RNA-guided CRISPR-Cas technologies for genome-scale investigation of disease processes

From its discovery as an adaptive bacterial and archaea immune system, the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system has quickly been developed into a powerful and groundbreaking programmable nuclease technology for the global and precise editing of the genome in cells. This system allows for comprehensive unbiased functional studies and is already advancing the field by revealing genes that have previously unknown roles in disease processes. In this review, we examine and compare recently developed CRISPR-Cas platforms for global genome editing and examine the advancements these platforms have made in guide RNA design, guide RNA/Cas9 interaction, on-target specificity, and target sequence selection. We also explore some of the exciting therapeutic potentials of the CRISPR-Cas technology as well as some of the innovative new uses of this technology beyond genome editing

Supervised Associative Learning in Spiking Neural Network

In this paper, we propose a simple supervised associative learning approach for spiking neural networks. In an excitatory-inhibitory network paradigm with Izhikevich spiking neurons, synaptic plasticity is implemented on excitatory to excitatory synapses dependent on both spike emission rates and spike timings. As results of learning, the network is able to associate not just familiar stimuli but also novel stimuli observed through synchronised activity within the same subpopulation and between two associated subpopulations

An Innovative Approach To Housing Hearing Impaired Students On A College Campus

1981 V 14 Issue

The focus of spatial attention determines the number and precision of face representations in working memory

The capacity of visual working memory for faces is extremely limited, but the reasons for these limitations remain unknown. We employed event-related brain potential (ERP) measures to demonstrate that individual faces have to be focally attended in order to be maintained in working memory, and that attention is allocated to only a single face at a time. When two faces have to be memorized simultaneously in a face identity matching task, the focus of spatial attention during encoding predicts which of these faces can be successfully maintained in working memory and matched to a subsequent test face. We also show that memory representations of attended faces are maintained in a position-dependent fashion. These findings demonstrate that the limited capacity of face memory is directly linked to capacity limits of spatial attention during the encoding and maintenance of individual face representations. We suggest that the capacity and distribution of selective spatial attention is a dynamic resource that constrains the capacity and fidelity of working memory for faces

Identifying the Effects of Unprocessed let-7a-1 and let-7a-3 in Non-Small Cell Lung Cancer

MicroRNAs (miRNAs) are small, noncoding RNAs that regulate protein levels typically by interacting with the 3′ untranslated region (3′-UTR) of target messenger RNA (mRNAs) and are often aberrantly expressed in cancer. The let-7 miRNA family members are commonly regarded as cancer suppressors, by down-regulating the expression of oncoproteins such as RAS, HMGA2, and MYC. However, prior work indicates that unprocessed let-7 RNAs may be positively correlated with cancer phenotypes in lung cancer cell lines. Our study aims to identify the effects of unprocessed let-7a-1 and let-7a-3 in non-small cell lung cancer, by transfecting plasmids that express unprocessed let-7a-1 and let-7a-3 into 3 different lung cancer cell lines. We then proceeded to conduct functional assays to measure the differences in anchorage independent growth, cell proliferation, and cell migration in all cell lines transfected with unprocessed let-7, in contrast to cells transfected with a control vector and thus far determined that unprocessed let-7a-1 can enhance anchorage independent growth. Thus, we created truncations of the let-7a-1 miRNA to identify the cis regions of this miRNA that is responsible for the change in phenotype. Our results suggest that cells transfected with truncated, yet unprocessed let-7a-1 have increased anchorage independent growth, a major hallmark of cancer cell. There is still a need to replicate the functional assays that were conducted while continuing to create constructs of both let-7a-1 and let-7a-3 in order to further identify the sequence of the miRNAs responsible for the enhanced cancer phenotypes

Histone 4 lysine 20 tri-methylation: a key epigenetic regulator in chromatin structure and disease

Chromatin is a vital and dynamic structure that is carefully regulated to maintain proper cell homeostasis. A great deal of this regulation is dependent on histone proteins which have the ability to be dynamically modified on their tails via various post-translational modifications (PTMs). While multiple histone PTMs are studied and often work in concert to facilitate gene expression, here we focus on the tri-methylation of histone H4 on lysine 20 (H4K20me3) and its function in chromatin structure, cell cycle, DNA repair, and development. The recent studies evaluated in this review have shed light on how H4K20me3 is established and regulated by various interacting partners and how H4K20me3 and the proteins that interact with this PTM are involved in various diseases. Through analyzing the current literature on H4K20me3 function and regulation, we aim to summarize this knowledge and highlights gaps that remain in the field