Oncogenes, Tumor Suppressor Genes, and DNA Repair: Cancer Development
Oncogenes, Tumor Suppressor Genes, and DNA Repair Genes
Oncogenes
Oncogenes are altered (mutated) versions of normal genes that can promote malignant transformation. Normal genes, when not mutated, are called proto-oncogenes and usually promote growth. They can be growth factors, growth factor receptors, plasma kinases, or transcription factors. Oncogenes are a group of damaged genes involved in cancer development. Their presence, overactivity, or both, can stimulate cancer development. When oncogenes
Read MoreRecombinant DNA Technology: Methods and Applications
Restriction Enzymes
Saccharomyces cerevisiae plays a crucial role in recombinant DNA technology. This process involves coding sequences and regulatory elements. Restriction endonucleases, bacterial enzymes capable of cutting DNA, are fundamental. They recognize specific palindromic sequences, producing either blunt or cohesive ends. DNA fragments are then separated by gel electrophoresis, using agarose or polyacrylamide gels.
Plasmids and DNA Ligases
Plasmids, bacterial or viral genomes, and artificially
Read MoreDNA Recombination, Biotechnology, and Genetic Engineering
DNA Recombination
DNA recombination is a process that allows the combination of DNA fragments from different origins. This can be done in a laboratory using cellular machinery and enzymes. DNA can be cut into fragments using enzymes called restriction endonucleases. The resulting fragments have cohesive or sticky edges complementary to other DNA cut with the same enzyme, so you can join different fragments of recombinant DNA origin. In this way, it is possible to introduce DNA into the genome of
Read MoreAlternative Toxicity Assays: Replacing Rodent Models
Describe 5 alternative toxicity assays that complement or might be able to replace rodent assays
Several alternatives to the traditional rodent bioassay have been proposed, of which the most promising are non-animal assays such as quantitative structure-activity relationship expert systems, in vitro assays, the use of cDNA microarrays to detect genetic expression changes, human clinical trials, & epidemiological research.
- QSAR expert systems, particularly for initial screening, should be further
Cellular Membrane and Extracellular Matrix: Structure and Function
Cellular Membrane: Structure and Function
The cellular membrane is a structure common to all cells of living beings. It surrounds a portion of cytoplasm (cytoplasmic membrane). The same membranous structure also delimits most internal cell structures. Biological membranes (plasma membrane or internal membranes of the cell) are called unitary membranes.
Structure
A clear strip (osmiophobic), bordered by two dark stripes (osmiophilic).
Composition
- Membrane Lipids: Phospholipids, cholesterol, and glycolipids.
3Rs Alternatives: Reduction, Refinement, and Replacement in Animal Testing
The 3Rs in Animal Research
Reduction: Fewer animals used to obtain information of a given amount and precision.
Refinement: Less painful procedures applied to animals necessarily used.
Replacement: Substitution of conscious living vertebrates by non-sentient material.
Reduction Alternatives
Good planning of studies:
- Rational & efficient use of animals:
- No wasting
- Pilot studies
- Screening tests
- Proper statistical design
- Use of inbred strains (for some study types)
Refinement Alternatives
Minimized potential
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