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Karyotype analysis of selected representatives of two pedipalpid orders, Amblypygi and Uropygi
Sember, Alexandr ; Král, Jiří (advisor) ; Ráb, Petr (referee)
Karyotype analysis of selected species from arachnid orders Amblypygi and Uropygi Whip spiders (Amblypygi) and whip scorpions (Uropygi) represent relict arachnid orders which has been found already at Upper Carboniferous strata. Although cytogenetic data from amblypygids and uropygids might be important to reconstruct karyotype evolution of arachnids, cytogenetics of these orders is almost unknown. Presented study is aimed in analysis of karyotype and meiosis in 16 species of Amblypygi and 4 species of Uropygi. Both groups are characterized by considerable range of diploid chromosome numbers (2n = 24 - 86 in Amblypygi and 36 - 66 in Uropygi). Analysed species does not exhibit morfologically differentiated sex chromosomes. Differentiation of sex chromosomes on molecular level was revealed in amblypygid Paraphrynus mexicanus by comparative genome hybridization. Obtained data indicate XY/XX sex chromosome system in this species. Comparison of karyotype data indicates reduction of chromosome numbers during evolution of both orders. In Amblypygi, this reduction was accompanied by increase of number of biarmed chromosomes. This trend is not apparent in Uropygi. Karyotypes of most analysed amblypygids and uropygids are also characterized by low amount of heterochromatin. Most studied species exhibit two pairs...
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Signaling pathways and genes regulating gonadotropin-induced maturation of porcine oocytes and cumulus expansion
Blaha, Milan ; Němcová, Lucie (advisor) ; Král, Jiří (referee)
In vitro, meotic maturation of porcine oocytes and cumulus expansion are induced by FSH and EGF-like peptides AREG and EREG. FSH and EGF-like peptides induce expression of cumulus expansion-related genes (HAS2, PTGS2 and TNFAIP6). To define signaling pathways that control FSH- and AREG-induced cumulus expansion, porcine cumulus-oocyte complexes were treated with specific protein kinase inhibitors. Inhibitors of MAPK3/1, MAPK14 and ERBB1 significantly reduced both FSH- and AREG-induced expression of HAS2, PTGS2 and TNFAIP6. These inhibitors decreased FSH/LH-induced expression of AREG and EREG in mural granulosa cells. Surprisingly, inhibitor of PKA had no effect on AREG expression in cumulus-oocyte complexes but the inhibitor decreased expression of TNFAIP6 induced by AREG. Inhibitor of PI3K increased expression levels of AREG and PTGS2 but EREG, HAS2 and TNFAIP6 were reduced. Expression levels of the cumulus expansion-related genes were not affected by an analog of cGMP (8-CPT-cGMP). However, 8-CPT-cGMP blocked spontaneous in vitro meiotic maturation of porcine oocytes and its effect was abolished by FSH. Key words: cumulus expansion, cumulus expansion-related genes, meotic maturation, FSH, amphiregulin, cGMP
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Chromosomal investigation in foetuses with developmental abnormalities
Štolfa, Miroslav ; Novotná, Drahuše (advisor) ; Král, Jiří (referee)
Chromosomal aberrations are common causes of abnormal development of fetuses leading to the birth of malformed indvidual or to the intrauterine death. Half of miscarriages in the first trimester and a third in the second trimester are caused by fetal chromosomal abnormalities, mainly aneuploidies. If fetus is abnormally developed, invasive prenatal cytogenetic diagnosis should be recommended. Positive cytogenetic finding can be reason for induced abortion till the end of 24th week of gestation. We investigated 81 miscarriages, 46 fetuses from induced abortions and 80 fetuses with abnormal development from ongoing pregnancies. G-banding analysis was used as the main method for investigating miscarriages. Genomic DNA isolated from abnormally developed fetuses was screened by array CGH technique. We found 43,75 % chromosomal abnormal miscarried fetuses, majority of them with numerical aberrations (91,4 %). In group of induced abortions, 25,71 % fetuses carried chromosomal abnormality. The lowest rate 11,67 % of chromosoal aberrations was detected in group of prenatally diagnosed fetuses from ongoing pregnancies. Array CGH detected submicroscopic aberrations in 13,41 % fetuses with ultrasound findings. All together 25,74 % microscopic and causal submicroscopic chromosomal abnormalities were found to be...
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Cytogenetic characteristics of the genus Cimex (Heteroptera: Cimicidae)
Sadílek, David ; Vilímová, Jitka (advisor) ; M. Grozeva, Snejana (referee) ; Král, Jiří (referee)
The present thesis deals with the phenomenon of additional sex chromosomes in Cimex lectularius (Hemiptera: Heteroptera: Cimicidae) using genome size analysis combined with the classical cytogenetic approach. Also, five other cimicid species and 12 species from the family Nabidae were analysed identically for comparative purposes. The thesis also pursues a description of methodical approaches of cytogenetics and flow cytometry in the study of C. lectularius. Recently analysed European specimens of C. lectularius from human host exhibited 12 distinct cytotypes, with a variable number of chromosomes X from two to 20 (2n♂ = 26+X1X2Y to 26+X1-20+Y). The fragmentation hypothesis of C. lectularius additional chromosomes X origin was established in the second half of the 20th century. However, the present genome size measurements suggest that various chromosomal rearrangements as duplication or deletion besides the fragmentation could occur. Males with basic cytotype 2n = 26+X1X2Y had average genome size of 2C = 1.94 pg, in contrast male with 2n = 26+X1-7+Y yielded 2C = 2.26 pg and also specimens with genome size decrease 2C = 1.69 pg appeared. The most informative turned up to be the relative genome size of sperm cells n = 13+X1X2 and n = 13+Y, where specimens with higher chromosome number showed...
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Karyotype analysis of mesothelid spiders
Prokopcová, Lenka ; Král, Jiří (advisor) ; Zrzavá, Magda (referee)
Cytogenetics of mesothelid spiders is largely unkown. The presented diploma thesis is focused on the karyotype evolution of these spiders. As it is the most basal group of spiders, the analysis of its cytogenetics can bring important data about ancestral spider karyotype. In the framework of my thesis, I analysed diploid chromosome numbers, chromosome morphology, meiotic division, sex chromosomes and the pattern of selected molecular markers that were detected by fluorescence in situ hybridization. According to my results, mesothelid spiders have a high number of chromosomes and the prevalence of monoarmed chromosomes. Unlike other spiders, mesothelids have little differentiated sex chromosomes. Key words: evolution, spider, chromosome, karyotype, fluorescence in situ hybridization, nucleolar organiser region, sex chromosomes
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Karyotype evolution of the family Araneidae
Pajpach, Filip ; Král, Jiří (advisor) ; Sember, Alexandr (referee)
Orb-weavers (Araneidae) are a diversified spider family comprising more than 3,100 species in more than 170 genera. Together with 13 other families, they con- stitute to superfamily Araneoidea. The presented thesis focuses on karyotype evo- lution of Araneidae, including its comparison with a related family Tetragnathidae. The results obtained from 19 araneid and four tetragnathid species confirm previ- ously postulated hypothesis that the ancestral karyotype of Araneoidea (including Araneidae) consists of 24 acrocentric chromosomes in males, including two acro- centric X chromosomes of system X1X20. However, there is a tendency of 2n decrease in some araneids due to centric fusions. In these cases, centric fusions affected most autosomes (and sometimes gonosomes as well); number of chromosome pairs de- creased from 11 to six. Three independent reduction events were detected in this thesis. Furthermore, pattern of nucleolar organizer regions (NORs) was studied in this thesis using fluorescent in situ hybridization, since data on evolution of this marker are scarce in spiders. Striking variability in NORs number was discovered, ranging from one to 13 loci. Remarkably, multiple centric fusions were always ac- companied by considerable increase of NORs number. In araneids and tetragnathids possessing...
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Frequency of occurrence of selected single nucleotide polymorphisms of CYP2C8 and MDR1 in the Czech population and their influence on the effect of amiodarone
Pechandová, Kristina ; Perlík, František (advisor) ; Král, Jiří (referee) ; Anzenbacher, Pavel (referee)
Frekvence výskytu vybraných bodových polymorfismů CYP2C8 a MDR1 v české populaci a jejich vliv na působení amiodaronu Úvod: Variabilita lékové odpovědi je někdy podmíněna genetickými rozdíly v metabolismu a transportu léčiv. Interindividuální rozdíly jsou často způsobeny polymorfismy, které ovlivňují biotransformační aktivitu enzymů a expresi transportérů. V disertační práci jsme věnovali pozornost cytochromu P450 izoenzymu CYP2C8 a MDR1. Nejprve jsme popsali frekvenci výskytu vybraných variantních alel CYP2C8*2, CYP2C8*3 (2 substituce v exonu 3 a 8, CYP2C8*3G416A a CYP2C8*3A1196G), CYP2C8*4, CYP2C8 P404A u zdravé české populace a variantních alel MDR1 v exonech: 26 C3435T, 21 G2677A/T, 12 C1236T a 17 T-76A. Následně jsme sledovali vliv těchto polymorfismů na působení amiodaronu u vybraného souboru pacientů. Metody: Genotyp MDR1 a CYP2C8 jsme stanovili pomocí PCR-RFLP za využití specifických restrikčních enzymů a primerů. Frekvence genotypů MDR1jsme určili u 189 zdravých dobrovolníků a CYP2C8 u 161 zdravých osob. Do sledování jsme dále zařadili 63 pacientů užívajících amiodaron déle než dva měsíce. Jejich léčbu jsme posuzovali ze záznamů lékařské dokumentace, s využitím standardních biochemických a hematologických vyšetření a záznamů EKG. Koncentrace amiodaronu a jeho metabolitu N-...
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Developmental mechanisms of arrhythmias - role of connexins in arrhythmogenesis
Beneš, Jiří ; Sedmera, David (advisor) ; Kolář, František (referee) ; Král, Jiří (referee)
Developmental mechanisms of arrhythmias - role of connexins in arrhythmogenesis MUDr.Jiří Beneš Abstract: Objective: The aim of this study is an improvement of our knowledge concerning the role of connexins in arrhythmogenesis. The main focus is on the role of connexin40 (Cx40) in heart development in mice and changes in connexin43 expression in volume overload heart failure rat model. Methods: The infuence of Cx40 on heart develoment was studied on transgenic mouse Cx40:GFP model using the method of optical mapping. Volume overload heart failure was examined in the rats with aortocaval shunt. Morphological changes in hearts were examined using imunofluorescence microscopical techniques. Results: In the atria, Cx40 is important especially during the early stages. Cx43 can partially substitute its function from 12.5 embryonic day on. Cx40 deficiency leads to decreased conduction velocity and ectopic sites of activation. Absence of Cx40 in ventricular conduction system leads to the development of right bunde branch block. Volume overload in rats leads to excentric hypertrofy and later to heart failure. We described morphological as well as microscopical changes in failing hearts. Without the presence of fibrosis, the main arrhythmogenic substrate we found was reduced amount of Cx43 and its dephosphorylation....
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Karyotype evolution of selected families of entelegyne spiders
Kotz, Matěj ; Král, Jiří (advisor) ; Nguyen, Petr (referee)
The Araneoidea superfamily is a diverse clade of spiders with a great species diversity. The whole superfamily displays considerable conservativeness of observed karyotypes. Most likely ancestral karyotype in males is 24 acrocentric chromosomes with X1X2 sex determination system. The goal of this study is to explore the karyotype diversity of two araneoid families - Araneidae and Mimetidae. The majority of studied species exhibit the ancestral karyotype. In some species of the aformentioned families was observed sudden increase in chromosome numbers, up to 2n♂ = 52 in Araneidae and up to 2n♂ = 57 in Mimetidae. The latter number is the highest chromosome count observed in Entelegynae so far. Increase in 2n goes hand in hand with increase in sex chromosome numbers, leading up to X1X2X3X40 system in Araneidae and up to X1X2X3X4X5X6X70 in Mimetidae. I suggest polyploidy as a possible mechanism of the increase. To test this hypothesis, I measured the size of the genome using flow cytometry and used fluorescence in situ hybridization for the detection of 18S rRNA and 5S rRNA genes. For one species, probe for U2 snRNA gene was also optimized as part of this thesis. In many species studied, these techniques were used for the first time ever. In the case of the family Mimetidae, the largest genomes in...
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