Search icone
Search and publish your papers

Genes and Chromosomes

Or download with : a doc exchange

About the author


About the document

Published date
documents in English
research papers
6 pages
1 times
Validated by
1 Comment
Rate this document
  1. Introduction
  2. Gene expression
  3. Transcriptional control
    1. Regulatory sequences within DNA
    2. Transcription factors
    3. Regulation of gene expression by extracellular signals
    4. Cyclic adenosine monophosphate (cAMP) response
  4. CRE binding protein
  5. The convergence of multiple signaling pathways
  6. AP 1 family of proteins
  7. Immediate early genes
  8. Steroid hormones
  9. Bibliography

As a first approximation, genes can be defined as stretches of DNA that encode a single protein or a single functional RNA, such as an rRNA or tRNA. There are exceptions to this rule because there are mechanisms, such as alternative splicing of the primary RNA transcript into different mRNAs, that may intervene between a given gene and a finished protein. As a result, in some cases a single gene may actually encode multiple proteins.

[...] Understanding how CREB activation by extracellular stimuli leads to the altered expression of target genes that lead to the formation of memory in the hippocampus, or aspects of addiction in the nucleus accumbens and locus coeruleus, are currently areas of intense research. Overall, the mechanisms underlying the many forms of plasticity of which the nervous system is capable are likely to be quite complex, involving a multitude of different target genes and many different types of regulation. Nevertheless, CREB appears to be important, and also provides a good model to understand the role of gene expression in long- term changes in neural function. [...]

[...] The spliced mRNA leaves the nucleus and binds to a ribosome in the cytoplasm where it can direct the synthesis of a protein; however, the entire mature mRNA is not translated. All mRNAs contain untranslated flanking sequences at their ends. Many genes contain multiple introns and exons that may not be spliced identically in every cell type or in a given cell type at every stage of development. This mechanism, alternative splicing, can produce functionally very different forms of a protein or even entirely different proteins from a single gene. [...]

[...] Immediate Early Genes Genes that are transcriptionally activated by synaptic activity, drugs, and growth factors have often been classified into two main groups. Genes, such as the c-fos gene, that are activated rapidly (within minutes), transiently, and without requiring new protein synthesis are frequently referred to as cellular immediate early genes (IEGs). Genes that are induced or repressed more slowly (over hours), and are dependent on new protein synthesis, may be described as late-response genes. The term IEG was initially applied to describe viral genes that are activated immediately upon infection of eukaryotic cells by commandeering host cell transcription factors for their expression. [...]

Similar documents you may be interested in reading.

Sexual differentiation revisited: Contributions of gene expression to a hormonal process

 Science & technology   |  Medical studies   |  Term papers   |  01/22/2010   |   .doc   |   7 pages

The moral issues of gene therapy and genetic engineering

 Science & technology   |  Medical studies   |  Term papers   |  03/24/2010   |   .doc   |   5 pages

Top sold for medical studies

Reflex Physiology Lab Report

 Science & technology   |  Medical studies   |  Case study   |  10/23/2007   |   .doc   |   4 pages

Drug error in a practice placement

 Science & technology   |  Medical studies   |  Term papers   |  07/15/2009   |   .doc   |   7 pages