Allen Leave a Comment A Holistic Approach to Change Technologies have promised companies faster and better services to help them gain new customers and stay ahead of the competition. In some cases, these promises have been fulfilled. In other cases, however, the promised gains have been elusive, and many organizations have found themselves caught in a frenzied game of technological catch-up with no end in sight and little time to catch their breath. This continual rush to upgrade technologies has frequently obscured the chaos these constant changes are creating in the rest of the organization, hiding the underlying need these companies have to streamline and stabilize their structures, systems, and work processes to fit their rapidly changing strategies and technologies.
History[ edit ] Transformation in bacteria was first demonstrated in by the British bacteriologist Frederick Griffith.
However, he discovered that a non-virulent strain of Streptococcus pneumoniae could be made virulent after being exposed to heat-killed virulent strains. Griffith hypothesized that some "transforming principle" from the heat-killed strain was responsible for making the harmless strain virulent.
They isolated DNA from a virulent strain of S. Transformation using electroporation was developed in the late s, increasing the efficiency of in-vitro transformation and increasing the number of bacterial strains that could be transformed.
Natural genetic transformation appears to be an adaptation for repair of DNA damage that also generates genetic diversity.
Natural competence As of about 80 species of bacteria were known to be capable of transformation, about evenly divided between Gram-positive and Gram-negative bacteria ; the number might be an overestimate since several of the reports are supported by single papers.
The transport of the exogenous DNA into the cells may require proteins that are involved in the assembly of type IV pili and type II secretion systemas well as DNA translocase complex at the cytoplasmic membrane. The translocated single-stranded DNA may then be integrated into the bacterial chromosomes by a RecA -dependent process.
In Gram-negative cells, due to the presence of an extra membrane, the DNA requires the presence of a channel formed by secretins on the outer membrane. Pilin may be required for competence, but its role is uncertain.
Transformation, in biology, one of several processes by which genetic material in the form of “naked” deoxyribonucleic acid is transferred between microbial cells. Its discovery and elucidation constitutes one of the significant cornerstones of molecular genetics. Transformation definition is - an act, process, or instance of transforming or being transformed. How to use transformation in a sentence. an act, process, or instance of transforming or being transformed; false hair worn especially by a woman to replace or supplement natural hair. "Transformation" may also be used to describe the insertion of new genetic material into nonbacterial cells, including animal and plant cells; however, because "transformation" has a special meaning in relation to animal cells, indicating progression to a cancerous state, the process is usually called "transfection".
Transformation process definition order for a bacterium to bind, take up and recombine exogenous DNA into its chromosome, it must become competent, that is, enter a special physiological state. Competence development in Bacillus subtilis requires expression of about 40 genes. Transformation in Haemophilus influenzae occurs most efficiently at the end of exponential growth as bacterial growth approaches stationary phase.
For instance, transformation is induced in Streptococcus pneumoniae by the DNA damaging agents mitomycin C a DNA crosslinking agent and fluoroquinolone a topoisomerase inhibitor that causes double-strand breaks. Of these only six, all DNA damaging agents, caused strong induction.
These DNA damaging agents were mitomycin C which causes DNA inter-strand crosslinksnorfloxacin, ofloxacin and nalidixic acid inhibitors of DNA gyrase that cause double-strand breaks bicyclomycin causes single- and double-strand breaks and hydroxyurea induces DNA base oxidation .
UV light also induced competence in L. Logarithmically growing bacteria differ from stationary phase bacteria with respect to the number of genome copies present in the cell, and this has implications for the capability to carry out an important DNA repair process.
During logarithmic growth, two or more copies of any particular region of the chromosome may be present in a bacterial cell, as cell division is not precisely matched with chromosome replication.
The process of homologous recombinational repair HRR is a key DNA repair process that is especially effective for repairing double-strand damages, such as double-strand breaks.
This process depends on a second homologous chromosome in addition to the damaged chromosome. During logarithmic growth, a DNA damage in one chromosome may be repaired by HRR using sequence information from the other homologous chromosome.
Once cells approach stationary phase, however, they typically have just one copy of the chromosome, and HRR requires input of homologous template from outside the cell by transformation. The particular process responsible for repair was likely HRR. Transformation in bacteria can be viewed as a primitive sexual process, since it involves interaction of homologous DNA from two individuals to form recombinant DNA that is passed on to succeeding generations.
Bacterial transformation in prokaryotes may have been the ancestral process that gave rise to meiotic sexual reproduction in eukaryotes see Evolution of sexual reproduction ; Meiosis.
Methods and mechanisms of transformation in laboratory[ edit ] Schematic of bacterial transformation — for which artificial competence must first be induced. Bacterial[ edit ] Artificial competence can be induced in laboratory procedures that involve making the cell passively permeable to DNA by exposing it to conditions that do not normally occur in nature.
Calcium chloride partially disrupts the cell membrane, which allows the recombinant DNA enter the host cell.
Cells that are able to take up the DNA are called competent cells. It has been found that growth of Gram-negative bacteria in 20 mM Mg reduces the number of protein-to- lipopolysaccharide bonds by increasing the ratio of ionic to covalent bonds, which increases membrane fluidity, facilitating transformation.
The surface of bacteria such as E. One function of the divalent cation therefore would be to shield the charges by coordinating the phosphate groups and other negative charges, thereby allowing a DNA molecule to adhere to the cell surface.
DNA entry into E. Their role was established when cobalamine which also uses these channels was found to competitively inhibit DNA uptake.
In this poly HB is envisioned to wrap around DNA itself a polyphosphateand is carried in a shield formed by Ca ions. The heat-pulse is thought to create a thermal imbalance across the cell membrane, which forces the DNA to enter the cells through either cell pores or the damaged cell wall.
Electroporation is another method of promoting competence."Transformation" may also be used to describe the insertion of new genetic material into nonbacterial cells, including animal and plant cells; however, because "transformation" has a special meaning in relation to animal cells, indicating progression to a cancerous state, the process is usually called "transfection".
The Transformation Process (see the model down below) is a change process which guides organizations toward High Performance. The methodology outlines a sequence of interventions and change activities designed to create frame-breaking and sustainable organization change.
Definition of transformation: In an organizational context, a process of profound and radical change that orients an organization in a new direction and takes it to an entirely different level of effectiveness.
Business Transformation is a change management strategy which has the aim to align People, Process and Technology initiatives of a company more closely with its business strategy and vision.
In turn this helps to support and innovate new business strategies. The process is important historically since, following transformation experiments by Frederick GRIffiTH, on the Streptococcus (Diplococcus) pneumoniae bacterium, DNA was shown to be the genetical material of cells by AVERY, MacLeod and McCarthy.
transformation process, such as information and skills. You might have noticed that, midway down the list, the activities changed from primarily the production of goods to the provision of services.