Love in the time of climate change: A review of sexual reproduction in the order Onygenales

Life-threatening infections caused by fungi in the order Onygenales have been rising over the last few decades. Increasing global temperature due to anthropogenic climate change is one potential abiotic selection pressure that may explain the increase in infections. The generation of genetically novel offspring with novel phenotypes through the process of sexual recombination could allow fungi to adapt to changing climate conditions. The basic structures associated with sexual reproduction have been identified in Histoplasma, Blastomyces, Malbranchea, and Brunneospora. However, for Coccidioides and Paracoccidioides, the actual structural identification of these processes has yet to be identified despite having genetic evidence that suggests sexual recombination is occurring in these organisms. This review highlights the importance of assessing sexual recombination in the order Onygenales as a means of understanding the mechanisms these organisms might employ to enhance fitness in the face of a changing climate and provides details regarding the known reproductive mechanisms in the Onygenales.