Global Gene Profiling of Laser-Captured Pollen Mother Cells Indicates Molecular Pathways and Gene Subfamilies Involved in Rice Meiosis    

Abstract

Pollen mother cells (PMCs) represent a critical early stage in plant sexual reproduction in which the stage is set for male gamete formation. Understanding the global molecular genetics of this early meiotic stage has so far been limited to whole stamen or floret transcriptome studies, but since PMCs are a discrete population of cells in developmental synchrony, they provide the potential for precise transcriptome analysis and for enhancing our understanding of the transition to meiosis. As a step toward identifying the premeiotic transcriptome, we performed microarray analysis on a homogenous population of rice (Oryza sativa) PMCs isolated by laser microdissection and compared them with those of tricellular pollen and seedling. Known meiotic genes, including OsSPO11-1, PAIR1, PAIR2, PAIR3, OsDMC1, OsMEL1, OsRAD21-4, OsSDS, and ZEP1, all showed preferential expression in PMCs. The Kyoto Encyclopedia of Genes and Genomes pathways significantly enriched in PMC-preferential genes are DNA replication and repair pathways. Our genome-wide survey showed that, in the buildup to meiosis, PMCs accumulate the molecular machinery for meiosis at the mRNA level. We identified 1,158 PMC-preferential genes and suggested candidate genes and pathways involved in meiotic recombination and meiotic cell cycle control. Regarding the developmental context for meiosis, the DEF-like, AGL2-like, and AGL6-like subclades of MADS box transcription factors are PMC-preferentially expressed, the trans-zeatin type of cytokinin might be preferentially synthesized, and the gibberellin signaling pathway is likely active in PMCs. The ubiquitin-mediated proteolysis pathway is enriched in the 127 genes that are expressed in PMCs but not in tricellular pollen or seedling.

Analysis of the Developmental Roles of the Arabidopsis Gibberellin 20-Oxidases Demonstrates That GA20ox1, -2, and -3 Are the Dominant Paralogs

“…It is possible that, in contrast with the early GA biosynthesis genes, one or more GA20ox genes is expressed in pollen prior to meiosis and rescues mutant pollen development by migration of protein and/or mRNA into the subsequent microspores, as was suggested for components of the GA-signaling pathway in rice (Chhun et al, 2007). Indeed, on the basis of microarray data, Tang et al (2010) found expression of rice GA20ox1 and GA20ox3 in PMCs, while Hirano et al (2008) showed rice GA20ox4 expression in pollen at meiosis. Although comparable transcript analyses are not available for A. thaliana, we see weak GUS expression in PMCs for GA20ox1 and GA20ox2 ( Figure 7B).…”

Polyploidy enhances F1 pollen sterility loci interactions that increase meiosis abnormalities and pollen sterility in autotetraploid rice

“…It used to be technically challenging to isolate meiotic cells at a specific stage for RNA-seq analysis. Bright-field microscopy, 4',6-diamidino-2-phenylindole (DAPI) fluorescence staining, and laser capture of individual cells have made it possible to dissect these cells (Fujita et al, 2010;Tang et al, 2010;Yang et al, 2011). Using DAPI fluorescence staining and WE-CLSM techniques, we were able to obtain PMCs at precise stages of meiosis and identify genes that were differentially expressed during these stages in rice (Feng et al, 2001;Lu et al, 2002;Zhang et al, 2005Zhang et al, , 2006He et al, 2011aHe et al, , 2011bWu et al, 2014).…”

“…The complexity of gene expression during anther and ovary development has been revealed using microarrays or RNA sequencing in diploid rice (Tang et al, 2010;Aya et al, 2011;Deveshwar et al, 2011;Jin et al, 2013;Pan et al, 2014), maize (Zea mays; DukowicSchulze et al, 2014), wheat (Triticum aestivum; Crismani et al, 2006), and Arabidopsis (Arabidopsis thaliana; Twell, 2003, 2004;Yang et al, 2011;Zhao et al, 2014). Microarrays have been used to identify differentially expressed genes in autotetraploid plants.…”

Evidence of Human-to-Swine Transmission of the Pandemic (H1N1) 2009 Influenza Virus in South Korea

“…To clarify it, we examined the gene expression profile data of stamen meiotic cells generated in Tang's and Matsuoka's labs. Their data clearly revealed that OsTGA10 is detected in meiotic cells in rice stamen (Hobo et al, 2008;Tang et al, 2010).…”