (referee) ; Hortová, Kateřina (advisor)
An increasing infertility due to pathological changes on sperm has become a serious issue. A rising concentration of fluorides in the environment could be a potentially negative factor affecting the male fertility. Eco-toxicological effect of fluorides can be enhanced in the present of aluminium ions by forming fluoro-metallic complexes, analogues of phosphate groups that interfere with the activity of G-proteins and P-type ATPases, which are part of several signalling pathways during sperm maturation. The aim of this thesis was monitoring the effect of fluorides on mouse sperm capacitation in vitro, analysis of the effect of fluorides on male reproductive organ and on the level of mouse spermatogenesis. Fluorides were administered to mice through table water at the concentrations of 0, 1, 10, 100 ppm and at the same time we monitored their synergic action with aluminium at 10 ppm dose. The level of tyrosine phosphorylation in the sperm head was the main marker for successful capacitation in vitro. The results show that an oversized load of ions, to which mice were exposed, affected negatively spermatogenesis and ability of sperm to capacitate in vitro. Besides that, a multigenerational study in mice demonstrated that even low concentrations of aluminium fluorides can have a negative effect on...
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Estrogens in environment, their impact on male fertility
Daniel, Michal ; Heráček, Jiří (advisor)
Build-up of estrogen and other endocrine disruptors in our habitat has been recently an issue widely debated not only amongst health professionals but also by main stream media. Their impact on wild animals has been observed and documented for some time now and several studies on rodents and other mammals have demonstrated a highly probable connection between exposure in early stages of development to endocrine disrupting chemicals and abnormal sexual maturation of males (hypospadia, cryptorchism), as well as impaired male reproductive functions. Epidemiological studies have been claiming significant drop in sperm count and quality of spermatozoa in last several decades, increased incidence of testicular cancer, which is being among other causes attributed also to pooling of endocrine disruptors in the environment. This reasoning brings a lot of controversy since the respective chemicals are by-products of substances commonly used in agriculture and industry and replacing them is expensive and logistically challenging. It is also quite difficult to determine and quantify the long term effects of specific chemicals on human body since the population is being exposed to not just one substance but to a whole cocktail of them and the symptomatology is subjected to age, length of the exposure, quantity of the...
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