Genotype-Specific Microsatellite (SSR) Markers for the Sugarcane Germplasm from the Karst Region of Guizhou, China

Genetic variability among sugarcane genotypes from the Karst region of China was evaluated using genotype-specific microsatellite (SSR) markers. Eighteen sugarcane genotypes including 13 active cultivars and five elite QT-series clones bred locally were screened for genetic variability with 21 SSR primer pairs. All the primer pairs were highly polymorphic and amplified a total of 167 alleles with an average of eight alleles per primer pair. The average polymorphism information content (PIC) value was 0.86 with a range of 0.68 and 0.92. A UPGMA dendrogram categorized the 18 sugarcane genotypes into three major groups containing three, ten and five genotypes, respectively. No geographical affinity was observed among genotypes within the same group. Eight SSR primer pairs produced cultivar-specific alleles, of which five alleles were unique to the QT-series clones, namely, SMC334BS-165 and SMC851MS-145 in QT 08-558, mSSCIR43-229 in QT 4, SM597CS-182 in QT 08-536 and SMC7CUQ-168 in QT 06-212. The clone-specific SSR alleles will be useful in identifying elite QT-series clones for use in the sugarcane crossing programs in China.

Whole genome variants across 57 pig breeds enable comprehensive identification of genetic signatures that underlie breed features

Background:A large number of pig breeds are distributed around the world,their features and characteristics vary among breeds,and they are valuable resources.Understanding the underlying genetic mechanisms that explain across-breed variation can help breeders develop improved pig breeds.Results:In this study,we performed GWAS using a standard mixed linear model with three types of genome variants(SNP,InDel,and CNV)that were identified from public,whole-genome,sequencing data sets.We used 469 pigs of 57 breeds,and we identified and analyzed approximately 19 million SNPs,1.8 million InDels,and 18,016 CNVs.We defined six biological phenotypes by the characteristics of breed features to identify the associated genome variants and candidate genes,which included coat color,ear shape,gradient zone,body weight,body length,and body height.A total of 37 candidate genes was identified,which included 27 that were reported previously(e.g.,PLAG1 for body weight),but the other 10 were newly detected candidate genes(e.g.,ADAMTS9 for coat color).Conclusion:Our study indicated that using GWAS across a modest number of breeds with high density genome variants provided efficient mapping of complex traits.

Vibration Effect and Damage Evolution Characteristics of Tunnel Surrounding Rock Under Cyclic Blasting Loading

Model test studies based on the similarity theory were conducted to investigate vibration effect and damage evolution characteristics of tunnel surrounding rock under push-type cyclic blasting excavation.The model was constructed with a ratio of 1∶15.By simulating the tunnel excavation of push-type cyclic blasting,the influence of the blasting parameter change on vibration effect was explored.The damage degree of tunnel surrounding rock was evaluated by the change of the acoustic wave velocity at the same measuring point after blasting.The relationship between the damage evolution of surrounding rock and blasting times was established.The research results show that：（1）In the same geological environment,the number of delay initiation is larger,the main vibration frequency of blasting seismic wave is higher,and the attenuation of high frequency signal in the rock and soil is faster.The influence of number of delay initiation on blasting vibration effect cannot be ignored;（2）Under push-type cyclic blasting excavation,there were great differences in the decreasing rates of acoustic wave velocity of the measuring points which have the same distance to the blasting region at the same depth,and the blasting damage ranges of surrounding rock were typically anisotropic at both depth and breadth;（3）When blasting parameters were basically kept as the same,the growth trend of the cumulative acoustic wave velocity decreasing rate at the measuring point was nonlinear under different cycle blasting excavations;（4）There were nonlinear evolution characteristics between the blasting cumulative damage（D）of surrounding rock and blasting times（n）under push-type cyclic blasting loading,and different measuring points had corresponding blasting cumulative damage propagation models,respectively.The closer the measuring point was away from the explosion source,the faster the cumulative damage extension.Blasting cumulative damage effect of surrounding rock had typically nonlinear evolution properties and anisotropic characteristics.

自噬小体绑定化合物(ATTEC)靶向降解线粒体及其潜在治疗效果

功能异常的线粒体的累积会诱发多种神经退化相关疾病,如帕金森氏病(PD)和唐氏综合征(DS).借助小分子化合物促进线粒体的降解被认为可以缓解这类疾病的进程.然而,目前尚缺乏这样一类高效、安全的靶向降解线粒体的小分子化合物.本研究借助一种名为自噬小体绑定化合物(ATTEC)的新型靶向降解技术,创造性地合成一种能同时结合自噬关键分子LC3B以及线粒体外膜蛋白TSPO的小分子化合物—mT1,并发现该化合物能够有效地降解细胞中的线粒体.借助分子生物学及细胞生物学手段,作者证明mT1能够促进LC3B和TSPO结合,从而将线粒体靶向自噬小体,并进一步与溶酶体融合而降解.此外,在PD的细胞模型和DS的类器官模型中证明mT1能够通过促进线粒体的清除而改善相应的病理学表型.该研究将ATTEC技术的应用范畴拓展到亚细胞器的层面,并为以PD和DS为代表的一类线粒体异常引起的疾病提供了一种潜在的新治疗策略.

Autophagic Clearance of Lipid Droplets Alters Metabolic Phenotypes in a Genetic Obesity–Diabetes Mouse Model

Lipid droplets(LDs)are intracellular organelles that store neutral lipids,and their aberrant accumulation is associated with many diseases including metabolic disorders such as obesity and diabetes.Meanwhile,the potential pathological contribu-tions of LDs in these diseases are unclear,likely due to a lack of chemical biology tools to clear LDs.We recently developed LD-clearance small molecule compounds,Lipid Droplets·AuTophagy TEthering Compounds(LD·ATTECs),that are able to induce autophagic clearance of LDs in cells and in the liver of db/db(C57BL/6J Leprdb/Leprdb)mouse model,which is a widely used genetic model for obesity–diabetes.Meanwhile,the potential effects on the metabolic phenotype remain to be elucidated.Here,using the metabolic cage assay and the blood glucose assay,we performed phenotypic characteriza-tion of the effects of the autophagic degradation of LDs by LD·ATTECs in the db/db mouse model.The study reveals that LD·ATTECs increased the oxygen uptake of mice and the release of carbon dioxide,enhanced the heat production of animals,partially enhanced the exercise during the dark phase,decreased the blood glucose level and improved insulin sensitivity.Collectively,the study characterized the metabolic phenotypes induced by LD·ATTECs in an obesity–diabetes mouse model,revealing novel functional impacts of autophagic clearance of LDs and providing insights into LD biology and obesity–dia-betes pathogenesis from the phenotypic perspective.

Inhibition of HIPK3 by AST487 Ameliorates Mutant HTT-Induced Neurotoxicity and Apoptosis via Enhanced Autophagy

Dear Editor,Accumulation of misfolded and aggregation-prone proteins is the common hallmark of many neurodegenerative disorders,and lowering the levels of these proteins may provide promising strategies for the potential treatment of some of these diseases[1,2].Among them,Huntington’s disease(HD)is a monogenic disease caused by mutation of the HTT(huntingtin)gene[3],which encodes the mutant HTT protein(mHTT)with an expanded polyglutamine tract(polyQ).

Correction:Inhibition of HIPK3 by AST487 Ameliorates Mutant HTT-Induced Neurotoxicity and Apoptosis via Enhanced Autophagy

We are sorry that we have made a few minor errors regarding the description of the scale bars and data presentation in the figure legends(not the figures)of the following manuscript:We’d like to make the following corrections:The authors would like to correct the following errors in the figure legends of Fig.1B–1D and Fig.2F–2I by changing“mean±SEM”to“mean±SD”.

A bacterial artificial chromosome-based physical map of Manihot esculenta ssp. flabellifolia

Cassava(Manihot esculenta) is known as the third most important food crop in the tropics and also used for industrial feedstock for biofuels. Two new bacterial artificial chromosome(BAC) libraries were constructed for W14(M. Esculenta ssp. flabellifolia), a wild ancestor of domesticated cassava. The libraries were constructed with EcoR I and Hind III insertion vectors, respectively.The EcoR I library has 29952 clones with an average insert size of 115 kb, while the Hind III library consists of 29952 clones with an average insert of 129 kb. The combined libraries contain a total of 59904 clones with an average insert size of 125 kb, representing approximately 10 ?haploid genome equivalents. A total of 29952 clones were fingerprinted and resulted in a cassava physical map composed of 2485 contigs with an average physical length of 336 kb and 2909 singletons, representing approximately762 Mb of the cassava genome. 5000 clones located at the ends of BAC contigs were selected and sequenced. A total of 6077 SNPs and 231 indels were identified, that covered459 gene sequences, of which 6 genes were associated with starch and sucrose metabolism. This BAC-based physical map provides valuable tools to understand the genetics and evolution of cassava.