Operator
In bacterial and phage DNA, a sequence of nucleotides near the start of an operon to which an active repressor can attach. The binding of the repressor prevents RNA polymerase from attaching to the promoter and transcribing the genes of the operon.
Operon
A unit of genetic function found in bacteria and phages, consisting of a promoter, an operator, and a coordinately regulated cluster of genes whose products function in a common pathway.
Repressor
a protein that inhibits gene transcription. In prokaryotes, repressors bind to the DNA in or near the promoter. In eukaryotes, repressors may bind to control elements within enhancers, to activators, or to other proteins in a way that blocks activators fr
Regulatory Gene
a gene that codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes.
Corepressor
a small molecule that binds to a bacterial repressor protein and changes the protein's shape, allowing it to bind to the operator and switch an operon off.
Inducer
A specific small molecule that binds to a bacterial repressor protein and changes the repressor's shape so that it cannot bind to an operator, thus switching an operon on.
Cyclic AMP (cAMP)
Cyclic adenosine monophosphate, a ring-shaped molecule made from ATP that is a common intracellular signing molecule (second messenger) in eukaryotic cells. It is also a regulator of some bacterial operons.
Activator
a protein that binds to DNA and stimulates gene transcription. In prokaryotes, activators bind in or near the promoter; in eukaryotes, activators generally bind to control elements in enhancers.
Differential gene expression-
The expression of different sets of genes by cells with the same genome.
Histone modifications
? Changed by covalent modification, particularly in the tails
? Enzymes change and mark histones by acetylation, methylation of the histone side-chain and N-terminal tails. Reversible.
DNA methylation
The addition of methyl groups (�CH3) to bases of DNA after DNA synthesis; may serve as a long-term control of gene expression.
Epigenetic inheritance
Inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence.
Control elements
Segments of noncoding DNA that help regulate transcription of a gene by binding proteins called transcription factors.
Enhancers
A DNA sequence that recognizes certain transcription factors that can stimulate transcription of nearby genes.
Alternative RNA splicing
a type of eukaryotic gene regulation at the RNA-processing level in which different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exons and which as introns
Proteasomes
a giant protein complex that recognizes and destroys proteins tagged for elimination by the small protein ubiquitin
Differentiation
process in which cells become specialized in structure and function
Morphogenesis
physical processes that give an organism its shape
Cytoplasmic determinants-
maternal substances in the egg that influence the course of early development
Induction
the process in which one group of embryonic cells influences the development of another, usually by causing changes in gene expression
Determination
the events that lead to the observable differentiation of a cell
Pattern formation
the development of a multicellular organism's spatial organization, the arrangement of organs and tissues in the characteristic places in three-dimensional space. (what is head and what is tail. Setting up the axis)
Homeotic genes
any of the master regulatory genes that control placement and spatial organization of body parts in animals, plants, and fungi by controlling the developmental fate of groups of cells. (control pattern)
Embryonic lethals
Mutations with phenotypes leading to death at the embryo or larval stage.
Maternal effect gene
a gene that, when mutant in the mother, results in a mutant phenotype in the offspring, regardless of the offsprings own genotype
Egg-polarity genes
Another name for maternal effect genes, these genes control the orientation (polarity) of the egg
Bicoid
a morphogen determining head structures. Only has maternal genome
Morphogens
gradients of substances establish an embryo's axes and other features of form
Oncogense
are cancer-causing genes. They arise from mutations.
Proto-oncogenes
normal versions of the cellular genes code for proeins that stimulate normal cell growth and division