Abdallah, H. | Search bioRxiv

bioRxiv2026

A versatile, positive-going voltage indicator that enables accessible two-photon recordings in vivo

Genetically encoded voltage indicators (GEVIs) enable cell-type-specific optical readout of membrane potential, but two-photon (2P) spike detection has been hampered by low signal-to-noise and ultrafast off-kinetics, restricting use to specialized microscopes. We introduce FORCE1s, a green, positive-going GEVI engineered to make robust 2P voltage imaging broadly accessible. FORCE1s brightens from a dark baseline during depolarization, reports spikes with [~]100% {Delta}F/F in awake mice, and displays repolarization kinetics that are tuned for reliable spike detection at sub-kilohertz frame rates. As a result, FORCE1s supports spike-resolved multi-cell recordings on standard resonant-scanning microscopes, and further scales to larger fields of view and neuron counts on advanced modalities. FORCE1s also enables multiplexed voltage-neurotransmitter imaging and extended recordings in freely moving mice using a compact, affordable MEMS-based 2P miniscope. Together, these advances establish FORCE1s as a community-ready tool that democratizes deep-tissue voltage imaging across platforms and experimental contexts.

neuroscience↗

bioRxiv2023

The relationships between genetic ancestry, somatic mutation frequency, and histologic subtypes in high-grade endometrial cancer

High-grade endometrial cancer, like numerous other cancer types, exhibits clear racial disparities in the United States for both the incidence and outcomes of the disease. While institutional factors are likely the primary contributor to these disparities, other underlying causes cannot be ignored (i.e., molecular, genetic, and histopathologic factors). This study seeks to interrogate the role that germline genetic influences, specifically genetic ancestry, may play in contributing to characteristics of high-grade endometrial cancer. This is mainly accomplished by examining the relationship between local ancestry inferences and somatic mutation frequency as well as histologic subtypes. An association between clinical characteristics and patient survival was also interrogated, and while global ancestry was seen to have no significant effect, tumor mutation burden (TMB) did impact patient survival. Here, we identify associations between local ancestry segments on chromosomes 1 and 14 and an increased TMB in self-described (SD) Black patients. We also highlight a complex relationship between heterozygous ancestry combinations within genomic regions (i.e., [European/African] vs. [African/African]) and an increase in local somatic mutation frequency. Furthermore, we explore the relationship between local ancestry and histologic subtype. We identify one region (chr9q32) wherein the African/European local ancestry diplotype was associated with a higher incidence of serous carcinoma. We also underline a difference in somatic mutation frequency between endometrioid and serous carcinoma. While highly exploratory, these findings begin to characterize the complex relationship between genetic ancestry and characteristics of high-grade endometrial cancer, which may impact patient survival.

genomics↗