No description available.

No description available.

Thesis (M. Ed.)--Kutztown State College. / Source: Masters Abstracts International, Volume: 45-06, page: 3060. Typescript. Includes bibliographical references (leaves 32-34).

Electrophoretic karyotypes were obtained from intact cells of four wild type strains of Tilletia caries and T. controversa, and 5 inter specific hybrid progeny using clamped homogeneous electric field, pulsed field gel electrophoresis (CHEF PFGE). Each karyotype was polymorphic and unique relative to the other strains. However, the relative size range of all the chromosomes was consistent and typically ranged from approximately 850 to 4,490 kilobasepairs (Kb) for all strains, accept for two atypically small chromosomes in one strain of T. caries. The minimum estimated number of chromosomes was 19 or 20 for strains of T. controversa, 14 to 20 for T. caries, and from 19 to 22 for the hybrid progeny. The minimum estimated total genome size ranged from 28 to 39 megabasepairs (mb) for T. caries, 34 to 40 mb for T. controversa, and 36 to 42 mb for the hybrid progeny. Southern hybridization analysis performed with cloned, single copy homologous DNA fragments identified a single similar-sized chromosome in all strains. The maximum percent variability of the linkage groups defined by the single copy probes was 10% or less. The rDNA from Neurospora crassa hybridized with 2 or 3 chromosomes in the wild type stains of T. caries and T. controversa, and with 1 to 3 chromosomes in the hybrid progeny. The maximum percent variability among chromosomes that hybridized with the rDNA probe ranged from 35 to 40%. Either 1 or 2 chromosomes were identified by the single copy actin gene from Aspergillus nidulans, and the maximum percent variability ranged from 4 to 14% for these chromosomes. It was not possible to differentiate between the karyotypes of strains of either T. caries or T. controversa using the physical appearance of the karyotypes, the number and sizes of chromosomes, the genome sizes, or by Southern hybridization analysis. Analysis of the karyotypes of the hybrid progeny revealed that all were unique relative to each other and the parental stains, providing circumstantial evidence for the presence of recombinant chromosomes. That the genome size and chromosomes numbers of the hybrid progeny were similar to their monokaryotic parental strains strongly argues that the reduction division stage of meiosis had occurred. Seven teliospore samples from Oregon and Turkey were examined for their germination and autofluorescence properties. The teliospore samples were analyzed to determine if low temperature germination (0-4° C) and autofluorescing spore-wall reticulations associated with spores of T. controversa were usually linked. Two of the seven teliospore samples showed these characteristics to be unlinked. In an attempt to clone the mating type genes of T. caries and T. controversa, total genomic DNA was probed with a fragment of the b west mating type gene from Ustilago hordei. Although single 1.4 kb BamHI fragment from both pathogens was cloned by homology and sequenced, its role in mating type function remains uncertain. / Graduation date: 1993

No description available.

No description available.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Proefschrift Maastricht. / Met lit. opg. en een samenvatting in het Nederlands.

Multicolor fluorescence in-situ hybridization (M-FISH) techniques provide color karyotyping that allows simultaneous analysis of numerical and structural abnormalities of whole human chromosomes. Chromosomes are stained combinatorially in M-FISH. By analyzing the intensity combinations of each pixel, all chromosome pixels in an image are classified. Often, the intensity distributions between different images are found to be considerably different and the difference becomes the source of misclassifications of the pixels. Improved pixel classification accuracy is the most important task to ensure the success of the M-FISH technique. Along with a reliable pixel classification method, automation of the karyotyping process is another important goal. The automation requires segmentation of chromosomes, which not only involves object/background separation but also involves separating touching and overlapping chromosomes. While automating the segmentation of partially occluded chromosomes is an extremely challenging problem, a pixel classification method that satisfies both high accuracy and minimum human intervention has not been realized. The main contributions of this dissertation include development of a new feature normalization method for M-FISH images that reduces the difference in the feature distributions among different images, and development of a new decomposition method for clusters of overlapping and touching chromosomes. A significant improvement was achieved in pixel classification accuracy after the new feature normalization. The overall pixel classification accuracy improved by 40% after normalization. Given a cluster, a number of hypotheses was formed utilizing the geometry of a cluster, pixel classification results, and chromosome sizes, and a hypotheis that maximized the likelihood function was chosen as the correct decomposition. Superior decomposition results were obtained using the new method compared to the previous methods. Contributions also include development of a color compensation method for combinatorially stained FISH images (including M-FISH images) based on a new signal model for multicolor/multichannel FISH images. The true signal was recovered based on the signal model after color compensation. The resulting true signal does not have color spreading (channel crosstalk) among different color channels. Two new unsupervised nonparametric classification methods for M-FISH images are also introduced in this dissertation: a fuzzy logic classifier and a template matching method (a minimum distance classifier). While both methods produce an equivalent accuracy compared to a supervised classification method, their computation time is significantly less than a Bayes classifier. Highly sophisticated and practical algorithms have been developed through this research. Using the developed methods, the amount of human intervention required will be significantly reduced: chromosomes are reliably and accurately segmented from the background, pixels are accurately classified, and clusters of overlapping and touching chromosomes are automatically decomposed. / text

Orientador: Sergio de Freitas / Coorientador: Sérgio Antonio de Bortoli / Banca: Nilza Maria Martinelli / Banca: Marielle Cristina Schneider / Resumo: A família Chrysopidae, pertencente à ordem Neuroptera, é a mais numerosa, compreendendo mais de 1200 espécies válidas, distribuídas em várias regiões do mundo, principalmente na Neotropical. A classificação desta família em gêneros e espécies é baseada em estudos da morfologia externa e da genitália de machos e fêmeas adultos. No entanto tem-se buscado novas metodologias para auxiliar tanto na taxonomia, quanto no conhecimento da evolução. A citogenética é uma ferramenta bastante importante para o conhecimento da extensão da biodiversidade, pois a partir de diferenças presentes nos cromossomos podem-se distinguir grupos, bem como padrões de evolução. Assim, o objetivo deste estudo foi caracterizar citogeneticamente 18 espécies de crisopídeos de ocorrência em Jaboticabal - SP., quanto ao número diplóide, morfologia e tamanho dos cromossomos, sistema cromossômico sexual, e quando possível, analisar o comportamento meiótico. Os cromossomos foram obtidos a partir de preparações gonadais masculinas e femininas de indivíduos adultos e de embriões, submetidos à coloração convencional e fotografados com câmara MOTICAM acoplada a microscópio e software IMAGE da Motic. Das 18 espécies analisadas, somente em Chrysoperla defreitasi não foi possível observar o par heteromórfico, no entanto as demais espécies exibiram sistema sexual do tipo XY/XX. O número diplóide variou entre 2n=16 nas espécies do gênero Leucochrysa a 2n=6 em Chrysopodes delicata, e esta diferença refletiu na morfologia cromossômica e permitiu diferenciar algumas das espécies. Nas espécies em que foram obtidas células meióticas observou-se a formação de bivalentes autossômicos com quiasmas terminais e univalentes sexuais assinápticos e aquiasmáticos / Abstract: The family Chrysopidae, belonging to the Neuropteran order, is the most numerous, comprising more than 1200 valid species, distributed in various regions of the world, mainly in the Neotropical. The classification of this family into genera and species is based on the study of external morphology and male and female adults genitalia. However, new methods to assist the taxonomy and the evolution have been studied. The cytogenetic is a very important tool for to understand the extent of biodiversity, because the differences in the chromosomes can be distinguished group, and pattern of evolution. The objective of this study was to perform cytogenetic analysis of 18 species of green lacewings of occurrence in the city of Jaboticabal - SP, characterizing them as to the diploid number, shape and size of chromosomes, and when was possible, analyzed the meiotic behavior. The chromosomes preparations were obtained from adults male and female gonodals and embryos that were conventional stained and photographed with a MOTIC camera coupled in a microscope and software IMAGE from Motic. Of the 18 species analyzed, only Chrysoperla defreitasi was not possible to observe the heteromorphic pair, however the other species exhibited sexual system of the type XY / XX. The diploid number varied from 2n = 16 in the genus Leucochrysa to 2n = 6 in Chrysopodes delicata, and this difference reflected in chromosome morphology and allowed to differentiate some of the species. In the species in which meiotic cells had obtained it was possible observed the formation of autosomal bivalents with terminal chiasmata and univalents sex without chiasmata and synaptic / Mestre