THE FUNGAL MITOCHONDRIAL GENOME PROJECT - EVOLUTION OF FUNGAL MITOCHONDRIAL GENOMES AND THEIR GENE-EXPRESSION

The goal of the fungal mitochondrial genome project (FMGP) Is to seque nce complete mitochondrial genomes for a representative sample of the major fungal lineages; to analyze the genome structure, gene content, and conserved sequence elements of these sequences. and to study the e volution of gene expression in fungal mitochondria. By using our new s equence data for evolutionary studies, we were able to construct phylo genetic trees that provide further solid evidence that animals and fun gi share a common ancestor to the exclusion of chlorophytes and protis ts. With a database comprising multiple mitochondrial gene sequences, the level of support for our mitochondrial phylogenies is unprecedente d, in comparison to trees inferred with nuclear ribosomal RNA sequence s. We also found several new molecular features in the mitochondrial g enome of lower fungi including: (1) tRNA editing, which is the same ty pe as that found in the mitochondria of the amoeboid protozoan Acantha moeba castellani; (2) two novel types of putative mobile DNA elements, one encoding a site-specific endonuclease that confers mobility on th e element, and the other constituting a class of highly compact, struc tured elements; and (3) a large number of introns, which provide insig hts into intron origins and evolution. Here, we present an overview of these results, and discuss examples of the diversity of structures fo und in the fungal mitochondrial genome.