RRC ID 6970
Author Kobayashi S, Noro Y, Nagano H, Yoshida KT, Takano-Shimizu T, Kishima Y, Sano Y.
Title Evidence for an evolutionary force that prevents epigenetic silencing between tail-to-tail rice genes with a short spacer.
Journal Gene
Abstract During the course of evolution, the genome should have toned down various types of genomic noise, such as those that cause the unstable expression or gene silencing observed in transgenic organisms. We found a rice genomic segment where two genes, encoding 5-enolpyruvylshikimate-3-phosphate synthase (EPSPs) and ribosomal protein small subunit 20 (rps20), are located in a tail-to-tail orientation and separated by only 300 bp of spacer. It is possible that this kind of structure would give rise to unstable expression due to antisense RNA derived from the neighboring gene. We examined this possibility using Northern blot, reverse transcription-polymerase chain reaction (RT-PCR), and 3' RACE analyses, but obtained no evidence for instability or antisense RNAs of these housekeeping genes. Comparison of the sequences in the corresponding regions among related rice species revealed a lower level of genetic divergence of both the 3'-untranslated region (3'-UTRs) than of the other noncoding regions; in particular both of the boundaries between the 3'-UTRs and the spacer were markedly conserved. The conservation of both the terminal regions is most likely the result of purifying selection, implying a functional role for the strict termination of the transcription of these genes to prevent gene-silencing-related events.
Volume 346
Pages 231-40
Published 2005-2-14
DOI 10.1016/j.gene.2004.11.012
PII S0378-1119(04)00699-7
PMID 15716045
MeSH Amino Acid Sequence Base Sequence Blotting, Northern DNA Primers DNA, Complementary Epigenesis, Genetic* Evolution, Molecular* Gene Silencing* Genes, Plant* Molecular Sequence Data Oryza / genetics* Sequence Homology, Amino Acid
IF 2.638
Times Cited 2
Rice W0107 W1945 W0025(=>C0025) W1579 W1185 W1561 W1034 W1422 W1514 W1272