The role of quantitative trait loci (QTL) in the pathogenesis of experimental autoimmune vasculitis (EAV)

Stagonospora nodorum blotch (SNB) is a significant disease in some wheat-growing regions of the world. Resistance in wheat to Stagonospora nodorum is complex, whereby genes for seedling, flag leaf, and glume resistance are independent. The aims of this study were to identify alternative genes for flag leaf resistance, to compare and contrast with known quantitative trait loci (QTL) for SNB resistance, and to determine the potential role of host-specific toxins for SNB QTL. Novel QTL for flag leaf resistance were identified on chromosome 2AS inherited from winter wheat parent ‘P92201D5’ and chromosome 1BS from spring wheat parent ‘EGA Blanco’. The chromosomal map position of markers associated with QTL on 1BS and 2AS indicated that they were unlikely to be associated with known host–toxin insensitivity loci. A QTL on chromosome 5BL inherited from EGA Blanco had highly significant association with markers fcp001 and fcp620 based on disease evaluation in 2007 and, therefore, is likely to be associated with Tsn1-ToxA insensitivity for flag leaf resistance. However, fcp001 and fcp620 were not associated with a QTL detected based on disease evaluation in 2008, indicating two linked QTL for flag leaf resistance with multiple genes residing on 5BL. This study identified novel QTL and their effects in controlling flag leaf SNB resistance.

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Role of genetic markers in fisheries and aquaculture: useful tools or stamp collecting?

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f98-096 ◽

1998 ◽

Vol 55 (7) ◽

pp. 1553-1563 ◽

Cited By ~ 50

Author(s):

Moira M Ferguson ◽

Roy G Danzmann

Keyword(s):

Quantitative Trait Loci ◽

Genetic Markers ◽

Family Relationships ◽

Quantitative Trait ◽

Genome Structure ◽

Restriction Endonuclease Analysis ◽

Randomly Amplified Polymorphic Dna ◽

Trait Loci ◽

Marker Loci

We comment on the role of genetic markers in fisheries and aquaculture with a view to the future. Our goal is to encourage researchers to evaluate the molecular markers they need to deploy and shift their thinking away from analyses of stock structure towards more aggressive pursuit of questions related to genome structure and function. Examples illustrate that no one marker type is appropriate for all applications. Choice should be based on the evolutionary genetic attributes of both the species and the marker loci themselves. We evaluate three relatively new marker types: mitochondrial DNA (mtDNA) sequences, randomly amplified polymorphic DNA, and hypervariable nuclear loci. We conclude that (i) sequences of mtDNA do not necessarily detect greater polymorphism than restriction endonuclease analysis, (ii) the technical ease of randomly amplified polymorphic DNA is offset by questionable repeatability, and (iii) simulations illustrate that even new marker systems with large numbers of alleles need not detect differences among closely related yet significantly differentiated populations. Increasing the number of alleles per locus did not increase the probability of detecting significant differences. Finally, we consider the roles of genetic markers in helping to determine family relationships in pooled lots of fishes and locate genes that control an organism's phenotype (quantitative trait loci). We discuss how knowledge of quantitative trait loci can help us to understand the basis of individual differences in performance.

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