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Background: Yield and quality are the two most important traits in crop breeding. Exploring the regulatory mechanisms that affect both yield and quality traits is of great significance for understanding the molecular genetic networks controlling these key crop attributes. Expansins are cell wall loosening proteins that play important roles in regulating rice grain size. Results: We investigated the effect of OsEXPA7, encoding an expansin, on rice grain size and quality. OsEXPA7 overexpression resulted in increased plant height, panicle length, grain length, and thousand-grain weight in rice. OsEXPA7 overexpression also affected gel consistency and amylose content in rice grains, thus affecting rice quality. Subcellular localization and tissue expression analyses showed that OsEXPA7 is localized on the cell wall and is highly expressed in the panicle. Hormone treatment experiments revealed that OsEXPA7 expression mainly responds to methyl jasmonate, brassinolide, and gibberellin. Transcriptome analysis and RT-qPCR experiments showed that overexpression of OsEXPA7 affects the expression of OsJAZs in the jasmonic acid pathway and BZR1 and GE in the brassinosteroid pathway. In addition, OsEXPA7 regulates the expression of key quantitative trait loci related to yield traits, as well as regulates the expression levels of BIP1 and bZIP50 involved in the seed storage protein biosynthesis pathway. Conclusions: These results reveal that OsEXPA7 positively regulates rice yield traits and negatively regulates grain quality traits by involving plant hormone pathways and other trait-related pathway genes. These findings increase our understanding of the potential mechanism of expansins in regulating rice yield and quality traits and will be useful for breeding high-yielding and high-quality rice cultivars. [ABSTRACT FROM AUTHOR]

The phenotype of SCA patients are diversities, make prenatal counseling and parental decision‐making following the prenatal diagnosis of SCA more complicated and challenging. NIPT has higher sensitivity and specificity in screening trisomy 21 syndrome, but the effectiveness of NIPT in detecting SCA is still controversial. This study is a large‐scale retrospective cohort of positive SCA screened from unselected singleton pregnancies by non‐invasive prenatal testing (NIPT) from a single prenatal center of a tertiary hospital. Clinical information, indications, diagnostic results, ultrasound findings, pregnancy determinations, and follow‐up were reviewed and analyzed. 596 cases of SCA positive were screened out of 122 453, giving a positive detection rate of 0.49%. 510 cases (85.6%) conducted with amniocentesis to detect fetal chromosome, of which 236 were confirmed as true positive of SCA with PPV of 46.3% (236/510). Of the 236 cases confirmed as true positive SCA, 114 cases (48.3%)chose to terminate the pregnancy (93.0%, 65.3%, 15.4% and 10.9% for 45,X, 47,XXY, 47,XXX and 47,XYY, respectively), 122 cases (51.7%) elected to continue the pregnancy. In conclusions, NIPT as a first‐tier routine method for screening autosomal aneuploidies, also could play an important role in screening SCA. Low‐risk pregnant women are the main indication for the detection of SCA as NIPT test provides to non‐selective population. For 47,XXX and 47,XYY with mild phenotype, couples would like to continue the pregnancy. But for 45,X and 47,XXY, parents apt to terminate pregnancy no matter ultrasound abnormalities were found or not. [ABSTRACT FROM AUTHOR]

Objective: This study aims to perform a prenatal genetic diagnosis of a high-risk fetus with trisomy 7 identified by noninvasive prenatal testing (NIPT) and to evaluate the efficacy of different genetic testing techniques for prenatal diagnosis of trisomy mosaicism. Methods: For prenatal diagnosis of a pregnant woman with a high risk of trisomy 7 suggested by NIPT, karyotyping and chromosomal microarray analysis (CMA) were performed on an amniotic fluid sample. Low-depth whole-genome copy number variation sequencing (CNV-seq) and fluorescence in situ hybridization (FISH) were used to clarify the results further. In addition, methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) was performed to analyze the possibility of uniparental disomy(UPD). Results: Amniotic fluid karyotype analysis revealed a 46, XX result. Approximately 20% mosaic trisomy 7 was detected according to the CMA result. About 16% and 4% of mosaicism was detected by CNV-seq and FISH, respectively. MS-MLPA showed no methylation abnormalities. The fetal ultrasound did not show any detectable abnormalities except for mild intrauterine growth retardation seen at 39 weeks of gestation. After receiving genetic counseling, the expectant mother decided to continue the pregnancy, and follow-up within three months of delivery was normal. Conclusion: In high-risk NIPT diagnosis, a combination of cytogenetic and molecular genetic techniques proves fruitful in detecting low-level mosaicism. Furthermore, the exclusion of UPD on chromosome 7 remains crucial when NIPT indicates a positive prenatal diagnosis of trisomy 7. [ABSTRACT FROM AUTHOR]

RNA‐binding proteins (RBPs) are components of the post‐transcriptional regulatory system, but their regulatory effects on complex traits remain unknown. Using an integrated strategy involving map‐based cloning, functional characterizations, and transcriptomic and population genomic analyses, we revealed that RBP‐K (LOC_Os08g23120), RBP‐A (LOC_Os11g41890), and RBP‐J (LOC_Os10g33230) encode proteins that form an RBP‐A‐J‐K complex that negatively regulates rice yield‐related traits. Examinations of the RBP‐A‐J‐K complex indicated RBP‐K functions as a relatively non‐specific RBP chaperone that enables RBP‐A and RBP‐J to function normally. Additionally, RBP‐J most likely affects GA pathways, resulting in considerable increases in grain and panicle lengths, but decreases in grain width and thickness. In contrast, RBP‐A negatively regulates the expression of genes most likely involved in auxin‐regulated pathways controlling cell wall elongation and carbohydrate transport, with substantial effects on the rice grain filling process as well as grain length and weight. Evolutionarily, RBP‐K is relatively ancient and highly conserved, whereas RBP‐J and RBP‐A are more diverse. Thus, the RBP‐A‐J‐K complex may represent a typical functional model for many RBPs and protein complexes that function at transcriptional and post‐transcriptional levels in plants and animals for increased functional consistency, efficiency, and versatility, as well as increased evolutionary potential. Our results clearly demonstrate the importance of RBP‐mediated post‐transcriptional regulation for the diversity of complex traits. Furthermore, rice grain yield and quality may be enhanced by introducing various complete or partial loss‐of‐function mutations to specific RBP genes using clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR‐associated protein 9 technology and by exploiting desirable natural tri‐genic allelic combinations at the loci encoding the components of the RBP‐A‐J‐K complex through marker‐assisted selection. [ABSTRACT FROM AUTHOR]

Amylose content (AC) is the main factor determining the palatability, viscosity, transparency, and digestibility of rice (Oryza sativa) grains. AC in rice grains is mainly controlled by different alleles of the Waxy (Wx) gene. The AP2/EREBP transcription factor OsEBP89 interacts with the MYC‐like protein OsBP5 to synergistically regulate the expression of Wx. Here, we determined that the GLYCOGEN SYNTHASE KINASE 5 (OsGSK5, also named SHAGGY‐like kinase 41 [OsSK41]) inhibits the transcriptional activation activity of OsEBP89 in rice grains during amylose biosynthesis. The loss of OsSK41 function enhanced Wx expression and increased AC in rice grains. By contrast, the loss of function of OsEBP89 reduced Wx expression and decreased AC in rice grains. OsSK41 interacts with OsEBP89 and phosphorylates four of its sites (Thr‐28, Thr‐30, Ser‐238, and Thr‐257), which makes OsEBP89 unstable and attenuates its interaction with OsBP5. Wx promoter activity was relatively weak when regulated by the phosphomimic variant OsEBP89E–OsBP5 but relatively strong when regulated by the nonphosphorylatable variant OsEBP89A–OsBP5. Therefore, OsSK41‐mediated phosphorylation of OsEBP89 represents an additional layer of complexity in the regulation of amylose biosynthesis during rice grain development. In addition, our findings provide four possible sites for regulating rice grain AC via precise gene editing. [ABSTRACT FROM AUTHOR]

The development of the electrochemical biosensing approaches for creatine kinase (CK) has attracted great interests for clinical and healthcare applications. One of the major challenges is the synergistic integration of the sensing principle, the device configuration, the fabrication method, and the materials on the devices. In recent years, there have been various types of the enzymatic biosensors, the electrochemical immunosensors, and the electrochemiluminescence-based approaches that have been used to construct the electrochemical biosensors for CK. To successfully construct an electrochemical biosensor for CK, there are several interesting questions: What sensing principle should be chosen? Which device configuration should be used? What materials and fabrication methods should be adopted to construct the device? How are the signals generated and detected? What is the current commercial status for the electrochemical biosensors for CK. This review will highlight the early attempts to address these research challenges and explore the fundamental and practical aspects for the CK electrochemical biosensors. [ABSTRACT FROM AUTHOR]

Objective: To investigate factors associated with fetal fraction and to develop a new predictive method for low fetal fraction before noninvasive prenatal testing. Methods: The study was a retrospective cohort analysis based on the results of noninvasive prenatal testing, complete blood count, thyroxin test, and Down's syndrome screening during the first or second trimester in 14,043 pregnant women. Random forests algorithm was applied to predict the low fetal fraction status (fetal fraction < 4%) through individual information and laboratory records. The performance of the model was evaluated and compared to predictions using maternal weight. Results: Of 14,043 cases, maternal weight, red blood cell, hemoglobin, and free T3 were significantly negatively correlated with fetal fraction while gestation age, free T4, pregnancy-associated plasma protein-A, alpha-fetoprotein, unconjugated estriol, and β-human chorionic gonadotropin were significantly positively correlated with fetal fraction. Compared to predictions using maternal weight as an isolated parameter, the model had a higher area under the curve of receiver operating characteristic and overall accuracy. Conclusions: The comprehensive predictive method based on combined multiple factors was more effective than a single-factor model in low fetal fraction status prediction. This method can provide more pretest quality control for noninvasive prenatal testing. [ABSTRACT FROM AUTHOR]

Developing methods for increasing the biomass and improving the plant architecture is important for crop improvement. We herein describe a gene belonging to the RING_Ubox (RING (Really Interesting New Gene) finger domain and U-box domain) superfamily, PLANT ARCHITECTURE and GRAIN NUMBER 1 (PAGN1), which regulates the number of grains per panicle, the plant height, and the number of tillers. We used the CRISPR/Cas9 system to introduce loss-of-function mutations to OsPAGN1. Compared with the control plants, the resulting pagn1 mutant plants had a higher grain yield because of increases in the plant height and in the number of tillers and grains per panicle. Thus, OsPAGN1 may be useful for the genetic improvement of plant architecture and yield. An examination of evolutionary relationships revealed that OsPAGN1 is highly conserved in rice. We demonstrated that OsPAGN1 can interact directly with OsCNR10 (CELL NUMBER REGULATOR10), which negatively regulates the number of rice grains per panicle. A transcriptome analysis indicated that silencing OsPAGN1 affects the levels of active cytokinins in rice. Therefore, our findings have clarified the OsPAGN1 functions related to rice growth and grain development. [ABSTRACT FROM AUTHOR]

SUMMARY The diversity in alternative splicing of long noncoding RNAs (lncRNAs) poses a challenge for functional annotation of lncRNAs. Moreover, little is known on the effects of alternatively spliced lncRNAs on crop yield. In this study, we cloned nine isoforms resulting from the alternative splicing of the lncRNA LAIR in rice. The LAIR isoforms are generated via alternative 5′/3′ splice sites and different combinations of specific introns. All LAIR isoforms activate the expression of the neighboring LRK1 gene and enhance yield‐related rice traits. In addition, there are slight differences in the binding ability of LAIR isoforms to the epigenetic modification‐related proteins OsMOF and OsWDR5, which affect the enrichment of H4K16ac and H3K4me3 at the LRK1 locus, and consequently fine‐tune the regulation of LRK1 expression and yield‐related traits. These differences in binding may be caused by polymorphic changes to the RNA secondary structure resulting from alternative splicing. It was also observed that the composition of LAIR isoforms was sensitive to abiotic stress. These findings suggest that the alternative splicing of LAIR leads to the formation of a functional transcript population that precisely regulates yield‐related gene expression, which may be relevant for phenotypic polymorphism‐based crop breeding under changing environmental conditions. [ABSTRACT FROM AUTHOR]