ABSTRACT. Grain shape and weight are the most important components of rice yield and are controlled by quantitative trait loci (QTLs). In this study, a double-haploid population, derived from the cross of japonica CJ06 and indica TN1, was used to analyze QTLs for grain shape and weight under two conditions: normal growth with unbroken husk and removing partial husk after flowering. Correlation analysis revealed that these traits, except grain weight, had a connection between the two conditions. Twenty-nine QTLs for grain shape and weight were detected on chromosomes 1 to 3; 6; 8 to 10; and 12, with the likelihood of odds value ranging from 2.38 to 5.36, including 10 different intervals. Some intervals were specifically detected after removing partial husk. The results contribute to the understanding of the genetic basis of grain filling and growth regulation, and provide us some assistance for improving grain plumpness in rice breeding.

Background The restoration of immune responses is thought as a complementary approach to the nucleos(t)ide analogue (NUC) therapy of chronic HBV infection. The antiviral immunity is negatively regulated by the programmed cell death-1/programmed death ligand-1 (PD-1/PD-L1) axis. Here, the soluble form of PD-L1 (sPD-L1) that represents the amount of PD-L1 expression cells was used as an indicator to investigate the involvement of this axis in chronic HBV infection, especially in the setting of NUC therapy. Methods A total of 273 adult patients with chronic HBV infection, regardless of the treatment, and 86 healthy controls were consecutively enrolled. Serum sPD-L1 was measured using an ELISA assay. Its correlations with clinical/virological characteristics were analyzed. Results Serum sPD-L1 levels in patients with chronic HBV infection (median 425.2 IQR 245.8-558.6 pg/mL) were significantly higher than those in healthy controls (median 81.69 IQR 54.62-121.1 pg/mL). Among patients at various disease phases, those with immune-tolerant CHB had the lowest sPD-L1 levels (median 205.3 IQR 92.27-340.7 pg/mL). These results indicated that serum sPD-L1 was significantly increased in a manner of two steps from health to infection and from immunotolerance to immunoactivation in chronic HBV infection. Furthermore, the serum sPD-L1 in immune-active CHB was correlated with HBsAg positively, HBV DNA negatively and liver damage marginally. Interestingly, the increased serum sPD-L1 levels were strongly associated with the treatment of NUCs, especially in HBeAg-positive immune-active CHB. Conclusions Serum sPD-L1 might be a meaningful indicator to monitor the immune status and disease progression in chronic HBV infection. The correlations of the increased sPD-L1 with HBsAg and NUC treatment suggest that the activated PD-1/PD-L1 axis may explain the rarity of HBsAg seroconversion of NUC therapy and the clinically available checkpoint inhibitors may serve as partners for NUCs to improve their anti-HBV efficacy in the future