Whole-genome sequencing reveals a possible molecular basis of sex determination in the dioecious wild yam Dioscorea tokoro

Dioecious plants, which have distinct male and female individuals, constitute ~5% of angiosperm species and have emerged frequently and independently from hermaphroditic ancestors. Although recent molecular studies of sex determination have started to reveal the diversity of the genetic systems underlying dioecy, research on the evolution of dioecy is limited, especially in monocots. Here, we explore the molecular basis of sex determination in the monocot Dioscorea tokoro, a dioecious wild yam endemic to East Asia. Chromosome-scale and haplotype-resolved genome assemblies and linkage analysis suggested that this plant has a male heterogametic sex-determination (XY) system, with sex-determination regions located on chromosome 3. Sequence comparison between the X- and Y-chromosomes and read coverage analysis revealed X- and Y-specific regions in putative pericentromeric chromosome regions. Within the Y-specific region, we propose two candidate genes that are likely involved in sex determination: BLH9, encoding a homeobox protein, and HSP90, encoding a molecular chaperone. BLH9 functions in a similar way as AtBLH9 in Arabidopsis thaliana. BLH9 could be involved in suppression of female organ development, whereas HSP90 might be required for pollen development. These results shed light on the complex evolution of dioecy in plants.

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Journal
PLoS Genetics
Published
2026-04-20
DOI
https://doi.org/10.1371/journal.pgen.1012123
Primary Topic
Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
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article
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0.00

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article

Whole-genome sequencing reveals a possible molecular basis of sex determination in the dioecious wild yam Dioscorea tokoro

Hiroaki Adachi, Satoshi Natsume, Takuma Ishizaki, Hideki Innan et al.
PLoS Genetics
Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
article

Whole-genome sequencing reveals a possible molecular basis of sex determination in the dioecious wild yam Dioscorea tokoro

Hiroaki Adachi, Satoshi Natsume, Takuma Ishizaki, Hideki Innan, Motoki Shimizu, Yoshitaka Takano, Toshiyuki Sakai, Ryohei Terauchi, Aoi Kudoh, Hiroaki Kato, Mina Ohtsu, Mai Tsujimura, Yu Sugihara, Akira Abe, Kaori Oikawa, Toru Terachi, Atsushi Ohta, Kazue Itoh
article en

Abstract

Dioecious plants, which have distinct male and female individuals, constitute ~5% of angiosperm species and have emerged frequently and independently from hermaphroditic ancestors. Although recent molecular studies of sex determination have started to reveal the diversity of the genetic systems underlying dioecy, research on the evolution of dioecy is limited, especially in monocots. Here, we explore the molecular basis of sex determination in the monocot Dioscorea tokoro, a dioecious wild yam endemic to East Asia. Chromosome-scale and haplotype-resolved genome assemblies and linkage analysis suggested that this plant has a male heterogametic sex-determination (XY) system, with sex-determination regions located on chromosome 3. Sequence comparison between the X- and Y-chromosomes and read coverage analysis revealed X- and Y-specific regions in putative pericentromeric chromosome regions. Within the Y-specific region, we propose two candidate genes that are likely involved in sex determination: BLH9, encoding a homeobox protein, and HSP90, encoding a molecular chaperone. BLH9 functions in a similar way as AtBLH9 in Arabidopsis thaliana. BLH9 could be involved in suppression of female organ development, whereas HSP90 might be required for pollen development. These results shed light on the complex evolution of dioecy in plants.

PLoS GeneticsVol. 22(4)
Ryukoku University (JP), University of East Anglia (GB), Kyoto Sangyo University (JP), The Graduate University for Advanced Studies, SOKENDAI (JP), Hokkaido University (JP), Kyoto University (JP), Norwich Research Park (GB), Sainsbury Laboratory (GB), Japan Science and Technology Agency (JP), Japan International Research Center for Agricultural Sciences (JP), Iwate Biotechnology Research Center (JP)
Japan Society for the Promotion of Science
Openalex Percentile: Top 13%
Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
DOIOpen Access PDFOpenAlex
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