To extend the frontier of genome editing and enable editing of repetitive elements of mammalian genomes, we made use of a set of dead-Cas9 base editor (dBE) variants that allow editing at tens of thousands of loci per cell by overcoming the cell death associated with DNA double-strand breaks and single-strand breaks. We used a set of gRNAs targeting repetitive elements-ranging in target copy number from about 32 to 161 000 per cell. dBEs enabled survival after large-scale base editing, allowing targeted mutations at up to ∼13 200 and ∼12 200 loci in 293T and human induced pluripotent stem cells (hiPSCs), respectively, three orders of magnitude greater than previously recorded. These dBEs can overcome current on-target mutation and toxicity barriers that prevent cell survival after large-scale genome engineering.
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http://dx.doi.org/10.1093/nar/gkaa239 | DOI Listing |
J Ovarian Res
January 2025
Department of Medical Genetics, National Taiwan University Hospital, 19F, No. 8, Chung-Shan South Road, Taipei City, Taiwan.
Background: The homologous recombination deficiency (HRD) test is an important tool for identifying patients with epithelial ovarian cancer (EOC) benefit from the treatment with poly(adenosine diphosphate-ribose) polymerase inhibitor (PARPi). Using whole exome sequencing (WES)-based platform can provide information of gene mutations and HRD score; however, the clinical value of WES-based HRD test was less validated in EOC.
Methods: We enrolled 40 patients with EOC in the training cohort and 23 in the validation cohort.
BMC Pediatr
January 2025
Nutrition & Health Innovation Research Institute, Edith Cowan University, Perth, WA, Australia.
Background: Growing evidence shows that dysregulated metabolic intrauterine environments can affect offspring's neurodevelopment and behaviour. However, the results of individual cohort studies have been inconsistent. We aimed to investigate the association between maternal diabetes before pregnancy and gestational diabetes mellitus (GDM) with neurodevelopmental, cognitive and behavioural outcomes in children.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
State Key Laboratory of Genetic Engineering, School of Life Sciences, Liver Cancer Institute of Zhongshan Hospital, Fudan University, Shanghai 200438, China.
Aging is a complex process that affects multiple organs, and the discovery of a pharmacological approach to ameliorate aging is considered the Holy Grail of medicine. Here, we performed an N-ethyl-N-nitrosourea forward genetic screening in zebrafish and identified an accelerated aging mutant named (), harboring a mutation in the - () gene. Loss of leads to a short lifespan and age-related characteristics in the intestine of zebrafish embryos, such as cellular senescence, genomic instability, and epigenetic alteration.
View Article and Find Full Text PDFWe lack tools to edit DNA sequences at scales necessary to study 99% of the human genome that is noncoding. To address this gap, we applied CRISPR prime editing to insert recombination handles into repetitive sequences, up to 1697 per cell line, which enables generating large-scale deletions, inversions, translocations, and circular DNA. Recombinase induction produced more than 100 stochastic megabase-sized rearrangements in each cell.
View Article and Find Full Text PDFG3 (Bethesda)
January 2025
School of Life Sciences, Center for Evolution & Medicine, Arizona State University, Tempe, AZ 85281, USA.
The demographic history of a population, and the distribution of fitness effects (DFE) of newly arising mutations in functional genomic regions, are fundamental factors dictating both genetic variation and evolutionary trajectories. Although both demographic and DFE inference has been performed extensively in humans, these approaches have generally either been limited to simple demographic models involving a single population, or, where a complex population history has been inferred, without accounting for the potentially confounding effects of selection at linked sites. Taking advantage of the coding-sparse nature of the genome, we propose a 2-step approach in which coalescent simulations are first used to infer a complex multi-population demographic model, utilizing large non-functional regions that are likely free from the effects of background selection.
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