Identification and characterization of anaerobic gut fungi using molecular methodologies based on ribosomal ITS1 and 18S rRNA The GenBank accession numbers for the sequences determined in this work are given in Methods.

Abstract

The gut fungi are an unusual group of zoosporic fungi occupying a unique ecological niche, the anaerobic environment of the rumen. They exhibit two basic forms, with nuclear migration throughout the hyphal mass for polycentric species and with concentration of nuclear material in a zoosporangium for monocentric species. Differentiation between isolates of these fungi is difficult using conventional techniques. In this study, DNA-based methodologies were used to examine the relationships within and between two genera of monocentric gut fungi gathered from various geographical locations and host animals. The ribosomal ITS1 sequence from 16 mono-and 4 polycentric isolates was PCR-amplified and sequenced ; the sequences obtained were aligned with published sequences and phylogenetic analyses were performed. These analyses clearly differentiate between the two genera and reflect the previously published physiological conclusions that Neocallimastix spp. constitute a more closely related genus than the relatively divergent genus Piromyces. The analyses place two type species N. frontalis and N. hurleyensis together but, contrary to a recent suggestion in the literature, place them apart from the other agreed species N. patriciarum. In situ hybridization and slot-blotting were investigated as potential methods for detection of and differentiation between monocentric gut fungi. DNA slot-blot analysis using ribosomal sequences is able to differentiate between gut fungal genera and thus has considerable potential for use in ecological studies of these organisms.

Hydrogenosomes: convergent adaptations of mitochondria to anaerobic environments

“…The anaerobic chytrids Neocallimastix and Piromyces are biochemically, physiologically and phylogenetically related to aerobic yeasts and fungi (see Akhmanova et al, 1998bAkhmanova et al, , 1999Brookman et al, 2000). They thrive in the gastro-intestinal tract of large herbivorous vertebrates (Fig.…”

Molecular Biological Detection of Anaerobic Gut Fungi ( Neocallimastigales ) from Landfill Sites

“…There is a high degree of conservation in 18S rRNA gene sequences across the Neocallimastigales, for which morphological criteria have been used as the principal means of classifying the six genera and their species that constitute the order. There has, however, been more recent progress on the use of internally transcribed spacer region sequences as a reliable means of identifying anaerobic fungi to the genus level (2,10).…”

Genetic variability in the ITS and IGS regions of the ribosomal DNA of Acremonium cavaraeanum exhibiting antimicrobial activity

“…The 18S and 28S ribosomal genes, along with the internal transcribed spacer (ITS) and intergenic spacer (IGS) regions, are the sites that have been targeted in studies involving fungi. The information found in these sequences has been extensively used in population diversity and characterization studies (Smit et al, 1999;van Elsas et al, 2000;Schabereiter-Gurtner et al, 2001;Sterflinger and Prillinger 2001), identification and detection (Brookman et al, 2000;Redecker 2000;Abd-Elsalam et al, 2003;Wu et al, 2003;Abliz et al, 2004), typing (Sutar et al, 2004), and for the establishment of phylogenetic relationships (LoBuglio and Taylor, 1995;Peintne et al, 2003).…”