Global gene profiling of laser-captured pollen mother cells indicates molecular pathways and gene subfamilies involved in rice meiosis.
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.
Tang
Xiang
X
National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Zhang
Zhi-Yong
ZY
Zhang
Wen-Juan
WJ
Zhao
Xing-Ming
XM
Li
Xuan
X
Zhang
Dong
D
Liu
Qiao-Quan
QQ
Tang
Wei-Hua
WH
D004260:DNA Repair; D004261:DNA Replication; D020869:Gene Expression Profiling; D017343:Genes, Plant; D007834:Lasers; D008540:Meiosis / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000166:cytology / Q000235:genetics* / Q000502:physiology; D011058:Pollen; D015398:Signal Transduction