Exploring the genetic characteristics of 93-11 and Nipponbare recombination inbred lines based on the Golden Gate SNP assay

Understanding genetic characteristics in rice populations will facilitate exploring evolutionary mechanisms and gene cloning. Numerous molecular markers have been utilized in linkage map construction and quantitative trait locus(QTL) mappings. However, segregation-distorted markers were rarely considered, which prevented understanding genetic characteristics in many populations. In this study, we designed a 384-marker Golden Gate SNP array to genotype 283 recombination inbred lines(RILs) derived from 93-11 and Nipponbare Oryza sativa crosses. Using 294 markers that were highly polymorphic between parents, a linkage map with a total genetic distance of 1,583.2 c M was constructed, including 231 segregation-distorted markers. This linkage map was consistent with maps generated by other methods in previous studies. In total, 85 significant quantitative trait loci(QTLs) with phenotypic variation explained(PVE) values?5% were identified. Among them, 34 QTLs were overlapped with reported genes/QTLs relevant to corresponding traits, and 17 QTLs were overlapped with reported sterility-related genes/QTLs. Our study provides evidence that segregation-distorted markers can be used in linkage map construction and QTL mapping. Moreover, genetic information resulting from this study will help us to understand recombination events and segregation distortion. Furthermore, this study will facilitate gene cloning and understanding mechanism of inter-subspecies hybrid sterility and correlations with important agronomic traits in rice.

A genome wide association study between copy number variation (CNV) and human height in Chinese population

Copy number variation （CNV） is a type of genetic variation which may have important roles in phenotypic variability and disease susceptibility. To hunt for genetic variants underlying human height variation, we performed a genome wide CNV association study for human height in 618 Chinese unrelated subjects using Affymetrix 500K array set. After adjusting for age and sex, we found that four CNVs at 6p21.3, 8p23.3-23.2, 9p23 and 16p12.1 were associated with human height （with borderline significant p value： 0.013, 0.011, 0.024, 0.049; respectively）. However, after multiple tests correction, none of them was associated with human height. We observed that the gain of copy number （more than 2 copies） at 8p23.3-23.2 was associated with lower height （normal copy number vs. gain of copy number： 161.2 cm vs. 153.7 cm, p = 0.011）, which accounted for 0.9% of height variation. Loss of copy number （less than 2 copies） at 6p21.3 was associated with 0.8% lower height （loss of copy number vs. normal copy number： 154.5 cm vs. 161.1 cm, p = 0.013）. Since no important genes influencing height located in CNVs at loci of 8p23.3-23.2 and 6p21.3, the two CNVs may cause the structural rear- rangements of neighbored important candidate genes, thus regulates the variation of height. Our results expand our knowledge of the genetic factors underlying height variation and the biological regulation of human height.