The formation of the embryonic brain and spinal cord begins as the neural plate bends to form the neural folds, which meet and adhere to close the neural tube. The neural ectoderm and surrounding ...tissues also coordinate proliferation, differentiation, and patterning. This highly orchestrated process is susceptible to disruption, leading to neural tube defects (NTDs), a common birth defect. Here, we highlight genetic and epigenetic contributions to neural tube closure. We describe an online database we created as a resource for researchers, geneticists, and clinicians. Neural tube closure is sensitive to environmental influences, and we discuss disruptive causes, preventative measures, and possible mechanisms. New technologies will move beyond candidate genes in small cohort studies toward unbiased discoveries in sporadic NTD cases. This will uncover the genetic complexity of NTDs and critical gene-gene interactions. Animal models can reveal the causative nature of genetic variants, the genetic interrelationships, and the mechanisms underlying environmental influences.
Challenges conventional views of the Edwardian period as either a hangover of Victorianism or a bystander to literary modernism.In this ground-breaking study, Jonathan Wild investigates the literary ...history of the Edwardian decade. This period, long overlooked by critics, is revealed as a vibrant cultural era whose writers were determined to break away from the stifling influence of preceding Victorianism. In the hands of this generation, which included writers such as Arnold Bennett, Joseph Conrad, E. M. Forster, Beatrix Potter, and H.G. Wells, the new century presented a unique opportunity to fashion innovative books for fresh audiences. Wild traces this literary innovation by conceptualising the focal points of his study as branches of one of the new department stores that epitomized Edwardian modernity. These 'departments' – war and imperialism, the rise of the lower middle class, children's literature, technology and decadence, and the condition of England – offer both discrete and interconnected ways in which to understand the distinctiveness and importance of the Edwardian literary scene. Overall, The Great Edwardian Emporium offers a long-overdue investigation into a decade of literature that provided the cultural foundation for the coming century.
Searching for factors to improve knockin efficiency for therapeutic applications, biotechnology, and generation of non-human primate models of disease, we found that the strand exchange protein RAD51 ...can significantly increase Cas9-mediated homozygous knockin in mouse embryos through an interhomolog repair (IHR) mechanism. IHR is a hallmark of meiosis but only occurs at low frequencies in somatic cells, and its occurrence in zygotes is controversial. Using multiple approaches, we provide evidence for an endogenous IHR mechanism in the early embryo that can be enhanced by RAD51. This process can be harnessed to generate homozygotes from wild-type zygotes using exogenous donors and to convert heterozygous alleles into homozygous alleles without exogenous templates. Furthermore, we identify additional IHR-promoting factors and describe features of IHR events. Together, our findings show conclusive evidence for IHR in mouse embryos and describe an efficient method for enhanced gene conversion.
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•Interhomolog repair (IHR) occurs throughout the genome in the early mouse embryo•RAD51, BCCIP, and USP1/WDR48 enhance IHR at sites of Cas9-induced DNA breaks•Embryonic IHR occurs via gene conversion without crossover•Enhanced IHR can be used for homozygous knockin and donor-free allelic conversion
Co-injection of mouse zygotes with RAD51 and Cas9 can enhance interhomolog repair and facilitate conversion of heterozygous alleles to homozygous alleles.
Approximately 15 to 30% of thyroid nodules evaluated by means of fine-needle aspiration are not clearly benign or malignant. Patients with cytologically indeterminate nodules are often referred for ...diagnostic surgery, though most of these nodules prove to be benign. A novel diagnostic test that measures the expression of 167 genes has shown promise in improving preoperative risk assessment.
We performed a 19-month, prospective, multicenter validation study involving 49 clinical sites, 3789 patients, and 4812 fine-needle aspirates from thyroid nodules 1 cm or larger that required evaluation. We obtained 577 cytologically indeterminate aspirates, 413 of which had corresponding histopathological specimens from excised lesions. Results of a central, blinded histopathological review served as the reference standard. After inclusion criteria were met, a gene-expression classifier was used to test 265 indeterminate nodules in this analysis, and its performance was assessed.
Of the 265 indeterminate nodules, 85 were malignant. The gene-expression classifier correctly identified 78 of the 85 nodules as suspicious (92% sensitivity; 95% confidence interval CI, 84 to 97), with a specificity of 52% (95% CI, 44 to 59). The negative predictive values for "atypia (or follicular lesion) of undetermined clinical significance," "follicular neoplasm or lesion suspicious for follicular neoplasm," or "suspicious cytologic findings" were 95%, 94%, and 85%, respectively. Analysis of 7 aspirates with false negative results revealed that 6 had a paucity of thyroid follicular cells, suggesting insufficient sampling of the nodule.
These data suggest consideration of a more conservative approach for most patients with thyroid nodules that are cytologically indeterminate on fine-needle aspiration and benign according to gene-expression classifier results. (Funded by Veracyte.).
RAD21 Mutations Cause a Human Cohesinopathy Deardorff, Matthew A.; Wilde, Jonathan J.; Albrecht, Melanie ...
American journal of human genetics,
06/2012, Letnik:
90, Številka:
6
Journal Article
Recenzirano
Odprti dostop
The evolutionarily conserved cohesin complex was originally described for its role in regulating sister-chromatid cohesion during mitosis and meiosis. Cohesin and its regulatory proteins have been ...implicated in several human developmental disorders, including Cornelia de Lange (CdLS) and Roberts syndromes. Here we show that human mutations in the integral cohesin structural protein RAD21 result in a congenital phenotype consistent with a “cohesinopathy.” Children with RAD21 mutations display growth retardation, minor skeletal anomalies, and facial features that overlap findings in individuals with CdLS. Notably, unlike children with mutations in NIPBL, SMC1A, or SMC3, these individuals have much milder cognitive impairment than those with classical CdLS. Mechanistically, these mutations act at the RAD21 interface with the other cohesin proteins STAG2 and SMC1A, impair cellular DNA damage response, and disrupt transcription in a zebrafish model. Our data suggest that, compared to loss-of-function mutations, dominant missense mutations result in more severe functional defects and cause worse structural and cognitive clinical findings. These results underscore the essential role of RAD21 in eukaryotes and emphasize the need for further understanding of the role of cohesin in human development.
Human genetic studies have established a link between a class of centrosome proteins and microcephaly. Current studies of microcephaly focus on defective centrosome/spindle orientation. Mutations in ...WDR62 are associated with microcephaly and other cortical abnormalities in humans. Here we create a mouse model of Wdr62 deficiency and find that the mice exhibit reduced brain size due to decreased neural progenitor cells (NPCs). Wdr62 depleted cells show spindle instability, spindle assembly checkpoint (SAC) activation, mitotic arrest and cell death. Mechanistically, Wdr62 associates and genetically interacts with Aurora A to regulate spindle formation, mitotic progression and brain size. Our results suggest that Wdr62 interacts with Aurora A to control mitotic progression, and loss of these interactions leads to mitotic delay and cell death of NPCs, which could be a potential cause of human microcephaly.
Common polygenic diseases result from compounded risk contributed by multiple genetic variants, meaning that simultaneous correction or introduction of single nucleotide variants is required for ...disease modeling and gene therapy. Here, we show precise, efficient, and simultaneous multiplex base editing of up to three target sites across 11 genes/loci in cynomolgus monkey embryos using CRISPR-based cytidine- and adenine-base editors. Unbiased whole genome sequencing demonstrates high specificity of base editing in monkey embryos. Our data demonstrate feasibility of multiplex base editing for polygenic disease modeling in primate zygotes.
Novel developments in therapies for various hereditary hemolytic anemias reflect the pivotal role of pyruvate kinase (PK), a key enzyme of glycolysis, in red blood cell (RBC) health. Without PK ...catalyzing one of the final steps of the Embden-Meyerhof pathway, there is no net yield of adenosine triphosphate (ATP) during glycolysis, the sole source of energy production required for proper RBC function and survival. In hereditary hemolytic anemias, RBC health is compromised and therefore lifespan is shortened. Although our knowledge on glycolysis in general and PK function in particular is solid, recent advances in genetic, molecular, biochemical, and metabolic aspects of hereditary anemias have improved our understanding of these diseases. These advances provide a rationale for targeting PK as therapeutic option in hereditary hemolytic anemias other than PK deficiency. This review summarizes the knowledge, rationale, (pre)clinical trials, and future advances of PK activators for this important group of rare diseases.
•PK is a key enzyme of anaerobic glycolysis on which RBCs depend for cellular energy.•PK activators are a novel targeted therapeutic option for the treatment of PK deficiency.•Activation of PK is promising for other forms of hereditary hemolytic anemia.
Parkinson's disease (PD) is a debilitating neurodegenerative disorder. Its symptoms are typically treated with levodopa or dopamine receptor agonists, but its action lacks specificity due to the wide ...distribution of dopamine receptors in the central nervous system and periphery. Here, we report the development of a gene therapy strategy to selectively manipulate PD-affected circuitry. Targeting striatal D1 medium spiny neurons (MSNs), whose activity is chronically suppressed in PD, we engineered a therapeutic strategy comprised of a highly efficient retrograde adeno-associated virus (AAV), promoter elements with strong D1-MSN activity, and a chemogenetic effector to enable precise D1-MSN activation after systemic ligand administration. Application of this therapeutic approach rescues locomotion, tremor, and motor skill defects in both mouse and primate models of PD, supporting the feasibility of targeted circuit modulation tools for the treatment of PD in humans.
Cornelia de Lange syndrome (CdLS) is a dominantly inherited congenital malformation disorder, caused by mutations in the cohesin-loading protein NIPBL for nearly 60% of individuals with classical ...CdLS, and by mutations in the core cohesin components SMC1A (~5%) and SMC3 (<1%) for a smaller fraction of probands. In humans, the multisubunit complex cohesin is made up of SMC1, SMC3, RAD21 and a STAG protein. These form a ring structure that is proposed to encircle sister chromatids to mediate sister chromatid cohesion and also has key roles in gene regulation. SMC3 is acetylated during S-phase to establish cohesiveness of chromatin-loaded cohesin, and in yeast, the class I histone deacetylase Hos1 deacetylates SMC3 during anaphase. Here we identify HDAC8 as the vertebrate SMC3 deacetylase, as well as loss-of-function HDAC8 mutations in six CdLS probands. Loss of HDAC8 activity results in increased SMC3 acetylation and inefficient dissolution of the ‘used’ cohesin complex released from chromatin in both prophase and anaphase. SMC3 with retained acetylation is loaded onto chromatin, and chromatin immunoprecipitation sequencing analysis demonstrates decreased occupancy of cohesin localization sites that results in a consistent pattern of altered transcription seen in CdLS cell lines with either NIPBL or HDAC8 mutations.
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