Molecular systematics of the ascomycete genus Farrowia (Chaetomiaceae)

Abstract

The genus Farrowia D. Hawksworth was established for members of the Chaetomiaceae with Botryotrichum-like anamorphs and long-necked ascomata, but the separation of Farrowia from Chaetomium Kunze has been questioned by mycologists who did not consider these characters to be significant at the generic level. The recent description of a species of Chaetomium with an aleurioconidial anamorph and long-necked ascomata prompted us to explore this question employing molecular characters. We sequenced a portion of the nuclear large ribosomal subunit rRNA gene (28S) of members of the Sordariales including species of Chaetomium, Farrowia and Thielavia. Phylogenetic analyses confirmed the monophyly of the Sordariales and the close relationship of Aporothielavia leptoderma to the genus Chaetomium. A sequence-based phylogeny identified a well-supported clade that included Chaetomium floriforme, Chaetomium sphaerale, members of the genus Farrowia, and longicollous species of Chaetomium with aleurioconidial anamorphs. A clade containing Chaetomium brevipilium, Chaetomium cuyabenoensis, Chaetomium homopilatum and species of Farrowia was inferred from the analysis of morphological characters, but this data set was found to be incongruent with the 28S sequence data. While these results are in agreement with the hypothesis that species of Farrowia comprise a group of closely related taxa, they do not provide strong support for the recognition of the genus Farrowia.Key words: anamorph, aleurioconidia, Botryotrichum, Chaetomium, 28S ribosomal RNA gene sequences.

A re-evaluation of genusChaetomidiumbased on molecular and morphological characters

“…and Thielavia, taxa representative of the Chaetomiaceae. Our results are consistent with studies that supported the placement of Chaetomidium within the Chaetomiaceae, while at the same time indicating the polyphyletic nature of related taxa such as Chaetomium and Farrowia (Untereiner et al 2001) as well as other genera in the Sordariales such as Cercophora Fuckel, Podospora Ces. and Zopfiella G. Winter Huhndorf 2005, Cai et al 2006a).…”

Distribution of sterigmatocystin in filamentous fungi

“…The result of the phylogenetic analysis of Aspergillus (Eurotiomycetes) showed that ST is produced by three closely related sections, Nidulantes, Usti (Houbraken et al 2007) and Aenei (Varga et al 2010) and in more distantly related sections: Ochraceorosei, Cremei and Flavi. Examining the results of the phylogenetic analysis of Chaetomiaceae by Untereiner et al (2001) reveals that also here the ST producing species are rather unrelated.…”

“…The phylogenetic analysis of Chaetomium (synonym Farrowia) by Untereiner et al (2001), shows that Bo. (C.) pillulifera and Chaetomium cellulolyticum are distantly related within Chaetomium, so here the ST pathway may have evolved independently twice.…”

Chaetomiaceae Fungi, Novel Pathogens of Equine Neurotropic Phaeohyphomycosis

“…Over the past several years, many fungi within this family have already been reclassified based on such genetic analysis. 12,13,33,40,42 Although encephalitis caused by fungi within the Chaetomiaceae family has not been previously reported in horses, these fungi are well recognized as opportunistic neurotropic pathogens in immunocompromised people. [1][2][3][4][5]14,22 Affected human patients are most frequently reported to be adults, as were the 4 affected horses, and only 1 person survived infection.…”