The unique chromosome biology of the fungus fly Sciara coprophila has fascinated investigators for over 80 years. Male meiosis exhibits a monopolar spindle, nonrandom segregation of imprinted chromosomes and nondisjunction of the X chromosome. The unusual mechanism of sex determination requires selective elimination of X chromosomes in embryogenesis. Super-numerary (L) chromosomes are also eliminated from the soma during early cleavage divisions. Distinctive DNA puffs on the larval salivary gland chromosomes are sites of DNA amplification. As a foundation for future genome studies to explore these many unusual phenomena, we have used DNA-Feulgen cytophotometry to determine genome size from hemocyte nuclei of male (X0) and female (XX) larvae and adults. The DNA content of the X chromosome is ∼0.05 pg DNA and the autosomal complement is ∼0.45 pg DNA. Measurements of DNA levels for individual sperm from adults showed that the DNA contribution of the germ line-limited (L) chromosomes constitutes as much as 35% of the DNA of the male gamete. A parallel study using Sciara ocellaris, a related species lacking L chromosomes, confirmed the presence of two X chromosomes in the sperm of this species.

Freshwater cyclopoid copepods exhibit at least a fivefold range in somatic genome size and a mechanism, chromatin diminution, which could account for much of this interspecific variation. These attributes suggest that copepods are well suited to studies of genome size evolution. We tested the nucleotypic hypothesis of genome size evolution, which poses that variation in genome size is adaptive due to the 'bulk' effects of both coding and noncoding DNA on cell size and division rates, and their correlates. We found a significant inverse correlation between genome size and developmental (growth) rate in five freshwater cyclopoid species at three temperatures. That is, species with smaller genomes developed faster. Species with smaller genomes had significantly smaller bodies at 22°C, but not at cooler and warmer temperatures. Species with smaller genomes developed faster at all three temperatures, but had smaller bodies only at 22°C. We propose a model of life history evolution that adds genome size and cell cycle dynamics to the suite of characters on which selection may act to mold life histories and to influence the distribution of traits among different habitats.

This work attempts to offer an insight into the problematic of the genus Elettariopsis Baker, the last unrevised genus in the subfamily Alpinioideae (Zingiberaceae). Phylogenetic analyses are performed on ITS, matK and DCS sequence data and correlated with absolute genome size and biogeographical distribution of the samples. Elettariopsis as a genus is found to be weakly supported and strongly supported only with the addition of some species of Amomum Roxb., including the type species A. subulatum. The absolute genome size in this group is greater than in the outgroup represented by members of the Zingiberoideae subfamily. The evidence given by sequence data further suggests that Elettariopsis is divided into two well-supported groups, the "E. curtisii" group and the "E. triloba/E. unifolia" group, each of which contains several well-supported clades. In the analysis of absolute genome size it is shown that the absolute genome size in the "E. triloba/E.unifolia" group is higher than in the "E. curtisii" group. These two groups also differ slightly in their biogeographical distribution, the group G being distributed in only in Vietnam, Laos, and Thailand, while members of group H are also occurring in Singapore and Indonesia (Borneo). Keywords: Zingiberaceae, Elettariopsis, South-East Asia, ITS,...

Although the genus Nymphaea (waterlily) includes only two native species (N. alba and N. candida) in Central Europe, it poses a great challenge to taxonomy and biosystematics. The determination of both species is hampered by their phenotypic similarities, and species boundaries can be further blurred by interspecific hybridization. In addition, ornamental cultivars of different parentage often escape from cultivation and make the situation even more complex. To get insight into the caryological and phenotypic variability of czech waterlilies, the DNA flow cytometry and both distance-based and geometric morphometrics were used. Collections showed two different groups of fluorescence intensities, corresponding to N. alba and N. candida, respectively. In addition, intermediate values of nuclear DNA amount were found in some plants from South Bohemia, indicating their hybrid origin. Surprisingly, ornamental cultivars possessed the smallest genome sizes. The amount of nuclear DNA therefore seems to be a promising species-specific marker that enables not only native species but also cultivars to be distinguished. Cytometrically-proven individuals have been subjected to multivariate morphometrics, and high differenciation was discovered especially between native species. More complicated seems the distinction...

The variability of the genome size reaches several grades even within relatively close groups of plants. The study of the genome size in the phylogenetic context provides interesting results which characterize the evolution of the individual groups of plants. In this respect, tropical plants have yet not been studied. Tropical genus Globba (ca. 100 species) belongs to an economically significant family Zingiberaceae. The diversity centre is found in Thailand but it spreads from east India and southern China up to Indonesia and the Philippines. It is a polyploid complex which exists in two cytotypes within one genus (2n = 32 a 2n = 48); it is characteristic minimally in three out of seven distinguished sections. The aim of this thesis has been a reconstruction of the group phylogeny, discovering the role of the polyploid and evaluation of the genome size evolution of the Globba genus in the phylogenetic context. To this end, modern biosystematic methods were used (flow cytometry, chromosome counting, sequencing of the nuclear and chloroplast DNA regions). Many types of software and statistical methods were used to process and interpret the data. In this group, the genome size was measured for the first time. Out of 87 individuals, the smallest size was measured with Globba nuda (2C = 1.11 pg). The...

Botryococcus braunii (Chlorophyta, Botryococcaceae) is a colony-forming green microalga that produces large amounts of liquid hydrocarbons, which can be converted into transportation fuels. While B. braunii has been well studied for the chemistry of the hydrocarbon production, very little is known about the molecular biology of B. braunii. As such, this study developed both apparatus and techniques to culture B. braunii for use in the genetic and biochemical characterization. During genetic studies, the genome size was determined of a representative strain of each of the three races of B. braunii, A, B, and L, that are distinguished based on the type of hydrocarbon each produces. Flow cytometry analysis indicates that the A race, Yamanaka strain, of B. braunii has a genome size of 166.0 +/- 0.4 Mb, which is similar to the B race, Berkeley strain, with a genome size of 166 +/- 2.2 Mb, while the L race, Songkla Nakarin strain, has a substantially larger genome size at 211.3 +/- 1.7 Mb. Phylogenetic analysis with the nuclear small subunit (18S) rRNA and actin genes were used to classify multiple strains of A, B, and L races. These analyses suggest that the evolutionary relationship between B. braunii races is correlated with the type of liquid hydrocarbon they produce. Biochemical studies of B. braunii primarily focused on the B race, because it uniquely produces large amounts of botryococcenes that can be used as a fuel for internal combustion engines. C30 botryococcene is metabolized by methylation to generate intermediates of C31, C32, C33, and C34. Raman spectroscopy was used to characterize the structure of botryococcenes. The spectral region from 1600?1700 cm^-1 showed v(C=C) stretching bands specific for botryococcenes. Distinct botryococcene Raman bands at 1640 and 1647 cm^-1 were assigned to the stretching of the C=C bond in the botryococcene branch and the exomethylene C=C bonds produced by the methylations, respectively. A Raman band at 1670 cm^-1 was assigned to the backbone C=C bond stretching. Finally, confocal Raman microspectroscopy was used to map the presence and location of methylated botryococcenes within a living colony of B. braunii cells.

DNA content varies significantly over land plants, and is known to correlate with various aspects of plant form and function. In the present study, two measures of DNA content were examined in taxa across the land plant phylogeny: genome size (or C-value) and endopolyploidy (or endoreduplication index, EI). Additionally, the relationships between DNA content and various morphological and ecological traits were assessed. DNA content was determined for 64 liverwort species from 33 families. There was a large range in 1C-values from 0.27 to 20.46 pg, but no endopolyploidy was observed. There was no correlation between genome size and breeding system (monoecy vs. dioecy). Genome size and degree of endopolyploidy were determined for 74 moss species from 21 families. Genome sizes were constrained in this group, with 1C-values ranging from 0.25 to 1.21 pg. Endopolyploidy was high in all species except from the Sphagnaceae. Additionally, 1C-value was negatively correlated with desiccation tolerance but was not correlated with breeding system. DNA content variation was determined in 31 monilophyte (fern) species (including three horsetails) and 6 lycophyte (clubmoss) species. There was a wide range in 1C-values from 2.79 to 26.90 pg, and there was no indication of endopolyploidy in any of the species. Multivariate analyses were used to explore the relative contribution of traits and phylogenetic placement to DNA content varation in 41 angiosperm species. Six measures of DNA content (2C-value, 1Cx-value, leaf EI, stem EI, petal EI and root EI) were assessed. Phylogeny explained more of the variation observed in the six measures of DNA content than 21 ecological and morphological traits. However, many of the traits were able to explain some of the variation in DNA content, both with and without phylogeny included as a covaraite. One trait that was consistently correlated with DNA content was the association with arbuscular mycorrhizal (AM) fungi. In a controlled experiment, the EI in root cells colonized by AM fungi significantly increased compared to non-mycorrhizal plants. This thesis increases our knowledge regarding the extent and significance of variation in DNA content in land plants.

This thesis concerns genomic variation within the Annelida, for which genome size studies are few and provide data for only a handful of groups. Genome size estimates were generated using Feulgen image analysis densitometry for 35 species of leeches and 61 polychaete species. Relationships were explored utilizing collection location and supplementary biological data from external sources. A novel, inverse correlation between genome size and maximum adult body size was found across all leeches. Leeches that provide parental care had significantly larger genome sizes than leeches that do not. Additionally, specimens identified as Nephelopsis obscura exhibited geographic genome size variation. Within the Polychaeta, Polar region polychaete genomes were significantly larger than those of Atlantic and Pacific polychaetes. These studies represent the first exploration of leech genome sizes, and provide base evidence for numerous future studies to examine relationships between genome size and life history traits across and within different annelid groups.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-04-13T14:16:02Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 00 Santelmo Vasconcelos Tese Final.pdf: 5907295 bytes, checksum: f9f2150b754187a5591b2d05cd74670d (MD5) / Made available in DSpace on 2016-04-13T14:16:02Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 00 Santelmo Vasconcelos Tese Final.pdf: 5907295 bytes, checksum: f9f2150b754187a5591b2d05cd74670d (MD5) Previous issue date: 2015-02-13 / CAPES / CNPq / FACEPE / O gênero Philodendron, um dos principais componentes da flora Neotropical, é o segundo maior da família Araceae, contando com aproximadamente 500 espécies e uma enorme diversidade ecológica. Assim como vários outros grupos vegetais da América tropical, ainda há uma grande defasagem de estudos para o gênero, principalmente no que concerne à sistemática filogenética e à evolução cariotípica das espécies de Philodendron. Desta forma, foram realizadas análises de filogenia molecular baseadas em marcadores plastidiais (rpl32-trnL, trnQ-5’-rps16 e trnV-ndhC) e nucleares (ITS), bem como contagens cromossômicas e estimativas do conteúdo de DNA, levando em consideração espécies das principais subdivisões do gênero e dos grupos irmãos. Ao todo, foram realizadas contagens cromossômicas para 48 espécies, sendo 38 novas, assim como uma revisão de todos os números diploides disponíveis, totalizando 69 espécies, onde a maioria (32 spp.) apresentou 2n = 32, seguido de 2n = 34 (20 spp.). Nas análises filogenéticas foi confirmada a hipótese de parentesco dos subgêneros de Philodendron, onde P. subg. Philodendron e P. subg. Pteromischum apareceram como grupos irmãos e P. subg. Meconostigma como a primeira linhagem a divergir, com os três formando um grupo monofilético. Adicionalmente, foram realizadas estimativas de conteúdo de DNA para 163 acessos, incluindo 108 espécies de Philodendron, bem como 17 espécies de grupos relacionados, onde foi observada uma grande diversidade no tamanho genômico no gênero, variando entre 2,48 e 7,58 pg, indicando uma maior importância da amplificação/eliminação de DNA repetitivo para a evolução cariotípica do grupo, em vez das alterações drásticas nos números cromossômicos, como poliploidizações. / Philodendron, one of the most important components of the Neotropical flora, is the second largest genus within Araceae, which presents approximately 500 species and a huge ecologic diversity. As well as it is observed for other plant groups from tropical America, one can still note a remarkable lack of studies on the evolution of the genus, mainly regarding to phylogenetic systematics and karyotype evolution analyses among Philodendron species. Thus, a molecular phylogeny based on chloroplast (rpl32-trnL, trnQ-5’-rps16 e trnV-ndhC) and nuclear (ITS) markers, as well as chromosome counts and DNA C-value estimations were performed, with species from the main subdivisions within the genus and sister groups. Fortyeight chromosome numbers were described herein, from which 38 were new. Besides, all the available diploid numbers were revised, totalizing 69 species with known chromosome numbers, from which the major part (32 spp.) presented 2n = 32, followed by 2n = 34 (20 spp.). In the phylogenetic analyses, the morphological hypothesis of relationship among the subgenera was confirmed, in which P. subg. Philodendron and P. subg. Pteromischum were recovered as sister groups and P. subg. Meconostigma as the first diverging lineage of the monophyletic group. In addition, DNA content estimations were performed for 163 accessions, including 108 species from Philodendron and 17 from related groups, in which a wide variation of genome sizes were observed, ranging from 2.48 to 7.58 pg. Therefore, it was indicated that the mechanisms of amplification/elimination of repetitive DNA might be more important for the karyotype evolution within the group, in comparison to drastic numeric changes in chromosome numbers such as polyploidization.

Family Poaceae is one of the most derived groups of monocots. Major mechanisms of grasses evolution and particularly of tribe Triticeae and genus Elymus are polyploidisation and hybridisation. Presented diploma thesis assessed frequency and direction of hybridisation between Elymus hispidus and E. repens in Central Europe. Thesis also evaluated evolutionary importance (significantly higher ratio of hybridisation and polyploidisation) of hybrid swarm in Nature Reserve Čertoryje (Bílé Karpaty Mountains/the White Carpathians, the Czech Republic). Putative hybridizing populations were 14,4 % of sampled localities, i.e. direct presence hybrids (7,9 %) or both parental species (8,4 %). Aneuploids and higher polyploids were found exclusively in Čertoryje hybrid swarm, except one putative DNA nonaploid plant. The genome in situ hybridisation confirmed and improved knowledge of particular species/cytotypes chromosome counts and further specified their genome composition. GISH newly characterized genome composition of interspecific hybrids and higher allopolyploids and revealed their heterogeneous origin. Flow cytometry revealed continuum of absolute genome sizes among parental species and their hybrid. The continuum was rather asymmetric in direction towards E. hispidus. Model hybrid swarm Čertoryje produce...