Biology subjects

Sentmanat, M.

Publications and source records attributed to Sentmanat, M..

4 recordsLinked to original sources

bioRxiv2026

High-order enhancer hubs buffer allelic regulatory variation through kinetic compensation

Diploid genomes carry millions of heterozygous variants in cis-regulatory DNA, yet most genes produce similar RNA output from two parental alleles. How this balance is maintained is unclear. We developed Nanopore-HiChIP, a long-read method that maps high-order enhancer hubs on each haplotype. Over half of these enhancer hubs differ in chromatin architecture and transcription-factor occupancy between homologous chromosomes, but their target genes show substantially lower rates of allele-specific expression than genes lacking hub regulation. Single-cell kinetic modeling shows that burst frequency and burst size change in opposite directions, thereby preserving balanced transcriptional output. This hub-mediated kinetic buffering is enriched at haploinsufficient genes and coincides with smaller effects of expression quantitative trait loci. Enhancer hubs therefore absorb allelic regulatory variation through kinetic compensation, protecting dosage-sensitive transcription.

genomics↗

bioRxiv2026

Fully T2T pedigree assemblies reveal genetic stability and epigenetic plasticity of human centromeres across inheritance and cell-fate transitions

Centromeres are essential chromosome components yet remain poorly understood due to their highly repetitive sequence architecture. Using fully-phased telomere-to-telomere diploid assemblies from a three-generation pedigree integrated with long-read epigenomes from matched peripheral blood mononuclear cells, induced pluripotent stem cells, and neural progenitor cells, we generate allele-resolved single basepair resolution maps of centromere genetic and epigenetic dynamics across inheritance, reprogramming, and differentiation. We show that centromeric dip regions (CDRs), which define the functional core of centromeres, are positionally stable across generations and cell-fate transitions. In contrast, CDR epigenetic architecture is highly dynamic. Reprogramming markedly attenuates CDR hypomethylation, which is partially restored during differentiation in parallel with global hypomethylation of active alpha-satellite arrays and coordinated changes in nucleosome organization and protein occupancy. Centromeric remodeling is insulated from X-chromosome status, including Xa, Xi, and erosion. Finally, de novo mutations arising during reprogramming are enriched in centromeric regions but depleted within functional centromeric cores.

genomics↗

bioRxiv2026

Intellectual disability risk gene RFX4 regulates cortical neurogenesis by restraining neuronal differentiation

Despite the recent identification of RFX4 as a neurodevelopmental disorder risk gene, its role in cortical development remained unclear. Here, we identified both shared and lineage-specific RFX4 requirements for human cortical development using new human stem cell models of deficiency and pathogenic mutation. We found that RFX4 restrains neurogenesis by acting cooperatively with NOTCH signaling, specifically repressing pro-neuronal and synaptic gene expression in neural progenitors. We also determined that genome-wide binding of RFX3, another neurodevelopmental disorder risk gene, depends upon RFX4 to regulate synaptic gene expression. Furthermore, we identified lineage-specific functions for RFX4 in regulating proliferation during cortical inhibitory neuron development. Ultimately, we demonstrated that RFX4 deficiency persistently dysregulates neuronal gene expression through neuronal differentiation and disrupts cortical neuron stratification in organoid models. These consequences were absent in neurons generated by direct differentiation, confirming that neuronal phenotypes resulted from unconstrained neurogenesis. Finally, we modeled pathogenic missense mutation of the RFX4 DNA-binding domain. While this mutation strongly reduced DNA binding, it dysregulated synaptic gene expression distinctly from our deficiency models, supporting pathogenic mechanisms distinct from haploinsufficiency. Together, this work identified both shared and lineage-specific requirements for RFX4 during cortical development, building a necessary foundation for elucidating the etiology of RFX4-associated disorders.

developmental biology↗

bioRxiv2020

One-step RNA extraction for RT-qPCR detection of 2019-nCoV

The global outbreak of coronavirus disease 2019 (COVID-19) has placed an unprecedented burden on healthcare systems as the virus spread from the initial 27 reported cases in the city of Wuhan, China to a global pandemic in under three month[1]. Resources essential to monitoring virus transmission have been challenged with a demand for expanded surveillance. The CDC 2019-nCoV Real-Time Diagnostic Panel uses a real-time reverse transcription polymerase chain reaction (RT-PCR) consisting of two TaqMan probe and primer sets specific for the 2019-nCoV N gene, which codes for the nucleocapsid structural protein that encapsulates viral RNA, for the qualitative detection of 2019-nCoV viral RNA in respiratory samples. To isolate RNA from respiratory samples, the CDC lists RNA extraction kits from four manufacturers. In anticipation of a limited supply chain of RNA extraction kits and the need for test scalability, we sought to identify alternative RNA extraction methods. Here we show that direct lysis of respiratory samples can be used in place of RNA extraction kits to run the CDC 2019-nCoV Real-Time Diagnostic assay with the additional benefits of higher throughput, lower cost, faster turnaround and possibly higher sensitivity and improved safety.

molecular biology↗