Glossary of common terms in genetic engineering.
Ablation | Elimination of undesired tissues by causing cell death |
Agrobacterium | A bacterium that transfers DNA into plant cells; used for genetic engineering of plants |
Antisense-suppression | A method for inhibiting a gene’s expression by introducing a reverse copy of the gene |
cDNA | Synthesized from a mRNA in vitro; corresponds to the expressed form of a gene (without introns) |
Constitutive gene expression | A gene expressed in virtually all cells at all times |
Cytotoxin | A protein that, when expressed in specific cells, causes cell death |
Dominant negative mutation (DNWI) | A mutation in a gene that results in a nonfunctional protein that also inhibits the activity of the wild-type protein |
Homeotic gene | A gene that when rendered nonfunctional causes an organ to develop in the wrong place (e.g., petals develop where stamens normally form) |
Inflorescence | Structure on which flowers occur (e.g., a catkin) |
Intron | DNA sequence that interrupts the protein-coding sequence of a gene; present in nearly all genes in higher organisms |
Gene expression | The process by which genetic information is read and turned into mRNA and then protein |
Gene silencing | Inhibition of a gene’s expression |
Genome | All the DNA sequence contained in an organism |
Meristem | Groups of undifferentiated cells from which organ-forming cells arise (e.g., within apical buds and cambium) |
Messenger RNA(mRNA) | Complimentary to one strand of DNA, after introns are removed; serves as the template for synthesizing a protein |
Promoter | A regulatory DNA sequence located in front of the coding portion of a gene; it controls when, where, and to what level a gene is expressed |
Sense-suppression | A method for inhibiting a gene’s expression by introducing a duplicate or slightly mutated version of the gene |
Sequence conservation | The sequence of a particular gene is similar across diverse species; sequence of a gene isolated in one species can be used to easily isolate the corresponding gene (homolog) from a different species |
Transcription | The synthesis of RNA from DNA |
Transcription factor | A protein that regulates the expression of genes by interacting with their promoters |
Transgene | A gene introduced into the chromo-some of a plant via a nonsexual process |
Translation | The synthesis of a protein from a mRNA template |
Wild-type gene | A “normal” gene that encodes a fully functional protein |