CircRNA Chordc1 protects mice from abdominal aortic aneurysm by contributing to the phenotype and growth of vascular smooth muscle cells.

Circular RNAs (circRNAs) have important potential in modulating vascular smooth muscle cell (VSMC) activity, but their roles in abdominal aortic aneurysm (AAA) are unknown. We performed in situ hybridization and immunohistochemistry and determined that circChordc1 (cysteine and histidine-rich domain containing 1) was markedly downregulated in aneurysm tissue compared with normal arteries. A gene gain and loss strategy was used to confirm that circChordc1 transformed VSMCs into a contracted phenotype and improved their growth, which significantly suppressed aneurysm formation and reduced the risk of rupture in mouse models of angiotensin (Ang) II- and CaCl2-induced AAA. RNA pull-down, immunoprecipitation, and immunoblotting indicated that circChordc1 facilitated the VSMC phenotype and growth determination by binding to vimentin and ANXA2 (annexin A2), which not only increased vimentin phosphorylation to promote its degradation but also promoted the interaction between ANXA2 and glycogen synthase kinase 3 beta (GSK3ß) to induce the nuclear entry of ß-catenin. Thus, our present study revealed that circChordc1 optimized the VSMC phenotype and improved their growth by inducing vimentin degradation and increasing the activity of the GSK3ß/ß-catenin pathway, thereby extenuating vascular wall remodeling and reversing pathological aneurysm progression.

A high density SLAF-seq SNP genetic map and QTL for seed size, oil and protein content in upland cotton.

BACKGROUND: Cotton is a leading natural fiber crop. Beyond its fiber, cottonseed is a valuable source of plant protein and oil. Due to the much higher value of cotton fiber, there is less consideration of cottonseed quality despite its potential value. Though some QTL controlling cottonseed quality have been identified, few of them that warrant further study are known. Identifying stable QTL controlling seed size, oil and protein content is necessary for improvement of cottonseed quality. RESULTS: In this study, a recombinant inbred line (RIL) population was developed from a cross between upland cotton cultivars/lines Yumian 1 and M11. Specific locus amplified fragment sequencing (SLAF-seq) technology was used to construct a genetic map that covered 3353.15 cM with an average distance between consecutive markers of 0.48 cM. The seed index, together with kernel size, oil and protein content were further used to identify QTL. In total, 58 QTL associated with six traits were detected, including 13 stable QTL detected in all three environments and 11 in two environments. CONCLUSION: A high resolution genetic map including 7033 SNP loci was constructed through specific locus amplified fragment sequencing technology. A total of 13 stable QTL associated with six cottonseed quality traits were detected. These stable QTL have the potential for fine mapping, identifying candidate genes, elaborating molecular mechanisms of cottonseed development, and application in cotton breeding programs.

Natural variation in a CENTRORADIALIS homolog contributed to cluster fruiting and early maturity in cotton.

BACKGROUND: Plant architecture and the vegetative-reproductive transition have major impacts on the agronomic success of crop plants, but genetic mechanisms underlying these traits in cotton (Gossypium spp.) have not been identified. RESULTS: We identify four natural mutations in GoCEN-Dt associated with cluster fruiting (cl) and early maturity. The situ hybridization shows that GhCEN is preferentially expressed in cotton shoot apical meristems (SAM) of the main stem and axillary buds. Constitutive GhCEN-Dt overexpression suppresses the transition of the cotton vegetative apex to a reproductive shoot. Silencing GoCEN leads to early flowering and determinate growth, and in tetraploids causes the main stem to terminate in a floral bud, a novel phenotype that exemplifies co-adaptation of polyploid subgenomes and suggests new research and/or crop improvement approaches. Natural cl variations are enriched in cottons adapted to high latitudes with short frost-free periods, indicating that mutants of GoCEN have been strongly selected for early maturity. CONCLUSION: We show that the cotton gene GoCEN-Dt, a homolog of Antirrhinum CENTRORADIALIS, is responsible for determinate growth habit and cluster fruiting. Insight into the genetic control of branch and flower differentiation offers new approaches to develop early maturing cultivars of cotton and other crops with plant architecture appropriate for mechanical harvesting.

Sirt1 Antisense Long Noncoding RNA Promotes Cardiomyocyte Proliferation by Enhancing the Stability of Sirt1.

Background Antisense long noncoding RNAs (lnc RNA s) are single-stranded RNA s that overlapped gene-coding regions on the opposite DNA strand and play as critical regulators in cardiovascular diseases. The high conservation and stability may be good advantages for antisense lnc RNA s. However, the roles of antisense lnc RNA s in cardiomyocyte proliferation and cardiac regeneration are still unknown. Methods and Results In this study, we found that Silent information regulator factor 2 related enzyme 1 (Sirt1) antisense lnc RNA expression was significantly increased during heart development. By gain and loss function of Sirt1 antisense lnc RNA using adenovirus and locked nucleic acid, respectively, we demonstrated that Sirt1 antisense lnc RNA promoted cardiomyocyte proliferation in vitro and in vivo, and the suppression of Sirt1 antisense lnc RNA inhibited cardiomyocyte proliferation. Moreover, overexpression of Sirt1 antisense lnc RNA enhanced cardiomyocyte proliferation, attenuated cardiomyocyte apoptosis, improved cardiac function, and decreased mortality rate after myocardial infarction. Furthermore, Sirt1 antisense lnc RNA can bind the Sirt1 3'-untranslated region, enhancing the stability of Sirt1 and increasing Sirt1 abundance at both the mRNA and protein levels. Finally, we found that Sirt1 was involved in Sirt1 antisense lnc RNA -induced cardiomyocyte proliferation. Conclusions The present study identified Sirt1 antisense lnc RNA as a novel regulator of cardiomyocyte proliferation and cardiac regeneration by interacting and stabilizing Sirt1 mRNA , which may serve as an effective gene target for preventing myocardial infarction.

Chromosome structural variation of two cultivated tetraploid cottons and their ancestral diploid species based on a new high-density genetic map.

A high-resolution genetic map is a useful tool for assaying genomic structural variation and clarifying the evolution of polyploid cotton. A total of 36956 SSRs, including 11289 released in previous studies and 25567 which were newly developed based on the genome sequences of G. arboreum and G. raimondii, were utilized to construct a new genetic map. The new high-density genetic map includes 6009 loci and spanned 3863.97 cM with an average distance of 0.64 cM between consecutive markers. Four inversions (one between Chr08 and Chr24, one between Chr09 and Chr23 and two between Chr10 and Chr20) were identified by homology analysis. Comparative genomic analysis between genetic map and two diploid cottons showed that structural variations between the A genome and At subgenome are more extensive than between D genome and Dt subgenome. A total of 17 inversions, seven simple translocations and two reciprocal translocations were identified between genetic map and G. raimondii. Good colinearity was revealed between the corresponding chromosomes of tetraploid G. hirsutum and G. barbadense genomes, but a total of 16 inversions were detected between them. These results will accelerate the process of evolution analysis of Gossipium genus.