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Flow cytometry in insects biosystematics
Javůrková, Jaroslava ; Šípek, Petr (advisor) ; Sadílek, David (referee)
The size of the genome, or DNA content in cells, is expressed using the so-called C-value, i.e. the weight of DNA in units of pg, or as 2C-values for the DNA content in somatic cells of diploid organisms. A simple method used, among other things, to determine the size of the genome is flow cytometry. This method has traditionally been very popular, especially among botanists, where it is mainly used in taxonomic and population studies or for determining the ploidy of individual lines. Conversely, genome size in animals and insects is relatively little studied. Of the more than a million described insect species, the genome size is known for only hundreds of them. This work provides information on the genome size of eighty-eight species of insects from selected orders of the Polyneoptera group - four species of earwigs (Dermaptera), four species of weavers (Embioptera), fourteen species of mantises (Mantodea), seventeen species of stick insects (Phasmatodea), forty-six species of grasshoppers, locusts, and crickets (Orthoptera), one species of termite (Isoptera, Blattodea) and two species of stoneflies (Plecoptera). The determined absolute genome sizes and variance rates were compared within individual orders, within the Polyneoptera group, and compared with the genome sizes of other insect taxa....
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Flow cytometry in insects biosystematics
Javůrková, Jaroslava ; Šípek, Petr (advisor) ; Sadílek, David (referee)
The size of the genome, in other words the content of DNA in the gametic cells of organisms, is expressed using the C-value indicating the number of nuclear base pairs in units of Mpb or the mass of DNA in units of pg. A simple method used, among other things, to determine the size of the genome is flow cytometry, which in recent years has been very popular, especially among botanists. The study of insects is lagging behind in regard to the number of described species of insect numbering more than one million in comparison to the number of species whose genome size is known (only a few hundred of them). This diploma thesis therefore aims to expand the dataset on the size of the genomes of representatives of the Polyneoptera group, to compare the data found within individual orders and to help understand the links of genome size to the evolution and ecology of insects. This work provides genome size information for eighty species of insects of the Polyneoptera group. The results showed the largest insect genome measured so far - the locust Dictyophorus griseus (149.33 pg), whose genome size exceeds the previously published results by several times. Key words: flow cytometry, genome size, c-value, Polyneoptera
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Evolution of karyotype, sex chromosomes and gene clusters in selected taxa of araneomorph spiders
Voráčková, Diana ; Forman, Martin (advisor) ; Sadílek, David (referee)
Spiders (Araneae) are a diverse group with various sex chromosome systems. The most common is X1X20 sex determination, X1X2 denotes two non-homologous X chromosomes and 0 the absence of Y. The presence of Y chromosome is rare among spiders and has been described mainly in Synspermiata, X1X2Y is probably ancestral constitution for this clade. The family Sicariidae was chosen to elucidate the evolution of sex chromosomes in Synspermiata. Karyotypes of 10 species whose 2n ranged from 19 to 23 were investigated in this study. The most common finding was X1X2Y in all studied Loxosceles species. The derived XY system was discovered in Sicarius. Furthermore, the distributional pattern of molecular cytogenetic markers (genes for 18S rRNA, 5S rRNA, histone H3 and U2 snRNA) was analysed using fluorescence in situ hybridization (FISH). These markers were found exclusively on autosomes, on one or two pairs. FISH with whole-genome probes of both sexes was performed to reveal distribution of Y specific sequences. Various patterns of Y differentiation were found in certain species. Y chromosome was small in all Sicariidae. A larger Y with a pronounced accumulation of Y-specific sequences has been detected in previous works - in the X1X2Y system of a synspermiate Pholcus phalongoides (Pholcidae). Pilot...
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Cytogenetics of bed bugs (Cimicidae) as a model representative of true bugs (Heteroptera)
Sadílek, David ; Vilímová, Jitka (advisor) ; Johnson Pokorná, Martina (referee)
Cytogenetics of bed bugs (Cimicidae) as a model true bugs (Insecta: Heteroptera) The thesis provides current opinions about a phylogeny of bed bugs, family Cimicidae, and their classification within the order Heteroptera. There are briefly summarized cytological data about the order Heteroptera, known karyotypes of the cimicid subfamilies and introduction to cytogenetics of species Cimex lectularius Linnaeus, 1758. Heteroptera species differ from other organisms by holokinetic chromosomes, a character, in which quite frequently take place chromosomal fragmentation and fusion. Several families posses smaller pair of m chromosomes, which behave during meiosis differently from the other chromosomes. Diploid chromosomal number is extremely variable, it ranges from four (family Belostomatidae) to 80 chromosomes (family Miridae). The behavior of chromosomes in the family Cimicidae is very specific. Sex-chromosomes univalents are connected by thread-like collochores and form so-called pseudobivalents during achiasmatic post-reductional meiosis. Rare polymorphism in a number of X chromosomes occurs in Cimex lectularius populations. The diploid karyotype always consists of 26 autosomal chromosomes and at least two but up to 15 X chromosomes and one Y chromosome. The number of X chromosomes can be variable...
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Comparative cytogenetics of bed bug Cimex lectularius (Heteroptera: Cimicidae)
Sadílek, David ; Vilímová, Jitka (advisor) ; Ráb, Petr (referee)
Comparative cytogenetics of the bed bug Cimex lectularius (Heteroptera: Cimicidae) The human bed bug Cimex lectularius has started enormous spreading to all developed countries of temperate climate zone during the last ten years. Bed bug was almost eradicated by a mass use of DDT in these areas until the 70's in the 20th century. This temporal haematophagous ectoparasite occupies particularly human dwellings and bat roosts. Cimex lectularius shows unusual combination of cytogenetic characteristics, general for all Heteroptera, however, not usual for other organisms. The chromosomes are holokinetic, with completely achiasmatic meiosis and inverted meiosis of the sex chromosomes. Especialy remarkable feature is intraspecific variation of the number of the X chromosomes. The variable number of chromosomes of 43 populations of Cimex lectularius from the Czech Republic and 27 populations from other European countries was studied in the present study. The 10 variants of karyotype were found out by using the "hotplate spreading" method and the standard Giemsa staining. There were male karyotypes with 2n = 29, 30, 31, 32, 33, 34, 35, 37, 42 and 47 chromosomes and two females with peculiar odd number of sex chromosomes X, 2n = 33 and 43, not complementary with any male. A stable number of 2n = 26 autosomes...
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Flow cytometry and its use for study of insects
Stuchlíková, Magdalena ; Janšta, Petr (advisor) ; Sadílek, David (referee)
Flow cytometry is a modern technique in research, playing a significant role in biomedicine and botanics. Despite its benefits (speed, simplicity, low costs), flow cytometry is currently not used in the study of insects on a large scale. This thesis gives an overview as to how flow cytometry is used in research on insects and summarises the results of such study. This pertains to genome size and its connections to other phenomena. Other focal points of research, such as ploidy and base pair ratios, are addressed to a lesser extent. Key words: flow cytometry, use in study of insects, genome size, ploidy, invertebrates
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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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Cytogenetic characteristics of the genus Cimex (Heteroptera: Cimicidae)
Sadílek, David
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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Flow cytometry and its use for study of insects
Stuchlíková, Magdalena ; Janšta, Petr (advisor) ; Sadílek, David (referee)
Flow cytometry is a modern technique in research, playing a significant role in biomedicine and botanics. Despite its benefits (speed, simplicity, low costs), flow cytometry is currently not used in the study of insects on a large scale. This thesis gives an overview as to how flow cytometry is used in research on insects and summarises the results of such study. This pertains to genome size and its connections to other phenomena. Other focal points of research, such as ploidy and base pair ratios, are addressed to a lesser extent. Key words: flow cytometry, use in study of insects, genome size, ploidy, invertebrates
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Comparative cytogenetics of bed bug Cimex lectularius (Heteroptera: Cimicidae)
Sadílek, David ; Vilímová, Jitka (advisor) ; Ráb, Petr (referee)
Comparative cytogenetics of the bed bug Cimex lectularius (Heteroptera: Cimicidae) The human bed bug Cimex lectularius has started enormous spreading to all developed countries of temperate climate zone during the last ten years. Bed bug was almost eradicated by a mass use of DDT in these areas until the 70's in the 20th century. This temporal haematophagous ectoparasite occupies particularly human dwellings and bat roosts. Cimex lectularius shows unusual combination of cytogenetic characteristics, general for all Heteroptera, however, not usual for other organisms. The chromosomes are holokinetic, with completely achiasmatic meiosis and inverted meiosis of the sex chromosomes. Especialy remarkable feature is intraspecific variation of the number of the X chromosomes. The variable number of chromosomes of 43 populations of Cimex lectularius from the Czech Republic and 27 populations from other European countries was studied in the present study. The 10 variants of karyotype were found out by using the "hotplate spreading" method and the standard Giemsa staining. There were male karyotypes with 2n = 29, 30, 31, 32, 33, 34, 35, 37, 42 and 47 chromosomes and two females with peculiar odd number of sex chromosomes X, 2n = 33 and 43, not complementary with any male. A stable number of 2n = 26 autosomes...
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