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Use of cytogenetical methods in taxonomy of Arachnida (Arachnida)
Alaverdyan, Argam ; Šťáhlavský, František (advisor) ; Johnson Pokorná, Martina (referee)
This bachelor thesis deals with the use of cytogenetic methods in taxonomy of Arachnida. To understand this matter, we need to analyse available information about inter and intraspecific karyotype variability of individual orders. At the beginning of the thesis there is a description of cytogenetic methods used with Arachnida.They are used to gather the karyotype's fundamental information, such as the diploid number of chromosomes, chromosome morfology and possible occurence of sex chromosomes. Main part of the thesis is focused on describing karyotypes of selected orders (Amblypygi, Palpigradi, Pseudoscorpiones, Scorpions, Opiliones and Araneae) and considering the convenience of use of cytogenetic methods for their taxonomy based on these information. The thesis includes current number of described genera (species) of the orders, as well as a number of cytogenetically analyzed genera (species) for comparison.
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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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Evolution of sex chromosomes and karyotypes in boas and pythons
Charvát, Tomáš ; Rovatsos, Michail (advisor) ; Majtánová, Zuzana (referee)
- ABSTRACT - Snakes (Serpentes) are a group of squamate reptiles (Squamata) that represents more than one third of the total reptile species diversity. Snake karyotype is generally conserved with the most common chromosome number of 36 (16 macro- and 20 microchromosomes) in diploid state. It is believed that this karyotype was also present in the common ancestor of all snakes. The majority of snake species belong to the group Caenophidia and share homologous ZW sex chromosomes. Snakes from the groups "Scolecophidia" and "Henophidia" have mostly poorly differentiated, homomorphic sex chromosomes, which made them impossible to distinguish from the autosomes in the past. These snakes were for many years assumed to have ZW sex chromosomes as well. However, recent studies demonstrated not only ZW but also two non- homologous XY sex chromosome systems in non-caenophidian snakes and thus the sex determination systems in snakes are much more variable than previously thought. In this thesis, eight species of henophidian snakes (representatives from the genera Eryx, Cylidrophis, Python and Tropidophis) and one caenophidian species (Ophiophagus hannah) were examined using conventional and molecular cytogenetic methods. However, sex chromosomes were not detected in the henophidian species, only in Ophiophagus hannah,...
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Use of cytogenetical methods in taxonomy of Arachnida (Arachnida)
Alaverdyan, Argam ; Šťáhlavský, František (advisor) ; Johnson Pokorná, Martina (referee)
This bachelor thesis deals with the use of cytogenetic methods in taxonomy of Arachnida. To understand this matter, we need to analyse available information about inter and intraspecific karyotype variability of individual orders. At the beginning of the thesis there is a description of cytogenetic methods used with Arachnida.They are used to gather the karyotype's fundamental information, such as the diploid number of chromosomes, chromosome morfology and possible occurence of sex chromosomes. Main part of the thesis is focused on describing karyotypes of selected orders (Amblypygi, Palpigradi, Pseudoscorpiones, Scorpions, Opiliones and Araneae) and considering the convenience of use of cytogenetic methods for their taxonomy based on these information. The thesis includes current number of described genera (species) of the orders, as well as a number of cytogenetically analyzed genera (species) for comparison.
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Fylogeneze vybraných druhů letounů Afriky na základě cytogenetického a molekulárního přístupu
Koubínová, Darina ; Zima, Jan (advisor) ; Macholán, Miloš (referee) ; Martínková, Natália (referee)
Phylogenetic relationships of a sample comprising 248 bats belonging to 19 species and four families (Hipposideridae, Rhinolophidae, Molossidae and Vespertilionidae) from Senegal (Western Africa) were investigated with the use of multi-locus sequence data and non- differentially stained chromosomes. The karyotypes of Hipposideros ruber, H. tephrus, H. jonesi and H. cyclops were described for the first time. The standard Hipposideros formula was recorded in H. tephrus, H. jonesi and H. ruber (2n = 32, FNa = 60, FN = 64). The karyotypes of H. cyclops (2n = 36, FN = 66) and H. gigas (2n = 52, FN = 64) substantially diverged from this typical chromosomal complement. Rhinolophus landeri and R. fumigatus shared the same diploid number (2n = 58), but differed in the chromosome morphology (R. fumigatus - FNa = 60, FN = 64; R. landeri - FNa = 64, FN = 68). Rhinolophus landeri was found karyotypically distinct to other African populations, thus signalling a possible presence of cryptic forms within this species. The karyotypes of Chaerephon pumilus and Mops condylurus had a 2n = 48, FN = 54 and were similar to other previously studied species of this chromosomally conservative family. Chromosomal, Bayesian, maximum likelihood and genetic distance analyses revealed an indication for the existence of cryptic...
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