Chlamydospore

Chlamydospore is a thick-walled resting spore formed by certain fungi and yeasts as a survival structure. It typically arises from a single hyphal cell and can be produced terminally at the end of a hypha or intercalary within a hyphal strand. Chlamydospores are not part of the active reproductive cycle; instead, they serve to endure unfavorable environmental conditions and nutrient limitation.

In terms of structure, a chlamydospore is usually larger than surrounding hyphal cells and features a multilayered, resistant wall. The interior contains condensed cytoplasm and stored nutrients, which support germination when conditions become favorable. The walls are often rich in lipids and sometimes pigments, contributing to their durability against desiccation, heat, and other stresses.

The primary function of chlamydospores is survival and long-term persistence. They can persist in soil, plant debris, or on host surfaces until environmental conditions improve, at which point they germinate to form new hyphae. Because they are resting structures rather than actively dispersing propagules, chlamydospores are typically less involved in rapid spread than conidia or sporangia.

Occurrence and significance vary among fungi. Chlamydospores are observed in several yeasts and filamentous fungi, including some Candida species and various plant- and animal-associated fungi. In the laboratory, their presence can aid taxonomic identification and differentiation of certain species, particularly in diagnostic microbiology where chlamydospore formation is a characteristic morphological feature.