Manifold Interpolating Optimal-Transport Flows for Trajectory Inference
Guillaume HuguetDaniel Sumner MagruderAlexander TongOluwadamilola FasinaManik KuchrooGuy WolfSmita Krishnaswamy
Develops MIOFlow, a framework combining neural ordinary differential equations and optimal transport to reconstruct continuous biological trajectories from static snapshot measurements while respecting intrinsic data geometry.
Modern biomedical technologies, such as single-cell RNA sequencing, capture rich biological snapshots but destroy cells during measurement, making it impossible to observe continuous individual cell trajectories directly over time. Reconstructing continuous, dynamic cellular processes from these discrete, static snapshots is critical for understanding developmental biology, disease progression, and treatment response mechanisms.
The article develops and evaluates a computational framework called Manifold Interpolating Optimal-Transport Flow (MIOFlow) to learn continuous, stochastic population dynamics and infer individual trajectories from static snapshot data. The objective is to demonstrate that MIOFlow accurately interpolates unmeasured intermediate states while constraining dynamic paths to the natural geometry of the data manifold.
The researchers designed a two-part computational approach combining manifold learning and neural ordinary differential equations regularized by optimal transport. First, they constructed a Geodesic Autoencoder that maps high-dimensional data into a low-dimensional latent space while preserving intrinsic manifold distances using a newly defined diffusion geodesic metric. Second, they trained neural differential equations with an added diffusion term to model population trajectories directly in this latent space, penalizing deviations between predicted and observed distributions using optimal transport. The method was evaluated on synthetic branching datasets and two real-world biological datasets: human embryoid body differentiation over 27 days and acute myeloid leukemia cells undergoing a seven-day chemotherapy regimen.
The evaluation revealed several key findings in order of importance. First, MIOFlow accurately reconstructed continuous paths along complex bifurcations and merging branches without taking artificial shortcuts across empty space, substantially outperforming alternative models like TrajectoryNet and Diffusion Schrödinger Bridges. Second, in held-out timepoint evaluations, MIOFlow reduced interpolation error metrics by roughly 50% to over 60% compared to baseline and competing methods on synthetic benchmarks. Third, MIOFlow operated dramatically faster than continuous normalizing flow baselines, reducing training times from over an hour to under five minutes on benchmark tasks because it avoids high-order Jacobian trace calculations. Fourth, on biological single-cell data, the framework accurately captured non-monotonic gene expression patterns during neuronal development and revealed how leukemia cells transition toward drug-resistant stem cell signatures during chemotherapy.
These findings demonstrate that embedding dynamic flows within an intrinsic manifold geometry provides a scalable, computationally efficient solution for modeling complex biological trajectories. By operating in latent space and eliminating the need for rigid Gaussian priors or heavy derivative computations, the approach lowers computational costs and minimizes modeling artifacts. This allows researchers to reliably map out cellular drug-resistance pathways, reducing technical risk when identifying therapeutic targets and biomarkers.
Organizations analyzing dynamic population snapshots can adopt this framework to reconstruct lineage trajectories and study time-dependent interventions. To support future implementation, practitioners should evaluate unbalanced optimal transport formulations when addressing severe cell proliferation or death, and conduct preliminary validation on sampling density before scaling up analysis.
The primary limitations include sensitivity to irregular timepoint spacing and the potential for standard differential equation solvers to struggle with numerically stiff dynamics. Confidence in the empirical results is high given rigorous benchmarking across both synthetic datasets and real-world genomic datasets, though caution is recommended when applying the model to populations with extreme, unmeasured growth-rate imbalances.
- Paper: Neural Ordinary Differential Equations, Ricky T. Q. Chen et al. (2018). Introduces Neural Ordinary Differential Equations and continuous-time normalizing flows, providing the fundamental differential equation framework that MIOFlow adapts for latent trajectory learning.
- Paper: Score-Based Generative Modeling through Stochastic Differential Equations, Yang Song et al. (2021). Establishes the continuous stochastic differential equation formulation for generative modeling that underlies continuous population dynamics and diffusion bridge approaches.
- Paper: Supervised Training of Conditional Monge Maps, Charlotte Bunne et al. (2022). Develops methods for learning continuous optimal transport maps between unpaired single-cell populations across biological conditions, framing the core snapshot-matching problem addressed by MIOFlow.
- Paper: Variational Inference with Normalizing Flows, Danilo Jimenez Rezende et al. (2015). Provides the foundational principles of continuous density transformations and normalizing flows used to construct invertible latent representations.
- Paper: Denoising Diffusion Probabilistic Models, Jonathan Ho et al. (2020). Introduces the standard formulation of denoising diffusion models, establishing the stochastic path mechanics that MIOFlow constrains along data manifolds.
- Paper: Matching Normalizing Flows and Probability Paths on Manifolds, Heli Ben-Hamu et al. (2022). Generalizes flow matching directly to Riemannian manifolds without requiring numerical ODE solvers during training, extending continuous probability path learning on non-Euclidean geometries.
- Paper: Flow Matching for Generative Modeling, Yaron Lipman et al. (2023). Introduces simulation-free Flow Matching with optimal transport paths, offering an alternative fast framework for learning continuous flows between distributions.
- Paper: Flow Straight and Fast: Learning to Generate and Transfer Data with Rectified Flow, Xingchao Liu et al. (2023). Develops rectified flow to straighten ODE trajectories between arbitrary distributions, continuing the effort to build computationally efficient, straight-path dynamical generative models.
- Paper: SE(3)-Stochastic Flow Matching for Protein Backbone Generation, Avishek Joey Bose et al. (2024). Applies optimal transport-guided continuous flows and stochastic bridges to non-Euclidean SE(3) manifold geometries for generative macromolecular modeling.
- Paper: Stochastic Interpolants: A Unifying Framework for Flows and Diffusions, Michael S. Albergo et al. (2025). Unifies deterministic flows and stochastic diffusions bridging arbitrary boundary distributions in finite time through stochastic interpolants.
