Opisthosporidia is asuperphylum of intracellularparasites with amoeboid vegetative stage, defined as a common group ofeukaryotic groupsMicrosporidia,Cryptomycota (also known as Rozellida, Rozellomycota, orRozellosporidia) andAphelidea.[1] They have been considered to represent a monophyletic lineage with shared ecological and structural features, being a sister clade of theFungi.[1][2] Together with the Fungi they represent a sister clade of theCristidiscoidea, together forming theHolomycota.
Several other basal groups of the freshwater, marine and soil-inhabiting Holomycota were identified in recent studies, as the 'basal clone group 1' (BCG1=NCLC1), 'basal clone group 2' (BCG2), 'basal marine group' (NAMAKO-37), 'basal group GS01', the inner relationships of Opisthosporidia were clarified and theirmonophyly questioned: Cryptomycota and Microsporidia were proposed to join the phylum Rozellomycota, while Aphelidea were considered as a separate, though related phylum and all these groups were considered basal lineages of the kingdom Fungi.[3][4][2][5]
Instead of probablyparaphyletic Opisthosporidia, the phylaRozellomycota andAphelidiomycota (ormonotypic subkingdoms Rozellomyceta and Aphelidiomyceta) are recently applied in some taxonomical systems of the kingdom Fungi for the basal lineages, and the other fungal lineages are grouped into a clade ofTrue Fungi (Eumycota).[6][note 1] However, the taking up of the name Rozellomycota in such a broad sense can be considered premature, especially as the structure and biological features of a larger part of these organisms are unclear as they are known only from environmental sequences. The borders between Fungi andProtista are therefore unstable and final delimitation of taxa is problematic due to poor coverage of molecular data for the representatives of the basal groups.[6]
^Galindo, Luis Javier; Torruella, Guifré; López-García, Purificación; Ciobanu, Maria; Gutiérrez-Preciado, Ana; Karpov, Sergey A; Moreira, David (17 June 2023). "Phylogenomics Supports the Monophyly of Aphelids and Fungi and Identifies New Molecular Synapomorphies".Systematic Biology.72 (3). Oxford University Press:505–515.doi:10.1093/sysbio/syac054.ISSN1076-836X.PMID35900180.
