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Plasmids
A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria and archaea; however plasmids are sometimes present in and eukaryotic organisms as well. Plasmids often carry useful genes, such as those involved in antibiotic resistance, virulence, secondary metabolism and bioremediation. While chromosomes are large and contain all the essential genetic information for living under normal conditions, plasmids are usually very small and contain additional genes for special circumstances. Artificial plasmids are widely used as vectors in molecular cloning, serving to drive the replication of recombinant DNA sequences within host organisms. In the laboratory, plasmids may be introduced into a cell via transformation. Synthetic plasmids are available for procurement over the internet by various vendors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmid (english)
A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from gDNA, chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria and archaea; however plasmids are sometimes present in and eukaryote, eukaryotic organisms as well. Plasmids often carry useful genes, such as those involved in antibiotic resistance, virulence, secondary metabolism and bioremediation. While chromosomes are large and contain all the essential genetic information for living under normal conditions, plasmids are usually very small and contain additional genes for special circumstances. Artificial plasmids are widely used as Vector (molecular biology), vectors in molecular cloning, serving to drive the replication of recombinant DNA sequences within host organisms. In the laboratory, plasmids may be introduced into a cell via transformation (genetics), transformation. Synthetic plasmids are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmid Replication (english)
A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria and archaea; however plasmids are sometimes present in and eukaryotic organisms as well. Plasmids often carry useful genes, such as those involved in antibiotic resistance, virulence, secondary metabolism and bioremediation. While chromosomes are large and contain all the essential genetic information for living under normal conditions, plasmids are usually very small and contain additional genes for special circumstances. Artificial plasmids are widely used as vectors in molecular cloning, serving to drive the replication of recombinant DNA sequences within host organisms. In the laboratory, plasmids may be introduced into a cell via transformation. Synthetic plasmids are available for procurement over the internet by various vendors usi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vector (molecular Biology)
In molecular cloning, a vector is any particle (e.g., plasmids, cosmids, Lambda phages) used as a vehicle to artificially carry a foreign nucleic acid sequence, nucleic sequence – usually DNA – into another Cell (biology), cell, where it can DNA replication, be replicated and/or Gene expression, expressed. A vector containing foreign DNA is termed recombinant DNA. The four major types of vectors are plasmids, viral vectors, cosmids, and Bacterial artificial chromosome, artificial chromosomes. Of these, the most commonly used vectors are plasmids. Common to all engineered vectors are an origin of replication, a multiple cloning site, multicloning site, and a selectable marker. The vector itself generally carries a DNA sequence that consists of an Insert (molecular biology), insert (in this case the transgene) and a larger sequence that serves as the "backbone" of the vector. The purpose of a vector which transfers genetic information to another cell is typically to isolate, mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaea
Archaea ( ) is a Domain (biology), domain of organisms. Traditionally, Archaea only included its Prokaryote, prokaryotic members, but this has since been found to be paraphyletic, as eukaryotes are known to have evolved from archaea. Even though the domain Archaea Cladistics, cladistically includes eukaryotes, the term "archaea" (: archaeon , from the Greek "ἀρχαῖον", which means ancient) in English still generally refers specifically to prokaryotic members of Archaea. Archaea were initially Taxonomy (biology), classified as bacteria, receiving the name archaebacteria (, in the Archaebacteria Kingdom (biology), kingdom), but this term has fallen out of use. Archaeal cells have unique properties separating them from Bacteria and Eukaryote, Eukaryota. Archaea are further divided into multiple recognized phylum, phyla. Classification is difficult because most have not been Isolation (microbiology), isolated in a laboratory and have been detected only by their Gene, gene s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mobilome
The mobilome is the entire set of mobile genetic elements in a genome. Mobilomes are found in eukaryotes, prokaryotes, and viruses. The compositions of mobilomes differ among lineages of life, with transposable elements being the major mobile elements in eukaryotes, and plasmids and prophages being the major types in prokaryotes. Virophages contribute to the viral mobilome. Mobilome in eukaryotes Transposable elements are elements that can move about or propagate within the genome, and are the major constituents of the eukaryotic mobilome. Transposable elements can be regarded as genetic parasites because they exploit the host cell's transcription and translation mechanisms to extract and insert themselves in different parts of the genome, regardless of the phenotypic effect on the host. Eukaryotic transposable elements were first discovered in maize (''Zea mays'') in which kernels showed a dotted color pattern. Barbara McClintock described the maize Ac/Ds system in whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iteron
Iterons are directly repeated DNA sequences which play an important role in regulation of plasmid copy number in bacterial cell (biology), cells. It is one among the three negative regulatory elements found in plasmids which control its copy number. The others are antisense RNAs and ctRNAs. Iterons complex with cognate replication (Rep) initiator proteins to achieve the required regulatory effect. Regulation of replication Iterons have an important role in plasmid replication. An iteron-containing plasmid origin of replication can be found containing about five iterons about 20 base pairs in length total. These iterons provide a saturation site for initiator receptor proteins and promote replication, thus increasing plasmid copy number in a given cell. Limiting factors of initiation There are four main limiting factors leading to no initiation of replication in iterons: *Transcriptional autorepression *Initiator Dimer (chemistry), dimerization *Initiator titration *Handcuff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Replicon (genetics)
A replicon is a region of an organism's genome that is independently replicated from a single origin of replication. A bacterial chromosome contains a single origin, and therefore the whole bacterial chromosome is a replicon. The chromosomes of archaea and eukaryotes can have multiple origins of replication, and so their chromosomes may consist of several replicons. The concept of the replicon was formulated in 1963 by François Jacob, Sydney Brenner, and Jacques Cuzin as a part of their replicon model for replication initiation. According to the replicon model, two components control replication initiation: the replicator and the initiator. The replicator is the entire DNA sequence (including, but not limited to the origin of replication) required to direct the initiation of DNA replication. The initiator is the protein that recognizes the replicator and activates replication initiation. Sometimes in bacteriology, the term "replicon" is only used to refer to chromosomes containing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit the air, soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horizontal Gene Transfer
Horizontal gene transfer (HGT) or lateral gene transfer (LGT) is the movement of genetic material between organisms other than by the ("vertical") transmission of DNA from parent to offspring (reproduction). HGT is an important factor in the evolution of many organisms. HGT is influencing scientific understanding of higher-order evolution while more significantly shifting perspectives on bacterial evolution. Horizontal gene transfer is the primary mechanism for the spread of antibiotic resistance in bacteria, and plays an important role in the evolution of bacteria that can degrade novel compounds such as human-created Bactericide, pesticides and in the evolution, maintenance, and transmission of virulence. It often involves Temperateness (virology), temperate bacteriophages and plasmids. Genes responsible for antibiotic resistance in one species of bacteria can be transferred to another species of bacteria through various mechanisms of HGT such as Transformation (genetics), tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artificial Plasmids
A DNA construct is an artificially-designed segment of DNA borne on a vector that can be used to incorporate genetic material into a target tissue or cell. A DNA construct contains a DNA insert, called a transgene, delivered via a transformation vector which allows the insert sequence to be replicated and/or expressed in the target cell. This gene can be cloned from a naturally occurring gene, or synthetically constructed. The vector can be delivered using physical, chemical or viral methods. Typically, the vectors used in DNA constructs contain an origin of replication, a multiple cloning site, and a selectable marker. Certain vectors can carry additional regulatory elements based on the expression system involved. DNA constructs can be as small as a few thousand base pairs (kbp) of DNA carrying a single gene, using vectors such as plasmids or bacteriophages, or as large as hundreds of kbp for large-scale genomic studies using an artificial chromosome. A DNA construct may expres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell (biology)
The cell is the basic structural and functional unit of all life, forms of life. Every cell consists of cytoplasm enclosed within a Cell membrane, membrane; many cells contain organelles, each with a specific function. The term comes from the Latin word meaning 'small room'. Most cells are only visible under a light microscope, microscope. Cells Abiogenesis, emerged on Earth about 4 billion years ago. All cells are capable of Self-replication, replication, protein synthesis, and cell motility, motility. Cells are broadly categorized into two types: eukaryotic cells, which possess a Cell nucleus, nucleus, and prokaryotic, prokaryotic cells, which lack a nucleus but have a nucleoid region. Prokaryotes are single-celled organisms such as bacteria, whereas eukaryotes can be either single-celled, such as amoebae, or multicellular organism, multicellular, such as some algae, plants, animals, and fungi. Eukaryotic cells contain organelles including Mitochondrion, mitochondria, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recombinant DNA
Recombinant DNA (rDNA) molecules are DNA molecules formed by laboratory methods of genetic recombination (such as molecular cloning) that bring together genetic material from multiple sources, creating sequences that would not otherwise be found in the genome. Recombinant DNA is the general name for a piece of DNA that has been created by combining two or more fragments from different sources. Recombinant DNA is possible because DNA molecules from all organisms share the same chemical structure, differing only in the nucleotide sequence. Recombinant DNA molecules are sometimes called chimeric DNA because they can be made of material from two different species like the mythical chimera. rDNA technology uses palindromic sequences and leads to the production of sticky and blunt ends. The DNA sequences used in the construction of recombinant DNA molecules can originate from any species. For example, plant DNA can be joined to bacterial DNA, or human DNA can be joined with fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
