Identification and characterization of NARROW AND ROLLED LEAF 1, a novel gene regulating leaf morphology and plant architecture in rice

Leaf morphology is an important agronomic trait in rice breeding. We isolated three allelic mutants of NARROW AND ROLLED LEAF 1 (nrl1) which showed phenotypes of reduced leaf width and semi-rolled leaves and different degrees of dwarfism. Microscopic analysis indicated that the nrl1-1 mutant had fewer longitudinal veins and smaller adaxial bulliform cells compared with the wild-type. The NRL1 gene was mapped to the chromosome 12 and encodes the cellulose synthase-like protein D4 (OsCslD4). Sequence analyses revealed single base substitutions in the three allelic mutants. Genetic complementation and over-expression of the OsCslD4 gene confirmed the identity of NRL1. The gene was expressed in all tested organs of rice at the heading stage and expression level was higher in vigorously growing organs, such as roots, sheaths and panicles than in elsewhere. In the mutant leaves, however, the expression level was lower than that in the wild-type. We conclude that OsCslD4 encoded by NRL1 plays a critical role in leaf morphogenesis and vegetative development in rice.     

Improvement and Optimization of Standards for a Preclinical Animal Test Model of Laser Induced Choroidal Neovascularization

Background

As the murine model of laser-induced choroidal neovascularization (CNV) is becoming the most established and commonly utilized model worldwide for studying the pathogenesis of CNV and its response to treatment, specific operating standards are yet to be clarified. The purpose of this study is to compare the lesion size of CNV in mice with different ages, sex, durations of CNV process, and treated positions of laser spots, to make recommendations that may improve and optimize the quality of the model.

Methods and Results

C57/BL6 mice of different ages were treated with diode laser photocoagulation per eye and perfused with PBS containing fluorescein-labeled dextran at different time of observation. Choroid flat mounts, were then examined by fluorescence microscopy for the measurement of CNV area. Messenger-RNA expression levels of several angiogenic cytokines in eye cups of male and female C57BL/6 mice at 5–8 and 16–20 week-old were analyzed by real-time RT-PCR assay. The results showed significantly more CNV area in eyes of female mice compared to male mice with the expression level of several angiogenic cytokines elevated. 16–20-week-old female mice developed the biggest area of CNV. The mean area of CNV increased significantly at the 14^th day after photocoagulation. Laser spots delivered 1PD away from the optic disc induced the biggest area of CNV compared to those 2PD or 3PD away. Interaction of NV was observed in laser spots delivered less than 1PD away from each other.

Conclusion

The current results suggest that 16–20-week-old female C57BL/6 mice developed the most distinct CNV lesion size with laser spots delivered 1PD away from the optic disc. The best time to observe and analyze is the 14^th day after photocoagulation.     

Non-contiguous finished genome sequence of Anoxybacillus flavithermus subsp. yunnanensis type strain (E13T), a strictly thermophilic and organic solvent-tolerant bacterium

Anoxybacillus flavithermus subsp. yunnanensis is the only strictly thermophilic bacterium that is able to tolerate a broad range of toxic solvents at its optimal temperature of 55-60°C. The type strain E13^T was isolated from water-sediment slurries collected from a hot spring. This study presents the draft genome sequence of A. flavithermus subsp. yunnanensis E13^T and its annotation. The 2,838,393bp long genome (67 contigs) contains 3,035 protein-coding genes and 85 RNA genes, including 10 rRNA genes, and no plasmids. The genome information has been used to compare with the genomes from A. flavithermus subsp. flavithermus strains.     

Genetic diversity and population structure of Quercus fabri Hance in China revealed by genotyping‐by‐sequencing

Analysis of genetic diversity and population structure among Quercus fabri populations is essential for the conservation and utilization of Q. fabri resources. Here, the genetic diversity and structure of 158 individuals from 13 natural populations of Quercus fabri in China were analyzed using genotyping‐by‐sequencing (GBS). A total of 459,564 high‐quality single nucleotide polymorphisms (SNPs) were obtained after filtration for subsequent analysis. Genetic structure analysis revealed that these individuals can be clustered into two groups and the structure can be explained mainly by the geographic barrier, showed gene introgression from coastal to inland areas and high mountains could significantly hinder the mutual introgression of genes. Genetic diversity analysis indicated that the individual differences within groups are greater than the differences between the two groups. These results will help us better understand the genetic backgrounds of Q. fabri.     

Four New Diterpenoid Alkaloids from The Roots of Aconitum coreanum

Four new hetisine‐type C₂₀‐diterpenoid alkaloids, named as coreanines A–D ( 1 – 4 ), were isolated from the roots of Aconitum coreanum, together with thirteen known alkaloids ( 5 – 17 ). Their structures were elucidated by extensive spectroscopic methods including IR, HR‐ESI‐MS and NMR techniques. All the isolated compounds were screened for the acetylcholinesterase (AChE) inhibitory effects, and none of them showed considerable inhibitory activity.     

Crumbs proteins stabilize the cone mosaics of photoreceptors and improve vision in zebrafish

Although the unique organization of vertebrate cone mosaics was first described long ago,both their underlying molecular basis and physiological significance are largely unknown.Here,we demonstrate that Crumbs proteins,the key regulators of epithelial apical polarity,establish the planar cellular polarity of photoreceptors in zebrafish.Via heterophilic Crb2a-Crb2b interactions,the apicobasal polarity protein Crb2b restricts the asymmetric planar distribution of Crb2a in photoreceptors.The planar polarized Crumbs proteins thus balance intercellular adhesions and tension between photoreceptors,thereby stabilizing the geometric organization of cone mosaics.Notably,loss of Crb2b in zebrafish induces a nearsightedness-like phenotype in zebrafish accompanied by an elongated eye axis and impairs zebrafish visual perception for predation.These data reveal a detailed mechanism for cone mosaic homeostasis via previously undiscovered apical-planar polarity coordination and propose a pathogenic mechanism for nearsightedness.     

Altered sperm tsRNAs in aged male contribute to anxiety‐like behavior in offspring

Parental age at first pregnancy is increasing worldwide. The offspring of aged father has been associated with higher risk of several neuropsychiatric disorders, such as schizophrenia and autism, but the underlying mechanism remains elusive. Here we report that advanced paternal age in mice alters the profile of transfer RNA‐derived small RNAs (tsRNAs). Injection of sperm tsRNAs from aged male mice into zygotes induced anxiety‐like behaviors in F1 males. RNA sequencing of the cerebral cortex and hippocampus of those F1 male mice altered the gene expression of dopaminergic synapse and neurotrophin. tsRNAs from aged male mice injection also altered the neuropsychiatry‐related gene expression in two‐cell and blastocyst stage embryos. More importantly, the sperm tsRNA profile changes significantly during aging in human. The up‐regulated sperm tsRNA target genes were involved in neurogenesis and nervous system development. These results suggest that aging‐related changes of sperm tsRNA may contribute to the intergenerational transmission of behavioral traits.