Development- Exam IV Flashcards
What are the 4 important concepts of embryonic development?
- Universal mechanisms of animal development
- Proteins can be substituted across species
- Inductive signaling
- Regional determination
Once the cell mass has start to form a particular tissue, and is committed to forming that tissue:
Regional determination
What are the classes of signaling proteins that are used over and over again as inducers in animal development? (5)
- Receptor tyrosine kinase
- TGF-beta superfamily
- WNT
- Hedgehog
- Notch
EGF, FGF, and Ephrins are all ligand families involved in what signaling pathway?
Receptor Tyrosine Kinase
TGFB, BMP, and Nodal are all ligand families involved in what signaling pathway?
TGFB- superfamily
The delta ligand family is involved in what signaling pathway?
Notch
Typically, RTK pathways bind to their:
Own family of receptors
What is the largest family that includes the bone morphogenic proteins?
TGF-B superfamily
RTK, TGFB superfamily, WNT, Hedgehog, and Notch are all pathways found in all animals and are all important in different:
Developmental paradigms
In the process of tooth development: it starts off with an _______ and _____ .
Ectoderm and mesenchyme layers
In tooth development: The ectoderm and mesenchyme layers eventually form:
Dental placode
In tooth morphogenesis, from one stage to the next, different ____ are activated:
Signaling pathways
In tooth development: the signaling pathways that are activated in the _______ trigger signaling pathways in the _____.
Ectoderm; mesenchyme
The concept of proteins being substituted across different species has 2 important principles that include:
- Multicellular organisms are enriched in proteins mediating cell interactions and gene regulation
- Regulatory DNA defines the development program
Every nucleated cell in our body has a record of the:
Development program
Due to every cell in our body having a record of the developmental program- this means that virtually any cell in our body could:
Give rise to an entire organism under the right conditions
Inductive signaling includes (4)
- Cell-cell signaling
- Cell signaling cascades
- Signaling over great distances
- Starting points
_____ & _____ signaling function in inductive signaling:
Autocrine and paracrine
Signals that act over great distances:
Morphogenes
Morphogenes _____ out from the cell that they started at and then ____ the cells that they come into contact with.
Diffuse; alter
In terms of inductive signaling there is always a:
Starting point
The starting point in inductive signaling can be either:
Single cell or cluster of cells producing an inductive signal
With inductive signaling, what cells will see the highest concentration of morphogen?
The cells closest to the source
Cells a great distance from the source releasing the morphogen will:
Receive a lower concentration of the morphogen
The resulting phenotype of differentiated state that the cell achieves is a result of:
The numerous inductive signals acting on it
As the inductive signal is produces, the cells immediately surrounding that source begin to develop in:
A new developmental pathway
This images shows an example of:
Sequential signaling
Sequential singaling can result in a build up of:
Very complex multicellular layers
Sequential induction can be described as what type of process?
Back and forth
When cells are committed to forming a certain structure or layer, this is considered:
Regional determination
If you have a group of differentiated cells that are committed to creating thoracic vertebra and you take these cells out and put them in the cervical region of a different organism, what would be the end result?
Thoracic vertebra in the cervical region
What are the 4 essential processes by which an embryo is constructed?
- Cell proliferation
- Cell specialization
- Cell interaction
- Cell movement
What essential process is this in embryo construction? And what is occurring?
Cell proliferation- cells are increasing in number
What essential process is this in embryo construction? And what is occurring?
Cell specialization- where one cell changes into something more specific
Through inductive signaling processes and their reciprocal induction processes one cell changes into something that is going to be a different tissue or cell type. This process is called:
Cell specialization and differentiation
What essential process is this in embryo construction? And what is occurring?
Cell interaction: as cells divide they have different interactions with eachother dependent on cell type
What essential process is this in embryo construction? And what is occurring?
Cell movement- as gastrulation takes places these cells begin to migrate to ultimately determine location in final structures
The developmental processes in embryo formation are being repeated over and over again through out the animal kingdom however what factor varies?
Speed at which it takes place
Dependent upon the species, the ___ & ____ of the offspring varies.
Size and number
Cells produced by cleavage get organized into layers and groups of cell masses through what is known as:
Gastrulation
Process by which genetic material is used to drive cellular functions
Gene expression
Process by which a cell or group of cells secrete factors that influence neighboring cells:
Inductive signaling
Once embryonic tissues reach a certain stage of development, they are committed to form their adult structures independent of:
Their environment
Process by which the bilaminar embryonic disc becomes the 3 key germ cell layers needed to generate all the tissues/organs in the body:
Gastrulation
During the process of gastrulation, the bilaminar embryonic disc becomes:
3 key germ cell layers
Embryonic cell populations that are formed between the developing neural tube and the epidermis. These cells migrate at very restricted pathways to give rise to many of the craniofacial structures:
Neural crest cells
Describe the path that neural crest cells migrate along:
Very restricted
Neural crest cells are embryonic cell populations formed between:
Developing neural tube and epidermis
Neural crest cells give rise to many of the:
Craniofacial structures
A specialized set of genes that contain a homeodomain motif that carry a permanent record of positional information used to specify patterning:
Hox genes
the homeodomain motif:
Homeobox
Genetic programs that are precisely coordinated to create complex tissues and organs relies on:
Patterning
What are the 3 dimensions that patterning must occur in:
- Anterior-posterior
- Dorsal-ventral
- Proximal-distal
In the process of patterning: anterior-posterior dimension refers to:
Top to bottom
In the process of patterning: dorsal ventral dimension refers to:
Left-right
In the process of patterning: proximal-distal refers to:
Front-back
Since we are all 3D organisms, patterning must occur:
3-dimensionally
The stage of embryonic development where cells begin to form specific and specialized structures:
Differentiation
The stage of embryonic development where cell divisions form more cells with identical functions as the parental cell:
Growth
In cell growth (during embryonic development) the cell divisions that form more cells must have identical function to the:
Parental cell
In every species and at every level of organization, complex structures are made by:
Repeating a few basic themes with variations
If gastrulation fails to happen, then:
The embryo is not compatible with life
In humans, around day 15 of embryonic development, what is occurring:
Bilaminar disc formation and invagination
The invagination of the bilaminar disc during embryonic development, defines: (3)
Left side from right side
Head from tail
Front from back
Up at the head end of the neural tube, a pit forms and this is called:
Henson’s Node
The hensons node will result in the formation of:
Primitive streak
As the primitive streak begins to form, cells from this layer begin to:
Migrate
The cells migrating from the primitive streak, will migrate into the interiors and some of these cells will replace the ______ and form the _____.
Hypoblast (bottom layer) ; endoderm
The bottom layer of cells that get replaced with cells that are going to form the endoderm:
Hypoblast
The inner mass of the bilaminar disc will get filled up with migrating cells and from the:
Mesoderm
Once the mesoderm area is filled up with migrating cells, the remainder of these cells will form the:
Ectoderm
Ultimately, the process of gastrulation will result in the formation of what 3 cell layers?
Ectoderm, endoderm, mesoderm
All tissues in the body from from either the:
Ectoderm, endoderm, or mesoderm
Cells that can renew and give rise to multiple different cell types:
Stem Cells
Some neural crest cells exhibit:
Stemness
The restricted pathways that the neural cells migrate along are formed due to:
Specific morphogen growth factors
The invagination that forms on the neural plate border will ultimately give rise to:
The neural tube
The specific regions that neural crest cells migrate from in terms of craniofacial structures:
Rhombomeres
If you don’t have the correct number or location of neural crest cells migrating out from a specific rhombomere, the associated structure will:
Not develop correctly
Craniofacial structures develop as a result of:
Restricted movement of neural crest cells from the rhombomeres
Layer between the ectoderm and endoderm:
Mesoderm
Once we have formed the neural tube and other internal structures, the mesoderm layer will start getting :
Signals
Somites form from the:
Paraxial mesoderm
The somites formed from the paraxial mesoderm will start getting signals from:
Neural tube & notochord
The signals received from the neural tube and notochord by the somites will tell the somites to:
Change the way they differentiate
After receiving signals from the neural tube and mesoderm, the somites will differentiate into the:
Dermamyotome & sclerotome layers
What signals do the somites get that ultimately makes them differentiate into dermamyotome & sclerotome?
Ventralizing, dorsalizing, and lateralizing signals
In the process of paraxial mesoderm development and differentiation: the segmental plate mesoderm will give rise to:
Epithelial somites
In the process of paraxial mesoderm development and differentiation: The epithelial somites will give rise to:
Dermamyotome and sclerotome
In the process of paraxial mesoderm development and differentiation: The dermamyotome gives rise to:
Dermatomes & myotomes
In the process of paraxial mesoderm development and differentiation: dermatomes give rise to:
Dermis
In the process of paraxial mesoderm development and differentiation: myotomes give rise to:
Epaxial skeletal muscle & hypaxial skeletal muscle
In the process of paraxial mesoderm development and differentiation: The sclerotome give rise to:
Ribs, vertebra, base of skull, & some facial muscles
What drives the developmental process an dhow do we know what genes need to be turned on?
Developmental program embedded in the DNA
What is the ultimate type of gene control responsible for embryological development:
Hierarchical gene control
The first genes to be turned on: (the initial genes)
Coordinate genes
Coordinate genes turn on:
Gap genes
Genes that can regulate themselves and other members of their family, as well as turning on things like homeotic selector genes and the pair-rule genes:
Gap genes
Most important genes in the hierarchy of gene control
Homeotic genes
Replacement of one body part with another:
Homeosis
Genes responsible for establishing the fate of different segments
Homeotic genes
All of the products of homeotic genes are responsible for:
Regulating other genes
The homeotic genes all contain a highly conserved:
DNA binding homeodomain
The highly conserved DNA binding homeodomain of the homeotic genes is a:
60 amino acid sequence
Since the homeodomain is 60 amino acids long, it gives rise to:
180 base pairs of DNA
What are the most critical in terms of regulating, patterning, and determining other structures:
Hox genes
The corresponding segment in the 180 BP DNA sequence is called:
Homeobox
Hox genes are interspersed amongst the genome but the DNA to be organized:
Into structures
Hox genes are interspersed amongst large stretches of:
Regulatory DNA regions
Hox genes are expressed _____ according to their order in the Hox complex
Sequentially
The Hox complex contains a permanent record of:
Positional information
There are hundreds of other homeobox genes in the genomes, but what makes the hox genes unique is that:
They are clustered into complexes (not scattered)
The Hox genes must be expressed in what type of pattern?
Temporal and spatial
Cleft lip and cleft palate is a genetic defect that occurs early in:
Fetal development
In humans, the lip forms between:
In humans, the palate forms between:
4th & 7th week of pregnancy
6th & 9th week of pregnancy
The formation of craniofacial structures in early development requires the proper migration and number of:
Neural crest cells and their differentiation
Diagnose each type of cleft lip:
Unilateral incomplete, unilateral complete, B/L Complete
Diagnose the cleft palate:
- Incomplete cleft palate
- Unilateral complete lip and palate
- Bilateral complete lip and palate
Dolly the sheep was created by a process of an unfertilized egg that had its _____ and ______ removed.
Mitotic spindle and associated chromosomes
In dolly the sheep, _____from an oviduct were merged into the unfertilized enucleated egg.
Epithelial cells
The complexity of an animal is a function of the:
Gene expression control systems that drives development
Multicellular organisms are enriched in proteins that mediate: (2)
Cell-cell interactions & control gene expression
Cells in the adult organism retains record of ______, which is necessary for them to maintain their specialized characteristics.
Signals they received in early embryonic development
