Pornsawan Duangsuwan, Yotsawan Tinikul, Boonsirm Withyachumnarnkul, Charoonroj Chotwiwatthanakun and Prasert Sobhon

pp. 121 - 127

Abstract

Negative-stained intact yellow head virus (YHV) was an enveloped bacilliform particle measuring 40-50 x 175-210 nm
with spike-like projections measuring 7-9 nm. The space between projections was 4-7 nm. YHV nucleocapsid was rod-shaped,
measuring 35-40 x 160-200 nm, and the RNA genome had 40-50 turns in a helical structure. YHV infected both stromal matrix
cells and haemocytes in the lymphoid tubule wall. The patterns of localisation of viral particles were similar in both cells. The
fully enveloped viral particles were detected at the cell membrane, endosome, rough endoplasmic reticulum, Golgi complex
and secretory vesicles, and virions were exocytosed at the cell membrane. In the case of severe infection, unenveloped viral
particles could be detected in the cytoplasm, and they might be released by general breakdown and lysis of the highly infected
cells.

Keywords

• Penaeus monodon
• lymphoid organ
• yellow head virus
• electron microscopy
• cellular pathway