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Section: Legal use > Herbert Weinstein. In 1991, a sixty-five-year-old advertising executive with no prior history of crime or violence after an argument strangled his wife, opened the window and threw her out of their 12th-floor apartment. His defense team had a structural brain scan done using MRI and PET scan. The i... | Wikipedia - Neurocriminology - Legal use > Herbert Weinstein | 196 | 903 | null |
Section: Legal use > Antonio Bustamante. Bustamante was a well-behaved teenager who suddenly at the age of 22 became a career criminal. His crimes included theft, breaking and entering, drug offenses, and robbery. In 1990 Bustamante was charged with a homicide. The defense team discovered that the client had suffered a... | Wikipedia - Neurocriminology - Legal use > Antonio Bustamante | 154 | 730 | null |
Section: Crime prevention > Decisions based on brain imaging. Some scientists propose using brain imaging to help decide which soon-to-be-released offenders are at greater risk for reoffending. The brain imaging data would be used along with common factors like age, prior arrests, and marital status. To support this id... | Wikipedia - Neurocriminology - Crime prevention > Decisions based on brain imaging | 163 | 829 | null |
Section: Crime prevention > Stigma. In preventing crime on the basis of association to neurobiological function, there could also be adverse effects in increased stigma around those with atypical brain functioning and mental disorders. Although much research has been discovered in relation to neurocriminology, all atyp... | Wikipedia - Neurocriminology - Crime prevention > Stigma | 240 | 1,354 | null |
Article: Neurogenetics. Neurogenetics studies the role of genetics in the development and function of the nervous system. It considers neural characteristics as phenotypes (i.e. manifestations, measurable or not, of the genetic make-up of an individual), and is mainly based on the observation that the nervous systems o... | Wikipedia - Neurogenetics - Summary | 206 | 1,025 | null |
Section: History. The field of neurogenetics emerged from advances made in molecular biology, genetics and a desire to understand the link between genes, behavior, the brain, and neurological disorders and diseases. The field started to expand in the 1960s through the research of Seymour Benzer, considered by some to b... | Wikipedia - Neurogenetics - History | 326 | 1,641 | null |
Section: Neurological disorders. While the genetic basis of simple diseases and disorders has been accurately pinpointed, the genetics behind more complex, neurological disorders is still a source of ongoing research. New developments such as the genome wide association studies (GWAS) have brought vast new resources wi... | Wikipedia - Neurogenetics - Neurological disorders | 167 | 908 | null |
Section: Methods of research > Statistical analysis. Logarithm of odds (LOD) is a statistical technique used to estimate the probability of gene linkage between traits. LOD is often used in conjunction with pedigrees, maps of a family's genetic make-up, in order to yield more accurate estimations. A key benefit of this... | Wikipedia - Neurogenetics - Methods of research > Statistical analysis | 277 | 1,382 | null |
Section: Methods of research > Recombinant DNA. Recombinant DNA is an important method of research in many fields, including neurogenetics. It is used to make alterations to an organism's genome, usually causing it to over- or under-express a certain gene of interest, or express a mutated form of it. The results of the... | Wikipedia - Neurogenetics - Methods of research > Recombinant DNA | 177 | 807 | null |
Section: Methods of research > Animal research. Model organisms are an important tool in many areas of research, including the field of neurogenetics. By studying creatures with simpler nervous systems and with smaller genomes, scientists can better understand their biological processes and apply them to more complex o... | Wikipedia - Neurogenetics - Methods of research > Animal research | 261 | 1,384 | null |
Section: Methods of research > Human research. Many research facilities seek out volunteers with certain conditions or illnesses to participate in studies. Model organisms, while important, cannot completely model the complexity of the human body, making volunteers a key part to the progression of research. Along with ... | Wikipedia - Neurogenetics - Methods of research > Human research | 186 | 1,056 | null |
Section: Behavioral neurogenetics. Advances in molecular biology techniques and the species-wide genome project have made it possible to map out an individual's entire genome. Whether genetic or environmental factors are primarily responsible for an individual's personality has long been a topic of debate. Thanks to th... | Wikipedia - Neurogenetics - Behavioral neurogenetics | 243 | 1,291 | null |
Section: Behavioral neurogenetics > Cross-species gene conservation. While it is true that variation between species can appear to be pronounced, at their most basic they share many similar behavior traits which are necessary for survival. Such traits include mating, aggression, foraging, social behavior and sleep patt... | Wikipedia - Neurogenetics - Behavioral neurogenetics > Cross-species gene conservation | 199 | 1,125 | null |
Section: Development. A great deal of research has been done on the effects of genes and the formation of the brain and the central nervous system. The following wiki links may prove helpful: Neural development Neurogenesis The Brain Neural tube There are many genes and proteins that contribute to the formation and dev... | Wikipedia - Neurogenetics - Development | 326 | 1,622 | null |
Section: Current research. Neurogenetics is a field that is rapidly expanding and growing. The current areas of research are very diverse in their focuses. One area deals with molecular processes and the function of certain proteins, often in conjunction with cell signaling and neurotransmitter release, cell developmen... | Wikipedia - Neurogenetics - Current research | 342 | 1,643 | null |
Article: Neurogenomics. Neurogenomics is the study of how the genome of an organism influences the development and function of its nervous system. This field intends to unite functional genomics and neurobiology in order to understand the nervous system as a whole from a genomic perspective. The nervous system in verte... | Wikipedia - Neurogenomics - Summary | 317 | 1,752 | null |
Section: Approaches > Advent of high-throughput biology. In 1999, Cirelli & Tononi first reported the association of genome-wide brain gene expression profiling (using microarrays) with a behavioural phenotype in mice. Since then, global brain gene expression data, derived from microarrays, has been aligned to various ... | Wikipedia - Neurogenomics - Approaches > Advent of high-throughput biology | 331 | 1,630 | null |
Section: Approaches > Next-generation sequencing approaches. Twin studies have revealed that schizophrenia, bipolar disorder, autism spectrum disorder (ASD), and attention deficit hyperactivity disorder (ADHD) are highly heritable, genetically complex psychiatric disorders. However, linkage studies have largely failed ... | Wikipedia - Neurogenomics - Approaches > Next-generation sequencing approaches | 324 | 1,810 | null |
This approach is expected to be able to identify the secondary gene networks that are disrupted in neurological disorders, subsequently assisting drug development stratagems for brain diseases. The BRAIN initiative launched in 2013, for example, seeks to "inform the development of future treatments for brain disorders,... | Wikipedia - Neurogenomics - Approaches > Next-generation sequencing approaches | 220 | 1,199 | null |
Section: Approaches > Imaging studies and optical mapping. When autism was identified as a distinct biological disorder in the 1980s, researchers found that autistic individuals showed a brain growth abnormality in the cerebellum in their early developmental years. Subsequent research has indicated that 90% of autistic... | Wikipedia - Neurogenomics - Approaches > Imaging studies and optical mapping | 237 | 1,288 | null |
Section: Approaches > Imaging studies and optical mapping > MRI. Structural Magnetic Resonance Imaging (MRI) can be used to identify the structural composition of the brain. Particularly in the context of neurogenomics, MRI has played an extensive role in the study of Alzheimer's disease over the past four decades. It ... | Wikipedia - Neurogenomics - Approaches > Imaging studies and optical mapping > MRI | 349 | 1,846 | null |
Section: Approaches > Imaging studies and optical mapping > Optical mapping. One prohibitive feature of 2nd generation sequencing methodologies is the upper limit on the genomic range accessible by mate-pairing. Optical mapping is an emerging methodology used to span large-scale variants that cannot usually be detected... | Wikipedia - Neurogenomics - Approaches > Imaging studies and optical mapping > Optical mapping | 170 | 930 | null |
Section: Approaches > Imaging studies and optical mapping > Studying other brain diseases. Apart from neurological disorders, there are additional diseases that manifest in the brain and have formed exemplar use-case scenarios for the application of brain imaging in network analysis. In a classic example of imaging-gen... | Wikipedia - Neurogenomics - Approaches > Imaging studies and optical mapping > Studying other brain diseases | 197 | 1,082 | null |
Section: Research developmental models > In humans. The current approaches in collecting gene expression data in human brains are to use either microarrays or RNA-seq. Currently, it is rare to gather "live" brain tissue – only when treatments involve brain surgery is there a chance that brain tissue is collected during... | Wikipedia - Neurogenomics - Research developmental models > In humans | 349 | 1,779 | null |
Section: Research developmental models > Animal models > Zebrafish. Zebrafish development relies on gene networks that are highly conserved among all vertebrates. Additionally, with an extremely well annotated set of 12,000 genes and 1,000 early development mutants that are actually visible in the optically clear zebra... | Wikipedia - Neurogenomics - Research developmental models > Animal models > Zebrafish | 167 | 887 | null |
Section: Research developmental models > Animal models > Rodent. Rodent models have been preeminent in studying human disorders. These models have been extensively annotated with gene homologs of several monogenic disorders in humans. Knockout studies of these homologs have led to expansion of our understanding of netw... | Wikipedia - Neurogenomics - Research developmental models > Animal models > Rodent | 348 | 1,896 | null |
Section: Research developmental models > Animal models > Experimental mice models for psychiatric disorders. A common approach to using a mouse model is to apply an experimental treatment to a pregnant mouse in order to affect a whole litter. However, a key issue in the field is the treatment of litters in a statistica... | Wikipedia - Neurogenomics - Research developmental models > Animal models > Experimental mice models for psychiatric disorders | 308 | 1,705 | null |
Section: Research developmental models > Animal models > Challenges. The modelling and assessment of latent symptoms (thoughts, verbal learning, social interactions, cognitive behaviour) remains a challenge when using model organisms to study psychiatric disorders with a complex genetic pathology. For example, a given ... | Wikipedia - Neurogenomics - Research developmental models > Animal models > Challenges | 329 | 1,742 | null |
Section: Gene expression in the brain. The gene expression profile of the central nervous system (CNS) is unique. Eighty percent of all human genes are expressed in the brain; 5,000 of these genes are solely expressed in the CNS. The human brain has the highest amount of gene expression of all studied mammalian brains.... | Wikipedia - Neurogenomics - Gene expression in the brain | 151 | 810 | null |
Section: Gene expression in the brain > Spatial differences. Gene expression profiles also vary within specific regions of the brain. A microarray study showed that the transcriptome profile of the CNS clusters together based on region. A different study characterized the regulation of gene expression across 10 differe... | Wikipedia - Neurogenomics - Gene expression in the brain > Spatial differences | 191 | 1,024 | null |
Section: Gene expression in the brain > Development patterns in humans. Gene expression of the brain changes throughout the different phases of life. The most significant levels of expression are found during early development, with the rate of gene expression being highest during fetal development. This results from t... | Wikipedia - Neurogenomics - Gene expression in the brain > Development patterns in humans | 346 | 1,950 | null |
Section: Evolution of the mammalian brain. The evolution of Homo sapiens since the divergence from the primate common ancestor has shown a marked expansion in the size and complexity of the brain, especially in the cerebral cortex. In comparison to primates, the human cerebral cortex has a larger surface area but diffe... | Wikipedia - Neurogenomics - Evolution of the mammalian brain | 332 | 1,825 | null |
Despite this, comparative genomics has allowed us to connect the genetic changes found in a phylogeny to specific pathways. In order to determine this, lineages are tested for the functional changes that accrue over time. This is often measured as a ratio of nonsynonymous substitutions to synonymous substitutions or th... | Wikipedia - Neurogenomics - Evolution of the mammalian brain | 280 | 1,304 | null |
Section: Evolution of the mammalian brain > Network level expression differences between species. It is thought that gene expression changes, being the ultimate response for any genetic changes, are a good proxy for understanding phenotypic differences within biological samples. Comparative studies have revealed a rang... | Wikipedia - Neurogenomics - Evolution of the mammalian brain > Network level expression differences between species | 232 | 1,206 | null |
Section: Disorders. Neurogenomic disorders manifest themselves as neurological disorders with a complex genetic architecture and a non-Mendelian-like pattern of inheritance. Some examples of these disorders include Bipolar disorder and Schizophrenia. Several genes may be involved in the manifestation of the disorder, a... | Wikipedia - Neurogenomics - Disorders | 345 | 1,798 | null |
Since several diseases with neurogenomic underpinnings tend to have a polygenic basis, several nonspecific, rare, and partially penetrant de novo mutations in different patients can contribute to the same observed range of phenotypes, as is the case with Autism Spectrum Disorder and schizophrenia. Extensive research in... | Wikipedia - Neurogenomics - Disorders | 156 | 826 | null |
Section: Disorders > Modelling psychiatric disorders in neurogenomics research – issues. One major GWAS study identified 13 new risk loci for schizophrenia. Studying the impact of these candidates would ideally demonstrate a schizophrenia phenotype in animal models, which is usually difficult to observe due to its mani... | Wikipedia - Neurogenomics - Disorders > Modelling psychiatric disorders in neurogenomics research – issues | 348 | 1,857 | null |
Several disorders, especially at the more severe ends of the spectrum tend to be comorbid with each other. For example, more severe cases of ASD tend to be associated with intellectual disability (ID). This raises the question of whether or not there are true, unique ASD genes and unique ID genes or if there are just g... | Wikipedia - Neurogenomics - Disorders > Modelling psychiatric disorders in neurogenomics research – issues | 172 | 869 | null |
Section: Disorders > Network analysis. The main goal of network analysis in neurogenomics is to identify statistically significant nonrandom associations between genes that contain risk variants. While several algorithm implementations of this approach already exist, the general steps for network analysis remain the sa... | Wikipedia - Neurogenomics - Disorders > Network analysis | 342 | 1,905 | null |
Section: Neuropharmacology. Historically, due to the behavioural stimulation manifested as a symptom in several the neurogenomic disorders, the therapies would rely mostly on anti-psychotics or antidepressants. These classes of medications would suppress common symptoms of the disorders, but with questionable efficacy.... | Wikipedia - Neurogenomics - Neuropharmacology | 342 | 1,677 | null |
Section: Neuropharmacology > Blood brain barrier. Studies in animal models for several brain diseases has shown that the blood brain barrier (BBB) undergoes modification at many levels; for example, the surface glycoprotein composition can influence the types of HIV-1 strains transported by the BBB. The BBB has been fo... | Wikipedia - Neurogenomics - Neuropharmacology > Blood brain barrier | 150 | 740 | null |
Section: Neuropharmacology > Personalized neurobiology. The heterogenous nature of neurological diseases is the key motivation for personalized medicine approaches to their therapies. Genomic samples of individual patients could be used to identify predictive factors, or to better understand the specific prognosis of a... | Wikipedia - Neurogenomics - Neuropharmacology > Personalized neurobiology | 348 | 1,865 | null |
Ethical concerns have also been raised regarding the safeguarding of personal genomic information, and how best to approach the burden of incidental findings and family risk assessment. Consanguinity and in-breeding can lead to selective enrichment of rare, otherwise low penetrance genetic mutations attributed to vario... | Wikipedia - Neurogenomics - Neuropharmacology > Personalized neurobiology | 165 | 942 | null |
Article: Neuronal lineage marker. A neuronal lineage marker is an endogenous tag that is expressed in different cells along neurogenesis and differentiated cells such as neurons. It allows detection and identification of cells by using different techniques. A neuronal lineage marker can be either DNA, mRNA or RNA expre... | Wikipedia - Neuronal lineage marker - Summary | 349 | 1,642 | null |
This technique is known as in situ hybridization. Its application have been carried out in all different tissues, but particularly useful in neuroscience. Using this technique, it is possible to locate gene expression to specific cell types in specific regions and observe how changes in this distribution occur througho... | Wikipedia - Neuronal lineage marker - Summary | 230 | 1,204 | null |
Section: History. The study of the nervous system dates back to ancient Egypt but only in the ninetieth century it became more detailed. With the invention of the microscope and a technique of staining developed by Camillo Golgi, it was possible to study individual neurons. This scientist started to impregnate nervous ... | Wikipedia - Neuronal lineage marker - History | 340 | 1,579 | null |
This technique continues to be widely used in neuroscience studies for identifying different structures. The most important neural markers used nowadays are the GFAP, Nestin, NeuroD antibodies and others. For the past years there are still creating new neural markers for immunocytochemistry or/and immunohistochemistry.... | Wikipedia - Neuronal lineage marker - History | 207 | 1,015 | null |
Section: Techniques > In situ hybridization. This is one of the most powerful techniques to mark cells. This method consists of hybridizing a labeled complementary DNA or RNA strand to a specific DNA or RNA in the tissue. By doing this hybridization we will be able to reveal the location of a specific mRNA, giving us i... | Wikipedia - Neuronal lineage marker - Techniques > In situ hybridization | 267 | 1,281 | null |
Section: Techniques > Immunohistochemistry. Immunohistochemistry is a technique that uses antibodies with fluorescent staining tags that target a specific antigen present in a certain protein. This high specificity allows us to localize the peptidergic and classical transmitter compounds, their synthetic enzymes and ot... | Wikipedia - Neuronal lineage marker - Techniques > Immunohistochemistry | 226 | 1,043 | null |
Section: Lineage markers > Neural stem cells markers. Neural stem cells are an example of somatic stem cell found in various tissues, both during development and in the adult. They have two fundamental characteristics: they are self-renewing and upon terminal division and differentiation, they can give rise to the full... | Wikipedia - Neuronal lineage marker - Lineage markers > Neural stem cells markers | 337 | 1,669 | null |
Other non-immunological methods have been used to identify populations of cells from normal and tumorigenic CNS tissues, which demonstrate some of the in vitro properties of stem cells, including high aldehyde dehydrogenase (ALDH) enzyme activity. ALDH cells from embryonic rat and mouse CNS have been isolated and shown... | Wikipedia - Neuronal lineage marker - Lineage markers > Neural stem cells markers | 329 | 1,622 | null |
Section: Lineage markers > Differentiation markers > Neural progenitor markers. A neural progenitor cell is distinct from a neural stem cell since it is incapable of continuous self-renewal and usually has the capacity to give rise to only one class of differentiated progeny. They are tripotent cells which can give ris... | Wikipedia - Neuronal lineage marker - Lineage markers > Differentiation markers > Neural progenitor markers | 339 | 1,598 | null |
Section: Lineage markers > Differentiation markers > Neuron markers. Markers can detect neurons in different stages of development from nuclear, cytoplasmic, membrane or perisynaptic products present in neurons. It is also possible to label specifically cholinergic, dopaminergic, serotonergic, GABAergic or glutamatergi... | Wikipedia - Neuronal lineage marker - Lineage markers > Differentiation markers > Neuron markers | 329 | 1,477 | null |
NSE levels increase along the neuron development reaching higher level in later stages. It can be expressed in glial cells during oligodendrocyte differentiation with the same levels that have been found in neuron culture, but is repressed when cells become mature. In pathological conditions was also reported that glia... | Wikipedia - Neuronal lineage marker - Lineage markers > Differentiation markers > Neuron markers | 350 | 1,462 | null |
Generally, it is used as a marker for dopaminergic neurons, but it can also be found in some forebrain neurons which make norepinephrine (which is the product of dopamine and the enzyme dopamine β-hydroxylase). Choline Acetyltransferase (ChAT) is expressed in cholinergic neurons of both the CNS and PNS. In the CNS, ChA... | Wikipedia - Neuronal lineage marker - Lineage markers > Differentiation markers > Neuron markers | 302 | 1,261 | null |
Section: Clinical research. Neuronal lineage markers can be used in clinical research to identify diseased cells and/or in repair process. Since selective degeneration of functional neurons is associated with the pathogenesis of neurodegenerative disorders, such as degeneration of midbrain dopaminergic neurons in Parki... | Wikipedia - Neuronal lineage marker - Clinical research | 298 | 1,332 | null |
Section: Genetic and molecular causes. Neutral networks exist in fitness landscapes since proteins are robust to mutations. This leads to extended networks of genes of equivalent function, linked by neutral mutations. Proteins are resistant to mutations because many sequences can fold into highly similar structural fol... | Wikipedia - Neutral network (evolution) - Genetic and molecular causes | 233 | 1,319 | null |
Section: Evolution > Evolvability. Interest in the interplay between genetic drift and selection has been around since the 1930s when the shifting-balance theory proposed that in some situations, genetic drift could facilitate later adaptive evolution. Although the specifics of the theory were largely discredited, it d... | Wikipedia - Neutral network (evolution) - Evolution > Evolvability | 225 | 1,240 | null |
Section: Mathematical Framework. The fact that neutral mutations were probably widespread was proposed by Freese and Yoshida in 1965. Motoo Kimura later crystallized a theory of neutral evolution in 1968 with King and Jukes independently proposing a similar theory (1969). Kimura computed the rate of nucleotide substitu... | Wikipedia - Neutral network (evolution) - Mathematical Framework | 333 | 1,599 | null |
Waterman gave the first graph theoretic description of RNA secondary structures and their associated properties, and used them to produce an efficient minimum free energy (MFE) folding algorithm. An RNA secondary structure can be viewed as a diagram over N labeled vertices with its Watson-Crick base pairs represented a... | Wikipedia - Neutral network (evolution) - Mathematical Framework | 332 | 1,752 | null |
M. Zuker, implemented algorithms for computation of MFE RNA secondary structures based on the work of Nussinov et al., Smith and Waterman and Studnicka, et al. Later L. Hofacker (et al., 1994), presented The Vienna RNA package, a software package that integrated MFE folding and the computation of the partition function... | Wikipedia - Neutral network (evolution) - Mathematical Framework | 322 | 1,668 | null |
Section: Formation of nicks. The diagram shows the effects of nicks on intersecting DNA in a twisted plasmid. Nicking can be used to dissipate the energy held up by intersecting states. The nicks allow the DNA to take on a circular shape. Nicked DNA can be the result of DNA damage or purposeful, regulated biomolecular ... | Wikipedia - Nick (DNA) - Formation of nicks | 213 | 963 | null |
Section: Repair of nicks. Ligases are versatile and ubiquitous enzymes that join the 3’ hydroxyl and 5’ phosphate ends to form a phosphodiester bond, making them essential in nicked DNA repair, and ultimately genome fidelity. This biological role has also been extremely valuable in sealing the sticky ends of plasmids i... | Wikipedia - Nick (DNA) - Repair of nicks | 325 | 1,468 | null |
Section: Biological implications > Role in mismatch repair. Single-stranded nicks act as recognizable markers to help the repair machinery distinguish the newly synthesized strand (daughter strand) from the template strand (parental strand). DNA mismatch repair (MMR) is an important DNA repair system that helps maintai... | Wikipedia - Nick (DNA) - Biological implications > Role in mismatch repair | 339 | 1,548 | null |
Due to the continuous replication that occurs on the leading strand, the mechanism there is slightly more complex. During replication, ribonucleotides are added by replication enzymes and these ribonucleotides are nicked by an enzyme called RNase H2. Together, the presence of a nick and a ribonucleotide make the leadin... | Wikipedia - Nick (DNA) - Biological implications > Role in mismatch repair | 235 | 1,098 | null |
Section: Biological implications > Role in replication and transcription. Nicked DNA plays an important role in many biological functions. For instance, single-stranded nicks in DNA may serve as purposeful biological markers for the enzyme topoisomerase that unwinds packed DNA and is critical to DNA replication and tra... | Wikipedia - Nick (DNA) - Biological implications > Role in replication and transcription | 275 | 1,336 | null |
Nick idling is a biological process in which DNA polymerase may slow or stop its activity of adding bases to a new daughter strand during DNA replication at a nick site. This is particularly relevant to Okazaki fragments in lagging strand in double stranded DNA replication because the direction of replication is opposi... | Wikipedia - Nick (DNA) - Biological implications > Role in replication and transcription | 177 | 907 | null |
Section: Biological implications > Role in replication and transcription > In bacteria. The nic site or nick region is found within the origin of transfer (oriT) site and is a key in starting bacterial conjugation. A single strand of DNA, called the T-strand, is cut at nic by an enzyme called relaxase. This single stra... | Wikipedia - Nick (DNA) - Biological implications > Role in replication and transcription > In bacteria | 212 | 958 | null |
Section: Regulation > Regulation of Ni2+ uptake. Ni2+ is taken up into prokaryotic cells by one of two types of high-affinity transport systems. The first method involves ABC-type transporters (discussed in this article) and the second mechanism makes use of transition-metal permeases (such as HoxN of Ralstonia eutroph... | Wikipedia - Nik operon - Regulation > Regulation of Ni2+ uptake | 185 | 711 | null |
Section: Repression by NikR binding. Using profile-based sequence database searches, NikR was shown to be a member of the ribbon-helix-helix (RHH) family of transcription factors. It has been demonstrated that the N-terminal domain of NikR is responsible for binding to DNA and that it only binds in presence of Ni2+. Ni... | Wikipedia - Nik operon - Repression by NikR binding | 201 | 921 | null |
Article: Non-allelic homologous recombination. Non-allelic homologous recombination (NAHR) is a form of homologous recombination that occurs between two lengths of DNA that have high sequence similarity, but are not alleles. It usually occurs between sequences of DNA that have been previously duplicated through evoluti... | Wikipedia - Non-allelic homologous recombination - Summary | 323 | 1,434 | null |
Article: Nondisjunction. Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division (mitosis/meiosis). There are three forms of nondisjunction: failure of a pair of homologous chromosomes to separate in meiosis I, failure of sister chromatids to separate durin... | Wikipedia - Nondisjunction - Summary | 175 | 805 | null |
Section: Types > Meiosis II. Ovulated eggs become arrested in metaphase II until fertilization triggers the second meiotic division. Similar to the segregation events of mitosis, the pairs of sister chromatids resulting from the separation of bivalents in meiosis I are further separated in anaphase of meiosis II. In oo... | Wikipedia - Nondisjunction - Types > Meiosis II | 176 | 769 | null |
Section: Types > Mitosis. Division of somatic cells through mitosis is preceded by replication of the genetic material in S phase. As a result, each chromosome consists of two sister chromatids held together at the centromere. In the anaphase of mitosis, sister chromatids separate and migrate to opposite cell poles bef... | Wikipedia - Nondisjunction - Types > Mitosis | 317 | 1,377 | null |
Section: Molecular mechanisms > Sex-specific differences in meiosis. Surveys of cases of human aneuploidy syndromes have shown that most of them are maternally derived. This raises the question: Why is female meiosis more error prone? The most obvious difference between female oogenesis and male spermatogenesis is the ... | Wikipedia - Nondisjunction - Molecular mechanisms > Sex-specific differences in meiosis | 194 | 957 | null |
Section: Molecular mechanisms > Age-related loss of cohesin ties. Due to the prolonged arrest of human oocytes, weakening of cohesive ties holding together chromosomes and reduced activity of the SAC may contribute to maternal age-related errors in segregation control. The cohesin complex is responsible for keeping tog... | Wikipedia - Nondisjunction - Molecular mechanisms > Age-related loss of cohesin ties | 168 | 860 | null |
Section: Consequences > Mosaicism in malignant transformation. Development of cancer often involves multiple alterations of the cellular genome (Knudson hypothesis). Human retinoblastoma is a well studied example of a cancer type where mitotic nondisjunction can contribute to malignant transformation: Mutations of the ... | Wikipedia - Nondisjunction - Consequences > Mosaicism in malignant transformation | 155 | 767 | null |
Article: Noninvasive genotyping. Noninvasive genotyping is a modern technique for obtaining DNA for genotyping that is characterized by the indirect sampling of specimen, not requiring harm to, handling of, or even the presence of the organism of interest. Beginning in the early 1990s, with the advent of PCR, researche... | Wikipedia - Noninvasive genotyping - Summary | 207 | 1,014 | null |
Section: Medicine > Fetal Genotyping. The most common use of noninvasive genotyping in medicine is non-invasive prenatal diagnosis (NIPD), which provides an alternative to riskier techniques such as amniocentesis. With the discovery of cell-free fetal DNA in maternal plasma, NIPD became a popular method for determining... | Wikipedia - Noninvasive genotyping - Medicine > Fetal Genotyping | 165 | 731 | null |
Section: Medicine > Tumor detection. This same technique is also utilized to identify the incidence of tumor DNA in the blood, which can both provide early detection of tumor growth and indicate relapse in cancer. Circulating tumor DNA can be found in the blood before metastasis occurs and, therefore, detection of cert... | Wikipedia - Noninvasive genotyping - Medicine > Tumor detection | 188 | 983 | null |
Article: Nucleomodulin. Nucleomodulins are a family of bacterial proteins that enter the nucleus of eukaryotic cells. This term comes from the contraction between "nucleus" and "modulins", which are microbial molecules that modulate the behaviour of eukaryotic cells. Nucleomodulins are produced by pathogenic or symbiot... | Wikipedia - Nucleomodulin - Summary | 330 | 1,470 | null |
Section: Examples. Agrobacterium tumefaciens, responsible for crown gall disease, produces an arsenal of Vir proteins, including VirD2 and VirE2, enabling the precise integration of a piece of its DNA, called T-DNA, into that of the host plant Listeria monocytogenes, responsible for listeriosis, can modulate the expres... | Wikipedia - Nucleomodulin - Examples | 248 | 1,047 | null |
Section: Oogenesis in non-human mammals. In mammals, the first part of oogenesis starts in the germinal epithelium, which gives rise to the development of ovarian follicles, the functional unit of the ovary. Oogenesis consists of several sub-processes: oocytogenesis, ootidogenesis, and finally maturation to form an ovu... | Wikipedia - Oogenesis - Oogenesis in non-human mammals | 210 | 807 | null |
Section: Oogenesis in non-human mammals > Maintenance of meiotic arrest. Mammalian oocytes are maintained in meiotic prophase arrest for a very long time—months in mice, years in humans. Initially, the arrest is due to lack of sufficient cell cycle proteins to allow meiotic progression. However, as the oocyte grows, th... | Wikipedia - Oogenesis - Oogenesis in non-human mammals > Maintenance of meiotic arrest | 327 | 1,357 | null |
Section: Oogenesis in non-human mammals > Reinitiation of meiosis and stimulation of ovulation by luteinizing hormone. As follicles grow, they acquire receptors for luteinizing hormone, a pituitary hormone that reinitiates meiosis in the oocyte and causes ovulation of a fertilizable egg. Luteinizing hormone acts on rec... | Wikipedia - Oogenesis - Oogenesis in non-human mammals > Reinitiation of meiosis and stimulation of ovulation by luteinizing hormone | 177 | 738 | null |
Section: Human oogenesis > Oogenesis > Number of primary oocytes. It is commonly believed that, when oocytogenesis is complete, no additional primary oocytes are created, in contrast to the male process of spermatogenesis, where gametocytes are continuously created. In other words, primary oocytes reach their maximum d... | Wikipedia - Oogenesis - Human oogenesis > Oogenesis > Number of primary oocytes | 284 | 1,317 | null |
Section: Human oogenesis > Ootidogenesis > Meiosis I. Meiosis I of ootidogenesis begins during embryonic development, but halts in the diplotene stage of prophase I until puberty. The mouse oocyte in the dictyate (prolonged diplotene) stage actively repairs DNA damage, whereas DNA repair is not detectable in the pre-di... | Wikipedia - Oogenesis - Human oogenesis > Ootidogenesis > Meiosis I | 168 | 631 | null |
Section: Human oogenesis > Ovarian cycle. The ovarian cycle is divided into several phases: Follicologenesis: Synchronously with ootidogenesis, the ovarian follicle surrounding the ootid has developed from a primordial follicle to a preovulatory one. The primary follicle takes four months to become a preantral, two mon... | Wikipedia - Oogenesis - Human oogenesis > Ovarian cycle | 342 | 1,337 | null |
The innermost ones are called radiated corona cells. At this stage, the oocyte produces cortical granules containing acid glycoproteins. Dominant follicle selection: The follicle with more FSH receptors will be more favored, simultaneously inducing the death of the other follicles (3-10 antral follicles that enter this... | Wikipedia - Oogenesis - Human oogenesis > Ovarian cycle | 326 | 1,357 | null |
Formation of the corpus luteum: From the remaining structures of the follicle, the corpus luteum is formed. At first, there is a clot, which is then replaced by loose connective tissue; the cells that form solid cords are follicular cells and cells of the outer theca (Tecali lutein cells) and internal (granulosa cells)... | Wikipedia - Oogenesis - Human oogenesis > Ovarian cycle | 190 | 750 | null |
Section: Human oogenesis > Uterine cycle. The uterine cycle occurs parallel to the ovarian cycle and is induced by estrogen and progesterone. The endometrium, formed by a monostratified cylindrical epithelium, with uterine glands (simple tubular), connective with a functional superficial layer (divided into a spongy la... | Wikipedia - Oogenesis - Human oogenesis > Uterine cycle | 275 | 1,154 | null |
Section: Human oogenesis > In vitro maturation. In vitro maturation (IVM) is the technique of letting ovarian follicles mature in vitro. It can potentially be performed before an IVF. In such cases, ovarian hyperstimulation is not essential. Rather, oocytes can mature outside the body prior to IVF. Hence, no (or at lea... | Wikipedia - Oogenesis - Human oogenesis > In vitro maturation | 156 | 656 | null |
Section: Human oogenesis > In vitro oogenesis. By definition, it means to recapitulate mammalian oogenesis and produce fertilizable oocytes in vitro. It is a complex process involving several different cell types, precise follicular cell-oocyte reciprocal interactions, a variety of nutrients and combinations of cytokin... | Wikipedia - Oogenesis - Human oogenesis > In vitro oogenesis | 346 | 1,699 | null |
Section: Ovarian aging. BRCA1 and ATM proteins are employed in repair of DNA double-strand break during meiosis. These proteins appear to have a critical role in resisting ovarian aging. However, homologous recombinational repair of DNA double-strand breaks mediated by BRCA1 and ATM weakens with age in oocytes of human... | Wikipedia - Oogenesis - Ovarian aging | 273 | 1,240 | null |
Section: Oogenesis in non-mammals. Some algae and the oomycetes produce eggs in oogonia. In the brown alga Fucus, all four egg cells survive oogenesis, which is an exception to the rule that generally only one product of female meiosis survives to maturity. In plants, oogenesis occurs inside the female gametophyte via ... | Wikipedia - Oogenesis - Oogenesis in non-mammals | 279 | 1,163 | null |
Article: Parasitic chromosome. Parasitic chromosomes are "selfish" chromosomes that propagate throughout cell divisions, even if they confer no benefit to the overall organism's survival. Parasitic chromosomes can persist even if slightly detrimental to survival, as is characteristic of some selfish genetic elements. P... | Wikipedia - Parasitic chromosome - Summary | 164 | 912 | null |
Article: Partial dominance hypothesis. In genetics, the partial dominance hypothesis states that inbreeding depression is the result of the frequency increase of homozygous deleterious recessive or partially recessive alleles. The hypothesis can be explained by looking at a population that is divided into a large numbe... | Wikipedia - Partial dominance hypothesis - Summary | 165 | 845 | null |
Article: Pathogenicity island. Pathogenicity islands (PAIs), as termed in 1990, are a distinct class of genomic islands acquired by microorganisms through horizontal gene transfer. Pathogenicity islands are found in both animal and plant pathogens. Additionally, PAIs are found in both gram-positive and gram-negative ba... | Wikipedia - Pathogenicity island - Summary | 319 | 1,540 | null |
Section: Properties. Pathogenicity islands (PAIs) are gene clusters incorporated in the genome, chromosomally or extrachromosomally, of pathogenic organisms, but are usually absent from those nonpathogenic organisms of the same or closely related species. They may be located on a bacterial chromosome or may be transfer... | Wikipedia - Pathogenicity island - Properties | 313 | 1,474 | null |
The majority are surrounded by brief terminal inverted repeats that serve as homologous recombination sites, enhancing a PAI's stability. Bacteriophage integrases also found on pathogenicity islands (PAIs) are enzymes produced by bacteriophages to enable site-specific recombination between two recognition sequences, se... | Wikipedia - Pathogenicity island - Properties | 338 | 1,456 | null |
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