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Evolution and implications of genome rearrangements in ciliates
Author(s) -
KATZ LAURA A.
Publication year - 2005
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.2005.05202003_1_39.x
Subject(s) - biology , ciliate , genome , evolutionary biology , macronucleus , genetics , genome size , gene , tetrahymena , phylogenetics , genome evolution , phylogenetic tree
We are exploring genome evolution in diverse ciliates to assess whether patterns of protein evolution correspond to the presence of genome duality, and to levels of genome rearrangements among ciliates. Ciliate genomes contain an estimated 25,000–35,000 genes, a number higher than that of other characterized microbial eukaryotes and on a similar scale to that of humans and Arabidopsis thaliana . We have previously hypothesized that the divergence among ciliate proteins, and the accumulation of paralogs within ciliate taxa, is due to differential selection on the functional macronucleus and the transcriptionally inactive micronucleus. To assess this hypothesis, we are expanding our analyses of protein‐coding gene sequences to compare the fate of proteins in ciliates to that of other eukaryotes, and to test whether the most divergent ciliate proteins are found in ciliates with extensively processed genomes. These analyses, combined with a phylogenetic perspective that reveals multiple origins of extensive fragmentation in ciliates, provide a possible explanation for the large genome size and diversity of proteins in ciliates.