# 3D Electron Microscopy Reveals the Structural Complexity of the Intravacuolar Membranous Network in Cyrilia lignieresi‐Infected Erythrocytes of the Fish Synbranchus marmoratus

## TL;DR

3D electron microscopy reveals complex membrane structures inside fish red blood cells infected by a parasite, offering new insights into host-parasite interactions.

## Contribution

The study provides the first detailed 3D visualization of the intravacuolar membranous network in Cyrilia lignieresi-infected erythrocytes.

## Key findings

- The intravacuolar network includes vesicles, tubules, and interconnected membranes with diverse sizes and electron densities.
- Three-dimensional reconstructions reveal spatial organization of the membranous structures within the parasitophorous vacuole.
- The findings suggest dynamic functional roles of the membranous network in parasite-host interactions.

## Abstract

This study employs advanced three‐dimensional electron microscopy techniques, including Transmission Electron Microscopy (TEM) tomography and freeze‐fracture imaging via scanning electron microscopy (SEM), to investigate the ultrastructural organization of Cyrilia lignieresi‐infected red blood cells (iRBCs) in the host fish
Synbranchus marmoratus
. The analysis focuses on the parasitophorous vacuole (PV) and reveals a highly complex intravacuolar membranous network (IVN) composed of vesicles, tubules, and interconnected membranous structures. These elements exhibit considerable diversity in size, morphology, and electron density, suggesting dynamic functional roles in the parasite–host interaction. The electron tomography and three‐dimensional reconstructions data provide unprecedented insights into the spatial organization and potential functional significance of these membranous systems. These findings not only enhance our understanding of the cellular adaptations of C. lignieresi but also contribute to a broader knowledge of apicomplexan parasitism and host–pathogen interactions.