In vivo action of RNA G-quadruplex in phloem development

Phloem network integrates cellular energy status into post-embryonic growth, and development by tight regulation of carbon allocation. Phloem development involves complicated coordination of cell fate determination, cell division, and terminal differentiation into sieve elements (SEs), functional conduit All of these processes must be tightly coordinated, for optimization of systemic connection between source supplies and sink demands throughout plant life cycle, that has substantial impact on crop productivity. Despite its pivotal role, surprisingly, regulatory mechanisms underlying phloem development have just begun to be explored, and we recently identified a novel translational regulatory network involving RNA G-quadruplex and a zinc-finger protein, JULGI, for phloem development From this perspective, we further discuss the role of RNA G-quadruplex on post-transcriptional control of phloem regulators, as a potential interface integrating spatial information for asymmetric cell division, and phloem development.11Ysciescopuskc

Diffusion-Weighted MR Imaging of Unusual White Matter Lesion in a Patient with Menkes Disease

We report here on the diffusion-weighted imaging of unusual white matter lesions in a case of Menkes disease. On the initial MR imaging, the white matter lesions were localized in the deep periventricular white matter in the absence of diffuse cortical atrophy. The lesion showed diffuse high signal on the diffusion-weighted images and diffuse progression and persistent hyperintensity on the follow up imaging. Our case suggests that the white matter lesion may precede diffuse cortical atrophy in a patient with Menkes disease

Reversible Splenium Lesion of the Corpus Callosum in Hemorrhagic Fever with Renal Failure Syndrome

This is the first case of virus-associated encephalitis/encephalopathy in which the pathogen was Hantaan virus. A 53-yr-old man presented fever, renal failure and a hemorrhagic tendency and he was diagnosed with hemorrhagic fever with renal failure syndrome (HFRS). In the course of his illness, mild neurologic symptoms such as dizziness and confusion developed and magnetic resonance images revealed a reversible lesion in the splenium of the corpus callosum. This case suggests that HFRS patients with neurologic symptoms like dizziness and mental slowing should be considered to have structural brain lesions and to require brain imaging studies

Whole-exome sequencing in 168 Korean patients with inherited retinal degeneration

Background To date, no genetic analysis of inherited retinal disease (IRD) using whole-exome sequencing (WES) has been conducted in a large-scale Korean cohort. The aim of this study was to characterise the genetic profile of IRD patients in Korea using WES. Methods We performed comprehensive molecular testing in 168 unrelated Korean IRD patients using WES. The potential pathogenicity of candidate variants was assessed using the American College of Medical Genetics and Genomics and the Association for Molecular Pathology variant interpretation guidelines, in silico prediction tools, published literature, and compatibility with known phenotypes or inheritance patterns. Results Causative variants were detected in 86/168 (51.2%) IRD patients, including 58/107 (54.2%) with retinitis pigmentosa, 7/15 (46.7%) with cone and cone-rod dystrophy, 2/3 (66.6%) with Usher syndrome, 1/2 (50.0%) with congenital stationary night blindness, 2/2 (100.0%) with Leber congenital amaurosis, 1/1 (100.0%) with Bietti crystalline dystrophy, 1/1 (100.0%) with Joubert syndrome, 9/10 (90.0%) with Stargardt macular dystrophy, 1/10 (10.0%) with vitelliform macular dystrophy, 1/11 (9.1%) with other forms of macular dystrophy, and 3/4 (75.0%) with choroideraemia. USH2A, ABCA4, and EYS were the most common causative genes associated with IRD. For retinitis pigmentosa, variants of USH2A and EYS were the most common causative gene mutations. Conclusions This study demonstrated the distribution of causative genetic mutations in Korean IRD patients. The data will serve as a reference for future genetic screening and development of treatment modalities for Korean IRD patients.This study was supported by the Korean Association of Retinal Degenera‑tion, by a Grant Number 2620170060 from the SNUH Research Fund, and by a grant of the Korea Research-Driven Hospital (Grant Number: HI14C1277) through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health and Welfare (MHW), Republic of Korea. The funding bodies played no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript

HIGH CROSSOVER RATE1 encodes PROTEIN PHOSPHATASE X1 and restricts meiotic crossovers in Arabidopsis.

Meiotic crossovers are tightly restricted in most eukaryotes, despite an excess of initiating DNA double-strand breaks. The majority of plant crossovers are dependent on class I interfering repair, with a minority formed via the class II pathway. Class II repair is limited by anti-recombination pathways; however, similar pathways repressing class I crossovers have not been identified. Here, we performed a forward genetic screen in Arabidopsis using fluorescent crossover reporters to identify mutants with increased or decreased recombination frequency. We identified HIGH CROSSOVER RATE1 (HCR1) as repressing crossovers and encoding PROTEIN PHOSPHATASE X1. Genome-wide analysis showed that hcr1 crossovers are increased in the distal chromosome arms. MLH1 foci significantly increase in hcr1 and crossover interference decreases, demonstrating an effect on class I repair. Consistently, yeast two-hybrid and in planta assays show interaction between HCR1 and class I proteins, including HEI10, PTD, MSH5 and MLH1. We propose that HCR1 plays a major role in opposition to pro-recombination kinases to restrict crossovers in Arabidopsis.Marie Curie International Training Network COMREC European Research Council (ERC) National Research Foundation of Korea Suh Kyungbae Foundatio