A functional role for transposases in a large eukaryotic genome.
Despite comprising much of the eukaryotic genome, few transposons are active, and they usually confer no benefit to the host. Through an exaggerated process of genome rearrangement, Oxytricha trifallax destroys 95% of its germline genome during development. This includes the elimination of all transposon DNA. We show that germline-limited transposase genes play key roles in this process of genome-wide DNA excision, which suggests that transposases function in large eukaryotic genomes containing thousands of active transposons. We show that transposase gene expression occurs during germline-soma differentiation and that silencing of transposase by RNA interference leads to abnormal DNA rearrangement in the offspring. This study suggests a new important role in Oxytricha for this large portion of genomic DNA that was previously thought of as junk.
Nowacki
Mariusz
M
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA.
Higgins
Brian P
BP
Maquilan
Genevieve M
GM
Swart
Estienne C
EC
Doak
Thomas G
TG
Landweber
Laura F
LF
D000595:Amino Acid Sequence; D000818:Animals; D003227:Conjugation, Genetic; D004251:DNA Transposable Elements; D016054:DNA, Protozoan / Q000235:genetics; D015870:Gene Expression; D015321:Gene Rearrangement; D018503:Genome, Protozoan; D048631:Micronucleus, Germline / Q000235:genetics; D008969:Molecular Sequence Data; D016813:Oxytricha / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D034622:RNA Interference; D017384:Sequence Deletion; D019895:Transposases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
D004251:DNA Transposable Elements; D016054:DNA, Protozoan; D019895:Transposases