title: A complex dominance hierarchy is controlled by polymorphism of small RNAs and their targets.
abstract: In diploid organisms, phenotypic traits are often biased by effects known as Mendelian dominant-recessive interactions between inherited alleles. Phenotypic expression of SP11 alleles, which encodes the male determinants of self-incompatibility in Brassica rapa, is governed by a complex dominance hierarchy1-3. Here, we show that a single polymorphic 24 nucleotide small RNA, named SP11 methylation inducer 2 (Smi2), controls the linear dominance hierarchy of the four SP11 alleles (S44> S60> S40> S29). In all dominant-recessive interactions, small RNA variants derived from the linked region of dominant SP11 alleles exhibited high sequence similarity to the promoter regions of recessive SP11 alleles and acted in trans to epigenetically silence their expression. Together with our previous study4, we propose a new model: sequence similarity between polymorphic small RNAs and their target regulates mono-allelic gene expression, which explains the entire five-phased linear dominance hierarchy of the SP11 phenotypic expression in Brassica.
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Yasuda
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Wada
authors.affiliation: Division of Vegetable Breeding, Institute of Vegetable and Floriculture Science, NARO, Tsu, Mie 514-2392, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kakizaki
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tarutani
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Eiko
authors.initials: E
authors.lastname: Miura-Uno
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Kohji
authors.initials: K
authors.lastname: Murase
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Sota
authors.initials: S
authors.lastname: Fujii
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Hioki
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Taiki
authors.initials: T
authors.lastname: Shimoda
authors.affiliation: Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Takada
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shiba
authors.affiliation: Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo 657-8501, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Takasaki-Yasuda
authors.affiliation: Division of Natural Science, Osaka Kyoiku University, Kashiwara, Osaka 582-8582, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Suzuki
authors.affiliation: Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.|Department of Applied Biological Chemistry, The University of Tokyo, Tokyo 113-8657, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Takayama