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Several confirmed genetic susceptibility loci involved in the interferon signaling and Th17/B cell response for SLE in Chinese Han populations have been described. Available data also indicate that sex-specific genetic differences contribute to SLE susceptibility. The aim of this study was to test for gene-gene/gene-sex epistasis (interactions) in these known lupus susceptibility loci. Six single-nucleotide polymorphisms (SNPs) in MiR146a, IRF5, IKZF1, ETS1 and IL21 were genotyped by Sequenom MassArray system. A total of 1,825 subjects (858 SLE patients and 967 controls) were included in the final analysis. Epistasis was tested by additive model, multiplicative model and multifactor dimensionality reduction (MDR) method. Additive interaction analysis revealed interactions between IRF5 and IKZF1 (OR 2.26, 95% CI 1.48-3.44 [P = 1.21×104]). A similar tendency was also observed between IL21 and ETS1 by parametric methods. In addition, multiple high dimensional gene-gene or gene-sex interactions (three-and four-way) were identified by MDR analysis. Our study identified novel gene-gene/gene-sex interactions in lupus. Furthermore, these findings highlight sex, interferon pathway, and Th17/B cells as important contributors to the pathogenesis of SLE. [ABSTRACT FROM AUTHOR]

Quantitative trait loci (QTLs) influencing textural properties (hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness, and resilience)of wheat for Chinese northern-style steamed bread were studied using a doubled haploid (DH) population containing 168 lines derived from a cross between elite Chinese wheat cultivars Huapei 3 and Yumai 57 ( Triticum aestivum L .). The DH population and parents were grown in 2007 and 2008 in Tai'an and 2008 in Suzhou. QTL analyses were performed using the software QTL Network version 2.0 and IciMapping v2.2 based on the mixed linear model. Thirty nine putative QTLs were detected on 14 chromosomes: viz. 1A, 2A, 3A, 4A, 6A, 1B, 2B, 3B, 5B, 6B, 7B, 5D, 6D, and 7D, and single QTLs explained 3.91-35.17% of the phenotypic variation. Eight pairs of QTLs with epistatic effects and/or epistasis × environment (AAE) effects were detected for adhesiveness, resilience, hardness, and cohesiveness on chromosomes 2A, 1B and 3D. Several co-located QTLs with additive effects were detected on chromosomes 2B, 5D, 6A, 3A, 3B and 6D. Two clusters of three QTLs for steamed bread textural properties (chewiness, gumminess, and hardness) and for adhesiveness, cohesiveness and resilience were detected on chromosome 2B. Two co-located QTLs with epistatic effects were detected on chromosomes 1B and 3A. Both additive effects and epistatic effects were important for Chinese steamed bread textural properties, which were also subject to environmental modifications. The information obtained in this study will be useful for manipulating QTLs determining Chinese steamed bread textural properties by molecular marker-assisted selection. [ABSTRACT FROM AUTHOR]

Epistasis has sometimes been reported in qualitative and quantitative traits of soybean [Glycine max (L.) Merr.]. Our objective was to determine the extent to which epistasis occurred in crosses between soybean lines adapted to similar latitudes in Liaoning, China, and in Ohio, USA. We crossed 'Tiefeng #27' x HS97-4534 and 'Ohio FG1' x 'Shennong #6', and developed random F4-derived lines from each cross and BC1F3- derived lines from the backcross to each parent. We tested the lines, along with parents and their checks, at Plain City, OH, in 2005 to 2007, and at Shenyang, Liaoning, in 2005 and 2006. Comparison of the means of parents, biparental lines, and both backcrosses revealed significant epistasis for plant height, maturity, 100-seed weight, yield, internode length, number of branches, harvest index, and content of protein and oil, but the epistasis was not expressed consistently across environments or parental combinations. Further, in some cases simple digenic epistasis did not account for the results, implying higher-order interactions among loci. Some of the results could be explained by inter- actions of loci controlling timing of reproductive stages and interactions between such loci and the environment. Breeders who make crosses between soybean lines adapted to northeastern China and the midwestern United States should be prepared for a high frequency of poorly adapted progeny. [ABSTRACT FROM AUTHOR]

Flooding of vegetable crop fields along the Yangtze River basin in China has been an annual occurrence; therefore the cultivation of tolerant varieties has become one of the most promising control strategies. Our objective was to investigate the inheritance of waterlogging tolerance of cucumber at the early stage of growth with two cucumber parents consisting of PW0832 (tolerant) and PW0801 (susceptible). In 2006, 4-weeks-old potted plants of P1, P2, F1, F2, B1 and B2 generations were subjected to one week waterlogged stress, control plants were not flooded. The simple additive model explained the variations of tolerance score (TOL) adventitious root formation (ARF) and waterlogged root dry weight (RDW) while the additive-dominance model explained the control treatment of RDW. Non-allelic interactions were detected for waterlogged vine length (VLH) and root length (RLH). Complementary epistasis occurred in waterlogged VLH while additive × additive, additive × dominance and dominance × dominance epistastic effects were significant for waterlogged RLH. Transgressive segregation was also observed in most of the traits in the F2 generation indicating some alleles are dispersed in the parents used in this study. The estimates of narrow-sense heritabilities for TOL and ARF were moderately high. Backcross of F1 to both parents in ARF, waterlogged SDW and waterlogged RDW showed good convergence of genes in the B2. These results suggest that it should be possible to develop varieties with high levels of tolerance by selecting transgressive segregants in this cross. [ABSTRACT FROM AUTHOR]

Information on issues discussed at the 4th International Conference on Quantitative Genetics, held in Hangzhou, China on June 18, 2012, is presented. Topics include the prominent role of epistasis in the inheritance of complex traits in Drosophila, genomic selection, and the impact of having full bovine sequence data on improving the accuracy of genomic breeding value estimation. The conference featured notable individuals including Trudy Mackay, Ben Hayes, and Eric Lander.