|
|
| Initiation codon |
|
The mRNA sequence AUG, coding for methionine, which initiates translation of mRNA.
|
|
|
|
|
|
| Inositol lipid |
|
A membrane-anchored phospholipid that transduces hormonal signals by stimulating the release of any of several chemical messengers. (See Phospholipid.)
|
|
|
|
|
|
| Insertion mutations |
|
Changes in the base sequence of a DNA molecule resulting from the random integration of DNA from another source. See DNA, Mutation.
|
|
|
|
|
|
| Insulin |
|
A peptide hormone secreted by the islets of Langerhans of the pancreas that regulates the level of sugar in the blood.
|
|
|
|
|
|
| Interferon |
|
A family of small proteins that stimulate viral resistance in cells.
|
|
|
|
|
|
| Intergenic regions |
|
DNA sequences located between genes that comprise a large percentage of the human genome with no known function.
|
|
|
|
|
|
| Introgression |
|
Backcrossing of hybrids of two plant populations to introduce new genes into a wild population.
|
|
|
|
|
|
| Intron |
|
A noncoding DNA sequence within a gene that is initially transcribed into messenger RNA but is later snipped out. See Coding, DNA, Messenger RNA, Transcription.
|
|
|
|
|
|
| Invasiveness |
|
Ability of a plant to spread beyond its introduction site and become established in new locations where it may provide a deliterious effect on organisms already existing there.
|
|
|
|
|
|
|
|
|
| Isotope |
|
One of two or more forms of an element that have the same number of protons (atomic number) but differing numbers of neutrons (mass numbers). Radioactive isotopes are commonly used to make DNA probes and metabolic tracers.
|
|
|
|
|
|
| Joining (J) segment |
|
A small DNA segment that links genes to yield a functional gene encoding an immunogobulin.
|
|
|
|
|
|
| Kanamycin |
|
An antibiotic of the aminoglycoside family that poisons translation by binding to the ribosomes.
|
|
|
|
|
|
| kanr |
|
Kanamycin resistance gene. (See Selectable marker.)
|
|
|
|
|
|
| Karyotype |
|
All of the chromosomes in a cell or an individual organism, visible through a microsope during cell division.
|
|
|
|
|
|
| Lag phase |
|
The initial growth phase, during which cell number remains relatively constant prior to rapid growth. See growth phase.
|
|
|
|
|
|
| Lawn |
|
A uniform and uninterrupted laver of bacterial growth, in which individual colonies cannot be observed.
|
|
|
|
|
|
| Legume |
|
A member of the pea family that possesses root nodules containing nitrogen-fixing bacteria.
|
|
|
|
|
|
| Library |
|
A collection of cells, usually bacteria or yeast, that have been transformed with recombinant vectors carrying DNA inserts from a single species. (See cDNA library, Expression library, Genomic library.)
|
|
|
|
|
|
| Ligase (DNA ligase). |
|
An enzyme that catalyzes a condensation reaction that links two DNA molecules via the formation of a phosphodiester bond between the 3' hydroxyl and 5' phosphate of adjacent nucleotides.
|
|
|
|
|
|
| Ligate |
|
The process of joining two or more DNA fragments.
|
|
|
|
|
|
| Lineage |
|
A chart that traces the flow of genetic information from generation to generation.
|
|
|
|
|
|
| Linkage |
|
The frequency of coinheritance of a pair of genes and/or genetic markers, which provides a measure of their physical proximity to one another on a chromosome.
|
|
|
|
|
|
| Linkage map |
|
See Genetic linkage map.
|
|
|
|
|
|
| Linked genes/markers |
|
Genes and/or markers that are so closely associated on the chromosome that they are coinherited in 80% or more of cases.
|
|
|
|
|
|
| Linker. |
|
A short, double-stranded oligonucleotide containing a restriction endonuclease recognition site, which is ligated to the ends of a DNA fragment.
|
|
|
|
|
|
| Liposomes |
|
Membrane-bound vesicles constructed in the laboratory to transport biological molecules.
|
|
|
|
|
|
| Locus (plural = loci). |
|
A specific location or site on a chromosome.
|
|
|
|
|
|
| Log phase |
|
See Logarithmic phase.
|
|
|
|
|
|
| Logarithmic phase (log or |
|
The steepest slope of the growth curve--the phase of vigorous growth during which cell number doubles every 20-30 minutes. (See Growth phase.)
|
|
|
|
|
|
| Lysis |
|
The destruction of the cell membrane.
|
|
|
|
|
|
| Lysogen |
|
A bacterial cell whose chromosome contains in- tegrated viral DNA.
|
|
|
|
|
|
| Lysogenic |
|
A type or phase of the virus life cycle during which the virus integrates into the host chromosome of the infected cell, often remaining essentially dormant for some period of time. See Lysogen.
|
|
|
|
|
|
| Lytic |
|
A phase of the virus life cycle during which the vi- rus replicates within the host cell, releasing a new generation of viruses when the infected cell lyses.
|
|
|
|
|
|
| Malignant |
|
Having the properties of cancerous growth.
|
|
|
|
|
|
| Mapping |
|
Determining the physical location of a gene or genetic marker on a chromosome. (See Continuous map, Genetic map, Physical map.)
|
|
|
|
|
|
| Megabase cloning |
|
The cloning of very large DNA fragments. (See Cloning.)
|
|
|
|
|
|
| Meiosis |
|
The reduction division process by which haploid gametes and spores are formed, consisting of a single duplication of the genetic material followed by two mitotic divisions.
|
|
|
|
|
|
| Messenger RNA (mRNA). |
|
The class of RNA molecules that copies the genetic information from DNA, in the nucleus, and carries it to ribosomes, in the cytoplasm, where it is translated into protein. (See RNA.)
|
|
|
|
|
|
| Metabolism |
|
The biochemical processes that sustain a living cell or organism.
|
|
|
|
|
|
| Metallothionein |
|
A protective protein that binds heavy metals, such as cadmium and lead.
|
|
|
|
|
|
|
|
|
| Microbial mats (biofilms) |
|
Layered groups or communities of microbial populations.
|
|
|
|
|
|
| Microinjection |
|
A means to introduce a solution of DNA, protein, or other soluble material into a cell using a fine microcapillary pipet.
|
|
|
|
|
|
| Mitosis |
|
The replication of a cell to form two daughter cells with identical sets of chromosomes.
|
|
|
|
|
|
| Molecular biology |
|
The study of the biochemical and mo- lecular interactions within living cells.
|
|
|
|
|
|
| Molecular cloning |
|
The biological amplification of a specific DNA sequence through mitotic division of a host cell into which it has been transformed or transfected. (See Cloning.)
|
|
|
|
|
|
| Molecular genetics |
|
The study of the flow and regulation of genetic information between DNA, RNA, and protein molecules.
|
|
|
|
|
|
| Monoclonal antibodies |
|
Immunoglobulin molecules of single- epitope specificity that are secreted by a clone of B cells.
|
|
|
|
|
|
| Monoculture |
|
The agricultural practice of cultivating crops consisting of genetically similar organisms.
|
|
|
|
