Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 45 for “"sex chromosome"”.
-
Sex Chromosome Evolution in Blow Flies
Chromosomal mechanisms of sex determination vary greatly in phylogenetically closely related species, indicative of rapid evolutionary rates. Sex chromosome karyotypes are generally conserved within families; however, many species have derived sex chromosome configurations. Insects display a …
-
Molecular analysis of sex chromosome evolution in papaya
Sex chromosomes are of great interest due to their role in sexual reproduction. Sex chromosomes evolve through the suppression of recombination in the sex determining region between the X and Y chromosomes which allows for each region to evolve and change independently. Papaya’s trioecious sex is …
-
Detection, causes and consequences of sex chromosome mosaicism
Sex chromosome mosaicism, including male mosaic loss of chromosome Y (LOY) and female mosaic loss of chromosome X (LOX), is the most common form of clonal haematopoiesis (CH) that can be defined as the age-related clonal expansion of blood cells with somatic mutations. With the decreased cost of …
-
Dissecting the evolutionary forces shaping sex chromosome evolution in papaya
The human Y chromosome is an ancient relic of its autosomal precursor; most of the genes have been lost in its 166 million years of separation from the X, and it has drastically shrunken in size. The highly degenerated nature of the human sex chromosomes make it impossible to trace the events that …
-
Karyotypes and Case Studies of Ten Individuals With Suspected Sex Chromosome Anomalies
… and harvested according to standard procedures. Chromosomes were counted in 30-50 cells and karyotypes prepared with emphasis on identifying the X-chromosome complement of each cell line. Case studies of the family history and physical features of each individual were done. Findings. Six female …
-
Relation of the sex chromosome to DDT resistance in the German cockroach
1. Reciprocal crosses were made between a DDT-resistant and a nonresistant strain of the German cockroach. 2. The techniques employed in rearing the roaches and obtaining toxicological data on the different strains, as well as the genetical and statistical procedures, are described. 3. The …
-
Current Genetic Counseling Practice Following Positive Non-Invasive Prenatal Testing For Sex Chromosome Abnormalities
… prenatal testing (NIPT) result positive for a sex chromosome abnormality (SCA). The positive predictive value for SCA with NIPT is lower than seen for Trisomy 21 due to natural loss of the X chromosome from maternal cells during aging, confined placental mosaicism, and undiagnosed maternal sex …
-
Sex chromosome evolution of papaya: Dynamic structural and expression changes and identification of associated traits
Sex chromosomes are found throughout many diverse lineages across the animal and plant kingdom. Most of the sex chromosomes that have been studied are well established and have already experienced many evolutionary forces, making it difficult to reconstruct the dynamic changes involved in the …
-
Sex Chromosome Ratios and Aneuploidy Rates in the Zona Pellucida Selected Spermatozoa From Normal and Subfertile Men
… two key questions: (1) whether human X-chromosome bearing spermatozoa (X-sperm) and Y-chromosome bearing spermatozoa (Y-sperm) differ in their functional survival time (assessed by their capacity to bind to the human zona pellucida) after prolonged in vitro incubation, and (2) whether …
-
Genomic dissection of structural variations and evolution forces of the sex chromosomes in spinach (spinacia oleracea)
Sex chromosomes evolved independently and repeatedly animals and plants. Although considerable differences existed among diverse lineages in terms of sexual dimorphism and genetic basis of sex determination, the underlining principles and evolutionary forces that lead to the formation and …
-
Regulation of Chromatin Landscape on and by the Human Sex Chromosomes
Sex chromosome constitution is the largest and oldest source of genetic variation in the human population. One sex chromosome—the “active X” (Xa)—is present in all individuals. The second sex chromosome differs between sexes; most males have a Y while most females have a second X, which adopts a …
-
Executive and behavioural functioning in girls with Turner's syndrome
… the complete or partial absence of the second sex chromosome. The T S behavioural phenotype has been characterised by a specific neuropsychological profile of normal verbal skills, impaired visuo-spatial and/or visuo-perceptual abilities and difficulty with motor function. Recently there have …
-
Chromosome evolution in Rhabditina (Nematoda) with a focus on programmed DNA elimination
… enabled research on the mechanisms that shape chromosome evolution in diverse taxa. My thesis focuses on nematodes from the Rhabditina suborder, which exhibit a high rate of chromosome rearrangement and have several species with chromosome-level assemblies available for comparison. To study …
-
Age-related genetic and epigenetic chromosomal changes: A twin study
… The majority of micronuclei (32%) contained sex chromosomes and the frequency of sex chromosome-bearing micronuclei significantly increased with age (p<0.0001). The frequency of autosome-containing micronuclei was not significantly influenced by age or gender. However, some autosomes were …
-
Meiotic defects in infertile men
… to observe the synapsis and recombination of chromosomes during meiosis, and fluorescent in-situ hybridization (FISH) to assess sperm aneuploidy. We analyzed testicular tissue from thirty-one men (10 fertile and 21 infertile men). We observed that ~36% (5/14) of men with impaired …
-
The Evolutionary Causes and Consequences of Mammalian Hybridization
… to preferentially manifest in the heterogametic sex and frequently genetically maps to the sex chromosomes. Thus, the sex chromosomes appear to play a special role in hybrid incompatibilities, and disrupted gene regulation of the X chromosome may contribute to their outsized role. Here, I …
-
Bioinformatics pipeline development for analyses of data generated by target capture-based Next-Generation Sequencing, to characterise mutations and the utility of using off-target sequences to detect genomic imbalances in Multiple Myeloma patients.
… successfully identified +8/positive control, sex chromosome differences, and a previously unknown AML-relevant distal +8q amplification. Using an average normal karyotype reference achieved higher autosomal CNA acuity over single reference samples. Adapted to MM1-MM6 CGP data, all …
Page 1 of 3