One-dimensional Mapping Approaches

We start our journey with the discussion on one-dimensional QTL mapping approaches. Though more advanced methods are preferred, the onedimensional approaches are still commonly used in the genetics discipline because of their simplicity. Besides their own interests, the one-dimensional approaches can also serve as tools for preliminary analysis in more sophisticated methods, which will be elaborated later. By one-dimensional mapping approaches, we refer to the methods based on single-QTL models discussed in § 3.3.1, since these methods search for QTL over the genome in a linear manner. Three one-dimensional mapping approaches: single-marker analysis, single interval mapping and composite interval mapping, are discussed in § 4.1 to § 4.3. In the latter sections of this chapter, we discuss some common issues on one-dimensional mapping approaches. In § 4.4, we consider the determination of threshold values. In § 4.5, we consider the determination of sample size. In § 4.6, we discuss selective genotyping, a strategy for increasing the efficiency of QTL mapping.