Hydractinia Genome Project Portal

The Hydractinia Genome Project Portal provides a spatially validated single-cell atlas of Hydractinia symbiolongicarpus, integrating new datasets with previously published data to enable investigation of cellular diversity, dynamics, and developmental processes in this cnidarian model organism.

Key Features:

• Integrated single-cell atlas: Combines new fixed-cell datasets with previously published live-cell data, capturing over 47,000 cells from feeding polyps and stolon tissue.
• Cell lineage recovery and refinement: Identifies and characterizes major somatic cell lineages including cnidocytes, neurons, gland cells, epithelial cells, and stem cells (i-cells), plus a novel putative immune cell population.
• Spatial validation: Investigates spatial expression patterns of selected marker genes to validate all major cell types and several cell states.
• Cnidocyte trajectory analysis: Recovers a complete Hydractinia cnidocyte trajectory with two distinct endpoints, supported by spatial marker gene expression reflecting cnidoblast developmental progression and migration towards tentacles.
• I-cell subclustering: Reveals putative progenitor states and a potential population of true stem cells within somatic i-cells.
• Novel cell type identification: Uncovers a previously undescribed neural subtype, two spatially distinct gland cell populations, and a stolon-specific cell type.

Scientific Applications:

• Stem cell biology: Supports investigation of i-cell heterogeneity, progenitor states, and true stem cell populations in a cnidarian model system.
• Regeneration research: Provides validated cell type references for studying regenerative processes in Hydractinia symbiolongicarpus.
• Neural subtype discovery: Enables identification and characterization of previously undescribed neuronal subtypes through integrated spatial and single-cell analysis.
• Cnidocyte development: Facilitates study of cnidoblast maturation, migration, and differentiation endpoint determination via spatially resolved trajectory analysis.
• Immune cell biology: Allows exploration of a novel putative immune cell population in cnidarian tissue.
• Gland cell spatial organization: Supports analysis of spatially distinct gland cell populations and their tissue-specific distributions.

Methodology:

Single-cell RNA sequencing (scRNA-seq) of fixed cells integrated with previously published live-cell scRNA-seq data; spatial expression pattern analysis of selected marker genes for cell type validation; subclustering of somatic i-cells; trajectory analysis of cnidocyte differentiation with spatial marker gene expression support.