T7-based RNA amplification for genotyping from maize shoot apical meristem

Single Cell Type Specific RNA Isolation and Gene Expression Analysis in Rice Using Laser Capture Microdissection (LCM)-Based Method

The success of single cell type-specific gene expression or functional study largely depends on the efficient isolation of high-quality RNA from them. Laser capture microdissection (LCM) is an efficient technique that allows accessing and dissecting out a specific individual cell or cell type from a microscopic heterogeneous tissue in a minimally disruptive way. Here, we describe an efficient and inexpensive LCM-based method for the extraction of RNAs with high yield and integrity from laser-microdissected mesophyll and bundle sheath cells of rice leaf. The integrity of isolated RNA is assessed with bioanalyzer analysis, and the presence of mRNA of a specific gene is validated through RT-PCR. This RNA could further be used for uncovering single cell type-specific gene expression signature using next-generation transcriptome sequence or through regular RT-PCR.

An Efficient LCM-Based Method for Tissue Specific Expression Analysis of Genes and miRNAs

Laser Capture Microdissection (LCM) is a powerful tool to isolate and study gene expression pattern of desired and less accessible cells or tissues from a heterogeneous population. Existing LCM-based methods fail to obtain high quality RNA including small RNAs from small microdissected plant tissue and therefore, are not suitable for miRNA expression studies. Here, we describe an efficient and cost-effective method to obtain both high quality RNA and miRNAs from LCM-derived embryonic root apical meristematic tissue, which is difficult to access. We have significantly modified and improved the tissue fixation, processing, sectioning and RNA isolation steps and minimized the use of kits. Isolated RNA was checked for quality with bioanalyzer and used for gene expression studies. We have confirmed the presence of 19-24 nucleotide long mature miRNAs using modified stem-loop RT-PCR. This modified LCM-based method is suitable for tissue specific expression analysis of both genes and small RNAs (miRNAs).

Maize (Zea mays): a model organism for basic and applied research in plant biology

Zea mays ssp. mays is one of the world's most important crop plants, boasting a multibillion dollar annual revenue. In addition to its agronomic importance, maize has been a keystone model organism for basic research for nearly a century. Within the cereals, which include other plant model species such as rice (Oryza sativa), sorghum (Sorghum bicolor), wheat (Triticum spp.), and barley (Hordeum vulgare), maize is the most thoroughly researched genetic system. Several attributes of the maize plant, including a vast collection of mutant stocks, large heterochromatic chromosomes, extensive nucleotide diversity, and genic colinearity within related grasses, have positioned this species as a centerpiece for genetic, cytogenetic, and genomic research. As a model organism, maize is the subject of such far-ranging biological investigations as plant domestication, genome evolution, developmental physiology, epigenetics, pest resistance, heterosis, quantitative inheritance, and comparative genomics. These and other studies will be advanced by the completed sequencing and annotation of the maize gene space, which will be realized during 2009. Here we present an overview of the use of maize as a model system and provide links to several protocols that enable its genetic and genomic analysis.