Peleman Johan D, Wye Crispin, Zethof Jan, Sørensen Anker P, Verbakel Henk, van Oeveren Jan, Gerats Tom, van der Voort Jeroen Rouppe
Keygene N.V., NL-6708 PW, Wageningen, The Netherlands.
Genetics. 2005 Nov;171(3):1341-52. doi: 10.1534/genetics.105.045963. Epub 2005 Aug 5.
In the quest for fine mapping quantitative trait loci (QTL) at a subcentimorgan scale, several methods that involve the construction of inbred lines and the generation of large progenies of such inbred lines have been developed (Complex Trait Consortium 2003). Here we present an alternative method that significantly speeds up QTL fine mapping by using one segregating population. As a first step, a rough mapping analysis is performed on a small part of the population. Once the QTL have been mapped to a chromosomal interval by standard procedures, a large population of 1000 plants or more is analyzed with markers flanking the defined QTL to select QTL isogenic recombinants (QIRs). QIRs bear a recombination event in the QTL interval of interest, while other QTL have the same homozygous genotype. Only these QIRs are subsequently phenotyped to fine map the QTL. By focusing at an early stage on the informative individuals in the population only, the efforts in population genotyping and phenotyping are significantly reduced as compared to prior methods. The principles of this approach are demonstrated by fine mapping an erucic acid QTL of rapeseed at a subcentimorgan scale.
在寻求以亚厘摩尺度精细定位数量性状基因座（QTL）的过程中，已经开发了几种方法，这些方法涉及近交系的构建以及此类近交系的大量后代的产生（复杂性状联盟，2003年）。在此，我们提出一种替代方法，该方法通过使用一个分离群体显著加快了QTL精细定位的速度。第一步，对群体的一小部分进行粗定位分析。一旦通过标准程序将QTL定位到一个染色体区间，就使用位于已定义QTL两侧的标记对1000株或更多的大群体进行分析，以选择QTL同基因重组体（QIR）。QIR在感兴趣的QTL区间内发生了重组事件，而其他QTL具有相同的纯合基因型。随后仅对这些QIR进行表型分析以精细定位QTL。与先前的方法相比，通过在早期仅关注群体中有信息的个体，群体基因分型和表型分析的工作量显著减少。通过以亚厘摩尺度精细定位油菜籽的芥酸QTL，证明了这种方法的原理。
