Home • Mucor circinelloides MU402 v1.0
Visualization of nuclei (green) in germinating spores of a MU402 transformant that  expresses eGFP-tagged histone H3. Photo courtesy of M.I. Navarro-Mendoza and C. PĂ©rez-Arques.
Visualization of nuclei (green) in germinating spores of a MU402 transformant that expresses eGFP-tagged histone H3. Photo courtesy of M.I. Navarro-Mendoza and C. Pérez-Arques.

Mucor circinelloides is a dimorphic fungus that belongs to the Mucoromycota phylum, one of the early-diverging fungal lineages. Despite the importance of early-diverging fungi to understand the evolutionary transitions that finally gave rise to the current fungal diversity and the emergence of terrestrial fungi, this group of fungi is relatively understudied with few species being amenable for genetic manipulation. M. circinelloides represent an outstanding exception since the increasing number of molecular tools available to manipulate its genome has resulted in the broadest molecular tool repertoire within the early-diverging fungi. MU402, a strain derived from CBS277.49 (Nicolás et al., 2007; Corrochano et al., 2016), is crucial for manipulation of the M. circinelloides genome because it is auxotrophic for leucine and uracil, which has made possible the selection of transformants with specific genetic modifications (gene deletion, gene tagging, over-expression, etc.). Thus, most studies to characterize cellular processes in M. circinelloides have used MU402, including, among others, dimorphism, light responses, gene silencing (RNAi) and lipid accumulation.

M. circinelloides also has biotechnological interest as a source of carotenes and lipids, which are accumulated in high levels in the mycelium. Moreover, its lipids can be easily transformed into biodiesel, suggesting that M. circinelloides biomass could be an alternative to plant oils as a feedstock for biodiesel production. However, the regulation of lipid accumulation is far from being completely understood and requires further studies.

The MU402 genome sequence provides the primary scaffold to characterize the genetic and epigenetic changes associated with the regulation of gene expression involved in biological processes such as lipid accumulation. One of the epigenetic marks that has recently gained significant attention is N6-adenine DNA methylation because it is abundant and widespread in early diverging fungi, suggesting a relevant role in the regulation of gene expression. The genome sequence of MU402 will make it possible to analyze the functional relevance of this epigenetic modification in M. circinelloides, contributing to understanding epigenetic regulation in early-diverging fungi.


Nicolás FE, de Haro JP, Torres-Martínez S, Ruiz-Vázquez RM. 2007. Mutants defective in a Mucor circinelloides dicer-like gene are not compromised in siRNA silencing but display developmental defects. Fungal Genet Biol 44:504–516.

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