title: Engulfed pathogen-induced apoptosis in haemocytes of giant freshwater prawn, Macrobrachium rosenbergii.
abstract: Haemocytes of the giant freshwater prawn, Macrobrachium rosenbergii, were investigated for the induction of apoptosis after phagocytosis of pathogenic yeasts, bacteria and non-pathogenic latex beads in vitro. Isolated haemocytes of M. rosenbergii were cultured at a ratio of 1:50 haemocytes to pathogen with the yeast Debaryomyces hansenii, the bacteria Aeromonas hydrophila or Enterococcus faecium, or with latex beads at 25 degrees C for 2 h, followed by washing to remove free particles. At least 200 haemocytes were counted to determine the phagocytosis rate, and the results showed that haemocytes engulfed latex beads at a higher rate than the aquatic pathogens. By transmission electron microscopy, the yeast- or bacterium-engulfing haemocytes displayed morphological changes characteristic of apoptosis, including formation of cytoplasmic vacuoles, chromatin condensation and fragmentation of nuclei. This pathogen-induced apoptosis was further confirmed by DNA laddering and TUNEL (terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick-end-labelling) assays. Neither haemocytes treated with latex beads nor uninfected haemocytes (control group) showed signs of apoptosis after 48 h in culture.
authors.affiliation: Graduate Institute of Veterinary Pathology, National Chung-Hsing University, Taichung, Taiwan.
authors.forename: J-P
authors.initials: JP
authors.lastname: Hsu
authors.forename: C
authors.initials: C
authors.lastname: Huang
authors.forename: C-M
authors.initials: CM
authors.lastname: Liao
authors.forename: S-L
authors.initials: SL
authors.lastname: Hsuan
authors.forename: H-H
authors.initials: HH
authors.lastname: Hung
authors.forename: M-S
authors.initials: MS
authors.lastname: Chien
mesh_terms: D016980:Aeromonas hydrophila; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D016984:Enterococcus faecium; D006434:Hemocytes / Q000382:microbiology / Q000502:physiology* / Q000648:ultrastructure; D020287:In Situ Nick-End Labeling / Q000662:veterinary; D046529:Microscopy, Electron, Transmission / Q000662:veterinary; D008863:Microspheres; D033541:Palaemonidae / Q000382:microbiology* / Q000502:physiology*; D010587:Phagocytosis / Q000502:physiology*; D013624:Taiwan; D015003:Yeasts