|
|
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...
|
|
|
Gasotransmise v epigenetických regulacích gametogeneze a embryogeneze
BRICHCÍN, Jiří
As the problems with the reproduction of livestock and humans starting to increase, the need for knowledge of mechanisms involved in regulating the correct process of gametogenesis and embryogenesis also rises. For the experimental part of this work, two components from two different, mostly separately explored fields, i.e. gasotransmitters and epigenetic mechanisms, which are necessary for the correct process of gametes production and early embryonic evolution were chosen. Hydrogen sulfide was chosen from the series of gasotransmitters, and histone deacetylase Sirtuin 1 (SIRT1) was chosen as its possible substrate. Confirmation of the presence of these components was carried out on oocytes and embryos of laboratory mice (Mus musculus).
|
|
|
Biologie a diverzita kryptosporidií infikujících myši domácí (Mus musculus)
PRANTLOVÁ, Veronika
Cryptosporidium spp. are globally distributed unicellular parasitic protozoa of the phylum Apicomplexa that infect a wide range of vertebrates, including humans. Their exogenous developmental stages are resistant to most disinfectants and no effective drugs have been developed to date. Cryptosporidium infections of humans and many livestock have been well studied over the past 30 years, but our knowledge of Cryptosporidium spp. in small mammals has been inadequate. Recently, detailed studies of cryptosporidia have been carried out in a number of rodents, especially mice, voles, rats or tree and ground squirrels. This thesis aims to add to our mosaic of knowledge data on the prevalence, diversity and biological characteristics of cryptosporidia in the house mouse (Mus musculus), the most common unwelcome visitor to human settlements.
|
|
|
Factors affecting oetrous cycles in the house mouse (Mus musculus)
Havrdová, Leona ; Stopka, Pavel (advisor) ; Němec, Pavel (referee)
Factors affecting oetrous cycles in the house mouse (Mus musculus) Abstract This bachelor thesis deals with factors which have significant influence on house mouse (Mus musculus) oestrous cycle. Main theme is oestrous cycle modulation caused by male or female chemical signals. Familiar phenomena like Bruce effect, Whitten effect and Lee-Boot effect are described in detail along with newly explored social modulation issues (ovulation trigger, male genotype role etc.). Environmental impact is also included, especially role of Bisphenol A in connection with negative impacts on human reproduction (tested on mice). Key words: oestrus, pheromone, MUP, Mus musculus, vomeronasal organ
|
|
|
Behavioural patterns exhibited by three populations of house mouse ( Mus musculus lato) in five-tests battery: the effects of subspecies and commensal way of life
Voráčková, Petra ; Frynta, Daniel (advisor) ; Macholán, Miloš (referee)
The term "personality" nowadays occurs more often not only in psychological studies of humans but also in animal studies. Studying of personality help us to define the behavioural characteristics which can vary within the age, sexes, species or enviroments. Behavioral experiments are used to detect these behavioral patterns and they can divide the animals into the different groups. The subject of our research became three populations of house mouse (Mus musculus sensu lato) which we tested in a series of experiments involving free exploration, forced exploration, hole- board test, test of vertical activity and Elevated plus-maze. These experiments should reveal wheter the mice differ in their behaviour through the context of sex, comensalism or subspecies. We found (with in excepcion of one test) that intrapopulation variability differences are very small but interpopulation differences purely increase in the cas of comensalism and effects of subspecies. Keywords: Mus musculus, comensalism, open fieldtest, Elevated plus-maze, Principal Component Analysis (PCA)
|
|
|
Characterization of the Hstx1 and Hstx2 hybrid sterility candidate genes
Kašíková, Lenka ; Jansa, Petr (advisor) ; Rothová, Olga (referee)
Speciation, the formation of new species, is an essential evolutionary process that causes species diversity on the Earth. At the beginning of this process is the separation of two populations by a reproductive barrier that prevents gene flow between these populations. One of the mechanisms, which enable reproductive isolation, is hybrid sterility (HS). It is a mechanism of postzygotic isolation that is described in a number of eukaryotes. The first discovered gene of hybrid sterility in vertebrates is the mice gene Hst1, later identified as gene Prdm9. By genetic and molecular analysis the locus on the X chromosome was determined, whose interaction with Prdm9 causes sterility or reduced fitness in male hybrids. This locus contains two genetic factors: Hstx1, causing an abnormal morphology of spermatozoa, and Hstx2, causing an arrest in spermatogenesis in pachytene spermatocytes and sterility. In my thesis I focus on the effect of deletion of a candidate hybrid sterility gene Fmr1nb on the X chromosome. The analysis of males B6N.Fmr1nbmut with deletion variants of the Fmr1nb gene showed that Fmr1nb is one of the factors influencing spermatogenesis. An increase in morphologic abnormalities in spermatozoa occurred in males with Fmr1nb gene deletion. This phenotype is identical with Hstx1. The effect...
|
|
|
In vitro differentiation of Xenopus tropicalis and Mus musculus testicular somatic cells.
Hlaviznová, Michaela ; Tlapáková, Tereza (advisor) ; Hovořáková, Mária (referee)
Sertoli cells (SCs) are somatic cells of testicular tissue that are involved in spermatogenesis and maturation of germ cells. They are currently being extensively studied for their immunomodulatory abilities, and recent studies have shown that they share some properties with mesenchymal stromal cells (MSCs). Detailed characterization of SCs and clarification of their role in testicular tissue is crucial for potential use of SCs as a therapeutic tool in regenerative medicine. Cell culture of Xenopus tropicalis immature Sertoli cells (XtiSCs) and Mus musculus (mSCs) Sertoli cells were established in the Laboratories of Developmental Biology and Immunoregulations, Faculty of Science, Charles University. Previous research has characterized XtiSCs and demonstrated their multipotent potential by in vitro differentiation into a mesodermal line. Following this research, one of the goals of the diploma project was the induction of in vitro differentiation of XtiSC into other cell types, which would verify the differentiation potential of XtiSCs. The mSC expression profile confirmed the somatic origin of this culture as well as the transcription of Sertoli cell gene markers. Differentiation of mSCs along the mesodermal line into osteoblasts, chondrocytes and adipocytes has been successfully induced in vitro....
|
|
|
Mice and Rats: Space, Smell and Methods of Detection
Kaftanová, Barbora ; Frynta, Daniel (advisor) ; Sedláček, František (referee) ; Špinka, Marek (referee)
The coexistence of humans and rodents lasts from the beginnings of the history of agriculture. Many rodent populations accepted to synanthropic way of life and as commensals accompany human societies until today. In the first study we wanted to find out, how the evolution of non-commensal rodent species, a Cypriot mouse (Mus cypriacus), was influenced by people. This endemic island species evolved on the Cyprus Island without presence of any mammalian competitors or predators. In last 10.000 years humans arrived on the island, bringing several mammalian species, which affected the environment markedly. A black rat (Rattus rattus) is now dominant species there and presumably it is an important competitor for the Cypriot mouse. We supposed that the mice should avoid its odour. Nevertheless the rats odour was preferred by the mouse, probably as an odour of phylogenetically related species. On the contraty, the odour of domestic cat (species, which is also widespread on the island), was avoided. In conclusion, the long-term isolation from mammalian predators did not affect the antipredatory reactions of the Cypriot mouse. Our next study was focuse on changes in behavioural strategies of different populations of mice: the main question was how the commensal way of life affects their exploratory...
|
|
|
Mice and Rats: Space, Smell and Methods of Detection
Kaftanová, Barbora
The coexistence of humans and rodents lasts from the beginnings of the history of agriculture. Many rodent populations accepted to synanthropic way of life and as commensals accompany human societies until today. In the first study we wanted to find out, how the evolution of non-commensal rodent species, a Cypriot mouse (Mus cypriacus), was influenced by people. This endemic island species evolved on the Cyprus Island without presence of any mammalian competitors or predators. In last 10.000 years humans arrived on the island, bringing several mammalian species, which affected the environment markedly. A black rat (Rattus rattus) is now dominant species there and presumably it is an important competitor for the Cypriot mouse. We supposed that the mice should avoid its odour. Nevertheless the rats odour was preferred by the mouse, probably as an odour of phylogenetically related species. On the contraty, the odour of domestic cat (species, which is also widespread on the island), was avoided. In conclusion, the long-term isolation from mammalian predators did not affect the antipredatory reactions of the Cypriot mouse. Our next study was focuse on changes in behavioural strategies of different populations of mice: the main question was how the commensal way of life affects their exploratory...
|
|
|
Mice and Rats: Space, Smell and Methods of Detection
Kaftanová, Barbora
The coexistence of humans and rodents lasts from the beginnings of the history of agriculture. Many rodent populations accepted to synanthropic way of life and as commensals accompany human societies until today. In the first study we wanted to find out, how the evolution of non-commensal rodent species, a Cypriot mouse (Mus cypriacus), was influenced by people. This endemic island species evolved on the Cyprus Island without presence of any mammalian competitors or predators. In last 10.000 years humans arrived on the island, bringing several mammalian species, which affected the environment markedly. A black rat (Rattus rattus) is now dominant species there and presumably it is an important competitor for the Cypriot mouse. We supposed that the mice should avoid its odour. Nevertheless the rats odour was preferred by the mouse, probably as an odour of phylogenetically related species. On the contraty, the odour of domestic cat (species, which is also widespread on the island), was avoided. In conclusion, the long-term isolation from mammalian predators did not affect the antipredatory reactions of the Cypriot mouse. Our next study was focuse on changes in behavioural strategies of different populations of mice: the main question was how the commensal way of life affects their exploratory...
|
guest ::
