Transcribed enhancer sequences are required for maize p1 paramutation.

Autor:	Sidorenko LV; Department of Plant Sciences, The University of Arizona, Tucson, AZ 85721, USA.; Corteva Agriscience, 7300 NW 62nd Ave, Johnston, IA 50131, USA., Chandler VL; Department of Plant Sciences, The University of Arizona, Tucson, AZ 85721, USA.; Minerva University, 14 Mint Plaza, Suite 300, San Francisco, CA 94103, USA., Wang X; Corteva Agriscience, 7300 NW 62nd Ave, Johnston, IA 50131, USA.; Department of Genetics, Development, and Cellular Biology, Department of Agronomy, Iowa State University, Ames, IA 50010, USA., Peterson T; Department of Genetics, Development, and Cellular Biology, Department of Agronomy, Iowa State University, Ames, IA 50010, USA.
Jazyk:	angličtina
Zdroj:	Genetics [Genetics] 2024 Jan 03; Vol. 226 (1).
DOI:	10.1093/genetics/iyad178
Abstrakt:	Paramutation is a transfer of heritable silencing states between interacting endogenous alleles or between endogenous alleles and homologous transgenes. Prior results demonstrated that paramutation occurs at the P1-rr (red pericarp and red cob) allele of the maize p1 (pericarp color 1) gene when exposed to a transgene containing a 1.2-kb enhancer fragment (P1.2) of P1-rr. The paramutable P1-rr allele undergoes transcriptional silencing resulting in a paramutant light-pigmented P1-rr' state. To define more precisely the sequences required to elicit paramutation, the P1.2 fragment was further subdivided, and the fragments transformed into maize plants and crossed with P1-rr. Analysis of the progeny plants showed that the sequences required for paramutation are located within a ∼600-bp segment of P1.2 and that this segment overlaps with a previously identified enhancer that is present in 4 direct repeats in P1-rr. The paramutagenic segment is transcribed in both the expressed P1-rr and the silenced P1-rr'. Transcription is sensitive to α-amanitin, indicating that RNA polymerase II mediates most of the transcription of this sequence. Although transcription within the paramutagenic sequence was similar in all tested genotypes, small RNAs were more abundant in the silenced P1-rr' epiallele relative to the expressed P1-rr allele. In agreement with prior results indicating the association of RNA-mediated DNA methylation in p1 paramutation, DNA blot analyses detected increased cytosine methylation of the paramutant P1-rr' sequences homologous to the transgenic P1.2 subfragments. Together these results demonstrate that the P1-rr enhancer repeats mediate p1 paramutation. Competing Interests: Conflicts of interest statement The authors declare no conflict of interest. (© The Author(s) 2024. Published by Oxford University Press on behalf of The Genetics Society of America.)
Databáze:	MEDLINE
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