Dirofilaria immitis: the moulting of the infective larva in vitro.
A number of in vitro culture systems were tested for their ability to support the development of Dirofilaria immitis infective larvae to the fourth larval stage. In cultures of medium ML-15 containing a feeder layer of Dog Sarcoma (DS) cells larvae successfully moulted and showed a small but significant increase in length. Ultrastructural observations demonstrated that the fourth-stage cuticle was synthesized in vitro and in some larvae was fully formed by 60 hours of culture. The hypodermis of moulting larvae contained numerous multi-vesicular bodies. It is concluded that the moult in vitro is a true moult and not an atypical response of the larvae to the conditions of culture.
D000330:Aedes / Q000469:parasitology; D000818:Animals; D002478:Cells, Cultured; D004183:Dirofilaria immitis / Q000254:growth & development* / Q000648:ultrastructure; D005370:Filarioidea / Q000254:growth & development*; D066298:In Vitro Techniques; D007814:Larva / Q000254:growth & development / Q000648:ultrastructure; D013997:Time Factors