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P.4 left column bottom paragraph: "The recent report of a third complete mycoplasma genome sequence, that of U. urealyticum (0.75 Mb) [primary source], has allowed further comparative genomics of minimalism. The unusual genomic relationship of M. genitalium and M. pneumoniae does not apply to the 613-ORF genome of U. urealyticum. In this case, the findings are more as expected: unequal gene loss has occurred between U. urealyticum and the other two mycoplasma genomes. Phylogenetically, U. urealyticum is more distantly related to M. genitalium and M. pneumoniae than the latter two are to each other. A comparison of the more distantly related genomes has allowed greater insights into mycoplasma evolution to be made. Only 324 genes are shared between U. urealyticum and M. genitalium, and M. genitalium has some genes (74) that are absent from U. urealyticum." Primary source p.760 left column top paragraph: "Comparisons of two very closely related bacterial genomes, M. pneumoniae and M. genitalium, have helped to define the essential functions of a self-replicating minimal cell, as well as what constitutes a mycoplasma [refs 25,26]. Determining what is a minimal cell was aided by the fact that the gene set of M. genitalium was essentially a subset of the gene set of M. pneumonia: however, because the evolutionary divergence of those two mycoplasmas is so recent, the comparison has limited resolution. Phylogenetic analysis shows that U. urealyticum is a member of the same clade of the class Mollicutes as M. pneumoniae and M. genitalium: but it is different enough to make the comparison more informative. Of the 613 U. urealyticum protein-coding genes, only 324 are homologous to M. genitalium genes and M. pneumoniae genes (all M. genitalium genes have orthologues in M. pneumonia [ref 25]). No function can be predicted for 77 of the genes shared by the 3 mycoplasmas. Ten of those conserved hypothetical genes are found only in mycoplasmas (see Supplementary Information or link " Please note- the link is broken as of May 23rd 2019 |