EXAM III Flashcards
Critical transcription factor for driving definitive endoderm differentiation
Sox17
Process that involves embryonic disk/ectoderm edges moving ventrally with the amnion and fusing
Embryonic folding
Critical transcription factor for lung bud specification
Nkx2.1
Function of Surfactant in the lungs
Reduces surface tension at the air/liquid interface
Condition occurring in premature births caused by insufficient levels of surfactant
Infant Respiratory Distress Syndrome
Structure that arises from ventral outgrowth of the distal foregut (Hepatic diverticulum)
Liver and biliary system
Pancreatic fate determination factor
PDX1
Amount of enteric neurons in the human ENS
400-600 million
Neural crest populations which contribute to the Enteric Nervous System
Vagal and Sacral
Protein expressed by the dorsal Mesoderm leading to esophageal fate determination
Barx
Process responsible for lung development through growth from the center outward
Branching morphogenisis
Important regulators of enteric nervous system development
GDNF and Endothelins
% of familial cases of Hirschsprung’s dz linked to RET mutations
50
Tissue that surrounds the gut tube and forms smooth muscle
Mesoderm
Produced by pancreas to break down carbs and proteins
Digestive enzymes
Condition resulting in herniation of abdominal contents with a smaller abdominal cavity
Congenital Omphalocele
Process controlled by neurons in enteric ganglia along the gut tube
Peristalsis
Factor required from cardiac mesoderm for liver specification
FGF
Result of insufficient ENS development in Hirschsprung’s dz
Megacolon
Process in which Primordial germ cells (PGCs) are specified in mammals
Inductive interactions between cells
Proteins responsible for inducing mammalian PGCs
Bone Morphogenic Proteins (BMP4 and BMP8b)
Receptor expressed by PGCs that helps guide their migration
CXCR4
Function of sertoli cells in male development
They secrete anti-Mullerian hormone (AMH)
Cells in the developing testis that produce testosterone
Leydig cells
Structure that develops from Wolffian duct in males
Epididymis and vas deferens
Induces Miosis in developing germ cells
Retinoic Acid
Develops from Mullerian duct in females
Fallopian tubes, uterus, upper vagina
Origin of granulosa cells in the ovary
Cortical Cords
What happened to chromosomes during early development in Boveri’s observations of Parascaris
They fragmented in all cells except for the germ cell progenitor
Structure formed at level of mesonephric tubules to become the gonads
Genital Ridges
Number of PGCs in mammals
10-100 cells
Factor necessary for maintenance of PGCs during migration
Stem cell factor (SCF)
Embryonic origin of theca cells
Mesenchymal cells
Hormone responsible for scrotum and penis development
Dihydrotestosterone
Gene necessary for development of Mullerian and Wolffian ducts
Wnt4
When PGCs enter the developing gonad in mammals
E11.5
Function of CXCR7B in zebrafish PGC migration
Internalizes and degrades SDF1 to repel PGCs
In the developing ovary, oocytes…
Stop at diplotene I
Structure that develops urogenital sinus
Lower Vagina
3 Main mechanisms of sex determination
Environmental Action
Chromosomal Action
Hormonal Action
The gene that is the testis determining factor in temperature-dependent sex determination
Dmrt1
Sex determinator in Drosophila
Ratio of X chromosomes to autosomes
Chromosomal sex determination pattern in birds
ZZ male; ZW female
Testis determining factor gene in mammals
SRY
Sox9 Knockout in mice causes
Complete sex reversal of XY males
Role of Wnt4 and R-spondin 1 in sex determination
They activate beta-catenin and initiate ovary differentiation
Primary function of AMH during development
Indues degeneration of the Mullerian duct
Effect of 5a-reductase deficiency in XY individuals
Appear female at birth but masculine at puberty
Role of FGF9 in sex determination
Necessary for Leydig cell proliferation and Sertoli cell differentiation
Phenotype of XY individuals with androgen sensitivity syndrome
Female appearance with internal testis and no uterus
Regulator of sex determination in Drosophila at the molecular level
The sex-lethal gene
Role of aromatase in temperature-dependent sex determination
High activity leads to ovary formation
Function of Steroidogenic factor 1 (SF1)
Works with SOX9 to regulate AMH expression in Sertoli cells
Associated with Campomelic dysplasia
Only one functional copy of Sox9
Role of dihydrotestosterone in male development
Induces development of scrotum and penis
Wnt4 Knockout in Mice
Ovary not properly formed and cells express testis specific genes
Main characteristic of 21-hyroxylase deficiency
Excess androgen production by adrenal glands
Role of pSTAT3 in temp-dependent sex determination
It is elevated at female promoting temperatures
Effect of XX individuals with RSPO1 mutations
Develop phenotypically as male
Type of cell division that generates 2 stem cells
Symmetric self-renewing division
Major challenge in translating basic or pre-clinical discoveries to human tx
Over 95% of drugs entering human clinical trials fails
Basic technical themes for creating organoids
Collect and culture stem cells in specific media formulations
Activate key signaling pathways with morphogens
Grow cultures in 3 dimensions using specific matrices
Advantage of organoids
Genetically accessible
Human derived
Rapidly established
Defining aspect of human evolution regarding brain development
Relatively large brain to body weight ratio
Amount of cortical neurons generated in the human neocortex
> 15 billion
Protein localized on the ventricular side of NEP/radial glia soma
Par3
Copies of NOTCH2NL in humans
4
Observations in NOTCH3NL-deleted organoids
They are smaller than normal
Condition associated with chr1q21.1 microdeletions
Microcephaly
Technique used for NOTCH2NL deletions in human ES cells
CRISPR/Cas9
% of total forebrain mass represented by cortical neurons and glia
80
Clinical definition of microcephaly
head circumference >2 SDs below means
Protein evolved amino acid substitution not seen in Neanderthals
NOVA1
Happens inNotch2nl-deleted organoids regarding neuronal differentiation
Premature neuronal differentiation
Hox gene paralogs that are involved in patterning of limbs
Hox 9-13
Role of FGF10 in limb development
Expressed in the lateral plate mesoderm at sites of limb bud formation
Protein expressed in the Zone of Polarizing Activity (ZPA)
SHH
Structure required for limb bud outgrowth
Apical Ectodermal Ridge (AER)
Gene specifically expressed in forelimbs but not hindlimbs
Tbx5
Determinator of dorsal identity of the limb
Wnt7a
Effect if AER is removed during limb bud development
Distal outgrowth of the limb halts
Protein that induces Engrailed 1 expression in the ventral ectoderm
BMP
Result of ectopic SHH expression in the rostral/anterior limb bud
Polydactyly
Syndrome caused by mutations in LMX1B
Nail-Patella syndrome
Role of Retinoic Acid (RA) in forelimb development
Induces TBX5 expression
Structure that contains highly proliferative mesodermal cells right under the AER
Progress zone
Determinator of the type of limb formed when leg mesenchyme is inserted under the AER in the forelimb
The mesenchyme
Effect of Wnt7a knockout in mice
Ventral footpads on both sides
Signaling molecule in the AER is sufficient to induce underlying mesenchyme growth
FGF8
Function of Zone of Polarizing activity (ZPA)
Patterns the anterior-posterior axis
Digits that require SHH for specification
Digits 4 and 5
Occurs in Split-foot anomaly
Loss of normal AER function
Competence of limb development
There is a specific competency window for responding to signals
Relationship between RA and FGF8 in limb development
RA inhibits FGF8 expression
Regeneration
The regrowth of amputated body parts or nonfunctioning organs
4 Mechanisms of Regeneration
Compensatory
Epimorphic
Stem-cell mediated
Key characteristic of compensatory regeneration
Differentiated cells divide while maintaining their functions
Zebrafish heart regeneration, day 3 post-injury
Proliferation and migration of endocardial and epicardial cells
What age can mouse hearts regenerate after damage
7 days
Undifferentiated mass of cells formed during epimorphic regeneration
Blastema
1st Step of epimorphic limb regeneration
Epidermal cells migrate to cover wound surface
Organism that is a classic model of morphallactic regeneration
Hydra
Name of pluripotent stem cells in the planaria
Neoblasts
Signaling pathway that promotes tail development and represses head development in planaria
Wnt signaling
Role of Notum in planarian regeneration
Inhibits Wnt signaling and forms head
Protein necessary in zebrafish for spinal cord
Ctgfa
Repair in context of tissue recovery
Process of replacement of a singular type of cell tissue
In morphallactic regeneration of hydra, the size of the regenerated organism…
Becomes smaller than the original
Head inducing signal in hydra
Wnt3a
By day 7, cardiomyocytes in zebrafish heart regeneration…
Begin to proliferate at the edge of the injury
Similar structure in epimorphic regeneration to the AER in embryonic development
Apical Ectodermal Cap
Unique about ependymal cells in zebrafish spinal cord regeneration
They proliferate and form a bridge
Primary difference between repair and regeneration
Repair= one tissue type
Regeneration= multiple
Role of PCGs (Positional Control Genes) in planarian regeneration
Form a morhological memory cap
Regeneration of salamander limb
Epimorphic
Effect of injection of clodronate liposomes during digit tip regeneration
It kills macrophages
Sequence of stages in digit tip regeneration
(IHWBFD)
Inflammation
Histolysis
Wound Healing
Blastema
Formation
Differentiation
Histolysis
The dissolution of organic tissue
Cells responsible for bone histolysis during digit regeneration
Osteoclasts
Length in days of wound healing in mammalian digit regeneration
10-14
Key characteristic of mammalian blastema
Highly proliferative
Type of bone formation that occurs during digit tip regeneration
Intramembranous bone formation
Weakest type of bone
Woven bone
Role of Macrophages in digit regeneration
Differentiate into osteoclasts
If a wound is sutured during digit tip regeneration
Inhibits WE/AEC formation
Primary function of osteoclasts during digit regenration
Bone resorption
Protein that can replace nerves in the Accessory Limb Model
FGFs and BMP
Why excessive bone volume is regenerated in digit tip regeneration
To compensate for woven bone weakness
Purpose if histolysis in digit regeneration
Allow epidermis to heal over live bone
During morphallaxis
Repatterning of existing tissue
Protein combination that can induce bone and joint regeneration
BMP2 and BMP9
Characteristic of wound epithelium in digit regeneration
Ends the histolysis phase
Primary cell type from which placenta arises
Trophoblast
Growth factor from inner cell mass that promotes trophoblast development
FGF4
Approximate surface area of fully developed syncytiotrophoblast layer surrounding chorionic villi
12 sq meters
% Of maternal blood circulating through placenta at term
20
% Of birth defects related to teratogen exposure
4-5
Thalidomide original marketing
Sedative
Births affected by FAS in US
1-2 of every 1000 births
The proteins adhesive function that is blocked by alcohol exposure in fetal development
L1CAM
Years in which women in US were rx DES
1938-1970
Gene downregulated by DES in the female reproductive tract
Wnt7a
Hox genes required for female repro-tract development
Hoxa10 and Hoxa11
Molecular weight threshold above which teratogens do not easily cross the placenta
1000 daltons
Types of cells that produce testosterone in male repro development
Leydig cells
Compound found to cause transgenerational inheritance of male infertility
Vinclozolin
Process of Vinclozolin that causes transgenerational effects
DNA Methylation
Structure in which FGF8 is expressed during limb development
AER
Causes of craniofacial abnormalities in FAS
Altered neural crest migration
Types of molecules that are endocrine disruptors
Exogenous chemicals that interfere w/ hormones
Primary mechanism by which alcohol affects developing neurons
Generation of reactive oxygen species
Hormone that induces the differentiation of the Mullerian duct
Estrogen