Mackay T F
Department of Genetics, North Carolina State University, Raleigh, Box 7614, North Carolina 27695, USA.
Annu Rev Genet. 2001;35:303-39. doi: 10.1146/annurev.genet.35.102401.090633.
Phenotypic variation for quantitative traits results from the segregation of alleles at multiple quantitative trait loci (QTL) with effects that are sensitive to the genetic, sexual, and external environments. Major challenges for biology in the post-genome era are to map the molecular polymorphisms responsible for variation in medically, agriculturally, and evolutionarily important complex traits; and to determine their gene frequencies and their homozygous, heterozygous, epistatic, and pleiotropic effects in multiple environments. The ease with which QTL can be mapped to genomic intervals bounded by molecular markers belies the difficulty in matching the QTL to a genetic locus. The latter requires high-resolution recombination or linkage disequilibrium mapping to nominate putative candidate genes, followed by genetic and/or functional complementation and gene expression analyses. Complete genome sequences and improved technologies for polymorphism detection will greatly advance the genetic dissection of quantitative traits in model organisms, which will open avenues for exploration of homologous QTL in related taxa.
数量性状的表型变异源于多个数量性状基因座（QTL）上等位基因的分离，这些基因座的效应对遗传、性别和外部环境敏感。后基因组时代生物学面临的主要挑战是定位导致医学、农业和进化上重要的复杂性状变异的分子多态性；并确定它们在多种环境中的基因频率以及纯合、杂合、上位和多效性效应。将QTL定位到由分子标记界定的基因组区间的难易程度掩盖了将QTL与遗传位点匹配的困难。后者需要高分辨率的重组或连锁不平衡作图来提名假定的候选基因，随后进行遗传和/或功能互补以及基因表达分析。完整的基因组序列和改进的多态性检测技术将极大地推动模式生物中数量性状的遗传剖析，这将为探索相关分类群中的同源QTL开辟道路。
