26. Developmental Genetics Flashcards
the area of genetics concerned with the roles genes play in orchestrating the changes that occur during development.
Developmental Genetics
the spatial arrangement of different regions of the body. At the cellular level, it is due to the cells’ arrangement and specialization.
Body Pattern
signals in the form of chemical substances and other environmental cues that enable a cell to deduce its position relative to other cells.
Positional Information
a molecule that conveys positional information and promotes developmental changes.
Morphogen
(1) the effects of an inducer in increasing the transcription of a gene; (2) the process by which a cell or group of cells governs the developmental fate of neighboring cells.
Induction
the binding of the surfaces of cells to each other or of the surface of a cell to the extracellular matrix.
Cell Adhesion
a molecule (e.g., protein or carbohydrate) that acts as a surface receptor and plays a role in cell adhesion.
Cell Adhesion Molecule (CAMs)
a gene that functions in governing the developmental fate of a particular region of the body.
Homeotic Gene
an animal that has an anteroposterior axis with left-right symmetry.
Bilaterian
the process in which a cell or region of an organism adopts a particular fate that will be realized later in development.
Determination
transient subdivisions that occur in the Drosophila embryo prior to the formation of segments.
Parasegments
morphologically discrete body subdivisions that develop in the embryo of a species such as Drosophila.
Segments
an early stage of animal and plant development resulting in an embryo with organized tissue layers and a body plan.
Embryogenesis
in animals, the axis that runs from the head (anterior) to the tail or base of the spine or abdomen (posterior).
Anteroposterior Axis
in animals, the axis from the upper side of the back (e.g., the spine in humans) to the opposite side (e.g., the stomach in humans).
Dorsoventral Axis
in bilaterians, the axis that determines left-right symmetry.
Left-Right Axis
in animals, an axis for designating positions on limbs in which the part of the limb attached to the trunk is proximal, whereas the end of the limb is distal.
Proximodistal Axis
in animals, a gene whose encoded product is involved in the development of body segments.
Segmentation Gene
a gene that is expressed after fertilization.
Zygotic Gene
the morphological features that a cell or group of cells will ultimately adopt.
Cell Fate
an adjective that was originally coined to describe mutants in which one body part is replaced by another.
Homeotic
a mutation that changes a gene product so that it gains a new or abnormal function.
Gain-of-Function Mutation
a change in a genetic sequence that creates a loss-of-function allele.
Loss-of-Function Mutation
a 180-bp consensus sequence found in homeotic genes.
Homeobox
the protein domain encoded by the homeobox and promotes the binding of the protein to the major groove of DNA.
Homeodomain
an illustration of the cell division patterns and the fates of any cell’s descendants.
Cell Lineage Diagram
a series of cells that are derived from a particular cell by cell division.
Cell Lineage
a mutation that alters the timing of expression of a gene and thereby alters the outcomes of cell fates of particular cell lineages.
Heterochronic Mutation
describes attributes that are the result of homology. In the case of genes, this term describes two genes that are derived from the same ancestral gene.
Homologous
homologous genes in different species that were derived from the same ancestral gene.
Orthologs
a group of several homeotic genes located in a particular chromosomal region in vertebrates.
Hox Complex
an experimental strategy in which researchers first identify the wild-type gene using cloning methods. The next step is to make a mutant version of the wild-type gene, introduce it into an organism, and see how the mutant gene affects the phenotype of the organism.
Reverse Genetics
in the case of diploid species, the condition in which both copies of a gene have been altered to an inactive form.
Gene Knockout
the traditional method of genetics research, in which mutant alleles are first identified by their effect on phenotype and then identified at the molecular level.
Forward Genetics
a cell that is destined to differentiate into a specific cell type.
Determined Cell
a cell that has become a specialized type of cell within a multicellular organism.
Differentiated Cell
a domain found in transcription factors that enables them to dimerize and bind to DNA.
Basic Helix-Loop-Helix (bHLH) Domain
a type of transcription factor involved in muscle-cell differentiation.
Myogenic bHLH Protein
