Project description:Sex chromosomes evolved from autosomes many times across the eukaryote phylogeny. Several models have been proposed to explain this transition, some involving male and female sterility mutations linked in a region of suppressed recombination between X and Y (or Z/W, U/V) chromosomes. Comparative and experimental analysis of a reference genome assembly for a double haploid YY male garden asparagus (Asparagus officinalis L.) individual implicates separate but linked genes as responsible for sex determination. Dioecy has evolved recently within Asparagus and sex chromosomes are cytogenetically identical with the Y, harboring a megabase segment that is missing from the X. We show that deletion of this entire region results in a male-to-female conversion, whereas loss of a single suppressor of female development drives male-to-hermaphrodite conversion. A single copy anther-specific gene with a male sterile Arabidopsis knockout phenotype is also in the Y-specific region, supporting a two-gene model for sex chromosome evolution. Additionally, we test for the presence of Y-specific small RNA loci in several XX, XY, and YY genotypes that may be acting as sex determination loci.
Project description:Two independent small RNA (sRNA) libraries from male and female asparagus plants were sequenced, generating 4.13 and 5.88 million final cleaned reads, respectively. A total of 154 conserved miRNA belonging to 26 families, and 40 novel miRNA candidates that seemed to be specific to asparagus were identified, among them, 63 miRNAs exhibited significant differential expression between male and female plants, and 36 target mRNAs representing 44 conserved and fournovel miRNA in asparagus by high-throughput degradome sequencing analysis.
Project description:Two independent small RNA (sRNA) libraries from male and female asparagus plants were sequenced, generating 4.13 and 5.88 million final cleaned reads, respectively. A total of 154 conserved miRNA belonging to 26 families, and 40 novel miRNA candidates that seemed to be specific to asparagus were identified, among them, 63 miRNAs exhibited significant differential expression between male and female plants, and 36 target mRNAs representing 44 conserved and fournovel miRNA in asparagus by high-throughput degradome sequencing analysis. Examination of small RNA in male and female asparagus using high-throughput sequencing
