Narayanaswamy, S. | bioRxiv Science

bioRxiv2026

PanKbase Integrated Single-Cell Map: A Comprehensive Atlas of Human Pancreatic Islets

Single-cell RNA sequencing (scRNA-seq) of human pancreatic islet tissue is a powerful tool for investigating type 1 diabetes (T1D). However, individual datasets are limited in size and fragmented across donors, laboratories, and experimental conditions. To address this, we constructed a comprehensive, integrated scRNA-seq atlas of isolated human pancreatic islets by collating publicly available data generated from tissue provided by resources including the Human Pancreas Analysis Program, the Integrated Islet Distribution Program, and Prodo Labs. Systematic quality controls were implemented to select high-quality samples, reads, and cells. During integration, we accounted for important variables such as age, sex, body mass index, origin study, treatments, islet distribution resources, and sequencing chemistry. Our single-cell atlas comprises 191 high-quality samples from 140 donors (59 female, 81 male) across five phenotypic groups: no diabetes (controls, n=69), autoantibody positivity without diabetes (n=12), pre-diabetes (n=11), T1D (n=12), and type 2 diabetes (T2D) (n=36). In total, the atlas contains 448,935 cells, capturing 13 distinct populations, including alpha cells (43.3%) and beta cells (26.8%), as well as groups such as immune cells (0.6%). Publicly available at www.pankbase.org, this atlas provides a platform for hypothesis-driven investigation of diabetes pathophysiology and, given rigorous quality control, is well-suited for downstream machine-learning applications. Article HighlightsO_LICurrent scRNA-seq datasets of pancreatic islet tissue are limited in size and scattered across donors, laboratories, and experimental conditions, underscoring the need for a consolidated resource. C_LIO_LIWe harmonized datasets from multiple sources to build a comprehensive single-cell map of isolated human pancreatic islets. C_LIO_LIOur atlas captures 448,935 cells from 191 high-quality samples across 140 donors and multiple phenotypic groups, identifying 13 distinct cell populations. C_LIO_LIAvailable at www.pankbase.org, the atlas provides a scalable, rigorously curated platform to support hypothesis-driven diabetes research and can enable a broad range of downstream computational applications. C_LI

genomics↗

bioRxiv2025

Notch coordinates self-organization of germ layers and axial polarity in cnidarian gastruloids

Dissociation and reaggregation experiments in several animal systems have revealed the stunning capacity of self-organization. Reaggregated early gastrula cells (here called gastruloids) of the sea anemone Nematostella vectensis are able to regenerate with only little delay whole organisms that are virtually indistinguishable from normal developing polyps. However, the molecular control underlying the restoration of body axis and germ layers remains largely unknown. To address this, we established a standardized protocol, which reproducibly generates gastruloids developing into polys with a single body axis. Here, we show that committed mesodermal and endodermal cells are sorted out to the surface of the aggregate, where mesodermal cells form clusters of about 30 cells. At a critical time point, one mesodermal cluster immigrates, along with peripherally attached endodermal cells. Thereby, the inner germ layer and the oral-aboral axis is established in one and the same process. Functional studies demonstrated that this polarization of the endodermal cells requires a feedback loop of Notch and Wnt signaling. The dissociation of the early embryo disrupts Notch signaling in the endodermal cells, which leads to transient adoption of an endomesodermal profile, marked by the expression of the mesodermal cadherin1 until the boundaries between the germ layer identities are re-established. Our results highlight distinct morphogenetic behaviors of mesodermal and endodermal cells and the hitherto unknown role of Notch signaling in germ layer boundary formation in self-organizing gastruloids. Conservation of Notch-mediated boundary formation between endoderm and mesoderm mirrors bilaterian mechanisms, demonstrating how adoption of ancestral regulatory networks governing morphogenesis likely enabled the diversification of metazoan body plans.

developmental biology↗