Biology subjects

Erickson, A. G.

Publications and source records attributed to Erickson, A. G..

4 recordsLinked to original sources

bioRxiv2026

Clonal embeddings allow exploratory analysis of lineage-resolved single-cell data

Assays coupling high-throughput lineage tracing with single-cell transcriptomics are transforming studies of development and disease biology, revealing not only major differentiation routes but also continuous fate biases and their putative regulators. Yet, analysis of such data at scale presents challenges due to the sparse nature of clonal data and annotation dependencies. Towards that aim we developed a machine learning approach - clone2vec - which learns informative clone embeddings directly from the cellular expression manifold, bypassing discrete cell-type labels and remaining stable when clones are represented by few cells. This representation summarizes clonal variation as an interpretable geometry that supports exploration, statistics for clone-gene associations, and cross-dataset alignment. In prospective barcoding datasets spanning embryogenesis, tumorigenesis, and hematopoiesis, clone2vec recapitulates established clonal patterns and uncovers new axes of continuous variation that implicate regulatory programs and developmental pathways. In tumor microenvironments profiled with TCR sequencing, clone2vec robustly recovers distinct Treg lineages as well as conserved CD8+ T cell sublineages across cancer types, including several bystander-like clonal subsets. Overall, clone2vec provides a robust, general solution for the exploratory analysis of lineage-coupled scRNA-seq data.

bioinformatics↗

bioRxiv2026

Single-cell, clonal and spatial atlases of cranial placodes illuminate their specification and evolution

The vertebrate head is defined by complex sensory structures derived from cranial placodes. Placodes arise alongside the neural crest at the neural plate border, yet the mechanisms governing their identity, diversification, and evolutionary origins are unclear. We present an integrated single-cell, spatial, and clonal atlas of placode development to resolve the dynamics of their lineage segregation. Combining single-cell RNA-sequencing, spatial transcriptomics, and high-resolution clonal tracing, we show that placodal and neighboring progenitors form a continuous transcriptional landscape with gradual transitions between domains. Domain boundary cells co-express markers of adjacent territories, suggesting transient bipotent states. Consistent with this, clonal analysis reveals sharing of progenitors between neighboring placodes, supporting a model of competitive segregation. Comparisons with amphioxus suggests that vertebrate olfactory placodes emerged from an ancestral neuroectoderm that later partitioned into distinct neural and olfactory domains. Our findings provide a unified framework for understanding the developmental and evolutionary origins of vertebrate sensory organs.

developmental biology↗

bioRxiv2024

Unbiased profiling of multipotency landscapes reveals spatial modulators of clonal fate biases

The proportion of cell types varies systematically across the body, but it remains unclear how individual progenitor cells integrate positional information to establish patterns of cellular composition. In this study we profile the clonal landscape of the embryo, using single-cell lineage tracing of mouse embryos from neurulation until mid-gestation. To analyze the complex clonal patterns derived from highly multipotent progenitors, we developed clone2vec, which uses unsupervised learning to categorize individual clones into lineages based on shared transcriptional context. This revealed a body-wide gradient of clonal fate biases, in which anatomical position and clonal composition are mutually predictive. Comparison of clonal lineages revealed spatial transcription factor programs associated with dynamic cell biasing towards skeletal versus non-skeletal fates. Mosaic combinatorial perturbations targeting the Hedgehog pathway generated clones in which positional identity was mismatched with clonal composition, suggesting a potential signaling influence on somite patterning. We explore the effects of position and heterochrony on fate biases in cranial, trunk, and caudal neural crest clones. Altogether, our work demonstrates an effective practical approach for dissecting mechanisms of lineage specification.

developmental biology↗

bioRxiv2023

Motor nerves direct the development of the sympathetic nervous system

The sympathetic nervous system controls a wide spectrum of bodily functions including operation of vessels, cardiac rhythm, and the "flight or fight response". Sympathetic neurons, which are neural crest-derived, develop in coordination with presynaptic motor nerves extending from the central nervous system (CNS). By using nerve-selective genetic ablations, we revealed that sympathetic ganglia development depends on CNS-derived motor innervation. In the absence of preganglionic motor nerves, trunk sympathetic chain ganglia were fragmented and smaller in size, while cervical ganglia were severely misshapen. Sympathetic neurons were misplaced along sensory fibers and projected towards abnormal paths, in some cases invading the sensory dorsal root ganglia. The misplaced progenitors of sympathoblasts corresponded to the nerve-associated, neural crest-derived Schwann cell precursors (SCPs). Notably, we found that SCPs activate the autonomic marker PHOX2B while migrating along motor nerves towards the region of the dorsal aorta in wildtype embryos, suggesting that SCP differentiate into sympathetic neurons while still nerve-associated in motor-ablated embryos. Ligand-receptor prediction from single cell transcriptomic data coupled with functional studies identified Semaphorin 3A/3F as candidate motor nerve-derived signals influencing neural crest migration along axons. Thus, motor nerves control the placement of sympathoblasts and their subsequent axonal navigation during critical periods of sympathetic chain development.

developmental biology↗