Mouse studies have been instrumental in forming our current understanding of early cell-lineage decisions; however, similar insights into the early human development are severely limited. Here, we ...present a comprehensive transcriptional map of human embryo development, including the sequenced transcriptomes of 1,529 individual cells from 88 human preimplantation embryos. These data show that cells undergo an intermediate state of co-expression of lineage-specific genes, followed by a concurrent establishment of the trophectoderm, epiblast, and primitive endoderm lineages, which coincide with blastocyst formation. Female cells of all three lineages achieve dosage compensation of X chromosome RNA levels prior to implantation. However, in contrast to the mouse, XIST is transcribed from both alleles throughout the progression of this expression dampening, and X chromosome genes maintain biallelic expression while dosage compensation proceeds. We envision broad utility of this transcriptional atlas in future studies on human development as well as in stem cell research.
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•Transcriptomes of 1,529 individual cells from 88 human preimplantation embryos•Lineage segregation of trophectoderm, primitive endoderm, and pluripotent epiblast•X chromosome dosage compensation in the human blastocyst
A comprehensive transcriptional map of human preimplantation development reveals a concurrent establishment of trophectoderm, epiblast, and primitive endoderm lineages and unique features of X chromosome dosage compensation in human.
Developmental biologists have become increasingly aware that the wealth of knowledge generated through genetic studies of pre-implantation mouse development might not easily be translated to the ...human embryo. Comparative studies have been fueled by recent technological advances in single-cell analysis, allowing in-depth analysis of the human embryo. This field could shortly gain more momentum as novel genome editing technologies might, for the first time, also allow functional genetic studies in the human embryo. In this Spotlight article, we summarize the CRISPR-Cas9 genome editing system and discuss its potential applications and limitations in human pre-implantation embryos, and the ethical considerations thereof.
Human pluripotent stem cells (PSCs) exist in naive and primed states and provide important models to investigate the earliest stages of human development. Naive cells can be obtained through ...primed-to-naive resetting, but there are no reliable methods to prospectively isolate unmodified naive cells during this process. Here we report comprehensive profiling of cell surface proteins by flow cytometry in naive and primed human PSCs. Several naive-specific, but not primed-specific, proteins were also expressed by pluripotent cells in the human preimplantation embryo. The upregulation of naive-specific cell surface proteins during primed-to-naive resetting enabled the isolation and characterization of live naive cells and intermediate cell populations. This analysis revealed distinct transcriptional and X chromosome inactivation changes associated with the early and late stages of naive cell formation. Thus, identification of state-specific proteins provides a robust set of molecular markers to define the human PSC state and allows new insights into the molecular events leading to naive cell resetting.
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•Flow cytometry profiles cell surface proteins in naive and primed human PSCs•The human PSC state can be defined using robust state-specific protein markers•Identified cell surface proteins track the dynamics of naive-primed PSC conversions•Analyses of early-stage naive cells reveal transcription events during conversion
Collier et al. use profiling to identify cell surface proteins that are specific for naive versus primed human pluripotent cells and then use them to isolate and characterize live naive cells arising during primed-to-naive resetting.
Although endonuclease-mediated genome editing techniques offer significant improvement over traditional methods, they are still ineffective for introduction of large DNA sequences. Recently in Nature ...Biotechnology, Gu et al. (2018) developed a CRISPR-Cas strategy termed 2C-HR-CRISPR that generates fluorescent reporter tagging of genes with up to 95% knockin efficiency in mouse embryos.
Although endonuclease-mediated genome editing techniques offer significant improvement over traditional methods, they are still ineffective for introduction of large DNA sequences. Recently in Nature Biotechnology, Gu et al. (2018) developed a CRISPR-Cas strategy termed 2C-HR-CRISPR that generates fluorescent reporter tagging of genes with up to 95% knockin efficiency in mouse embryos.
In vitro differentiation of human pluripotent stem cells into functional retinal pigment epithelial (RPE) cells provides a potentially unlimited source for cell based reparative therapy of ...age-related macular degeneration. Although the inherent pigmentation of the RPE cells have been useful to grossly evaluate differentiation efficiency and allowed manual isolation of pigmented structures, accurate quantification and automated isolation has been challenging. To address this issue, here we perform a comprehensive antibody screening and identify cell surface markers for RPE cells. We show that these markers can be used to isolate RPE cells during in vitro differentiation and to track, quantify and improve differentiation efficiency. Finally, these surface markers aided to develop a robust, direct and scalable monolayer differentiation protocol on human recombinant laminin-111 and -521 without the need for manual isolation.
As part of agile methodologies seen in the past few years, IT organizations have continuously adopted new practices in their software delivery life-cycle to improve both efficiency and effectiveness ...of development teams. Two of these practices are continuous integration and continuous deployment, which are part of the DevOps cycle which has helped organizations build software effectively and efficiently. These practices must be considered for new technologies such as smart contracts, where security concerns and bugs might cost more once deployed than traditional software. This paper states the importance of using a proper DevOps routine and how it is possible to apply this practice to a smart contract build. Specifically, this paper introduces a framework to implement DevOps for smart contracts development by describing multiple DevOps tools and their applicability to smart contract development.
Strength training has, in recent years, been shown to be beneficial for people with Parkinson disease and multiple sclerosis. Consensus regarding its utility for these disorders nevertheless remains ...contentious among healthcare professionals. Greater clarity is required, especially in regards to the type and magnitude of effects as well as the response differences to strength training between individuals with Parkinson disease or multiple sclerosis. This study examines the effects, magnitude of those effects, and response differences to strength training between patients with Parkinson disease or multiple sclerosis. A comprehensive search of electronic databases including Physiotherapy Evidence Database scale, PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL was conducted from inception to July 2014. English articles investigating the effect of strength training for individuals with neurodegenerative disorders were selected. Strength training trials that met the inclusion criteria were found for individuals with Parkinson disease or multiple sclerosis. Individuals with Parkinson disease or multiple sclerosis were included in the study. Strength training interventions included traditional (free weights/machine exercises) and nontraditional programs (eccentric cycling). Included articles were critically appraised using the Physiotherapy Evidence Database scale. Of the 507 articles retrieved, only 20 articles met the inclusion criteria. Of these, 14 were randomized and 6 were nonrandomized controlled articles in Parkinson disease or multiple sclerosis. Six randomized and 2 nonrandomized controlled articles originated from 3 trials and were subsequently pooled for systematic analysis. Strength training was found to significantly improve muscle strength in people with Parkinson disease (15%-83.2%) and multiple sclerosis (4.5%-36%). Significant improvements in mobility (11.4%) and disease progression were also reported in people with Parkinson disease after strength training. Furthermore, significant improvements in fatigue (8.2%), functional capacity (21.5%), quality of life (8.3%), power (17.6%), and electromyography activity (24.4%) were found in individuals with multiple sclerosis after strength training. The limitations of the study were the heterogeneity of interventions and study outcomes in Parkinson disease and multiple sclerosis trials. Strength training is useful for increasing muscle strength in Parkinson disease and to a lesser extent multiple sclerosis.
El objetivo de este trabajo es realizar un análisis comparativo tanto de adaptación textual como contextual de lo que han llamado remake transnacional, en dos estudios de caso de producciones ...latinoamericanas que fueron adaptadas en Hollywood, la llamada capital del cine. En la escala del análisis textual ejecutamos análisis de secuencias y nos detenemos en la construcción y reconstrucción de los espacios y los personales; en la contextual abordamos la cadena de producción, distribución y exhibición. Implícitamente estudiamos la tensión entre lo trasnacional y lo nacional que encuentra vínculos y diferencia entre lo cinematográfico (lo discursivo, estético o estilístico) y lo extra cinematográfico (lo ideológico, económico o histórico). Finalmente encontramos algunos indicios que explican el fracaso económico y de traducción cultural en un terreno de producción aparentemente seguro como el del remake transnacional.
Functional genetics of early human development Ortega, Nicolás M; Winblad, Nerges; Plaza Reyes, Alvaro ...
Current opinion in genetics & development,
10/2018, Volume:
52
Journal Article
Peer reviewed
Open access
Understanding the genetic underpinning of early human development is of great interest not only for basic developmental and stem cell biology but also for regenerative medicine, infertility ...treatments, and better understanding the causes of congenital disease. Our current knowledge has mainly been generated with the use of laboratory animals, especially the mouse. While human and mouse early development present morphological resemblance, we know that the timing of the events as well as the cellular and genetic mechanisms that control fundamental processes are distinct between the species. The rapid technological development of single-cell sequencing and genome editing together with novel stem cell models of the early human embryo has made it feasible and relevant to perform functional genetic studies directly in human cells and embryos. In this review we will discuss these latest advances where combined transcriptional analysis and genome engineering has begun to shed new insights into the key processes of zygotic genome activation, lineage specification, X-chromosome inactivation and postimplantation development including primordial germ cell specification in the human embryo.
PurposeThe aim of this study is to estimate the technical efficiency of the massive and economically important crop of rice in Ecuador, and then conduct a comparison between groups of farmers with ...and without insurance.Design/methodology/approachThe authors use an input-oriented data envelopment analysis approach (DEA) to estimate technical efficiency scores. The DEA is combined with the double bootstrap approach in Simar and Wilson (2007) to study factors that may affect technical efficiency. This method overcomes the traditional two-stage DEA approach frequently used in the efficiency literature. The authors thus research the role of insurance on rice efficiency production using this technique and sizeable field-level survey data from 376 rice farmers distributed in five provinces during the 2019 winter cycle in Ecuador.FindingsMost uninsured rice farmers operate with increasing returns to scale, which means that farms improve their resource use efficiency by increasing their size. However, since scale efficiencies are relatively high, it appears that inefficiencies are explained by inadequate input use. Also, the authors find evidence that insured farmers have a negative relationship with technical efficiency in rice production. In other results, when exploring the influence of additional variables on efficiency, the authors find that parameters related to transplanting, high education, farm size and some locations are positive and statistically significant.Social implicationsThe results of this work are relevant for policymakers interested in evaluating technology performance, risk management instruments and farm efficiency in an industry in a developing country such as rice production in Ecuador.Originality/valueThis paper is the first attempt to estimate farm-level technical efficiency employing the double bootstrap approach to assess the efficiency and its determinants of Ecuadorian rice producers.
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