Short-read sequencing has enabled the de novo assembly of several individual human genomes, but with inherent limitations in characterizing repeat elements. Here we sequence a Chinese individual HX1 by single-molecule real-time (SMRT) long-read sequencing, construct a physical map by NanoChannel arrays and generate a de novo assembly of 2.93 Gb (contig N50: 8.3 Mb, scaffold N50: 22.0 Mb, including 39.3 Mb N-bases), together with 206 Mb of alternative haplotypes. The assembly fully or partially fills 274 (28.4%) N-gaps in the reference genome GRCh38. Comparison to GRCh38 reveals 12.8 Mb of HX1-specific sequences, including 4.1 Mb that are not present in previously reported Asian genomes. Furthermore, long-read sequencing of the transcriptome reveals novel spliced genes that are not annotated in GENCODE and are missed by short-read RNA-Seq. Our results imply that improved characterization of genome functional variation may require the use of a range of genomic technologies on diverse human populations.
Induced pluripotent stem cells (iPSCs) can differentiate into neural progenitor cells (NPC) under proper conditions. NPC can be used as a model and is a useful tool for disease mechanism exploration and drug screening. However, the characteristics of the cells in various stages from NPC to functional neurons have not been fully described. This study investigated the characteristics of iPSC-derived NPCs during differentiation. Morphological characteristics of the NPCs, including soma area, neurite length, and the number of neurite branches, were examined on selected differentiation days. Physiological functions were assessed by recordings of sodium current, spontaneous excitatory postsynaptic current (sEPSC), and spontaneous inhibitory postsynaptic current (sIPSC). Furthermore, gene expression patterns were assessed with RNA-seq. We found that NPCs derived from iPSCs can be differentiated into glutamatergic and gabaergic neurons. Cell growth peaked during differentiation day 7–12, as the soma area decreased after day 12, growth cone and the number of branches peaked at day 9 and decreased afterwards; whereas a functional synapse formed after day 23. RNA-seq analysis found that a differential expression pattern emerged by day 7. Overall, the study provides a framework for the differentiation process of hiPSC-derived NPCs.
SHANK3 mutations, including de novo deletions, have been associated with autism spectrum disorders (ASD). However, the effects of SHANK3 loss of function on neurodevelopment remain poorly understood. Here we generated human induced pluripotent stem cells (iPSC) in vitro, followed by neuro-differentiation and lentivirus-mediated shRNA expression to evaluate how SHANK3 knockdown affects the in vitro neurodevelopmental process at multiple time points (up to 4 weeks). We found that SHANK3 knockdown impaired both early stage of neuronal development and mature neuronal function, as demonstrated by a reduction in neuronal soma size, growth cone area, neurite length and branch numbers. Notably, electrophysiology analyses showed defects in excitatory and inhibitory synaptic transmission. Furthermore, transcriptome analyses revealed that multiple biological pathways related to neuron projection, motility and regulation of neurogenesis were disrupted in cells with SHANK3 knockdown. In conclusion, utilizing a human iPSC-based neural induction model, this study presented combined morphological, electrophysiological and transcription evidence that support that SHANK3 as an intrinsic, cell autonomous factor that controls cellular function development in human neurons.
Given the increasing incidence of neurodegenerative disease (ND), recent research efforts have intensified the search for curative treatments. Despite significant research, however, existing therapeutic options for ND can only slow down the progression of the disease, but not provide a cure. Light therapy (LT) has been used to treat some mental and sleep disorders. This review illustrates recent studies of the use of LT in patients with ND and highlights its potential for clinical applications. The literature was collected from PubMed through June 2020. Selected studies were primarily English articles or articles that could be obtained with English abstracts and Chinese main text. Articles were not limited by type. Additional potential publications were also identified from the bibliographies of identified articles and the authors’ reference libraries. The identified literature suggests that LT is a safe and convenient physical method of treatment. It may alleviate sleep disorders, depression, cognitive function, and other clinical symptoms. However, some studies have reported limited or no effects. Therefore, LT represents an attractive therapeutic approach for further investigation in ND. LT is an effective physical form of therapy and a new direction for research into treatments for ND. However, it requires further animal experiments to elucidate mechanisms of action and large, double-blind, randomized, and controlled trials to explore true efficacy in patients with ND.
Tctn3 belongs to the Tectonic (Tctn) family and is a single-pass membrane protein localized at the transition zone of primary cilia as an important component of ciliopathy-related protein complexes. Previous studies showed that mutations in Tctn1 and Tctn2, two members of the tectonic family, have been reported to disrupt neural tube development in humans and mice, but the functions of Tctn3 in brain development remain elusive. In this study, Tctn3 knockout (KO) mice were generated by utilizing the piggyBac (PB) transposon system. We found that Tctn3 KO mice exhibited abnormal global development, including prenatal lethality, microphthalmia, polysyndactyly, and abnormal head, sternum, and neural tube, whereas Tctn3 heterozygous KO mice did not show abnormal development or behaviors. Further, we found that the mRNA levels of Gli1 and Ptch1, downstream signaling components of the Shh pathway, were significantly reduced. Likewise, neural tube patterning-related proteins, such as Shh, Foxa2, and Nkx2.2, were altered in their distribution. Interestingly, Tctn3 KO led to significant changes in apoptosis-related proteins, including Bcl-2, Bax, and cleaved PARP1, resulting in reduced numbers of neuronal cells in embryonic brains. Tctn3 KO inhibited the PI3K/Akt signaling pathway but not the mTOR-dependent pathway. The small molecule SC79, a specific Akt activator, blocked apoptotic cell death in primary mouse embryonic fibroblasts from Tctn3 KO mice. Finally, NPHP1, a protein with anti-apoptotic ability, was found to form a complex with Tctn3, and its levels were decreased in Tctn3 KO mice. In conclusion, our results show that Tctn3 KO disrupts the Shh signaling pathway and neural tube patterning, resulting in abnormal embryonic development, cellular apoptosis, and prenatal death in mice.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.