Evidence map›Paper›PMID 42698111›Full record

ArticleMicrobiome2026

Phagocytosis of microbial symbionts supports embryonic nutrition in the sponge Halichondria panicea.

Marta Turon, Cristina Díez-Vives, Tyler J Carrier, Laura de la Cruz-Castillejo, Maria Conejero, Leon Steiner, Sabrina Jung, Lucía Pita, Vasiliki Koutsouveli, Sören Franzenburg and 2 more

Abstract read
In one paragraph

Article in Microbiome, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Sex Determination in Sponges.Molecular reproduction and development · 2026
    Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Marta TuronDepartment of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (MNCN-CSIC), c/José Gutiérrez Abascal 2, Madrid, 28006, Spain. mturonrodrigo@gmail.com.
Cristina Díez-VivesDepartment of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (MNCN-CSIC), c/José Gutiérrez Abascal 2, Madrid, 28006, Spain.
Tyler J CarrierResearch Unit Marine Symbioses, GEOMAR Helmholtz Centre for Ocean Research, Wischhofstr. 1-3, Kiel, 24148, Germany.
Laura de la Cruz-CastillejoDepartment of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (MNCN-CSIC), c/José Gutiérrez Abascal 2, Madrid, 28006, Spain.
Maria ConejeroDepartment of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (MNCN-CSIC), c/José Gutiérrez Abascal 2, Madrid, 28006, Spain.
Leon SteinerResearch Unit Marine Symbioses, GEOMAR Helmholtz Centre for Ocean Research, Wischhofstr. 1-3, Kiel, 24148, Germany.
Sabrina JungResearch Unit Marine Symbioses, GEOMAR Helmholtz Centre for Ocean Research, Wischhofstr. 1-3, Kiel, 24148, Germany.
Lucía PitaResearch Unit Marine Symbioses, GEOMAR Helmholtz Centre for Ocean Research, Wischhofstr. 1-3, Kiel, 24148, Germany.
Vasiliki KoutsouveliDepartment of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (MNCN-CSIC), c/José Gutiérrez Abascal 2, Madrid, 28006, Spain.
Sören FranzenburgInstitute of Clinical Molecular Biology, Christian-Albrechts University of Kiel, Am Botanischen Garten 11, Kiel, 24118, Germany.
Ute Hentschel *Research Unit Marine Symbioses, GEOMAR Helmholtz Centre for Ocean Research, Wischhofstr. 1-3, Kiel, 24148, Germany.
Ana Riesgo *Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (MNCN-CSIC), c/José Gutiérrez Abascal 2, Madrid, 28006, Spain.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundAnimal development is frequently supported by microbial symbionts that contribute to host nutrition, metabolism, and physiology. While the functional importance of microbiomes in adult hosts is increasingly recognized, the role of symbiotic microbes during gametogenesis and embryogenesis remains poorly understood, particularly in early-diverging metazoans. Sponges represent an ideal system to investigate these processes due to their dense and diverse microbial communities. Here, we examined host-symbiont dynamics across the reproductive cycle of the marine sponge Halichondria panicea to assess how microbial communities contribute to reproduction and early development.

resultsSpecimens were collected monthly from February to July and classified by reproductive stage using histological analyses. We combined ultrastructural imaging, dual RNA sequencing of host and symbionts, 16S rRNA gene amplicon sequencing, and quantitative PCR to characterize microbial and transcriptional dynamics throughout reproduction. Pronounced shifts in both host gene expression and microbial community composition occurred during early embryogenesis, particularly in May. Transmission electron microscopy revealed nurse cells phagocytosing bacterial aggregates in close proximity to late oocytes, presumably converting them into yolk precursors. This coincided with a significant decline in the abundance of the dominant obligate symbiont, Candidatus Halichondribacter symbioticus. Host transcriptomic analyses showed upregulation of immune and phagocytic pathways, including pattern recognition receptors, lectins, and vesicle trafficking components, specifically in females undergoing embryogenesis in May. Concurrently, symbiont gene expression profiles indicated responses to acidic conditions, consistent with exposure to phagosomal environments.

conclusionsOur results are consistent with intracellular digestion of microbial symbionts during early embryogenesis, potentially to supplement the nutritional requirements of embryogenesis. These findings reveal symbiont phagocytosis as a previously underappreciated nutritional strategy during animal development and highlight the dynamic functional integration of microbiomes into reproductive physiology in basal metazoans. Video Abstract.

Indexed as

BacteriaMicrobiotaPhagocytosisPoriferaSymbiosisAnimalsEmbryonic DevelopmentRNA, Ribosomal, 16SRNA, Ribosomal, 16SEmbryogenesisGonochorismMicrobiomePhagocytosisSymbiont

Identifiers

PMID42698111
PMCPMC13543439

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.