BIO - TERMS - GENE Flashcards
(324 cards)
1
Q
Abortive infection
A
An incomplete infectious cycle; virions infect a susceptible cell or host but do not complete reproduction, usually because an essential viral or cellular gene is not expressed. (Chapter 5)
2
Q
absolute strength
A
The amount of force that can be generated regardless of body size.
3
Q
Additive genetic variance
A
The portion of the total phenotypic variance in a quantitative trait that is due to the additive effects of alleles.
4
Q
Aerobic metabolism
A
Cell energy metabolism where electrons finally are transferred to molecular oxygen. This type of energy metabolism generates ATP with high efficiency.
5
Q
alcoholic liver disease
A
A general term that is used to describe alcohol-related liver diseases, such as fatty liver, hepatitis, fibrosis, and cirrhosis.
6
Q
Allele-specific oligonucleotide probes
A
Probes that can distinguish between different alleles (variants) of a gene.
7
Q
Allelic heterogeneity
A
Different disease-causing mutations in the same gene.
8
Q
allogeneic
A
Describes two individuals or two mouse strains that differ at genes in the MHC. The term can also be used for allelic differences at other loci.
9
Q
Allopolyploid
A
A polyploid having chromosome sets from different species; a polyploid containing genetically different chromosome sets derived from two or more species.
10
Q
Allotetraploid
A
An organism with four genomes derived from hybridization of different species. Usually, in forms that become established, two of the four genomes are from one species and two are from another species.
11
Q
Alport syndrome
A
Genetic disorder of type IV collagen leading to kidney failure.
12
Q
Amniotic fl uid
A
Liquid contents of the amniotic sac of higher vertebrates containing cells of the embryo (not of the mother). Both fl uid and cells are used for diagnosis of genetic abnormalities of the embryo or fetus.
13
Q
Amorphic
A
A term applied to a mutant allele that completely abolishes gene expression. Such a mutant allele is called an amorph.
14
Q
AMP-activated protein kinase (AMPK)
A
A protein kinase activated by 5’-adenosine monophosphate (AMP). AMPK action generally shifts metabolism away from biosynthesis toward energy production.
15
Q
Anchor gene
A
A gene that has been positioned on both the physical map and the genetic map of a chromosome.
16
Q
Antennapedia complex
A
One of two gene clusters in Drosophila that contain Hox genes; genes in the Antennapedia complex control the differences among the thoracic and head segments of the body.
17
Q
atopy
A
A genetically based increased tendency to produce IgE-mediated allergic reactions against innocuous substances.
18
Q
Attini
A
Taxonomic tribe of two genera of leaf-cutting ants (Atta,15 species; Acromyrmex,24 species) that are able to cultivate fungi in subterranean gardens of their nests.
19
Q
autoinflammatory diseases
A
Diseases due to unregulated inflammation in the absence of infection; they can have a variety of causes, including inherited genetic defects.
20
Q
Autopolyploid
A
A polyploid that has multiple and identical or nearly identical sets of chromosomes (genomes). A polyploid species with genomes derived from the same original species.
21
Q
Azo compounds
A
A class of compounds with the general structure R-N=N-R’.
22
Q
Back mutation
A
A second mutation at the same site in a gene as the original mutation, which restores the wild-type nucleotide sequence.
23
Q
Backcross
A
The cross of an F1 hybrid to one of the parental types. The offspring of such a cross are referred to as the backcross generation or backcross progeny. (See also Testcross.)
24
Q
Balanced lethal
A
Lethal mutations in different genes on the same pair of chromosomes that remain in repulsion because of close linkage or crossover suppression. In a closed population, only the trans-heterozygotes (l1 + / + l2) for the lethal mutations survive.
25
Balancer chromosome
In Drosophila genetics, a dominantly marked, multiply-inverted chromosome that suppresses recombination with a homologous chromosome that is structurally normal.
26
Bcr–Abl tyrosine kinase
Constitutively active tyrosine kinase fusion protein caused by a chromosomal translocation—the Philadelphia chromosome— between Bcr with the Abl tyrosine kinase genes associated with chronic myeloid leukemia.
27
bioaugmentation
The use of pollutant-acclimated microbes or genetically engineered microbes for bioremediation.
28
Biological filtration
Removal of dissolved organic substances from water by means of biofilms. The microorganisms absorb biodegradable material and convert it into metabolites (preferably CO2 and water) and biomass. This principle is generally applied to biological drinking and waste water purification.
29
biomotor abilities
Abilities whereby the body can perform a range of activities, such as strength, speed, and endurance. Biomotor abilities are influenced by training and may be genetically determined.
30
Bioreporters
Living and usually genetically engineered microbial cells producing a detectable signal in reponse to a specific (chemical or physical) agent present in their environment.
31
Bithorax complex
One of two gene clusters in Drosophila that contain Hox genes; genes in the Bithorax complex control the differences among the abdominal and thoracic segments of the body.
32
Blau syndrome
An inherited granulomatous disease caused by gain-offunction mutations in the NOD2 gene.
33
BRCA1, BRCA2
Two tumor suppressor genes associated with inherited susceptibility to breast and ovarian cancers.
34
Brown-Vialetto-Van Laere syndrome
A disorder of the nervous and muscle systems due to genetic defects in the genes encoding riboflavin transporters RFVT2 and 3.
35
c-Oncogene
A cancer-causing gene encoded in cellular genomes: may be formed via mutagenesis of a gene that does not cause cancer, known therefore as a proto-oncogene. (Chapter 7)
36
cAMP response element-binding protein (CREB)
Protein that mediates effects of cyclic AMP on gene transcription.
37
cancer-critical genes
Genes whose alteration contributes to the causation or evolution of cancer by driving tumorigenesis. capsid Protein coat of a virus, formed by the self-assembly of one or more types of protein subunit into a geometrically regular structure.
38
carcinogenesis
The generation of cancer.
39
Cdc42
Member of the Rho family of monomeric GTPases that regulate the actin and microtubule cytoskeletons, cell-cycle progression, gene transcription, and membrane transport.
40
center-surround receptive field
A visual receptive field with a circular center region and a surround region forming a ring around the center; stimulation of the center produces a response opposite that generated by stimulation of the surround.
41
central pattern generator
A neural circuit that gives rise to rhythmic motor activity.
42
channelopathy
A human genetic disease caused by alterations in the structure and function of ion channels.
43
chemiosmosis
A mechanism that uses a proton gradient across a cytoplasmic membrane to generate ATP.
44
Chimera (plant)
Part of a plant with a genetically different constitution as compared with other parts of the same plant. It may result from different zygotes that grow together or from artificial fusion (grafting); it may either be pernical, with parallel layers of genetically different tissues, or sectorial.
45
Chorionic biopsy
A procedure in which cells are taken from an embryo for the purpose of genetic testing.
46
Chromosome Theory of Heredity
The theory that chromosomes carry the genetic information and that their behavior during meiosis provides the physical basis for the segregation and independent assortment of genes.
47
chronic infantile neurologic cutaneous and articular syndrome (CINCA)
An autoinflammatory disease due to defects in the gene NLRP3, one of the components of the inflammasome.
48
cis-trans test
The construction and analysis of cis and trans heterozygotes of pairs of mutations to determine whether the mutations are in the same gene or in two different genes. For the test to be informative, the cis heterozygote must have the wild-type phenotype. If this condition is met, the two mutations are in the same gene if the trans heterozygote has the mutant phenotype, and they are in two different genes if the trans heterozygote has the wildtype phenotype.
49
clock gene
A gene that is critically involved in the molecular mechanism of the circadian rhythm; clock genes are translated into proteins that regulate their own transcription, and their expression rises and falls over a cycle of about 24 hours.
50
Co-repressor
An effector molecule that forms a complex with a repressor and turns off the expression of a gene or set of genes.
51
codominant
Describes the situation in which the two alleles of a gene are expressed in roughly equal amounts in the heterozygote. Most genes show this property, including the highly polymorphic MHC genes.
52
Coefficient of relationship
The fraction of genes two individuals share by virtue of common ancestry.
53
combinatorial control
Use of combinations of a limited repertoire of regulatory proteins to provide gene-specific regulation of many individual genes.
54
Comparative genomics
The branch of genomics that compares the structure and function of the genomes of different species.
55
Complementation
The ability of gene products of two different, individually nonreproducing mutants to interact functionally in the same cell to permit virus reproduction. (Chapter 3)
56
Compound heterozygote
Person who carries two different mutations in different copies of the same gene.
57
Continuous variation
Variation not represented by distinct classes. Individuals grade into each other, and measurement data are required for analysis (cf. Discontinuous variation). Multiple genes are usually responsible for this type of variation.
58
Controlling element
In maize, a transposable element such as Ac or Ds that is capable of influencing the expression of a nearby gene.
59
Coordinate repression
Correlated regulation of the structural genes in an operon by a molecule that interacts with the operator sequence.
60
CpG islands
Clusters of cytosines and guanines that often occur upstream of human genes.
61
CRE-binding (CREB) protein
Transcription regulator that recognizes the cyclic AMP response element (CRE) in the regulatory region of genes activated by cAMP. On activation by PKA, phosphorylated CREB recruits a transcriptional coactivator (CREB-binding protein; CBP) to stimulate transcription of target genes.
62
Crossover unit
A measure of distance on genetic maps that is based on the average number of crossing-over events that take place during meiosis. A map interval that is one crossover unit in length (sometimes called a centiMorgan) implies that only one in every hundred chromatids recovered from meiosis will have undergone a crossing-over event in this interval.
63
cryoelectron microscopy
Technique for examining a thin film of an aqueous suspension of biological material that has been frozen rapidly enough to create vitreous ice. The specimen is then kept frozen and transferred to the electron microscope. Image contrast is low, but is generated solely by the macromolecular structures present.
64
Cut-and-paste transposon
A transposable element that is excised from one position in the genome and inserted into another position through the action of a transposon-encoded enzyme called the transposase.
65
cytidine deaminase activity (CDA)
An enzymatic activity exhibited by AID-APOBEC family proteins of agnathan species that may mediate rearrangement and assembly of complete VLR genes.
66
Cytogenetics
Area of biology concerned with chromosomes and their implications in genetics.
67
Cytoplasmic inheritance
Hereditary transmission dependent on the cytoplasm or structures in the cytoplasm rather than the nuclear genes; extrachromosomal inheritance. Example: Plastid characteristics in plants may be inherited by a mechanism independent of nuclear genes.
68
Derepression
The process of turning on the expression of a gene or set of genes whose expression has been repressed (turned off).
69
diathesis–stress hypothesis of mood disorders
A hypothesis suggesting that depression is caused by a combination of genetic predisposition and environmental stress.
70
Disulfides (RSSR’)
A class of compounds of the general structure RSSR’.
71
Dominant selectable marker gene
A gene that allows the host cell to survive under conditions where it would otherwise die.
72
Dominant-negative mutation
A mutant allele of a gene that interferes with the function of a wild-type allele so that individuals heterozygous for the mutant and wild-type alleles have a mutant phenotype.
73
Dorsal protein
Transcription regulator of the NFκB family regulating gene expression and involved in establishing the dorsoventral axis in the embryo.
74
Dosage compensation
A phenomenon in which the activity of a gene is increased or decreased according to the number of copies of that gene in the cell.
75
Duplication
The occurrence of a segment more than once in the same chromosome or genome; also, the multiplication of cells.
76
E2F protein
Transcription regulatory protein that switches on many genes that encode proteins required for entry into the S phase of the cell cycle.
77
Effector molecule
A molecule that influences the behavior of a regulatory molecule, such as a repressor protein, thereby influencing gene expression.
78
egg-polarity genes
Genes in the Drosophila egg that define the anteroposterior and dorsoventral axes of the future embryo through the creation of landmarks (mRNA or protein) in the egg that provide signals organizing the developmental process.
79
Ehlers-Danlos syndrome
A group of genetic diseases characterized by stretchy skin and loose joints.
80
electrochemical cell
A device that uses redox reactions to generate electricity or an electrical current to drive a chemical reaction.
81
electroencephalogram (EEG)
A measurement of electrical activity generated by the brain and recorded from the scalp.
82
electron groups
A general term for lone pairs, single bonds, multiple bonds, or lone electrons in a molecule.
83
Epigenetics
Study of mitotically and/or meiotically heritable changes in phenotype, which are independent from genetic variation.
84
Epistasis
Interactions between products of nonallelic genes. Genes suppressed are said to be hypostatic. Dominance is associated with members of allelic pairs, whereas epistasis results from interactions of the products of nonalleles.
85
epistasis analysis
Analysis to discover the order in which the genes act, by investigating if a mutation in one gene can mask the effect of a mutation in another gene when both mutations are present in the same organism or cell.
86
Eugenics
The application of the principles of genetics to the improvement of humankind.
87
excitable cell
A cell capable of generating action potentials of electric current.
88
excitable membrane
Any membrane capable of generating action potentials. The membrane of axons and muscle cells is excitable.
89
experiment
A highly controlled procedure designed to generate observations that may support a hypothesis or prove it wrong.
90
Expression domain
The region of a riboswitch that can fold into two conformations, one facilitating gene expression and the other blocking gene expression.
91
F1
The first filial generation; the first generation of descent from a given mating.
92
F2
The second filial generation produced by crossing inter se or by self-pollinating the F1. The inbred “grandchildren” of a given mating, but in controlled genetic experimentation, self-fertilization of the F1 (or equivalent) is implied.
93
Familial combined hyperlipoproteinemia
A genetic predisposition to type II and type IV hyperlipoproteinemia.
94
familial Mediterranean fever (FMF)
A severe autoinflammatory disease, inherited as an autosomal recessive disorder. It is caused by mutation in the gene (MEFV) that encodes the protein pyrin, which is expressed in granulocytes and monocytes. In patients with this disorder, defective pyrin is thought to spontaneously activate inflammasomes.
95
filopodium (plural filopodia) (microspike)
Thin, spike-like protrusion with an actin filament core, generated on the leading edge of a crawling animal cell.
96
Fission
A mode of cell division among the prokaryotes in which the genetic material of the mother cell is first duplicated and then apportioned equally to the two daughter cells.
97
Flux control
Control of the transport rate of a transporter by the substrate.Magnesium ions are, for instance, able to bind to various magnesium transporters shutting off their activity when the cytoplasmic magnesium concentration is sufficiently high. Flux control functions in addition to other regulatory processes, e.g., control of gene expression.
98
Founder principle
The possibility that a new, small, isolated population may diverge genetically because the founding individuals are a random sample from a large, main population.
99
frontal eye field (FEF)
A cortical area in the frontal lobe involved in the generation of saccadic eye movements.
100
Gain-of-function mutation
A mutation that endows a gene product with a new function.
101
Gene addition
The addition of a functional copy of a gene to the genome of an organism.
102
Gene chip
A small silicon wafer or other solid support containing a large number of oligonucleotide or cDNA hybridization probes arranged on its surface in a specific pattern, or microarray.
103
Gene flow
The spread of genes from one breeding population to another by migration, possibly leading to allele frequency changes.
104
gene fusion
The enzymatic attachment of one gene, or part of a gene, to another.
105
Gene pool
The sum total of all different alleles in the breeding members of a population at a given time.
106
Gene replacement
The incorporation of a transgene into a chromosome at its normal location by homologous recombination, thus replacing the copy of the gene originally present at the locus.
107
general adaptation syndrome
(GAS)—A syndrome conceptualized by Hans Selye that explains the body’s response to stressors, including physiological and psychological stress. The GAS is often cited as being a foundational component of periodization theory.
108
general strength
The strength of the whole muscular system.
109
generalized seizure
Pathologically large and synchronous neural activity that spreads to encompass the entire cerebral hemispheres. See also partial seizure.
110
generation time
The time required for a cell or population to double in number.
111
Genetic bottleneck
A descriptive term evoking the extreme selective pressure on small populations that results in loss of diversity, accumulation of selected mutations, or both. (Chapter 10)
112
Genetic equilibrium
Condition in a group of interbreeding organisms in which the allele frequencies remain constant over time.
113
genetic instability
Abnormally increased spontaneous mutation rate, such as occurs in cancer cells.
114
genetic screen
Procedure for discovery of genes affecting a specific phenotype by surveying large numbers of mutagenized individuals.
115
Genetic selection
The exposure of a cell or an organism to environmental conditions in which it can survive only if it carries a specific gene or genetic element.
116
genetic sex
The sex of an animal or person based solely on genotype.
117
Genetic shift
Diversity in viral genomes that arises as a result of re-assortment of genome segments or recombination between genomes. (Chapter 10)
118
genetic testing
Techniques for determining which genes are in a cell’s genome.
119
genome annotation
Process attempting to mark out all the genes (protein-coding and noncoding) in a genome and ascribing functions to each.
120
genomic imprinting
Phenomenon in which a gene is either expressed or not expressed in the offspring depending on which parent it is inherited from.
121
genus (plural: genera)
The first name of the scientific name (binomial); the taxon between family and species.
122
Germ-line (heritable) gene therapy
Treatment of an inherited disorder by adding functional (wild-type) copies of a gene to reproductive (germ-line) cells of an individual carrying defective copies of that gene (cf. Somatic-cell [nonheritable] gene therapy).
123
Gilbert syndrome
Benign hyperbilirubinemia caused by a promoter mutation in the gene for bilirubin- UDP-glucuronyl transferase.
124
Green chemistry
The design and implementation of chemical products and processes that reduce waste and minimize or eliminate the generation of hazardous substances.
125
group transfer potential
A measure of the ability of a compound to donate an activated group (such as a phosphate or acyl group); generally expressed as the standard free energy of hydrolysis.
126
H-2 locus, H-2 genes
The major histocompatibility complex of the mouse. Haplotypes are designated by a lower-case superscript, as in H-2b.
127
haploinsufficient
Describes the situation in which the presence of only one normal allele of a gene is not sufficient for normal function.
128
Hardy–Weinberg Principle
Mathematical relationship that allows the frequencies of genotypes in a population to be predicted from their constituent allele frequencies; a consequence of random mating.
129
Hedgehog protein
Secreted extracellular signal molecule that has many different roles controlling cell differentiation and gene expression in animal embryos and adult tissues. Excessive Hedgehog signaling can lead to cancer.
130
Hemizygote
An individual that carries one copy of a chromosome or gene, as in sex linkage or as a result of deletion.
131
Hemoglobinopathies
Genetic diseases caused by abnormalities of hemoglobin structure or synthesis.
132
hereditary hemochromatosis
A disease caused by defects in the HFE gene characterized by abnormally high retention of iron in the liver and other organs.
133
Heteroalleles
Mutations that are functionally allelic but structurally nonallelic; mutations at different sites in a gene.
134
heterochronic
Describes genes involved in developmental timing; mutation results in cells of a specific fate behaving as cells at a different stage of development.
135
Heterologous chromosome
A chromosome that contains a different set of genes than the chromosome to which it is compared.
136
Heterosis
Superiority of heterozygous genotypes in respect to one or more traits in comparison with corresponding homozygotes.
137
Heterozygosity
The proportion of heterozygous individuals in a population; used as a measure of genetic variability.
138
HFE
A gene involved with iron metabolism. The HFE protein regulates iron absorption.
139
HLA
The genetic designation for the human MHC. Individual loci are designated by upper-case letters, as in HLA-A, and alleles are designated by numbers, as in HLA-A*0201.
140
Homoalleles
Mutations that are both functionally and structurally allelic; mutations at the same site in the same gene.
141
Homozygote (adj, homozygous)
An individual in which the two copies of a gene are the same allele.
142
Hox complex
A gene complex consisting of a series of Hox genes
143
Hox genes
Genes coding for transcription regulators, each gene containing a homeodomain, and specifying bodyregion differences. Hox mutations typically cause homeotic transformations.
144
Human artificial chromosomes
Vectors for germline genetic engineering.
145
Human Genome Organization (HUGO)
An international group of scientists formed to coordinate the sequencing and mapping of the human genome.
146
Human Genome Project
A huge international effort to map and sequence the entire human genome.
147
Hybrid
An offspring of homozygous parents differing in one or more genes; more generally, an offspring of a cross between unrelated strains.
148
hydronium ion (H3O+)
Water molecule associated with an additional proton. The form generally taken by protons in aqueous solution.
149
Hyperploid
A genetic condition in which a chromosome or a segment of a chromosome is overrepresented in the genotype (cf. Hypoploid).
150
hypomorphic mutations
Applied to mutations that result in reduced gene function.
151
Hypoploid
A genetic condition in which a chromosome or segment of a chromosome is underrepresented in the genotype (cf. Hyperploid).
152
immature B cells
B cells that have rearranged a heavy- and a light-chain V-region gene and express surface IgM, but have not yet matured sufficiently to express surface IgD as well.
153
Inbred line
A strain produced by many generations of systematic inbreeding, for example, by repeated self-fertilization or by repeated full-sib mating.
154
Independent assortment
The random distribution of alleles to the gametes that occurs when genes are located in different chromosomes. The distribution of one pair of alleles is independent of other genes located in nonhomologous chromosomes.
155
Inducible gene
A gene that is expressed only in the presence of a specific metabolite, the inducer.
156
inhibitory neurotransmitter
Neurotransmitter that opens transmitter-gated Cl– or K+ channels in the postsynaptic membrane of a nerve or muscle cell and thus tends to inhibit the generation of an action potential.
157
Insertional activation
Th e mechanism of oncogenesis by nontransducing retroviruses; integration of a proviral promoter or enhancer in the vicinity of a proto-oncogene results in inappropriate transcription of that gene, making it a cellular oncogene ( c-oncogene) ( Chapter 6)
158
interferon stimulated genes (ISGs)
A category of gene induced by interferons, which include many that promote innate defense against pathogens, such as oligoadenylate synthetase, PKR, and the Mx, IFITs, and IFITM proteins.
159
Inversion
A rearrangement that reverses the order of a linear array of genes in a chromosome.
160
ionic solids
Solids whose composite units are ions; they generally have high melting points.
161
Isoalleles
Different forms of a gene that produce the same phenotype or very similar phenotypes.
162
Isochromosome
A chromosome with two identical arms and identical genes. The arms are mirror images of each other.
163
isograft
A tissue graft from a genetically identical source (i.e., from an identical twin).
164
knock-in mice
Mice in which a gene has been replaced by another gene engineered to function differently.
165
Knockout mutation
A mutation that completely abolishes a gene’s function.
166
leaky mutant
A mutant gene that gives rise to a product with a detectable level of biological activity.
167
Lethal mutagenesis
Th e elevation of mutation rates by exposure to a mutagen or an error-prone polymerase to the point at which the resulting population of genomes has lost fi tness and is incapable of propagating. (Chapter 10)
168
Li-Fraumeni syndrome
A cancer susceptibility syndrome caused by germline mutations of the TP53 gene.
169
Linkage map
A linear or circular diagram that shows the relative positions of genes on a chromosome as determined by genetic analysis.
170
Linkage phase
The arrangement of linked genetic markers in a heterozygote. The markers can be in the coupling (A B/a b) or in the repulsion (A b/a B) phase.
171
Locus ( pl, loci)
A fixed position on a chromosome that is occupied by a given gene or one of its alleles.
172
Locus heterogeneity
A situation where mutations in more than one gene can lead to the same disease.
173
Long-latency retrovirus
A retrovirus that causes cancer in a host many years aft er infection; the viral genome does not encode cellular oncogenes, nor does it cause cancer by perturbing the expression of cellular oncogenes. (Chapter 6)
174
Loss-of-function mutation
A mutation that impairs or abolishes gene expression or the function of a gene product.
175
lysogenic phase
The phase of the viral life cycle in which the virus genome integrates into the host cell genome but remains dormant, employing mechanisms to avoid destroying its cellular host.
176
magnetoencephalography (MEG)
A measurement of electrical activity generated by the brain and recorded by detecting associated magnetic field fluctuations with sensors surrounding the scalp.
177
Mantoux test
A screening test for tuberculosis in which a sterile-filtered glycerol extract of Mycobacterium tuberculosis bacilli (Tb) is injected intradermally and the result is read 48–72 hours later. Induration, firm swelling caused by infiltration into the skin of inflammatory cells, can indicate previous exposure to Tb, either prior vaccination or current infection of M. tuberculosis. Generally, induration at the site of injection greater than 10 mm in diameter indicates the need for additional tests to assess whether infection with Tb is present.
178
Maternal effect
Trait controlled by a gene of the mother but expressed in the progeny.
179
maternal-zygotic transition (MZT)
Event in animal development where the embryo’s own genome largely takes over control of development from maternally deposited macromolecules.
180
maximum strength
The highest force that the neuromuscular system can generate during a maximal voluntary contraction.
181
Mendelian population
A natural interbreeding unit of sexually reproducing plants or animals sharing a common gene pool.
182
Meristem
Groups of omni- or pluripotent cells from which other cells of a tissue are generated.
183
Meta-omics
Approaches for studying the genome, (metagenomics), transcriptome (metatranscriptomics), and proteome (metaproteomics) from whole microbial communities.
184
metal
A member of the class of elements that are generally good conductors of heat and electricity, malleable, ductile, and lustrous, and tend to lose electrons during chemical changes.
185
MHC class II transactivator (CIITA)
Protein that activates transcription of MHC class II genes. Defects in the CIITA gene are one cause of MHC class II deficiency.
186
microtubule flux
Movement of individual tubulin molecules in the microtubules of the spindle toward the poles by loss of tubulin at their minus ends. Helps to generate the poleward movement of sister chromatids after they separate in anaphase.
187
Midparent value
In quantitative genetics, the average of the phenotypes of two mates.
188
Modifier (modifying gene)
A gene that affects the expression of some other gene.
189
modulation
A term used to describe the actions of neurotransmitters that do not directly evoke postsynaptic potentials but modify the cellular response to excitatory postsynaptic potentials and inhibitory postsynaptic potentials generated by other synapses.
190
molecular medicine
The approach of using genetic information to develop medical treatments for disease.
191
molecular solids
Solids whose composite units are molecules; they generally have low melting points.
192
monoallelic gene expression
Expression of only one of the two copies of a gene in a diploid genome, occurring, for example, as a result of imprinting or X-chromosome inactivation.
193
Monohybrid
An offspring of two homozygous parents that differ from one another by the alleles present at only one gene locus.
194
Monoploid
Organism or cell having a single set of chromosomes or one genome (chromosome number n).
195
mons (monz)
Anatomic prominence or slight elevation above the general level of the surface; e.g., mons pubis.
196
Mosaic
An organism or part of an organism that is composed of cells of different genotypes.
197
Muckle–Wells syndrome
An inherited episodic autoinflammatory disease caused by mutations in the gene encoding NLRP3, a component of the inflammasome.
198
Multiple alleles
A condition in which a particular gene occurs in three or more allelic forms in a population of organisms.
199
Mutable genes
Genes with an unusually high mutation rate.
200
Mutation pressure
A constant mutation rate that adds mutant genes to a population; repeated occurrences of mutations in a population.
201
Mutational load
“Genetic garbage” that accumulates from generation to generation.
202
Narrow-sense heritability
In quantitative genetics, the proportion of the phenotypic variance that is due to the additive effects of alleles.
203
Natural product
A catchall term generally taken to mean a secondary metabolite found in bacteria, plants, and other living organisms.
204
Negative control mechanism
A mechanism in which the regulatory protein(s) is required to turn off gene expression.
205
Neutral mutation
A mutation that changes the nucleotide sequence of a gene but has no effect on the fitness of the organism.
206
Neutral theory
The theory that the evolution of traits with little or no effect on fitness is a random process involving mutation and genetic drift.
207
NGS platforms
Next-generation sequencing (NGS); modern techniques for high-throughput genome sequencing based on pyrosequencing, reversible dye terminator sequencing, or sequencing by ligation.
208
Null allele
A mutant form of a gene that either produces no product or produces a totally nonfunctional product.
209
Null mutation
A mutation that abolishes the expression of a gene. (See also Amorphic.)
210
Octoploid
Cell or organism with eight genomes or sets of chromosomes (chromosome number 8n).
211
P-nucleotides
Short palindromic nucleotide sequences formed between gene segments of the rearranged V-region gene generated by the asymmetric opening of the hairpin intermediate during RAG-mediated rearrangement.
212
Packaging
Incorporation of the viral genome during assembly of virus particles. (Chapter 13)
213
Parental
Pertaining to the founding strains used in a cross; having the characteristics of these strains. In a series of crosses, the parental generation is symbolized as P.
214
partial seizure
Pathologically large and synchronous neural activity that remains localized to a relatively small region of the brain. See also generalized seizure.
215
Partitioning
The process of molecules distributing themselves between two domains. In transdermal drug delivery, partitioning is generally used to describe molecular redistribution from one domain to another, such as from an aqueous domain to a lipid domain.
216
Pathway engineering
Construction of new catabolic pathways in (micro)organisms to remove contaminants from the environment through the application of sophisticated molecular genetic, microbiological and protein engineering tools.
217
phage conversion
Genetic change in the host cell resulting from infection by a bacteriophage.
218
Phenocopy
An organism whose phenotype (but not genotype) has been changed by the environment to resemble the phenotype of a different (mutant) organism.
219
photosynthetic electron-transfer reactions
Light-driven reactions in photosynthesis in which electrons move along an electron-transport chain in a membrane, generating ATP and NADPH.
220
Pleiotropy (adj, Pleiotropic)
Condition in which a single gene influences more than one trait.
221
Polyadenylation signal
A conserved sequence (AAUAAA) at the 3′ end of eukaryotic genes.
222
Polycomb group
Set of proteins critical for cell memory for some genes. They form complexes as part of the chromatin of the Hox complex, where they maintain a repressed state in cells where Hox genes have not been activated.
223
Polygene (adj, polygenic)
One of many genes involved in quantitative inheritance.
224
Polygenic diseases
Diseases caused by interactions between multiple genes and the environment.
225
Polymorphic gene
A gene that has many allelic forms in outbred populations. (Chapter 4)
226
Polyploid
An organism with more than two sets of chromosomes (2n diploid) or genomes—for example, triploid (3n), tetraploid (4n), pentaploid (5n), hexaploid (6n), heptaploid (7n), octoploid (8n).
227
Population genetics
The branch of genetics that deals with frequencies of alleles and genotypes in breeding populations.
228
Portal
A specialized structure for entry and/or exit of a viral genome into a preassembled protein shell. (Chapter 4)
229
Positive control mechanism
A mechanism in which the regulatory protein(s) is required to turn on gene expression.
230
positive-inside rule
General observation that most plasma membrane proteins are oriented so that most of their positively charged residues (Lys and Arg) are on the cytosolic face.
231
Preimplantation genetic diagnosis
Diagnosis of genetic diseases in the early embryo after in vitro fertilization.
232
primary cell line
Human tissue cells that grow for only a few generations in vitro.
233
Primary nitrate response
Increased expression of NO3- related genes on NO3- perception.
234
pro-B cells
A stage in B-lymphocyte development in which cells have displayed B-cell surface marker proteins but have not yet completed heavychain gene rearrangement.
235
Procapsid
A closed, protein-only structure into which viral genomes are inserted; precursor to a capsid or nucleocapsid. (Chapter 13)
236
protein synthesis
The assembly of protein molecules in the cell’s cytoplasm according to genetic instructions.
237
protomer
A general term describing any repeated unit of one or more stably associated protein subunits in a larger protein structure. If a protomer has multiple subunits, the subunits may be identical or different.
238
protoplast fusion
A method of joining two cells by first removing their cell walls; used in genetic engineering.
239
Pseudoautosomal gene
A gene located on both the X and Y chromosomes.
240
Quantitative inheritance
Inheritance of measurable traits (height, weight, color intensity) that depend on the cumulative action of many genes, each producing a small effect on the phenotype.
241
Quantitative trait loci (QTL)
Two or more genes that affect a single quantitative trait.
242
Rac
Member of the Rho family of monomeric GTPases that regulate the actin and microtubule cytoskeletons, cell-cycle progression, gene transcription, and membrane transport.
243
Radiation hybrid mapping
The use of human–rodent hybrid cells containing fragments of human chromosomes (produced by irradiation) fused to rodent chromosomes to determine the linkage relationships of human genes.
244
RAG-1, RAG-2
Proteins encoded by the recombination-activating genes RAG-1 and RAG-2, which form a dimer that initiates V(D)J recombination.
245
Random genetic drift
Changes in allele frequency in small breeding populations due to chance fluctuations.
246
Rb gene
The gene that is defective in both copies in individuals with retinoblastoma; its protein product plays a central role in cell-cycle control.
247
rearrangement by inversion
In V(D)J recombination, the rearrangement of gene segments having RSS elements in an opposing orientation, leading to retention.
248
Reassortant
Viral genomes that have exchanged segments after coinfection of cells with viruses with segmented genomes. (Chapter 3)
249
Recessive lethal mutation
A mutant form of a gene that results in the death of an organism that is homozygous for it.
250
redox potential
The affinity of a redox pair for electrons, generally measured as the voltage difference between an equimolar mixture of the pair and a standard reference. NADH/ NAD+ has a low redox potential and O2/H2 has a high redox potential (high affinity for electrons).
251
reducing equivalent
A general term for an electron or an electron equivalent in the form of a hydrogen atom or a hydride ion.
252
regulon
A group of genes or operons that are coordinately regulated even though some, or all, may be spatially distant in the chromosome or genome.
253
Relative fitness
The survival and reproductive ability of a genotype in a population in comparison to the survival and reproductive ability of another genotype in that population.
254
Repressor gene
A gene that encodes a repressor.
255
Reproductive cloning
A process in which the nucleus of an egg cell is replaced with the nucleus of a cell from a developed organism with the purpose of producing a new organism genetically identical to the donor.
256
resveratrol
A nutraceutical that can be synthesized or derived from a natural origin, such as Japanese knotweed, grape skins, and red wines or from genetically modified yeast. It has a wide range of possible health benefits, including antiaging, cardioprotective, antidiabetic, neuroprotective, and cancer prevention effects.
257
Retroid virus
Viruses that replicate their genomes via reverse transcription. (Chapter 7)
258
Reversion (reverse mutation)
Restitution of a mutant gene to the wild-type condition, or at least to a form that gives the wild phenotype; more generally, the appearance of a trait expressed by a remote ancestor.
259
Revert
To change to the parental, or wild-type, genotype or phenotype. (Chapter 3)
260
Rho
Member of the Rho family of monomeric GTPases that regulate the actin and microtubule cytoskeletons, cell-cycle progression, gene transcription, and membrane transport.
261
ribotyping
Classification or identification of bacteria based on rRNA genes.
262
SAP (SLAM-associated protein)
An intracellular adaptor protein involved in signaling by SLAM (signaling lymphocyte activation molecule). Inactivating mutations in this gene cause X-linked lymphoproliferative (XLP) syndrome.
263
Satellite virus
A satellite with a genome that encodes one or two proteins. (Chapter 1)
264
Secondary ion mass spectrometry (SIMS)
A primary ion beam ejects secondary ions from a surface generating usually element mass spectra and element images of surfaces (dynamic SIMS) or enabling surface atomic monolayer and surface molecular analysis (static SIMS). NanoSIMS refers to a dynamic SIMS technique using an energetic primary ion beam of O- or Cs+ ions with spatial resolution down to 50 nm which allows, e.g., metabolism studies in single cells.
265
segmentation clock
The gene-expression oscillator controlling regular segmentation during vertebrate embryonic development.
266
Selectable marker
A gene that permits the selective survival of genetically modified cells.
267
Selection coefficient
A number that measures the fitness of a genotype relative to a standard.
268
Selector gene
A gene that influences the development of specific body segments in Drosophila; a homeotic gene.
269
sequence polymorphisms
Any alterations in genomic sequence (base-pair changes, insertions, deletions, rearrangements) that help distinguish subsets of individuals in a population or distinguish one species from another.
270
sequential induction
Development process that generates a progressively more complicated pattern. A series of local inductions whereby one of two cell types present in a developing tissue can produce a signal to induce neighboring cells to specialize in a third way; the third cell type can then signal back to the other two cell types nearby to generate a fourth and a fifth cell type, and so on.
271
Sex linkage
Association or linkage of a hereditary trait with sex; the gene is in a sex chromosome, usually the X; often used synonymously with X-linkage.
272
shotgun sequencing
A technique for determining the nucleotide sequence in an organism’s genome.
273
shunting inhibition
A form of synaptic inhibition in which the main effect is to reduce membrane resistance, thereby shunting depolarizing current generated at excitatory synapses.
274
Signal
Biochemical event that is generated by the plant on perception of a stimulus.
275
signaling center
Cluster of specialized cells in developing tissues that serves as a source of developmental signals—for example, the generation of a morphogen gradient.
276
silent mutation
A mutation in a gene that causes no detectable change in the biological characteristics of the gene product.
277
small pre-B cell
Stage in B-cell development immediately after the large pre-B cell in which cell proliferation ceases and light-chain gene rearrangement commences.
278
somatic gene therapy
The introduction of functional genes into somatic cells to treat disease.
279
somatic motor system
The skeletal muscles and the parts of the nervous system that control them; the system that generates behavior.
280
Somatic-cell (nonheritable) gene therapy
Treatment of an inherited disorder by adding functional (wild-type) copies of a gene to nongerm-line cells of an individual carrying defective copies of that gene (cf. Germ-line [heritable] gene therapy).
281
spatial summation
The combining of excitatory postsynaptic potentials generated at more than one synapse on the same cell. See also temporal summation.
282
specific language impairment
A delay in the mastery of language in the absence of hearing loss or more general developmental delays.
283
spontaneous generation
The idea that life could arise spontaneously from nonliving matter.
284
Sporophyte
The diploid generation in the life cycle of a plant that produces haploid spores by meiosis.
285
STING (stimulator of interferon genes)
A dimeric protein complex in the cytoplasm anchored to the ER membrane that functions in intracellular sensing for infection. It is activated by specific cyclic di-nucleotides to activate TBK1, which phosphorylates IRF3 to induce transcription of type I interferon genes.
286
strain
Genetically different cells within a clone. See serovar.
287
strength
The maximal force or torque a muscle or muscle group can generate.
288
Sulfone
A compound of the general structure RSO2R’.
289
Sulfoxide
A compound of the general structure RSOR.
290
switch regions
Genomic regions, several kilobases in length each, located between the JH region and the heavy-chain Cμ genes, or in equivalent positions upstream of other C-region genes (except Cδ), containing hundreds of G-rich repeated sequences that function in class switch recombination.
291
syngeneic graft
A graft between two genetically identical individuals. It is accepted as self.
292
T plasmid
An Agrobacterium plasmid carrying genes for tumor induction in plants.
293
T10, T22
Murine MHC class Ib genes expressed by activated lymphocytes and recognized by a subset of γ:δ T cells.
294
tag
An extra segment of protein that is fused via modification of its gene to a protein of interest, usually for purposes of purification.
295
Tandem repeats
Head-to-tail repeat sequences in eukaryotic genomes.
296
taper
An unloading phase of training prior to a major competition that generally lasts between 8 and 14 days.
297
TBK1 (TANK-binding kinase)
A serine-threonine kinase activated during signaling by TLR-3 and MAVS and serving to phosphorylate and activate IRF3 for induction of type I interferon gene expression.
298
temporal summation
The combining of excitatory postsynaptic potentials generated in rapid succession at the same synapse. See also spatial summation.
299
Testcross
Backcross to the recessive parental type, or a cross between genetically unknown individuals with a fully recessive tester to determine whether an individual in question is heterozygous or homozygous for a certain allele. It is also used as a test for linkage.
300
Tetraploid
An organism whose cells contain four haploid (4n) sets of chromosomes or genomes.
301
Therapeutic cloning
A process in which the nucleus of egg cell is replaced with the nucleus of a donor cell (possibly differentiated) to produce a population of stem cells that have the same genotype as the donor cell. These stem cells could then be used to replace lost cells in the donor organism.
302
Threshold trait
A trait that is manifested discontinuously but that is a function of underlying continuous genetic and environmental variation.
303
torque
The rotational force a muscle or muscle group can generate.
304
TP53
A tumor suppressor gene encoding the p53 protein; mutated in at least half of all spontaneous cancers.
305
TRAF3
An E3 ligase that produces a K63 polyubiquitin signaling scaffold in TLR-3 signaling to induce type I interferon gene expression.
306
Transducing oncogenic retroviruses
Retroviruses that include oncogenic, cell-derived sequences in their genomes and carry these sequences to each newly infected cell; such viruses are highly oncogenic. (Chapter 6)
307
Transgressive variation
The appearance in the F2 (or later) generation of individuals showing more extreme development of a trait than either of the original parents. trans heterozygote. A heterozygote that contains two mutations arranged in the trans configuration—for example, a b+ / a+ b.
308
Trihybrid
The offspring from homozygous parents differing in three pairs of genes.
309
Trinucleotide repeats
Tandem repeats of three nucleotides that are present in many human genes. In several cases, these trinucleotide repeats have undergone expansions in copy number that have resulted in inherited diseases.
310
Trithorax group
Set of proteins critical for cell memory that maintains the transcription of Hox genes in cells where transcription has already been switched on.
311
Turner syndrome
The phenotype due to the XO genotype in humans.
312
unfolded protein response
Cellular response triggered by an accumulation of misfolded proteins in the endoplasmic reticulum. Involves expansion of the ER and increased transcription of genes that code for endoplasmic reticulum chaperones and degradative enzymes.
313
Universality (of the genetic code)
The codons have the same meaning, with minor exceptions, in virtually all species.
314
unmethylated CpG dinucleotides
While mammalian genomes have heavily methylated the cytosine within CpG sequences, unmethylated CpG is more typically characteristic of bacterial genomes, and is recognized by TLR‑9 when encountered in the endosomal compartment.
315
v-Oncogene
An oncogene that is encoded in a viral genome. (Chapter 6)
316
vertical gene transfer
Transfer of genes from an organism or cell to its offspring.
317
viral integrase inhibitors
Drugs that inhibit the action of the HIV integrase, so that the virus cannot integrate into the host-cell genome.
318
Viral retroposons
The remnants of retroviral genomes.
319
viral species
A group of viruses sharing the same genetic information and ecological niche.
320
virulence gene
Gene that contributes to an organism’s ability to cause disease.
321
Whole-genome shotgun sequencing
An approach to sequencing genomes that involves randomly cleaving the entire genome into small fragments, sequencing the ends of these fragments, and using supercomputers to assemble the complete sequence by aligning overlapping sequences.
322
Wild-type allele
The normal form of a gene.
323
Wnt protein
Member of a family of secreted signal proteins that have many different roles in controlling cell differentiation, proliferation, and gene expression in animal embryos and adult tissues.
324
X-linked agammaglobulinemia (XLA)
A genetic disorder in which B-cell development is arrested at the pre-B-cell stage and no mature B cells or antibodies are formed. The disease is due to a defect in the gene encoding the protein tyrosine kinase Btk, which is encoded on the X chromosome.
