The genus Pythium is important in agriculture, since it contains many plant pathogenic species, as well as species that can promote plant growth and some that have biocontrol potential. In South Africa, very little is known about the diversity of Pythium species within agricultural soil, irrigation and hydroponic systems. Therefore, the aim of the study was to characterise a selection of 85 Pythium isolates collected in South Africa from 1991 through to 2007.
View Article and Find Full Text PDFWhile it is widely appreciated that prostate cancers vary substantially in their propensity to progress to a life-threatening stage, the molecular events responsible for this progression have not been identified. Understanding these molecular mechanisms could provide important prognostic information relevant to more effective clinical management of this heterogeneous cancer. Hence, through genetic linkage analyses, we examined the hypothesis that the tendency to develop aggressive prostate cancer may have an important genetic component.
View Article and Find Full Text PDFEvidence of the existence of major prostate cancer (PC)-susceptibility genes has been provided by multiple segregation analyses. Although genomewide screens have been performed in over a dozen independent studies, few chromosomal regions have been consistently identified as regions of interest. One of the major difficulties is genetic heterogeneity, possibly due to multiple, incompletely penetrant PC-susceptibility genes.
View Article and Find Full Text PDFCancer Epidemiol Biomarkers Prev
February 2005
Background: Variants in the gene encoding the macrophage scavenger receptor 1 (MSR1(4)) protein have been identified in men with prostate cancer, and several small studies have suggested that the 999C>T (R293X) protein-truncating mutation may be associated with an increased risk for this disease.
Methods: Using large case-control, cohort, and prostate cancer family studies conducted in several Western countries, we tested for the 999C>T mutation in 2,943 men with invasive prostate carcinoma, including 401 males from multiple-case families, 1,982 cases unselected for age, and 575 men diagnosed before the age of 56 years, and in 2,870 male controls. Risk ratios were estimated by unconditional logistic regression adjusting for country and by a modified segregation analysis.
Plants are constantly exposed to attack by an array of diverse pathogens but lack a somatically adaptive immune system. In spite of this, natural plant populations do not often suffer destructive disease epidemics. Elucidating how allelic diversity within plant genes that function to detect pathogens (resistance genes) counteracts changing structures of pathogen genes required for host invasion (pathogenicity effectors) is critical to our understanding of the dynamics of natural plant populations.
View Article and Find Full Text PDFBackground: The aggregation of prostate cancer within families suggests a major inherited component to the disease. Genetic linkage studies have identified several chromosomal regions that may contain prostate cancer susceptibility loci, but none has been definitively implicated.
Methods: We performed a genome-wide linkage search based on 64 families, 63 with at least 3 cases of prostate cancer, ascertained in five countries.
Studies of families with breast cancer have indicated that male carriers of BRCA2 mutations are at increased risk of prostate cancer, particularly at an early age. To evaluate the contribution of BRCA2 mutations to early-onset prostate cancer, we screened the complete coding sequence of BRCA2 for germline mutations, in 263 men with diagnoses of prostate cancer who were =55 years of age. Protein-truncating mutations were found in six men (2.
View Article and Find Full Text PDF