Identification of anther expressing genes in cotton (Gossypium hirsutum)
ABSTRACT: This study was initiated with the objective of identifying the anther/tapetum specific promoters from cotton floral buds. Cotton is an important commercial crop. Hybrid cotton varieties are developed to obtain improved yield and fiber quality. Most of the hybrid seed production in cotton is carried out by hand emasculation, which requires large amount of manpower, resulting in high cost of hybrid seed. We are developing barnase-barstar based male sterility system, which would be a better alternative for hybrid development. The tapetum specific promoters are main requirement for such a system. The study was thus carried out to identify genes expressed in the anthers. Cotton bud sizes were correlated with tapetum development. RNA was isolated from following tissues: • Anther tissues from buds at pre-meiotic stage of development (Tapetum absent) • Buds without anther tissues at pre-meiotic stage of development • Anther tissues from buds during meiosis (Tapetum present) • Buds without anther tissues during meiosis • Anther tissues from buds at post-meiotic stage of development (Tapetum degenerated) • Buds without anther tissues at post-meiotic stage of development • Leaf tissues • Seedling 5 days after germination Biotin labeled cRNA was hybridized on Affymertix cotton Genechip Genome array following Affymetrix protocols. Three biological replicates were maintained.
Project description:Transcriptomes from multiple pre-meiotic stages of wild type, mac1, and msca1 maize anthers were characterized by microarray hybridization. The goal was to characterize the developmental progression as the anther specifies five cell types and grows rapidly precedeing meiotic entry. The stages characterized were immature anther primordia (0.15 mm long in maize) containing just stem cells, through somatic and germinal cell fate specification (0.20 and 0.25 mm), mitotic proliferation (0.4 mm), and finally the birth of the middle layer and tapetum (0.7 mm). To obtain cell-type specific markers, at 0.7 mm we also compared whole anthers to collections of laser-microdissected anther cell types including the archesporial cells (pre-meiotic germinal cells), nutritive layers (middle layer and tapetum) and structural layers (endothecium and epidemis) of the anther lobe. keyword: anther development, maize, male-sterile Three loop designs covered the early stages (up to 0.7 mm) with two replicates for each comparison. The first loop had 0.2 mm long anthers and compared wild type versus mac1 mutant versus msca1 mutant in a three vertex loop design. The second loop had four vertices and compared 0.15 mm WT anther primordia, 0.25 mm WT anthers, 0.4 mm WT anthers and finally 0.4 mm mac1 mutant anthers. The third had 0.7 mm anthers in a three vertex loop with the nutritive layers (middle layer and tapetum) at one vertex, the germinal pre-meiotic cells at another vertex, and whole anthers at a third vertex. The whole anther samples were also, separately and outside of the loop, compared in four replicates to the structural layers (endothecium and epidermis).
Project description:Genetic male sterility (GMS) in cotton (Gossypium hirsutum) plays an important role in the utilization of hybrid vigor. However, the molecular mechanism of the GMS is still unclear. While numerous studies have demonstrated that microRNAs (miRNA) regulate flower and anther development, whether different small RNA regulations exist in GMS and its wild type is unclear. To investigate the global expression and complexity of small RNAs during cotton anther development, three small RNA libraries were constructed from the anthers of three development stages each from fertile wild type (WT) and its GMS mutant cotton. Examination of different miRNA profiles in 2 lines.
Project description:In flowering plants, the male gametophyte, the pollen, develops in the anther. Complex patterns of gene expression in both the gametophytic and sporophytic tissues of the anther regulate this process. The gene expression profiles of the microspore/pollen and the sporophytic tapetum are of particular interest. In this study, a microarray technique combined with laser microdissection (44K LM-microarray) was developed and used to characterize separately the transcriptomes of the microspore/pollen and tapetum in rice. Expression profiles of 11 known tapetum specific-genes were consistent with previous reports. Based on the spatiotemporal expression patterns and gene ontology (GO) categories of anther-expressed genes, some noteworthy expression patterns are discussed in connection with various important biological events of anther development. The separated transcriptomes of rice microspore/pollen and tapetum were measured at the premeiosis, meiosis, tetrad, uninuclear, bicellular, and tricelluar stages by using laser microdissection (LM)-mediated microarray.
Project description:Evidence from confocal microscopic reconstruction of maize anther development in fertile, mac1 (excess germ cells) and msca1 (no germ cells) flowers indicates that the male germ line is multiclonal and uses the MAC1 protein to organize the somatic niche. Furthermore, we identified redox status as a determinant of germ cell fate, defining a mechanism distinct from the animal germ cell lineage. Decreasing oxygen or H2O2 increases germ cell numbers, stimulates superficial germ cell formation, and rescues germinal differentiation in msca1 flowers. Conversly, oxidizing environments inhibit germ cell specification and cause ectopic differentiation in deeper tissues. We propose that hypoxia, arising naturally within growing anther tissue, acts as a positional cue to set germ cell fate. key words: anther development, maize, male-sterile Two replicates of laser microdissected pre-meiotic cells were compared to two replicates of whole anthers, which contains pre-meiotic cells and somatic cells, from the same developmental stage and individual wild type plants. In another experiment, laser microdissected pre-meiotic cells from wild type (mac1-heterozygous) anthers were compared to laser microdissected pre-meiotic cells from mac1 (mutant) anthers.
Project description:Arabidopsis thaliana MYB80 (formerly MYB103) is expressed in the tapetum and microspores between anther developmental stages 6 and 10. MYB80 encodes a MYB transcription factor that is essential for tapetal and pollen development. In order to identify the genes regulated by MYB80, microarray technology was employed to analyze the expression levels of genes that were differentially regulated in the myb80 mutant and wild- type anthers. Plant Cell 23:2209–2224 (2011) three mutant chips vs three wild-type chips
Project description:The 7B-1 tomato (Solanum lycopersicum L. cv Rutgers) is a male-sterile mutant with enhanced tolerance to abiotic stress, which makes it a potential candidate for hybrid seed breeding and stress engineering. Transcriptomic profiles of the 7B-1 male-sterile and wild type (WT) anthers were studied using mRNA sequencing (RNA-Seq). In total, 768 differentially expressed genes (DEGs) were identified, including 132 up-regulated and 636 down-regulated transcripts. Gene ontology (GO) enrichment analysis of DEGs suggested a general impact of the 7B-1 mutation on metabolic processes, such as proteolysis and carbohydrate catabolic process. Sixteen candidates with key roles in regulation of anther development were subjected to further analysis using qRT-PCR and in situ hybridization. Cytological studies showed several defects associated with anther development in the 7B-1 mutant, including unsynchronized anther maturation, dysfunctional meiosis, arrested microspores, defect in callose degradation and abnormal tapetum development. TUNEL assay showed a defect in programmed cell death (PCD) of tapetal cells in 7B-1 anthers. The present study provides insights into the transcriptome of the 7B-1 mutant. We identified several genes with altered expression level in 7B-1 (including beta-1,3 glucanase, GA2oxs, cystatin, cysteine protease, pectinesterase, TA29, and actin) that could potentially regulate anther developmental processes, such as meiosis, tapetum development, and cell-wall formation/degradation. Overall design: RNA-seq analysis of anthers from wild type and 7B-1 male-sterile mutant tomato plants.
Project description:This study compared the transcriptomes of maize anthers at both 1mm and 1.5mm lengths from male sterile mutants with either the am1-489 or am1-pra alleles as well as from fertile siblings of the mutant plants. Comparisons were done varying just the stage (1mm vs 1.5 mm), just the allele (am1-pra vs am1-489 at the same stage), and wild-type vs mutant (same stage and allele). Genes were categorized as On (expressed) or Off (not detected) and if both channels produced an intensity, the differential expression was determined. AM1 seems to be involved in establishing or stabilizing meiotic chromosomes and it had a profound impact on gene expression in the pollen mother cells during the maturation phase from 1.0 to 1.5 mm anther length. The two alleles shared some transcript changes but am1-489 showed a more dramatic loss (>3400) at 1.5mm than am1-pra. Most differentially expressed transcripts were allele-specific. KEYWORDS: male sterility, maize, microarray, meiosis Compared wild-type and male-sterile anthers from 2 ameiotic1 alleles at 2 stages of anther growth (1mm and 1.5mm)
Project description:We isolated pre-meiotic and early meiotic cells from 24 maize anthers, covering a week of development from the day after archesporial (AR) cell specification to the early zygotene stage of meiotic prophase I. Starting material was staged by anther length, and anther stages were densely sampled from throughout this period. High quality reads were obtained from 144 cells. Overall design: Single-cell RNA-seq of premeiotic and early meiotic cells from maize anthers. Libraries were constructed with a modified version of CelSeq2.
Project description:Transcriptomic analysis of single, double and triple mutant anthers of bhlh010, bhlh089 and bhlh091. We examine here three recently duplicated Arabidopsis bHLH genes, bHLH010, bHLH089 and bHLH091, using evolutionary, genetic, morphological and transcriptomic approaches, and uncover their redundant functions in anther development. These three genes are relatively highly expressed in the tapetum of the Arabidopsis anther; single mutants at each of the bHLH010, bHLH089 and bHLH091 loci are developmentally normal, but the various double and triple combinations progressively exhibit increasingly defective anther phenotypes (abnormal tapetum morphology, delayed callose degeneration, and aborted pollen development), indicating their redundant functions in male fertility. Note: Samples in SRA were assigned the same sample accession. This is incorrect as there are different samples, hence “Source Name” was replaced with new values. Comment[ENA_SAMPLE] contains the original SRA sample accessions.
Project description:We report the genome-wide transcriptome of soybean seeds across several stages of seed development and the entire life cycle using Illumina high-throughput sequencing technology. Specifically, we profiled whole seeds containing globular-stage, heart-stage, cotyledon-stage, and early maturation-stage embryos. We also profiled dry soybean seeds, and vegetative and reproductive tissues including leaves, roots, stems, seedlings, and floral buds. Illumina sequencing of transcripts from whole seeds at five stages of seed development (globular, heart, cotyledon, early-maturation, dry), and vegetative (leaves, roots, stems, seedlings) and reproductive (floral buds) tissues.