ABSTRACT
This chapter discusses the features of the nucleic acids, primarily deoxyribonucleic acid, of anaerobic gut fungi. Mitochondria, as recognizable organelles, are absent from the anaerobic fungi. The evolutionary origin of the fungi suggests that their ancestors possessed mitochondria and that these were lost from the line leading to the anaerobes. The transcript was substantially larger, however, than the corresponding messenger RNA identified in aerobic filamentous fungi. The cloning of structural genes and the resultant sequence information have an important contribution to make to the understanding of the biochemistry and physiology of the anaerobic fungi, and of the role in ruminai digestion. Sequence analysis of the internal transcribed spacer and its adjacent regions from four anaerobic fungi has been used to assess phylogenetic relationships. Microbial nucleic acids have been a popular target for investigators because they are accessible macromolecules with a high information content and are present in all cells.
