Defined hydrogels for spinal cord organoids:challenges and potential applications

Organoids of the central nervous system,primarily derived from pluripotent stem cells or neural stem cells,are three-dimensional tissue cultures with self-organizing properties.When exposed to the right combinations of signals,they differentiate into a 3D tissue consisting of complex cytoarchitecture and native cell types,including various neuron subtypes and glial cells.These features closely mimic native tissues,making them invaluable for developmental studies and disease modeling.In recent years,spinal cord organoids(SCOs)have been developed to investigate spinal cord development,injuries,and various neurological disorders.As an integral part of the central nervous system,SCOs play a vital role and serve as a site for studying both neurodevelopment and neurodegenerative diseases.

Design,challenges,and the potential of transcriptomics to understand social behavior

Rapid advances in Ribonucleic Acid sequencing(or RNA-seq)technology for analyzing entire transcriptomes of desired tissue samples,or even of single cells at scale,have revolutionized biology in the past decade.Increasing accessibility and falling costs are making it possible to address many problems in biology that were once considered intractable,including the study of various social behaviors.RNA-seq is opening new avenues to understand long-standing questions on the molecular basis of behavioral plasticity and individual variation in the expression of a behavior.As whole transcriptomes are examined,it has become possible to make unbiased discoveries of underlying mechanisms with little or no necessity to predict genes involved in advance.However,researchers need to be aware of technical limitations and have to make specific decisions when applying RNA-seq to study social behavior.Here,we provide a perspective on the applications of RNA-seq and experimental design considerations for behavioral scientists who are unfamiliar with the technology but are considering using it in their research.

Combating COVID-19 with Chloroquine

Since December 2019,the world is increasingly facing an unprecedented challenge by coronavirus disease 2019(COVID-19)caused by a virus called severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),which is structurally related to the human severe acute respiratory syndrome CoV(SARS-CoV)and Middle East respiratory syn-drome CoV(MERS-CoV)(Zhu et al.,2020).The World Health Organization(WHO)has declared COVID-19 a pandemic and is calling for forceful action from all countries,as the number of infected patients and the number of deaths are increasing daily,causing catastrophic consequence to the daily life,economy,and society.

Science:推翻常规认知! 科学家发现树突细胞或许源于特殊祖细胞

树突细胞是机体免疫力的”门卫”，其能够帮助机体有效检测并且开启抵御外来病原体或异物的免疫力，截止到目前为止，研究者认为树突细胞的亚型是从一种共同的祖细胞分化而来；近日，一项刊登在国际杂志science上的研究报告中，来自新加坡ASTAR研究所等机构的研究人员通过研究发现，人类机体的免疫细胞或许是从特殊的祖细胞衍生而来，相关研究或为后期开发新型疫苗并且优化疫苗提供了新的线索。

Cost-effective hybrid long-short read assembly delineates alternative GC-rich Streptomyces hosts for natural product discovery

With the advent of rapid automated in silico identification of biosynthetic gene clusters(BGCs),genomics pre-sents vast opportunities to accelerate natural product(NP)discovery.However,prolific NP producers,Strepto-myces,are exceptionally GC-rich(>80%)and highly repetitive within BGCs.These pose challenges in sequencing and high-quality genome assembly which are currently circumvented via intensive sequencing.Here,we outline a more cost-effective workflow using multiplex Illumina and Oxford Nanopore sequencing with hybrid long-short read assembly algorithms to generate high quality genomes.Our protocol involves subjecting long read-derived assemblies to up to 4 rounds of polishing with short reads to yield accurate BGC predictions.We successfully sequenced and assembled 8 GC-rich Streptomyces genomes whose lengths range from 7.1 to 12.1 Mb with a median N50 of 8.2 Mb.Taxonomic analysis revealed previous misrepresentation among these strains and allowed us to propose a potentially new species,Streptomyces sydneybrenneri.Further comprehensive characterization of their biosynthetic,pan-genomic and antibiotic resistance features especially for molecules derived from type I polyketide synthase(PKS)BGCs reflected their potential as alternative NP hosts.Thus,the genome assemblies and insights presented here are envisioned to serve as gateway for the scientific community to expand their avenues in NP discovery.