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Conditional Gene Knockout
Conditional gene knockout is a technique used to eliminate a specific gene in a certain tissue, such as the liver. This technique is useful to study the role of individual genes in living organisms. It differs from traditional gene knockout because it targets specific genes at specific times rather than being deleted from beginning of life. Using the conditional gene knockout technique eliminates many of the side effects from traditional gene knockout. In traditional gene knockout, embryonic death from a gene mutation can occur, and this prevents scientists from studying the gene in adults. Some tissues cannot be studied properly in isolation, so the gene must be inactive in a certain tissue while remaining active in others. With this technology, scientists are able to knockout genes at a specific stage in development and study how the knockout of a gene in one tissue affects the same gene in other tissues. Technique The most commonly used technique is the Cre-lox recombination syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Knockout
A gene knockout (abbreviation: KO) is a genetic technique in which one of an organism's genes is made inoperative ("knocked out" of the organism). However, KO can also refer to the gene that is knocked out or the organism that carries the gene knockout. Knockout organisms or simply knockouts are used to study gene function, usually by investigating the effect of gene loss. Researchers draw inferences from the difference between the knockout organism and normal individuals. The KO technique is essentially the opposite of a gene knock-in. Knocking out two genes simultaneously in an organism is known as a double knockout (DKO). Similarly the terms triple knockout (TKO) and quadruple knockouts (QKO) are used to describe three or four knocked out genes, respectively. However, one needs to distinguish between heterozygous and homozygous KOs. In the former, only one of two gene copies (alleles) is knocked out, in the latter both are knocked out. Methods Knockouts are accomplished throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryonic Death
Embryo loss (also known as embryo death or embryo resorption) is the death of an embryo at any stage of its development which in humans, is between the second through eighth week after fertilization. Failed development of an embryo often results in the disintegration and assimilation of its tissue in the uterus. Loss during the stages of prenatal development after organogenesis of the fetus results in the similar process of fetal resorption. Embryo loss often happens without an awareness of pregnancy, and an estimated 40 to 60% of all embryos do not survive. Fertility clinics Within fertility clinics embryo loss is associated with a high number of implanted embryos. The keeping of embryos in tanks can also increase risks of loss in instances where technical malfunctions can occur. See also * Perinatal death Perinatal mortality (PNM) refers to the death of a fetus or neonate and is the basis to calculate the perinatal mortality rate. Variations in the precise definition of the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis, or meiosis or other types of damage to DNA (such as pyrimidine dimers caused by exposure to ultraviolet radiation), which then may undergo error-prone repair (especially microhomology-mediated end joining), cause an error during other forms of repair, or cause an error during replication (translesion synthesis). Mutations may also result from insertion or deletion of segments of DNA due to mobile genetic elements. Mutations may or may not produce detectable changes in the observable characteristics (phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes including: evolution, cancer, and the development of the immune system, including junctional diversity. Mutation is the ultimate source o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conditional Knockout Mouse
Conditional (if then) may refer to: *Causal conditional, if X then Y, where X is a cause of Y *Conditional probability, the probability of an event A given that another event B has occurred *Conditional proof, in logic: a proof that asserts a conditional, and proves that the antecedent leads to the consequent *Strict conditional, in philosophy, logic, and mathematics *Material conditional, in propositional calculus, or logical calculus in mathematics * Relevance conditional, in relevance logic *Conditional (computer programming), a statement or expression in computer programming languages *A conditional expression in computer programming languages such as ?: *Conditions in a contract Grammar and linguistics *Conditional mood (or conditional tense), a verb form in many languages *Conditional sentence, a sentence type used to refer to hypothetical situations and their consequences **Indicative conditional, a conditional sentence expressing "if A then B" in a natural language **Cou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Recombination
Genetic recombination (also known as genetic reshuffling) is the exchange of genetic material between different organisms which leads to production of offspring with combinations of traits that differ from those found in either parent. In eukaryotes, genetic recombination during meiosis can lead to a novel set of genetic information that can be further passed on from parents to offspring. Most recombination occurs naturally and can be classified into two types: (1) ''interchromosomal'' recombination, occurring through independent assortment of alleles whose loci are on different but homologous chromosomes (random orientation of pairs of homologous chromosomes in meiosis I); & (2) ''intrachromosomal'' recombination, occurring through crossing over. During meiosis in eukaryotes, genetic recombination involves the pairing of homologous chromosomes. This may be followed by information transfer between the chromosomes. The information transfer may occur without physical exchange (a se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allele
An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution. ::"The chromosomal or genomic location of a gene or any other genetic element is called a locus (plural: loci) and alternative DNA sequences at a locus are called alleles." The simplest alleles are single nucleotide polymorphisms (SNP). but they can also be insertions and deletions of up to several thousand base pairs. Popular definitions of 'allele' typically refer only to different alleles within genes. For example, the ABO blood grouping is controlled by the ABO gene, which has six common alleles (variants). In population genetics, nearly every living human's phenotype for the ABO gene is some combination of just these six alleles. Most alleles observed result in little or no change in the function of the gene product it codes for. However, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mouse Brain
The mouse brain refers to the brain of Mus musculus. Various brain atlases exist. For reasons of reproducibility, genetically characterized, stable strains like C57BL/6 were chosen to produce high-resolution images and databases. Well known online resources include: *Allen Brain Atlas * Mouse Brain LibraryHigh resolution mouse brain atlas*BrainMaps High-Resolution Brain Maps and Brain Atlases of ''Mus musculus'' Despite superficial differences, especially in size and weight, the mouse brain and its function can serve as a powerful animal model for study of human brain diseases or mental disorders (see e.g. Reeler, Chakragati mouse). This is because the genes responsible for building and operating both mouse and human brain are 90% identical. Transgenic mouse lines also allow neuroscientists to specifically target the labeling of certain cell types to probe the neural basis of fundamental processes. Anatomy The cerebral cortex of a mouse has around 8–14 million neurons while in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alzheimer's Disease
Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term memory, remembering recent events. As the disease advances, symptoms can include primary progressive aphasia, problems with language, Orientation (mental), disorientation (including easily getting lost), mood swings, loss of motivation, self-neglect, and challenging behaviour, behavioral issues. As a person's condition declines, they often withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to death. Although the speed of progression can vary, the typical life expectancy following diagnosis is three to nine years. The cause of Alzheimer's disease is poorly understood. There are many environmental and genetic risk factors associated with its development. The strongest genetic risk factor is from an alle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclin-dependent Kinase 5
Cyclin-dependent kinase 5 is a protein, and more specifically an enzyme, that is encoded by the Cdk5 gene. It was discovered 15 years ago, and it is saliently expressed in post-mitotic central nervous system neurons (CNS). The molecule belongs to the cyclin-dependent kinase family. Kinases are enzymes that catalyze reactions of phosphorylation. This process allows the substrate to gain a phosphate group donated by an organic compound known as ATP. Phosphorylations are of vital importance during glycolysis, therefore, making kinases an essential part of the cell due to their role in the metabolism, cell signaling, and many other processes. Structure Cdk5 is a proline-directed serine/threonine kinase, which was first identified as a CDK family member due to its similar structure to CDC2/CDK1 in humans, a protein that plays a crucial role in the regulation of the cell cycle. The gene Cdk5 contains 12 exons in a region that contains around 5000 nucleotides (5kb), as it was det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
