Use of serial sections to delineate the structure of Porthetria dispar virus in the electron microscope

Area of Science:

• Entomology
• Virology
• Microscopy

Background:

• The P. dispar virus infects gipsy moth larvae, a significant forest pest.
• Understanding the morphology of viral particles is crucial for disease management.

Purpose of the Study:

• To characterize the structure of viral particles within polyhedra of P. dispar virus-infected gipsy moth larvae.
• To describe the arrangement and dimensions of viral rods.

Main Methods:

• Serial sectioning of polyhedra from infected gipsy moth larvae.
• Transmission electron microscopy to visualize viral structures.
• Analysis of viral rod dimensions and arrangement.

Main Results:

• Viral rods were observed in bundles scattered randomly within the polyhedral body.
• Each bundle was enclosed by a distinct membrane.
• Viral rods measured 18–22 µm in diameter and averaged 280 µm in length.
• No spherical viral particles were detected.

Conclusions:

• The P. dispar virus exists as rod-shaped particles within polyhedra.
• The observed morphology provides insights into the viral assembly and structure.
• Further studies may explore the impact of sectioning artifacts on viral appearance.