Biology subjects

Blanch-Asensio, A.

Publications and source records attributed to Blanch-Asensio, A..

3 recordsLinked to original sources

bioRxiv2025

Reconstitution of human fetal ovaries reveals niche requirements for primordial germ cell-like cell progression

Human primordial germ cell-like cells (hPGCLCs) can be specified from human induced pluripotent stem cells (hiPSCs), offering a valuable model for human germ cell development. However, further maturation steps of hPGCLCs rely on mouse feeders, or co-culture with mouse gonadal somatic cells. Exposure of hPGCLCs to human embryonic niche has not been attempted. Here, we co-cultured female hPGCLCs in two distinct somatic compartments. In reconstituted ovary (rOv) culture, human fetal germ cells proliferate and initiate meiosis, while hPGCLCs upregulate gonadal germ cell markers such as DDX4. Additionally, hPGCLCs can be supported in 3D culture by the amnion-like cells (AMLC) generated during PGCLC differentiation. Compared to rOV, hPGCLCs are less prone to dedifferentiation in PGCLC/AMLC aggregates. Finally, we demonstrated that SCF is crucial for the survival of hPGCLCs but not second trimester fetal germ cells. Together, this work highlights a shift in niche is required in human germ cell development. In BriefChang and colleagues utilized in vitro reconstituted human fetal ovary (rOv) as somatic niche to mature human primordial germ cell-like cells (PGCLCs). hPGCLCs in rOv upregulate gonadal germ cell markers but are prone to dedifferentiation. In contrast, hPGCLCs cultured with amnion-like cells can be maintained without dedifferentiation. In both culture systems, SCF is crucial for the survival of hPGCLCs. HighlightsO_LIReconstituted human fetal ovaries (rOvs) support meiosis entry of fetal germ cells C_LIO_LIThe rOVs support hPGCLCs to upregulate gonadal germ cell markers C_LIO_LIhPGCLCs show less dedifferentiation in amnion-like cell aggregates compare to rOv C_LIO_LISCF is not required for survival of fetal germ cells, but crucial for hPGCLCs C_LI

developmental biology↗

bioRxiv2025

Gene syntax defines supercoiling-mediated transcriptional feedback

Gene syntax--the order and arrangement of genes and their regulatory elements--shapes the dynamic coordination of both natural and synthetic gene circuits. Transcription at one locus profoundly impacts the transcription of nearby adjacent genes, but the molecular basis of this effect remains poorly understood. Here, using integrated reporter circuits in human cells, we show that the reciprocal effects of transcription and DNA supercoiling, which we term supercoiling-mediated feedback, regulates expression of adjacent genes in a syntax-specific manner. Using a suite of chromatin state assays, we measure syntax-and induction-dependent formation of chromatin structures in human induced pluripotent stem cells. Applying syntax as a design parameter and without altering sequence or copy number, we built compact gene circuits, tuning the expression mean, noise, and stoichiometry across diverse delivery methods and cell types. Integrating supercoiling-mediated feedback into models of gene regulation will expand our understanding of native systems and enhance the design of synthetic gene circuits.

synthetic biology↗

bioRxiv2021

STRAIGHT-IN: A platform for high-throughput targeting of large DNA payloads into human pluripotent stem cells

Inserting large DNA payloads (>10 kb) into specific genomic sites of mammalian cells remains challenging. Applications ranging from synthetic biology to evaluating the pathogenicity of disease-associated variants for precision medicine initiatives would greatly benefit from tools that facilitate this process. Here, we merge the strengths of different classes of site-specific recombinases and combine these with CRISPR/Cas9-mediated homologous recombination to develop a strategy for stringent site-specific replacement of genomic fragments at least 50 kb in size in human induced pluripotent stem cells (hiPSCs). We demonstrate the versatility of STRAIGHT-IN (Serine and Tyrosine Recombinase Assisted Integration of Genes for High-Throughput INvestigation) by: (i) inserting various combinations of fluorescent reporters into hiPSCs to assess excitation-contraction coupling cascade in derivative cardiomyocytes, and; (ii) simultaneously targeting multiple variants associated with inherited cardiac arrhythmic disorder into a pool of hiPSCs. STRAIGHT-IN offers a precise approach to generate genetically-matched panels of hiPSC lines efficiently and cost-effectively.

cell biology↗