title: Factors contributing to the in vitro development of Ascaris suum from second-stage larvae to mature adults.
abstract: When a three-step roller culture system was used, second-stage larvae of Ascaris suum, artificially hatched from eggs, developed in high numbers to the fourth stage, and a few to young and mature adults. The culture system consisted of (1) Medium KW-2 supplemented with 10 mM L-cysteine for the first 4 days, and with 5 mM L-cysteine for the following 7 days; (2) followed by Medium API-18 for 7 days; and (3) thereafter, by Medium API-1 supplemented with hemin (bovine) at a concentration of 24 micrograms/m1. Cultures were gassed with 95% nitrogen-5% carbon dioxide for the first 4 days and 85% nitrogen-5% oxygen-10% carbon dioxide thereafter, and incubated at 39 C. Two mature females that produced unfertilized eggs and a mature male with spermatozoa were the most advanced stages attained. The mature females were obtained in 67 and 73 days; and the largest female measured 110 mm. The latter produced 1,356,000 unfertilized eggs, from days 67 to 125. The mature male was obtained in 80 days; it measured 77 mm long and had paired spicules that were 1.5 mm long. Development of A. suum in three other culture systems showed that deletion of Medium API-18 or its substitution by Medium KW-2 limited development to late fourth stage and early, young adults, respectively; and the use of Medium API-1 without hemin limited development to early fourth stage.
mesh_terms: D000818:Animals; D001200:Ascaris / Q000033:anatomy & histology / Q000254:growth & development* / Q000502:physiology; D003470:Culture Media; D005260:Female; D008297:Male; D009024:Morphogenesis; D009866:Oogenesis; D010058:Oviposition; D010063:Ovum / Q000166:cytology; D010274:Parasitology / Q000379:methods*; D013091:Spermatogenesis; D013094:Spermatozoa / Q000166:cytology
chemical_list: D003470:Culture Media