Rhizoctonia species: taxonomy, molecular biology, ecology, pathology and disease control
The use of genetic markers in poultry breeding
This thesis focuses on the design of linkage and quantitative trait locus (QTL) mapping experiments and on the use of genetic markers in poultry breeding schemes. Criteria to optimize the design of experiments that use outbred populations to create a linkage map were described. Those criteria were used to evaluate designs of experiments to map codo...
Molecular characterization of the beet cyst nematode (Heterodera schachtii) resistance locus Hs1
The white beet cyst nematode (BCN), Heterodera schachtii Schm. is a serious pest in sugar beet ( B. vulgaris L.) cultivation and is widely distributed throughout most of the beet-growing areas in the world (Cooke 1987). The economical losses due to infestation with the nematode are considerable (approximately 1200 dutch guilders or $ 600 per ha. at...
Mouse models in leukemia
Human Philadelphia-positive leukemia results from a balanced chromosomal translocation, which fuses the BCR gene on chromosome 22 to the ABL proto-oncogene on chromosome 9. The understanding of Ph-positive leukemogenesis has advanced enormously over the last few decades. Although in vitro assay systems currently used, are not always relevant to hum...
Pathogenesis induced by (recombinant) baculoviruses in insects
Infection of insect larvae by a baculovirus leads to cessation of feeding and finally to the death of the larva. Under optimal conditions this process may take as little as five days during which the virus multiplies approximately a billion times and transforms 30% of the larval weight into viral products. The key question addressed in this thesis ...
Mitochondrial DNA sequence evolution in shorebird populations
This thesis describes the global molecular population structure of two shorebird species, in particular of the dunlin, Calidris alpina, by means of comparative sequence analysis of the most variable part of the mitochondrial DNA (mtDNA) genome. There are several reasons why mtDNA is the molecule of choice to probe the recent evolutionary history of...
Regulation of Azorhizobium caulinodans ORS571 nitrogen fixation (NIF/FIX) genes
Biological nitrogen fixation is the microbial process by which atmospheric dinitrogen (N 2 ) is reduced to ammonia. In all microbes studied, dinitrogen reduction is catalyzed by a highly conserved enzyme complex, called nitrogenase. The nitrogenase subunits and functions required for nitrogenase assembly and activity are encoded by the nitrogen fix...
Root nodule organogenesis : molecular characterization of the zonation central tissue
Legume plants form root nodules by interacting with the soil bacterium, Rhizobium. In these nodules bacteria are able to convert atmospheric nitrogen into ammonia which is used by the host plants as nitrogen source. Therefore symbiotic nitrogen fixation in root nodules is of great importance for agriculture.Root nodule formation involves several de...
Structure and expression of the tomato spotted wilt virus genome : a plant-infecting bunyavirus
This thesis describes studies which are aimed at the elucidation of the genetic organisation and expression strategy of the tomato spotted wilt virus (TSWV) RNA genome.Using specific cDNA clones, corresponding to all three genomic RNA segments, the synthesis of virus specific RNA species in systemically infected Nicotiana rustica plants was followe...
Molecular genetic evidence for a new sexually reproducing population of Phytophthora infestans in Europe
In the early 1980s the old A1 mating type population of the potato late blight pathogen, Phytophthora infestans, was displaced by new A1 and A2 mating type isolates in Europe. Analyses of virulence characteristics and DNA fingerprint patterns of a large number of isolates revealed that with the introduction of new P.infestans isolates the level of ...
