Combining QTL-seq and linkage mapping to fine map a candidate gene in qCTS6 for cold tolerance at the seedling stage in rice.

BACKGROUND: Cold stress caused by low temperatures is an important factor restricting rice production. Identification of cold-tolerance genes that can stably express in cold environments is crucial for molecular rice breeding. RESULTS: In this study, we employed high-throughput quantitative trait locus sequencing (QTL-seq) analyses in a 460-individual F2:3 mapping population to identify major QTL genomic regions governing cold tolerance at the seedling stage in rice. A novel major QTL (qCTS6) controlling the survival rate (SR) under low-temperature conditions of 9°C/10 days was mapped on the 2.60-Mb interval on chromosome 6. Twenty-seven single-nucleotide polymorphism (SNP) markers were designed for the qCST6 region based on re-sequencing data, and local QTL mapping was conducted using traditional linkage analysis. Eventually, we mapped qCTS6 to a 96.6-kb region containing 13 annotated genes, of which seven predicted genes contained 13 non-synonymous SNP loci. Quantitative reverse transcription PCR analysis revealed that only Os06g0719500, an OsbZIP54 transcription factor, was strongly induced by cold stress. Haplotype analysis confirmed that +376 bp (T>A) in the OsbZIP54 coding region played a key role in regulating cold tolerance in rice. CONCLUSION: We identified OsbZIP54 as a novel regulatory gene associated with rice cold-responsive traits, with its Dongfu-104 allele showing specific cold-induction expression serving as an important molecular variation for rice improvement. This result is expected to further exploration of the genetic mechanism of rice cold tolerance at the seedling stage and improve cold tolerance in rice varieties by marker-assisted selection.

Low deceleration capacity is associated with higher stroke risk in patients with paroxysmal atrial fibrillation.

BACKGROUND: Deceleration capacity (DC) is a non-invasive marker for cardiac autonomic dysfunction; however, few studies have shown that the influence factors of cardiac autonomic dysfunction and the correlations between DC and stroke risk in paroxysmal atrial fibrillation (AF). We aimed to explore the influencing factors of abnormal DC and the relationships between DC and stroke risk in patients with paroxysmal AF. METHODS: The study included hospitalized paroxysmal AF patients with DC measurements derived from 24-h Holter electrocardiography recordings taken between August 2015 and June 2016. Multivariable regression analysis was performed to evaluate the associations between correlated variables and abnormal DC values. The relationship between DC and ischemic stroke risk scores in patients with paroxysmal AF was analyzed. RESULTS: We studied 259 hospitalized patients with paroxysmal AF (143 [55.2%] male, mean age 66.4 ±â€Š12.0 years); 38 patients of them showed abnormal DC values. In the univariate analysis, age, hypertension, heart failure, and previous stroke/transient ischemic attack (TIA) were significantly associated with abnormal DC values. Among these factors, a history of previous stroke/TIA (odds ratio = 2.861, 95% confidence interval: 1.356-6.039) were independently associated with abnormal DC values in patients with paroxysmal AF. The abnormal DC group showed a higher stroke risk with the score of congestive heart failure, hypertension, age >75 years, diabetes mellitus, previous stroke and TIA (CHADS2) (2.25 ±â€Š1.48 vs. 1.40 ±â€Š1.34, t = -4.907, P = 0.001) and CHA2DS2-vascular disease, age 65-74 years and female category (VASc) (3.76 ±â€Š1.95 vs. 2.71 ±â€Š1.87, t = -4.847, P = 0.001) scores. Correlation analysis showed that DC was negatively correlated with CHADS2 scores (r = -0.290, P < 0.001) and CHA2DS2-VASc scores (r = -0.263, P < 0.001). CONCLUSIONS: Lower DC is closely associated with previous stroke/TIA, and is also correlated negatively with higher stroke risk scores in patients with paroxysmal AF. It could be a potential indicator of stroke risk in paroxysmal AF patients.

Circulating tumor cells in breast cancer and its association with tumor clinicopathological characteristics: a meta-analysis.

The aim of the study was to evaluate the association between tumor clinicopathological characteristics and circulating tumor cells (CTCs) in breast cancer. We searched PubMed, MEDLINE, BioMed, and EMbase databases for studies that assessed the association between tumor clinicopathological characteristics and CTCs in breast cancer. Studies obtained from search strategy were screened using pre-specified criteria, and necessary data were retrieved for meta-analysis. Fourteen studies with 2,336 patients were eligible for combined analysis. Presence of CTCs in peripheral blood (PB) was significantly associated with tumor size [OR 0.68, 95% confidence interval (CI) (0.54, 0.87), n = 10, P = 0.002], tumor grade [OR 0.71, 95% CI (0.55, 0.91), n = 8, P = 0.006], ER status [OR 0.72, 95% CI (0.57, 0.91), n = 9, P = 0.007], and PR status [OR 0.78, 95% CI (0.61, 0.98), n = 9, P = 0.04]. However, as to correlation between nodal status and CTCs presence in PB, no statistically significant difference was found [OR 0.83, 95% CI (0.67, 1.03), n = 12, P = 0.10]. The CTCs' presence in PB is correlated with tumor size, tumor grade, ER, and PR.