• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 97
  • 7
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 1
  • Tagged with
  • 145
  • 145
  • 50
  • 29
  • 23
  • 20
  • 18
  • 17
  • 17
  • 14
  • 13
  • 12
  • 10
  • 10
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Molecular Characterization Of Strawberry By Applying Dna Fingerprinting Technique Using Simple Sequence Repeats (ssrs) Markers

Dernaika, Maher 01 December 2009 (has links) (PDF)
In this study, strawberry fruit was taken as the studied model. An attempt was carried on trying to identify a unique DNA fingerprint in each of the selected different strawberry cultivars of Fragaria x ananassa Duch species available in Turkey. The basis of the study was to examine the fruit characteristics at the molecular level rather than at the morphological level. It is of great importance to differentiate and trace the origin of any variety by examining its DNA by using a very sophisticated molecular technique. In this case, DNA fingerprinting technique depending on the Simple Sequence Repeats (SSRs) markers which are also called Microsatellite markers were used. DNA fingerprinting technique reveals the specific DNA profile which is unique as a fingerprint for a fruit specimen and this DNA profile is the same and constant throughout different parts of the fruit as well as its developmental stages. In this thesis work, nine primers flanking the SSR markers already available in the online databases were designed hoping to detect SSRs that could differentiate among the five selected cultivars of strawberry.
122

Individual identification and parentage analysis of Struthio camelus (ostrich) using microsatellite markers.

Essa, Fatima. January 2005 (has links)
Ostrich (Struthio camelus) breeding is a well-developed industry in South Africa. However, successful genetic management has yet to be implemented. Parentage in colony breeding ostriches is unknown, where for a given offspring, a number of possible parents exist. Molecular markers have been extensively used in the livestock industry to resolve parentage issues and are only beginning to be utilized to address the issues of the ostrich industry. The aims of this investigation were to test known microsatellite markers developed for other ostrich subspecies in a South African Black ostrich population, and to further test these markers for their use in individual and parentage identification. DNA was extracted from venous blood obtained from two pair bred families and a colony of 97 individuals. Eleven polymorphic microsatellite markers were tested by PCR amplification of DNA samples followed by multiplexing on polyacrylamide gels to generate DNA fingerprints for each individual. Alleles were sized and quantified and used to create genotypes for each individual. Parentage analysis was performed using exclusion and likelihood methods. Pedigrees were constructed for the families by comparison of genotypes. Breeding statistics were calculated for the colony individuals. Three microsatellite markers did not amplify in this population and one marker was found to be monomorphic in this population. Four of the microsatellite markers that successfully amplified produced anonymous amplification products suggesting a second annealing site in the genome sequence of Blacks. All loci displayed low observed heterozygosities indicative of little genetic variation in this population. For the colony sample, four individuals were not assigned either parent and one female did not contribute any offspring. On average females produced 4.86 ± 2.71 fertile eggs during the sampling period with a coefficient of variation of 55.86%. A total of 79.2% of individuals were assigned paternity and 88.3% were assigned maternity. A greater number of loci are required to improve the power of parentage analysis within breeding flocks incorporating all eggs laid. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
123

Nesting and migration in the introduced Canada goose in Sweden

Sjöberg, Göran January 1993 (has links)
The aim of the thesis was to document patterns in breeding and migration in Swedish Canada geese Branta canadensis, to explain these against the genetic and historical background of the population, and to test predictions of hypotheses pertaining to parental investment. The Canada goose population in Sweden was founded by the introduction of a few individuals in the 1930's. DNA fingerprint similarity between geese breeding in Sweden was on average at the same level as between inbred close relatives in other wild bird species. The genetic variability of the population appeared to be considerably reduced in comparison to that of Canada geese breeding in North America. Dispersal and migration patterns were studied using plastic neck-bands that could be identified at long distance. Most Canada goose females nested at the lake where they grew up. Males were more prone to disperse than females, although most of them still returned to breed close to their area of origin. Geese from three breeding areas in Sweden had different winter distributions, although wintering areas overlapped considerably. Individual geese tended to return to the same wintering area as they had used in previous years. The females' investment in the egg clutch was related to the migration distance from spring foraging areas to the nesting area, suggesting an energetic cost of migration for egg production. Within breeding seasons, clutch size decreased with later initiation of nesting, but only in years with early breeding. A probable reason for this decrease was that body reserves available for egg production were larger in early layers. In years with late breeding, clutch size did not decrease, most likely because late-nesting females could supplement their body reserves by foraging on fresh vegetation. Nest defence intensity was studied by recording the behaviour of the female geese when a human approached the nest. The results largely confirmed predictions for nest defence intensity extracted from parental investment theory. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1993, härtill 6 uppsatser</p> / digitalisering@umu
124

Genetic variation and colony development of honey bees Apis mellifera in Kenya /

Wei, Shi. January 2001 (has links) (PDF)
Diss. (sammanfattning)--Uppsala : Sveriges lantbruksUniversity, 2001. / Härtill 4 uppsatser.
125

Characterization and use of a multiplex PCR-based system random amplified polymorphic DNA /

Halldén, Christer. January 1998 (has links)
Thesis (doctoral)--Lund University, 1998. / Includes bibliographical references.
126

Characterization and use of a multiplex PCR-based system random amplified polymorphic DNA /

Halldén, Christer. January 1998 (has links)
Thesis (doctoral)--Lund University, 1998. / Includes bibliographical references.
127

A molecular phylogenetic study and the use of DNA barcoding to determine its efficacy for identification of economically important scale insects (Hemiptera: Coccoidea) of South Africa

Sethusa, Mamadi Theresa 15 July 2014 (has links)
Ph.D. (Zoology) / Scale insects, plant pests of quarantine importance, with specialised anatomy and unresolved phylogenetic relationships, are responsible for major economic losses to South Africa and its trading partners. These losses may reach critical levels if the pests are not timely identified and controlled. They are currently identified based on published keys of adult females, a process that takes three days to two weeks depending on the family and the life stage of interception. In addition, agricultural commodities are often contaminated with different life stages, males or damaged specimen of these pests, making identification difficult or impossible. As a result, shipments of agricultural produce are often rejected and trade disrupted. Furthermore, pest invasions do not only occur by importation via formal channels. At times pests cross boarders as contaminants of undeclared material and may again spread on their own as they naturally expand their range. This expansion may be negatively or positively influenced by other factors such as climate change. Resolving the challenges associated with identification, phylogenetic relationships and the limited knowledge of the effects of climate change on distribution range of scale insects are the main goals of this study. Specifically (i) the development of a rapid method of species identification, (ii) the relationship between and within three major scale insect families the Coccoidea, Diaspididae and Pseudococcidae and (iii) the effect of climate change on the future distribution range of scale insects in South Africa were explored...
128

Evaluation of the genetic diversity of Malawian pigeonpea using simple sequence repeats markers

Michael, Vincent Njung'e 20 August 2014 (has links)
Pigeonpea (Cajanus cajan (L.) Millsp.) is a drought tolerant legume of the Fabaceae family in the order Fabales and the only cultivated species in the genus Cajanus. It is mainly cultivated in the semi-arid tropics of Asia and Oceania, Africa and America. In Malawi, one of the top producers of pigeonpea in Africa, it is grown by small scale farmers as a source of food and income and for soil improvement in intercropping systems. However, varietal contamination due to natural outcrossing causes significant yield losses for farmers. In this study, 48 polymorphic SSR markers were used to assess diversity in all pigeonpea varieties cultivated in Malawi with the aim of developing a genetic fingerprint to distinguish the released varieties. SSR alleles were separated by capillary electrophoresis on an ABI 3700 automated sequencer and allele sizes determined using GeneMapper 4.0 software. Allelic data was analysed with PowerMarker. A total of 212 alleles were revealed averaging 5.58 alleles per marker with a maximum number of 14 alleles produced by CCttc019 (Marker 40). Polymorphic information content (PIC) ranged from 0.03 to 0.89 with an average of 0.30. DARwin software was used to generate a neighbour-joining tree that displayed three major clusters with two sub clusters in Cluster I. The released varieties were scattered across all the clusters observed, indicating that they generally represent the genetic diversity available in Malawi, although it was observed that there is substantial variation that can still be exploited through further breeding. Screening of the allelic data associated with five popular pigeonpea varieties for which a DNA fingerprint was to be developed, revealed 6 markers – CCB1 (Marker 1), CCB7 (Marker 2), Ccac035 (Marker 7), CCttc003 (Marker 15), Ccac026 (Marker 37) and CCttc019 (Marker 40)– which gave unique allelic profiles for each of the five varieties. With further tests needed for its robustness, this genetic fingerprint can be used for seed certification to ensure only genetically pure seeds are delivered to Malawi farmers. / Agriculture and  Animal Health / M. Sc. (Agriculture)
129

Identification of H. Pylori in Saliva by a Nested PCR Assay Derived From a Newly Cloned DNA Probe

Jiang, C, Li, C, Ha, T, Ferguson, D. A., Chi, D. S., Laffan, J. J., Thomas, E. 01 June 1998 (has links)
A novel probe was developed from genomic DNA of Helicobacter pylori ATCC type strain 43629. It hybridized with all 73 H. pylori clinical isolates tested but not with any of 183 non-H. pylori DNAs in dot blot hybridization. Typing tests revealed 41 different HaeIII-digestion patterns from 57 H. pylori strains tested. Based on the sequence of the probe, a nested PCR was developed that detected as little as 2 fg of H. pylori DNA or approximately equivalent to one cell. No PCR products were amplified from any of 21 non-H. pylori strains tested. Using this nested PCR, H. pylori DNA was detected in 33 of 45 (73%) saliva samples collected from patients with gastric H. pylori infection. These data suggest that the probe is useful for typing H. pylori and that the nested PCR is a valuable tool for detecting H. pylori DNA in saliva.
130

Preimplantation genetic diagnosis : new methods for the detection of genetic abnormalities in human preimplantation embryos

Konstantinidis, Michalis January 2013 (has links)
Preimplantation genetic diagnosis (PGD) refers to the testing of embryos produced through in vitro fertilization (IVF) in order to identify those unaffected by a specific genetic disorder or chromosomal abnormality. In this study, different methodologies were examined and developed for performance of PGD. Investigation of various whole genome amplification (WGA) methods identified multiple displacement amplification as a reliable method for genotyping single cells. Furthermore, this technology was shown to be compatible with subsequent analysis using single nucleotide polymorphism (SNP) microarrays. Compared to conventional methods used in this study to perform single cell diagnosis (e.g. multiplex PCR), WGA techniques were found to be advantageous since they streamline the development of PGD protocols for couples at high risk of transmitting an inherited disorder and simultaneously offer the possibility of comprehensive chromosome screening (CCS). This study also aimed to develop a widely applicable protocol for accurate typing of the human leukocyte antigen (HLA) region with the purpose of identifying embryos that will be HLA-identical to an existing sibling affected by a disorder that requires haematopoietic stem cell transplantation. Additionally, a novel microarray platform was developed that, apart from accurate CCS, was capable of reliably determining the relative quantity of mitochondrial DNA in polar bodies removed from oocytes and single cells biopsied from embryos. Mitochondria are known to play an important role in oogenesis and preimplantation embryogenesis and their measurement may therefore be of clinical relevance. Moreover, real-time PCR was used for development of protocols for CCS, DNA fingerprinting of sperm samples and embryos and the relative quantitation of telomere length in embryos (since shortened telomeres might be associated with reduced viability). As well as considering the role of genetics in terms of oocyte and embryo viability assessment and the diagnosis of inherited genetic disorders, attention was given to a specific gene (Phospholipase C zeta) of relevance to male infertility. A novel mutation affecting the function of the resulting protein was discovered highlighting the growing importance of DNA sequence variants in the diagnosis and treatment of infertility.

Page generated in 0.0746 seconds