Insights into the circular RNA (circRNA) exploration have revealed that they are abundant in eukaryotic transcriptomes. Diverse genomic regions can generate different types of RNA circles, implying their diversity. Covalently closed loop structures elevate the stability of this new type of noncoding RNA. High-throughput sequencing analyses suggest that circRNAs exhibit tissue- and developmental-specific expression, indicating that they may play crucial roles in multiple cellular processes. Strikingly, several circRNAs could function as microRNA sponges and regulate gene transcription, highlighting a new class of important regulators. Here, we review the recent advances in knowledge of endogenous circRNA biogenesis, properties and functions. We further discuss the current findings about circRNAs in human diseases. In plants, the roles of circRNAs remain a mystery. Online resources and bioinformatics identification of circRNAs are essential for the analysis of circRNA biology, although different strategies yield divergent results. The understanding of circRNA functions remains limited; however, circRNAs are enriching the RNA world, acting as an emerging key player.

Sarcopenia a recognised geriatric syndrome. This study aims to evaluate the prevalence of possible sarcopenia, sarcopenia and severe sarcopenia among older Chinese adults and to identify any associated factors for possible sarcopenia according to the updated diagnostic criteria of the Asian Working Group for Sarcopenia 2019 (AWGS 2019). We used data from the China Health and Retirement Longitudinal Study (CHARLS). The main outcome of this study was possible sarcopenia. Handgrip strength was measured via a dynamometer. The muscle mass was estimated by anthropometric measures. Physical performance was measured by 5-time chair stand test and gait speed test. A multivariate logistic regression model with stepwise method was employed to identify factors associated with possible sarcopenia. A total of 6172 participants aged 60–94 years were included. The prevalence of possible sarcopenia, sarcopenia and severe sarcopenia was 38.5%, 18.6%, and 8.0%, respectively. Age, rural area, falls, higher C-reactive protein (CRP), and chronic diseases (including hypertension, chronic lung diseases, heart disease, psychiatric disease and arthritis) were associated with a higher risk of possible sarcopenia. Conversely, alcohol consumption, higher gait speed and high levels of hemoglobin were associated with decreased risk of possible sarcopenia. However, the associations between possible sarcopenia with alcohol consumption, heart disease, psychiatric disease and hemoglobin were not significant after Bonferroni correction. Our study reported a relatively high prevalence of sarcopenia among older Chinese population, and identified a range of factors associated with sarcopenia. We also found rural elders are more vulnerable to sarcopenia than urban elders. Additionally, we discovered systemic inflammation might be one of the contributing factors between sarcopenia and related comorbidities. We believe the findings of this study would help to identify individuals at high risk of sarcopenia early and therefore implement the prevention and treatment strategies to reduce the disease burden in China.

Chrysanthemums (Chrysanthemum morifolium Ramat.) exhibit a variety of flower colors due to their differing abilities to accumulate anthocyanins. One MYB member, CmMYB6, has been verified as a transcription regulator of chrysanthemum genes involved in anthocyanin biosynthesis; however, the co-regulators for CmMYB6 remain unclear in chrysanthemum. Here, the expression pattern of CmbHLH2, which is clustered in the IIIf bHLH subgroup, was shown to be positively correlated with the anthocyanin content of cultivars with red, pink and yellow flower colors, respectively. CmbHLH2 significantly upregulated the CmDFR promoter and triggered anthocyanin accumulation when co-expressed with CmMYB6. Yeast one-hybrid analyses indicated that CmbHLH2 was able to bind directly to the CmDFR promoter. Moreover, yeast two-hybrid assays indicated protein-protein interaction between CmbHLH2 and CmMYB6. These results suggest that CmbHLH2 is the essential partner for CmMYB6 in regulating anthocyanin biosynthesis in chrysanthemum.

Loquat (Eriobotrya japonica) is a model fruit for investigating flesh lignification during storage and response to chilling injury. However, the investigations of enzymes and coding genes and loquat fruit lignification under low-temperature storage are still limited. Here, the activity and transcript levels of up-stream enzymes of the phenylpropanoid pathway, including l-phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), and 4-coumarate:coenzyme A ligase (4CL), were investigated. The results indicated that activity of these enzymes was positively correlated with loquat fruit lignification and suppression of these increases by heat treatment (HT) and low-temperature conditioning (LTC) significantly alleviated loquat fruit lignification. Coding genes for these enzymes were subsequently isolated based on information from an RNA-seq database and expression of Ej4CL1 was found to be the most responsive to low temperature and inhibition by HT and LTC treatment, whereas the other genes were less responsive to these treatments. Furthermore, function of Ej4CL1 was analyzed by transient overexpression in tobacco leaves, where it stimulated lignin accumulation. Ej4CL1 may be a key candidate that involved in CI-related loquat fruit lignification.

Increasing numbers of common genetic variants associated with colorectal cancer (CRC) have been identified. Our study aimed to determine whether risk prediction based on common genetic variants might enable stratification for CRC risk. Metaanalysis of 11 genome-wide association studies comprising 16 871 cases and 26 328 controls was performed to capture CRC susceptibility variants. Genetic prediction models with several candidate polygenic risk scores (PRSs) were generated from Scottish CRC case-control studies (6478 cases and 11 043 controls) and the score with the best performance was then tested in UK Biobank (UKBB) (4800 cases and 20 287 controls). A weighted PRS of 116 CRC single nucleotide polymorphisms (wPRS 116) was found with the best predictive performance, reporting a c-statistics of 0.60 and an odds ratio (OR) of 1.46 (95% confidence interval [CI] = 1.41-1.50, per SD increase) in Scottish data set. The predictive performance of this wPRS 116 was consistently validated in UKBB data set with c-statistics of 0.61 and an OR of 1.49 (95% CI = 1.44-1.54, per SD increase). Modeling the levels of PRS with age and sex in the general UK population shows that employing genetic risk profiling can achieve a moderate degree of risk discrimination that could be helpful to identify a subpopulation with higher CRC risk due to genetic susceptibility.