Publish Your Research Online
Get Recognition - International Audience
Request for an Author Account | Login | Submit Article
|HOME||FAQ||TOP AUTHORS||FORUMS||PUBLISH ARTICLE|
Transcriptome - Aventure Into Crop ImprovementBY: SUNIL KUMAR, S.V. | Category: Agriculture | Submitted: 2012-04-02 10:42:19
Article Summary: "The transcriptome is the set of all RNA molecules, including mRNA, rRNA, tRNA, and other non-coding RNA produced in one or a population of cells..."
The transcriptome is the set of all RNA molecules, including mRNA, rRNA, tRNA, and other non-coding RNA produced in one or a population of cells.
The term can be applied to the total set of transcripts in a given organism, or to the specific subset of transcripts present in a particular cell type. Unlike the genome, which is roughly fixed for a given cell line (excluding mutations), the transcriptome can vary with external environmental conditions. Because it includes all mRNA transcripts in the cell, the transcriptome reflects the genes that are being actively expressed at any given time, with the exception of mRNA degradation phenomena such as transcriptional attenuation. The study of transcriptomics, also referred to as expression profiling, examines the expression level of mRNAs in a given cell population, often using high-throughput techniques based on DNA microarray technology. The use of next-generation sequencing technology to study the transcriptome at the nucleotide level is known as RNA-Seq.
Methods of construction
There are two general methods of creating transcriptomes. One approach maps sequence reads onto a reference genome, either of the organism itself (whose transcriptome is being studied) or of a closely related species. The other approach, de novo transcriptome assembly, utilizes algorithms built into assembly software to generate transcripts from short sequence reads.
DNA microarrays can provide a method for comparing on a genome-wide basis the abundance of DNAs in the same samples. The DNA in spots can only be PCR products that are specific for individual genes. A DNA copy of RNA is made using the enzyme reverse transcriptase. Sequencing is now being used instead of gene arrays to quantify DNA levels, at least semi quantitatively.
A number of organism-specific transcriptome databases have been constructed and annotated to aid in the identification of genes that are differentially expressed in distinct cell populations or subtypes.
The transcriptomes of stem cells and cancer cells are of particular interest to researchers who seek to understand the processes of cellular differentiation and carcinogenesis.
Analysis of the transcriptomes of human oocytes and embryos is used to understand the molecular mechanisms and signaling pathways controlling early embryonic development, and could theoretically be a powerful tool in making proper embryo selection in in vitro fertilisation.
Relation to proteome
The transcriptome can be seen as a precursor for the proteome, that is, the entire set of proteins expressed by a genome.
However, the analysis of relative mRNA expression levels can be complicated by the fact that relatively small changes in mRNA expression can produce large changes in the total amount of the corresponding protein present in the cell. One analysis method, known as Gene Set Enrichment Analysis, identifies coregulated gene networks rather than individual genes that are up- or down-regulated in different cell populations.
Although microarray studies can reveal the relative amounts of different mRNAs in the cell, levels of mRNA are not directly proportional to the expression level of the proteins they code for. The number of protein molecules synthesized using a given mRNA molecule as a template is highly dependent on translation-initiation features of the mRNA sequence; in particular, the ability of the translation initiation sequence is a key determinant in the recruiting of ribosomes for protein translation. The complete protein complement of a cell or organism is known as the proteome.
A study of 158,807 mouse transcripts revealed that 4,520 of these transcripts form antisense partners that are base pair complementary to the exons of genes.These results raise the possibility that significant numbers of "antisense RNA-coding genes" might participate in the regulation of the levels of expression of protein-coding mRNAs.
About Author / Additional Info:
Comments on this article: (0 comments so far)
• Green House Effect - A Myth Or Reality?
• Diabetes - Types, Pathophysiology and Treatment
• Clinical Research and its Condition in India
• Nanostructure: Its Introduction and Various Forms
Latest Articles in "Agriculture" category:
• Use of Biotechnology in Agriculture
• Plant Based Edible Vaccine
• Genetically Modified Food - Yes or No?
• Agricultural Biotechnology - Definition and Various Products
• Career Opportunities in Agriculture Science
• Synthetic Seed Production and Application
• Role of Biotechnology in Agriculture | Various Agricultural Technologies
• Biofortification - A Technique Used in Agriculture
• Biotechnology in Agriculture Development
• Biotechnology in Animal Feed and Feeding
• Biofertilizers: Types, Benefits and Applications
• Genetically Modified Food - Advantages and Disadvantages
• Genetically Modified Crops as Medicine
• Cryopreservation and Conservation of Plant Genetic Material
• Biotechnology and the Coconut
• Biotechnology in Rice Farming
• Bt Corn: Method, Mode of Action and Benefits
• Safe Insecticides For the Environment
• Plant Growth Promoting Substances
Important Disclaimer: All articles on this website are for general information only and is not a professional or experts advice. We do not own any responsibility for correctness or authenticity of the information presented in this article, or any loss or injury resulting from it. We do not endorse these articles, we are neither affiliated with the authors of these articles nor responsible for their content. Please see our disclaimer section for complete terms.
Copyright © 2010 biotecharticles.com - Do not copy articles from this website.
ARTICLE CATEGORIES :
| Disclaimer/Privacy/TOS | Submission Guidelines | Contact Us