“…Yet such knowledge is essential for locating the sources of new outbreaks, defining the relatedness of isolates recovered from different patients, and developing effective vaccines against the fungus. Recently, a molecular genetic analysis of nucleotide polymorphisms among isolates from a single hospital in Tucson, Arizona, provided strong evidence for sexual reproduction (15). To test whether the species is panmictic in its entire range or whether there is geographic differentiation among different populations, we have used a sample of 17 isolates, from California, Texas, Arizona, Mexico, and Argentina, covering the entire known species range (see Table 1).…”