Abstract
In vitro study to determine the sexual compatibility of 26 Cryptococcus neoformans isolates was conducted on sunflower (Helianthus annus) seed agar. Among 26 isolates examined, 14 were originated from animals, 6 from men and 6 from environmental substrates; 17 isolates were obtained in Japan and 9 in India. These isolates were crossed with each of the 2 mating types (α and a) of Filobasidiella neoformans var. neoformans or F. neoformans var. bacillispora. All the isolates produced basidiospores, basidia, dikaryotic hyphae with clamp connections when paired with the “a” mating type of F. neoformans var. neoformans. We could not find any isolate showing sexual reproduction with “α” mating type of either variety of F. neoformans. Furthermore, none of the isolates exhibited self-fertile behavior. Our results indicate that the “α” mating type occurs more frequently in both clinical and natural isolates of C. neoformans originated from Japan and India.
