Fungalpedia – Note 3315, Cryptomycocolacomycetes
Cryptomycocolacomycetes R. Bauer, Begerow, J.P. Samp., M. Weiss & Oberw., Mycol. Progr. 5(1): 46 (2006).
Citation when using this data: Wijayawardene NN et al. 2024 – Fungalpedia.
Index Fungorum, Faceoffungi, MycoBank, GenBank, Fig 1.
Classification: Pucciniomycotina, Basidiomycota, Dikarya, Fungi.
Cryptomycocolacomycetes is comprising the order Cryptomycocolacales, family Cryoptomycocolacaceae, and the two monotypic genera Cryptomycocolax and Colacosiphon (Oberwinkler and Bauer 1990; Kirschner et al. 2001; Bauer et al. 2006; Begerow et al. 2018). The class was introduced by Bauer et al. (2006) based on molecular phylogenetic reconstructions combined with ultrastructural and morphological observations. Both Cryptomycocolax abnormis and Colacosiphon filiformis are colacosome-interacting mycoparasites associated with ascomycetous hosts. At the ultrastructural level, both species are characterised by simple septal pores surrounded by woronin-like bodies, which are reminiscent of the woronin bodies found in Ascomycota. Colacosiphon abnormis was found to contain two distinct types of colacosomes with differences in their morphology and spatial organisation. In C. filiformis on the other hand, only one type of colacosomes was reported, which is presumably the same as one of the types found in C. abnormis, and in mycoparasites of Microbotryomycetes. The colacosomes are mostly organised in vesicular cells, which are invaginate dby host hyphae. Along the contact surface, a dense formation of colacosomes is observed, resulting in botryose structures in these cells. Reproductive structures in these two species are considerably different from each other and from other Basidiomycota. The sporogenous cells are elongated and produce a variable number of sessile spores. Oberwinkler and Bauer (1990) performed an excellent study of the lifecycle of C. abnormis by using transmission electron microscopy (TEM), and observed meiosis in the elongated cells, which they interpreted as basidia. During basidium development, a short phragmobasidial stage is present in which the basidium is transversally one-septate. Later in the development, the top cell is abscised and the basal cell elongates, eventually producing sessil spores apically. The nature of the sporogenous cells in Colacosiphon was not studied in such detail by TEM and remains unclear (Kirschner et al. 2001). Therefore, these structures are tentatively interpreted as conidiogenous cells for asexual reproduction. Yeast budding was microscopically observed in C. abnormis, but not in C. filiformis (Oberwinkler 2017).
Life modes and distribution: Both species in this class are colacosome-interacting mycoparasites, associated with ascomycetous hosts. Cryptomycocolax abnormis was isolated as a slimy layer overgrowing pyrenomycetes on a decaying branch of Circium subcoriaceum in Costa Rica (Oberwinkler and Bauer 1990). Colacosiphon filiformis was isolated from bark beetles (Ips sexdentatus) retrieved from decaying Pinus sylvestris logs in Germany. This species was obtained in co-culture with other fungi, in which it was found in a parasitic interaction with an ascomycetous host (Kirschner et al. 2001).
Notes: Currently, only DNA sequence data from the D1/D2 region of the LSU ribosomal nuclear DNA are available for these two species. Weiß et al. (2004) discussed the possibility that Cryptomycocolacomycetes is a sister to all other Basidiomycota, but the phylogenetic analyses rendered low bootstrap support for this scenario. Also in later studies, the phylogenetic position of this class was unresolved (e.g. Bauer et al. 2006). It can be expected that more diversity within this class remains to be discovered, and genome-scale data will help to determine the evolutionary relationships of this class and the species it comprises.
Type order: Cryptomycocolacales Oberw. & R. Bauer, Mycologia 82(6): 672 (1990).
Type family: Cryptomycocolacaceae Oberw. & R. Bauer, Mycologia 82(6): 672 (1990).
Type genus: Cryptomycocolax Oberw. & R. Bauer, Mycologia 82(6): 672 (1990).
Type species: Cryptomycocolax abnormis Oberw. & R. Bauer [as ‘abnorme’], Mycologia 82(6): 672 (1990).
Other accepted species: Species Fungorum – search Cryptomycocolacomycetes.
Figure 1 – Cryptomycocolax abnorme. a Habit sketch of fructification growing in and on sclerotia of the host; one sclerotium longitudinally sectioned. b Basidial development (a); globose probasidium (b,c); apical elongation of young basidium (d); two celled-basidium (phragmobasidial stage). c Basidial apices of mature, one-celled holobasidia with sessile basidiospores at different development stages. d Old apex of basidium with bases of spore attachments. e Sectional view of sclerotium with hyphae of the host, unclamped and hyphae and basidia of the parasite with clamps; note botryose structures of cellular interactions. The basidia are in different development stages. f Germination of basidiospores by hyphae. g Yeast-like budding of basidiospores. Scale bars: a=1 mm; b-g =10 μm (re-drawn from Oberwinkler and Bauer 1990).
References
Begerow D, McTaggart A, Agerer R. 2018 – 1/3 Basidiomycota and Entorrhizomycota In: Frey, W. (Ed.) A. Engler’s Syllabus der Pflanzenfamilien. Germany: Bontraeger Science Publishers.
Oberwinkler F. 2017 – Yeasts in Pucciniomycotina. Mycol Prog 16:831–856.
Entry by
Nalin N. Wijayawardene, Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, P.R. China, Tropical Microbiology Research Foundation, 96/N/10, Meemanagoda Road, 10230 Pannipitiya, Sri Lanka, Department of Bioprocess Technology, Faculty of Technology, Rajarata University, Sri Lanka
Published online 2 October 2026