Neurosecretory-like material in 3rd- and 4th-stage Dirofilaria immitis larvae (Nematoda: Filarioidea).
Phase-interference microscopic examination of the infective, post-infective 3rd-stage and 4th-stage larvae of Dirofilaria immitis has identified a single cell body in each of the paired lateral amphidial nerves which undergoes characteristic morphological change during the development from 3rd- to 4th-stage larvae. Acetaldehyde-fuchsin staining of worm sections revealed fuchsinophilic material in the precise location of the amphidial nerve-cell bodies observed by phase-interference microscopy. This material was found in 70% of infective larvae recovered from mosquitoes and in 100% of larvae recovered from micropore chambers 24 h after implantation into BALB/C mice. In pre-moult larvae recovered at 42 h (Experiment 1) and at 48 h (Experiment 2) fuchsinophilic material was demonstrable, but no staining was observed in those larvae in which separation of the 3rd- and 4th-stage cuticles had occurred. No such material was observed in 4th-stage larvae recovered from chambers after 74 h, and in these larvae the amphidial nerve-cell bodies were not discernible. These cytological observations are consistent with a cycle of elaboration and release of neurosecretion associated with moulting in D. immitis.
Delves
C J
CJ
Department of Parasitology, Liverpool School of Tropical Medicine.
Webb
R
R
Howells
R E
RE
D000818:Animals; D004183:Dirofilaria immitis / Q000254:growth & development / Q000378:metabolism*; D005370:Filarioidea / Q000378:metabolism*; D006651:Histocytochemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D009489:Neurosecretion; D009490:Neurosecretory Systems / Q000166:cytology; D012394:Rosaniline Dyes
D012394:Rosaniline Dyes