Abstract
Transcriptional regulation is one of the fundamental approaches for young plants to cope with environmental fluctuations and maintain active development. The transposable element (TE) subclass long terminal-repeat retrotransposons (LTR-RTs) can act as additional regulators for genes through enhancer and promoter activity, but their promoters, transcription initiation, and contributions during maize development remain uncharacterized. Here, we developed IsoClassifier to resolve the transcription start site (TSS) and RNA isoforms of LTR-RTs based on long-read transcriptomics, delineating LTR U3 regions as the native promoter and enhancer of LTR-RTs. We reveal conserved motifs associated with core promoter activity in transcribed LTR-RTs that are highly comparable to gene promoters. Further, we found that LTR-RT transcription in maize was dominated by spliced, long non-coding RNA. Finally, a genome-wide coexpression analysis revealed that LTR-RTs are transcribed as hub-like elements in coexpression networks, suggesting important roles in gene regulation. We conclude that LTR-RTs have similar promoter compositions to gene promoters and likely share similar transcription regulation programs.
Full text
1,449 characters
· extracted from
oa-doi-fallback
· click to expand
Abstract
Transcriptional regulation is one of the fundamental approaches for young plants to cope with environmental fluctuations and maintain active development. The transposable element (TE) subclass long terminal-repeat retrotransposons (LTR-RTs) can act as additional regulators for genes through enhancer and promoter activity, but their promoters, transcription initiation, and contributions during maize development remain uncharacterized. Here, we developed IsoClassifier to resolve the transcription start site (TSS) and RNA isoforms of LTR-RTs based on long-read transcriptomics, delineating LTR U3 regions as the native promoter and enhancer of LTR-RTs. We reveal conserved motifs associated with core promoter activity in transcribed LTR-RTs that are highly comparable to gene promoters. Further, we found that LTR-RT transcription in maize was dominated by spliced, long non-coding RNA. Finally, a genome-wide coexpression analysis revealed that LTR-RTs are transcribed as hub-like elements in coexpression networks, suggesting important roles in gene regulation. We conclude that LTR-RTs have similar promoter compositions to gene promoters and likely share similar transcription regulation programs.
Competing Interest Statement
The authors have declared no competing interest.
Data Availability
Raw Nanopore sequencing data generated in this work are available through the European Nucleotide Archive (ENA) BioProject ID PRJEB111639.
Text is read by the "Ask this paper" AI Q&A widget below.
Extraction quality varies by source — PMC NXML preserves structure
cleanly, OA-HTML may include some navigation residue, and OA-PDF can
have broken hyphenation. The publisher copy
(via DOI)
is the canonical version.