Abstract
Plant genomes contain numerous transposable elements (TEs), and many hypotheses on the evolutionary drivers that restrict TE activity have been postulated. Few models, however, have focused on the evolutionary epigenomic interaction between the plant host and its TE. The host genome recruits epigenetic factors, such as methylation, to silence TEs but methylation can spread beyond the TE sequence and influence the expression of nearby host genes. In this study, we investigated this epigenetic trade-off between TE and proximal host gene silencing by studying the epigenomic regulation of repressing long terminal repeat (LTR) retrotransposons (RTs) in Oryza sativa. Results showed significant evidence of methylation spreading originating from the LTR-RT sequences, and the extent of spreading was dependent on five factors: 1) LTR-RT family, 2) time since the LTR-RT insertion, 3) recombination rate of the LTR-RT region, 4) level of LTR-RT sequence methylation, and 5) chromosomal location. Methylation spreading had negative effects by reducing host gene expression, but only on host genes with LTR-RT inserted in its introns. Our results also suggested high levels of LTR-RT methylationmight have a role in suppressing TE-mediated deleterious ectopic recombination. In the end, despite the methylation spreading, no strong epigenetic trade-off was detected and majority of LTR-RT may have only minor epigenetic effects on nearby host genes.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 365-382 |
| Number of pages | 18 |
| Journal | Molecular Biology and Evolution |
| Volume | 35 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 1 2018 |
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Keywords
- epigenomics
- Oryza sativa
- retrotransposon
- transposable element
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Molecular Biology
- Genetics
Cite this
Evolutionary epigenomics of retrotransposon-mediated methylation spreading in rice. / Choi, Jae Young; Purugganan, Michael D.
In: Molecular Biology and Evolution, Vol. 35, No. 2, 01.02.2018, p. 365-382.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evolutionary epigenomics of retrotransposon-mediated methylation spreading in rice
AU - Choi, Jae Young
AU - Purugganan, Michael D.
PY - 2018/2/1
Y1 - 2018/2/1
N2 - Plant genomes contain numerous transposable elements (TEs), and many hypotheses on the evolutionary drivers that restrict TE activity have been postulated. Few models, however, have focused on the evolutionary epigenomic interaction between the plant host and its TE. The host genome recruits epigenetic factors, such as methylation, to silence TEs but methylation can spread beyond the TE sequence and influence the expression of nearby host genes. In this study, we investigated this epigenetic trade-off between TE and proximal host gene silencing by studying the epigenomic regulation of repressing long terminal repeat (LTR) retrotransposons (RTs) in Oryza sativa. Results showed significant evidence of methylation spreading originating from the LTR-RT sequences, and the extent of spreading was dependent on five factors: 1) LTR-RT family, 2) time since the LTR-RT insertion, 3) recombination rate of the LTR-RT region, 4) level of LTR-RT sequence methylation, and 5) chromosomal location. Methylation spreading had negative effects by reducing host gene expression, but only on host genes with LTR-RT inserted in its introns. Our results also suggested high levels of LTR-RT methylationmight have a role in suppressing TE-mediated deleterious ectopic recombination. In the end, despite the methylation spreading, no strong epigenetic trade-off was detected and majority of LTR-RT may have only minor epigenetic effects on nearby host genes.
AB - Plant genomes contain numerous transposable elements (TEs), and many hypotheses on the evolutionary drivers that restrict TE activity have been postulated. Few models, however, have focused on the evolutionary epigenomic interaction between the plant host and its TE. The host genome recruits epigenetic factors, such as methylation, to silence TEs but methylation can spread beyond the TE sequence and influence the expression of nearby host genes. In this study, we investigated this epigenetic trade-off between TE and proximal host gene silencing by studying the epigenomic regulation of repressing long terminal repeat (LTR) retrotransposons (RTs) in Oryza sativa. Results showed significant evidence of methylation spreading originating from the LTR-RT sequences, and the extent of spreading was dependent on five factors: 1) LTR-RT family, 2) time since the LTR-RT insertion, 3) recombination rate of the LTR-RT region, 4) level of LTR-RT sequence methylation, and 5) chromosomal location. Methylation spreading had negative effects by reducing host gene expression, but only on host genes with LTR-RT inserted in its introns. Our results also suggested high levels of LTR-RT methylationmight have a role in suppressing TE-mediated deleterious ectopic recombination. In the end, despite the methylation spreading, no strong epigenetic trade-off was detected and majority of LTR-RT may have only minor epigenetic effects on nearby host genes.
KW - epigenomics
KW - Oryza sativa
KW - retrotransposon
KW - transposable element
UR - http://www.scopus.com/inward/record.url?scp=85041128955&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85041128955&partnerID=8YFLogxK
U2 - 10.1093/molbev/msx284
DO - 10.1093/molbev/msx284
M3 - Article
VL - 35
SP - 365
EP - 382
JO - Molecular Biology and Evolution
JF - Molecular Biology and Evolution
SN - 0737-4038
IS - 2
ER -