Home • Chytriomyces hyalinus JEL632 v1.0
Chytriomyces cf. hyalinus JEL632. Image by Joyce E. Longcore.
Chytriomyces cf. hyalinus JEL632. Image by Joyce E. Longcore.

Chytriomyces cf. hyalinus JEL632 is considered the most commonly observed chytrid of the genus Chytriomyces, representing monocentric, eucarpic, extramatrical or endobiotic taxa with an apophysis, epibiotic resting spore, and operculate zoosporangium. When species in the genus release zoospores, they are bound together in a thin membrane, which ruptures as the zoospores emerge from the zoosporangium and begin to swarm. John S. Karling described this new genus in 1945 with the concurrent descriptions of C. hyalinus and C. aureus, observed on pieces of chitin or mayfly exuviae collected in Brazil and the eastern United States, but he provided no indication of which species was to be the type of the genus. Additional researchers began to find this species more and more frequently and were even able to observe its sexual formation of resting spores. Sexual behavior is rarely observed in chytrid taxa, but several isolates of C. hyalinus will readily undergo rhizoidal conjugation and form zygotic resting spores, even in pure culture on synthetic media, making the species a great model organism for mycology courses.

As study into chytrids continued, the generic concept of Chytriomyces became increasingly ambiguous, and in 2002 Peter M. Letcher and Martha J. Powell described the more commonly observed C. hyalinus as the lectotype of the genus. Subsequent studies have used multiple lines of evidence, including morphology and molecular phylogenetics, to place misclassified Chytriomyces species into other genera, families, and even orders. Chytriomyces cf. hyalinus JEL632 exhibits both asexual zoosporic development and sexual conjugative behavior, and because it can be grown in pure culture, study of its genome will lead to insights into the molecular regulation of sexual and asexual behavior in the presence of testable external stimuli. This fungus is also one of the most frequently isolated chytrids when baiting soils with substrates rich in chitin and keratin, and understanding the genes involved in these degradative pathways will enrich our understanding of these processes in aquatic ecosystems.