The dynamic nature of eukaryotic genomes.
Analyses of diverse eukaryotes reveal that genomes are dynamic, sometimes dramatically so. In numerous lineages across the eukaryotic tree of life, DNA content varies within individuals throughout life cycles and among individuals within species. Discovery of examples of genome dynamism is accelerating as genome sequences are completed from diverse eukaryotes. Though much is known about genomes in animals, fungi, and plants, these lineages represent only 3 of the 60-200 lineages of eukaryotes. Here, we discuss diverse genomic strategies in exemplar eukaryotic lineages, including numerous microbial eukaryotes, to reveal dramatic variation that challenges established views of genome evolution. For example, in the life cycle of some members of the "radiolaria," ploidy increases from haploid (N) to approximately 1,000N, whereas intrapopulation variability of the enteric parasite Entamoeba ranges from 4N to 40N. Variation has also been found within our own species, with substantial differences in both gene content and chromosome lengths between individuals. Data on the dynamic nature of genomes shift the perception of the genome from being fixed and characteristic of a species (typological) to plastic due to variation within and between species.
Parfrey
Laura Wegener
LW
Program in Organismic and Evolutionary Biology, University of Massachusetts, USA. lwegener@nsm.umass.edu
Lahr
Daniel J G
DJ
Katz
Laura A
LA
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis; D005057:Eukaryotic Cells / Q000378:metabolism*; D014644:Genetic Variation; D016678:Genome / Q000235:genetics*; D013045:Species Specificity
D004247:DNA