To increase the size of DNA fragments used in transgenesis, scientists are cloning them in yeast or bacterial artificial chromosomes (YACs and BACs). This has increased the use of transgenic mice as disease model. Single Gene Knock-Outs and Knock-Ins These are models to target a mutation to a specific gene locus and are particularly useful if a single gene is shown to be the primary cause of a disease. Knock-out mice carry a gene that has been inactivated while knock-out mice are produced by inserting a transgene at the exact location where it is overexpressed. Many knock-out and knock-in mice have similar, if not identical phenotype to human patients and are therefore good models for human
Genetic engineering is manually changing the genetic structure of cells by adding a new DNA which has one or more new traits that aren’t existent in the particular organism. The aim of the genetic engineering would be to improve organisms. An example of a genetically engineered organism would be plants that can handle herbicides or crops with higher or lower oil content. Genetic engineering works by removing a gene from an organism and inserting it into another organism, making it capable to express the trait given from the gene. One specific gene is located and copied from thousands of genes, this is called gene cloning.
Various assays have been devised to evaluate apoptosis at several points of the cascade. Based on the methodology, the commonly used assays can be classified into the following groups: 1. Changes in cell morphology: morphological changes such as cell shrinkage, membrane blebbing, nuclear condensation, DNA fragmentation and changes in plasma membrane occur. Each of these changes can be quantified using Flow Cytometry. For example, the forward scatter parameter reduces on cell shrinkage while nuclear condensation causes an increase in side scatter.
The movement of the endocytosed protein which is destined for the apical surface to fuse with and also the movement of extracellular materials from one side of the epithelial cells to another can be termed as transcytosis. With respect to concept, transcytosis can be grouped into three processes namely; endocytosis, exocytosis and transcellular transport (Pravda,2011). Though transcytosis is tightly controlled by the cell it also has the potential for transepithelial movement of bacteria and other pathogens, hence it sometimes becomes an etiologic factor in the body(Pravda,2011). Trancytosis occurs in hepatocytes and this phenomenon is a typical example of transcellular transport . Here the apical membrane form bile and the basolateral membrane face blood.
Somatoplasm is the fundamental component of germ cells (sperm and eggs) and is the inherited material that is gone from era to era. This perspective negated Lamarck's hypothesis of obtained attributes, which was a predominant hypothesis of heredity of the time. In spite of the fact that the points of interest of the germ-plasm hypothesis have been changed its reason of the progression of genetic material is the current's premise comprehension of the procedure of physical legacy. Germplasm:
Then, there was Alfred Russel Wallace, he had a major influence on Darwin theory. Wallace, did the same thing Darwin did, he went on a voyage but he went to different islands and he noticed the same thing Darwin noticed in other species but he could not exactly put a name on his findings, so he sent his work to Darwin. That is when Darwin came up with natural selection and he wrote his book and years later Wallace wrote a book called Darwinism. 2. Earth was formed 4.568 billion years ago and early earth consisted organic molecules; hydrogen compound, methane, water vapor, and ammonia.
osafety and Bioethics of GMO’s : Genetically modified organisms (GMOs) are organisms whose genetic material has been artificially modified to change their characteristics in some way or another [James,2006]. In essence, “genetic modification” or “genetic engineering” techniques enable scientists to find Unique genes that control specific characteristics, separate them from those unique source, Also exchange them straight forwardly under the units of an animal, plant, bacterium, or virus. Risk assessment is a common regulatory tool used in the decision-making process for a proposed commercial release of a GMO into the environment Biosafety describes the principles, procedures and policies to be adopted to ensure the environmental and personal safety. Biosafety linked to containment principles, technologies and practices that are required to avoid unintentional exposure to pathogens and toxins, or their accidental emitting into the environment. Currently Available GMOs: •
Through the reverse transcription, the viral RNA is transcribed to viral double-stranded DNA. This process is catalyzed by an RNA-dependent DNA polymerase, also known as reverse transcriptase, which is encoded by the viral genome, which is integrated within the cell genome by integrase. This protein cleaves nucleotides of each 3’ ends of the double helix DNA creating two sticky ends, transfers the modified provirus DNA into the cell nucleus and facilitates its integration into the host genome. The integration of proviral DNA and the expression of the provirus require that target cell is in an activated state. Monocytes/macrophages, microglial cells, and latently infected quiescent CD4+ T-cells contain integrated provirus and are important long-living cellular reservoirs of HIV.
Charles Darwin became famous for his theory of natural selection. This theory suggests that a change in heritability traits takes place in a population over time. This is due to random mutations that occur in the genome of an individual organism, and offspring can inherit these mutations. This was defined as the key to evolution, this is because random mutations arise in the genome of an individual. Until the 19th century, the prevailing view in western societies was that differences between individuals of species were uninteresting departures from their platonic ideals of created kinds.
Part of the conclusion of Mendel of work was that the inheritance of each character is determined by ‘‘something’’ passed from parent to offspring which today is referred to as ‘gene’. Mendel work brought the formulation of what is known today as Mendel’s law. Several questions have been answered in medicine using Mendel theories as the basis of genetics (Williams, 2009). Many diseases are now known to be inherited, and can be prevented from being passed on to the next generation by tracing the pedigrees to determine the probability of inheritance by the offsprings. The knowledge of Mendelism is used globally by agriculturalist and plant scientists to improve or get the desired traits in
Next step is translation, in which the RNA becomes a protein, which then can act as structural units or enzymes. 2. How does DNA replicate itself? In order to replicate itself, DNA undergoes DNA replication, a process in which the DNA unwinds and splits in two. From that point on, new nucleotides are added to each of the original strands (A to T, C to G) until the result is two identical sequence copies of DNA.
Furthermore, Acinetobactor baylyi ADP1 like most organisms undergoes a process known as DNA recombination, where two complementary DNA strands cross and exchange portions of DNA. During recombination, a structure known as a Holliday Junction forms and must be resolved, completing the exchange of DNA (Aravind et al. 2000). Recombination is a crucial mechanism in both gene amplification and deletion. Specifically, ADP1 contains a protein called YqgF, a putative Holliday Junction Resolvase, due to its structural similarity to a known resolvase named RuvC (Aravind et al.
Lynn Margulis is famous for discovering primary proponent in the symbiosis in biological evolution. Her “serial endosymbiotic theory of eukaryotic cell development revolutionized the modern concept of how life arose on earth” was her discovery on cells. In the 1960’s Lynn studied the structure of cells such as the mitochondria and chloroplasts. She found that the chloroplast DNA was alike to the genes in the algaes nuclei. “Algae have swallowed up bacterial partners, and have themselves been included within other single cells.
Darwinism is a theory of biological evolution developed by Charles Darwin and others, stating that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual 's ability to compete, survive, and reproduce. Also called Darwinian theory, it originally included the broad concepts of transmutation of species or of evolution which gained general scientific acceptance after Charles Robert Darwin published On the Origin of Species in 1859, including concepts which predated Darwin 's theories, but subsequently referred to specific concepts of natural selection, of the Weismann barrier or in genetics of the central dogma of molecular biology. Though the term usually refers strictly to biological evolution, creationists have appropriated it to refer to the origin of life, and it has even been applied to concepts of cosmic evolution, both of which have no connection to Darwin 's work. It is therefore considered the belief and acceptance of Darwin 's and of his predecessors ' work - in place of other theories, including divine design and extraterrestrial origins.
Avery-MacLeod-McCarty: In the 40’s genes were classified as a separate element of heredity that generates a metabolic function controlled by enzymes. It was also thought that genes were proteins. Experiments by Oswald T. Avery in 1944 explained that nucleic acid and deoxyribose acid previously known as the organisms ubiquitous turned out to be the chemical basis for heritable changes in the bacteria. Oswald Avery was a immunochemist in a hospital named The Hospital of the Rockefeller institute, which was for medical research. He worked for a long time with causes of pneumonia such as pneumococcus and bacterium.