Project description:In plants, multiple lineages have evolved sex chromosomes independently, providing a powerful comparative framework, but few specific determinants controlling the expression of a specific sex have been identified. We investigated sex-determinants in Caucasian persimmon, Diospyros lotus, a dioecious plant with heterogametic males (XY). Male-specific short nucleotide sequences were used to define a male determining region. A combination of transcriptomics and evolutionary approaches detected a Y-specific sex-determinant candidate, OGI, that displays male-specific conservation among Diospyros species. OGI encodes a small RNA targeting the autosomal MeGI gene, a homeodomain transcription factor regulating anther fertility in dosage-dependent fashion. This identification of a feminizing gene suppressed by a Y-chromosome-encoded small RNA contributes to our understanding of the evolution of sex chromosome systems in higher plants.
Project description:In plants, multiple lineages have evolved sex chromosomes independently, providing a powerful comparative framework, but few specific determinants controlling the expression of a specific sex have been identified. We investigated sex-determinants in Caucasian persimmon, Diospyros lotus, a dioecious plant with heterogametic males (XY). Male-specific short nucleotide sequences were used to define a male determining region. A combination of transcriptomics and evolutionary approaches detected a Y-specific sex-determinant candidate, OGI, that displays male-specific conservation among Diospyros species. OGI encodes a small RNA targeting the autosomal MeGI gene, a homeodomain transcription factor regulating anther fertility in dosage-dependent fashion. This identification of a feminizing gene suppressed by a Y-chromosome-encoded small RNA contributes to our understanding of the evolution of sex chromosome systems in higher plants. For expression analyses, mixed buds were sampled on June 17, and July 4, 2013, corresponding to the early differentiation stages of male/female primordia, respectively.
Project description:Purpose: Determine whether sex-determining genes are bivalent at the bipotential stage, poised between the testis and ovary fate, and whether H3K4me3 and H3K27me3 resolve into sex-specific patterns after sex determination, contributing to the canalization and stabilization of either the testis or ovary fate. Methods: XX and XY supporting cells of the gonad were FACS-purified before sex determination (at E10.5) and after sex determination (at E13.5), and submitted to ChIP-seq for H3K4me3, H3K27me3 and H3 as a means to normalize across cell populations. Results: We found that key sex-determining genes are bivalent at the bipotential stage. Genes that are upregulated affter sex determination are stripped of their repressive H3K27me3 mark, whereas repressed genes that promote the alternate pathway remain bivalent even after sex determination.
Project description:High CO2 treatment achieved significant acceleration of deastringency of ‘Jingmianshi’ persimmon fruit and subsequent softening, which could be retarded by adding 1-MCP. Comparison of the differentially expressed genes in the different treatments narrowed down the potential candidate genes for persimmon post-deastringency or softening.
Project description:The Salicaceae family is of growing interest in the study of dioecy in plants because the sex determination region (SDR) has been shown to be highly dynamic, with differing locations and heterogametic systems across taxa. Previous studies investigating the mechanisms regulating sex in the genus Salix have been limited to genome resequencing and differential expression, which are mostly descriptive in nature, and functional validation of candidate sex determination genes has not been conducted. Here we use functional analysis to test a suite of previously identified candidate genes involved in sex determination and sex dimorphism in the bioenergy shrub willow Salix purpurea. Six candidate master regulator genes for sex determination were overexpressed in Arabidopsis, followed by floral proteome analysis. Eleven transcription factors with predicted roles in mediating sex dimorphism downstream of the SDR were tested using DAP-Seq in both male and female S. purpurea DNA. The results of this study provide further evidence to support models for the roles of ARR17 and GATA15 as master regulator genes of sex determination in S. purpurea, contributing to a regulatory system that is notably different from that of the related genus Populus. Two transcription factors, an AP2/ERF family gene and a homeodomain-like transcription factor, have evidence supporting roles in downstream regulation of sex dimorphism.