Functional and evolutionary analysis of a eukaryotic parasitic genome

The DNA sequences of the 11 linear chromosomes of the similar to2.9 Mbp genome of Encephalitozoon cuniculi, an obligate intracellular parasite of mammals, include similar to2000 putative protein-coding genes. The compactness of this genome is associated with the length reduction of various genes. Essential functions are dependent on a minimal set of genes. Phylogenetic analysis supports the hypotheses that microsporidia are related to fungi and have retained a mitochondrion-derived organelle, the mitosome.