Sporulation: how to survive on planet Earth (and beyond)

Abstract

Sporulation is a strategy widely utilized by a wide variety of organisms to adapt to changes in their individual environmental niches and survive in time and/or space until they encounter conditions acceptable for vegetative growth. The spores produced by bacteria have been the subjects of extensive studies, and several systems such as Bacillus subtilis have provided ample opportunities to understand the molecular basis of spore biogenesis and germination. In contrast, the spores of other microbes, such as fungi, are relatively poorly understood. Studies of sporulation in model systems such as Saccharomyces cerevisiae and Aspergillus nidulans have established a basis for investigating eukaryotic spores, but very little is known at the molecular level about how spores function. This is especially true among the spores of human fungal pathogens such as the most common cause of fatal fungal disease, Cryptococcus neoformans. Recent proteomic studies are helping to determine the molecular mechanisms by which pathogenic fungal spores are formed, persist, and germinate into actively growing agents of human disease.

Genomes shed light on the secret life of Candida glabrata: not so asexual, not so commensal

“…Ploidy control and permanent availability to form diploid cells that can sporulate, may be the reason for the existence of such a complex phenomenon. Indeed, spores are the stage where cells can resist harsh conditions until the environment is more favorable to growth (Huang and Hull 2017). C. glabrata , like many other fungal pathogens of humans, is considered an asexual species and all attempts to make it mate in the laboratory have, so far, failed.…”

The cause and effect of Cryptococcus interactions with the host

“…Importantly, germination is a conversion from a metabolically inactive to active state, similar to Saccharomyces cerevisiae germination (reviewed in [9]). Consistent with this, whole proteome analysis of spore vs. yeast-enriched proteins identified proteins involved in carbohydrate metabolism, mating, and sporulation, rather than a specific germination program [1], and germination was delayed in the absence of micronutrients [2].…”

Quiescence, an individual journey

“…Dormancy has been brilliantly discussed for unicellular organisms (Lewis 2007;Jones and Lennon 2010;Rittershaus et al 2013) and plants (Considine and Considine 2016;Velappan et al 2017). Yet, while it is easy to acknowledge that spores are dormant since they undergo massive morphological changes (Huang and Hull 2017), this particular quiescent status is more debated in animals in which the frontiers of dormancy are more subjective (Rittershaus et al 2013;Rocheteau et al 2015). In sum, quiescence encompasses an infinite number of cellular situations depending on both the cell type and the environmental niche.…”