Coprinus species are cosmopolitan (.Padamsee et al. 2008), and widely renowned for a phenomenon called deliquescence (.Nagy et al. 2010). During this process, fruiting body tissues become blackish inky fluid by autodigestion of the fruiting body cells upon maturation (.Hopple and Vilgalys 1999). Another notable feature of Coprinus is that most species can produce fungal laccases(.Hoegger et al. 2004, Hu et al. 2019, Kilaru et al. 2006, Lin et al. 2013) and extracellular peroxygenases (.Aranda et al. 2009). Laccases are biologically important enzymes that belong to the oxidase group and are useful as green enzymes for cleaner industrial applications to reduce environmental pollution (.Senthivelan et al. 2016). Considering that these enzymes have various substrate catalytic properties and numerous applications in various fields, they have received attention from researchers for their use in further intensive studies worldwide (.Senthivelan, Kanagaraj and Panda 2016). Although laccases are produced by plants, bacteria, insects, and fungi(.Dwivedi et al. 2011, Senthivelan, Kanagaraj and Panda 2016), fungal laccases have been the most extensively studied (.Liu et al. 2022, Mougin et al. 2003). However, the distribution of deliquescence and laccase- and peroxygenase-coding genes in Coprinus species does not exhibit a clear pattern, which may be due to the unclear classification system of Coprinus and the relatively complex genomes of Coprinus species (.Nagy, Urban, Örstadius, Papp, Larsson and Vágvölgyi 2010, Örstadius et al. 2015).
Traditionally, Psathyrellaceae species have been classified into two large genera, Coprinus and Psathyrella. However, the two genera have many common features, including similar habitat preferences, spore characteristics, degradation of spore pigments in sulfuric acid, and developmental, morphological, and ecological traits that are significantly convergent; several alternative classifications have also been proposed(.Nagy, Urban, Örstadius, Papp, Larsson and Vágvölgyi 2010). Furthermore, it has long been recognized that deliquescent taxa within Psathyrellaceae do not form a monophyletic group (.Vašutová et al. 2008, Walther et al. 2005). The genus Coprinus was proposed to be split into four genera (.Redhead et al. 2001). Although some studies have added valuable information to our knowledge of the phylogeny of Psathyrellaceae (.Nagy, Urban, Örstadius, Papp, Larsson and Vágvölgyi 2010, Örstadius, Ryberg and Larsson 2015, Wächter and Melzer 2020). However, these studies were all based on the diversity analysis of one or several limited genes. Even though these studies provide substantial guidance for the study of the phylogeny of Psathyrellaceae, they fail to provide effective information to study the origin and maintenance mechanisms of Psathyrellaceae functional genes.
Comparative genomics provide an important technical means for studying the origin and maintenance of fungal genetic diversity(.de Vries et al. 2017, Kiss et al. 2019, Ma et al. 2013, Zhang et al. 2020). However, the genome structure and genetic diversity of Coprinus species have not been extensively studied. Therefore, in this study, we aimed to reveal the genomic structure and genetic diversity of Coprinus species by comparing and analyzing the genomes of five Coprinus species, i.e. Coprinellus angulatus, Coprinellus micaceus, Coprinopsis cinerea, Coprinopsis marcescibilis, and Candolleomyces aberdarensis .