数量性状遗传基础研究的回顾与思考——后基因组时代数量遗传领域的挑战

LOOK BACK AND REFLECT ON GENETIC RESEARCHES OF VARIATION FOR QUANTITATIVE TRAITS A CHALLENGE FOR QUANTITATIVE GENETICS IN POST-GENOME ERA

回顾了100多年来数量性状遗传研究的发展。数量性状的遗传研究长期落后于质量性状的研究,主要是对其遗传基础缺乏必要的了解。20世纪80年代开始,DNA分子标记的大量开发,提供了遍布于基因组的位置参照点,促进了数量性状遗传基础研究的迅速发展。迄今至少已对68个生物种的很多数量性状(包括动、植物的重要经济性状和人类疾病)作过全基因组的数量性状座位(QTL)扫描,建立了QTL图谱。但是一般地说,QTL仍然是一个相当大的DNA片断,往往含有多个基因。遗传基础的进一步研究应当从QTL到数量性状基因(QTG),再从QTG到相应于等位基因的数量性状核苷酸(QTN),逐步深入下去。这是后基因组时代数量遗传领域的主要挑战。基因组上数以万计的DNA序列变异(例如SNP)以及模式生物全基因组测序的完成,已为这种准确的遗传剖分提供了必要的条件。

The genetic researches of variation for quantitative traits were retrospected since 1885. The researches on quantitative traits lagged that on qualitative traits over long time because of poorly understanding of the genetic basis or architecture for quantitative variation. Since late 1980s, the DNA sequence variants, i.e., the molecular markers, were detected on a large\|scale, and provided densely positional controlls over whole\|genome. Thus, genetic basis researches for quantitative traits were strongly promoted. Up to now, many quantitative traits in 68 species of living things at least, including many important economic traits in plants and animals, and human diseases, have been conducted on the whole\|genome scan for quantitative trait loci (QTL), and QTL mappings were established. However, in generally speaking, a QTL is still a considerable DNA fragment frequently containing multiplex genes. Further investigations on the genetic basis should be deepened: i.e., from QTL to quantitative trait genes (QTG) and from QTG to quantitative trait nucleotides (QTN) corresponding to alleles or paralogs. This is a major challenge for quantitative genetics in the post\|genome era. Extremely abundant molecular polymorphisms such as single nucleotide polymorphisms (SNP) and complete genome sequences in model organisms will greatly advance accurately genetic dissection for quantitative trait variation.