Repro Flashcards
What is the SHH gene responsible for? What can mutation cause?
- Anterior posterior patterning at limb buds
- Holoprosencephaly
What is the WNT7 gene responsible for?
Distal limb development
Role of fibroblast growth factor in development? Mutation?
Limb lengthening: mutation can cause achondroplasia
What do mutations in HOX genes cause?
Synpolydactyly: fingers /toes in wrong place
- Code for DNA binding TF
- Vitamin A dysregulates HOX in pregnancy
What is egg arrested in before fertilization?
Metaphase of meiosis II
What does the trophoblast become?
The placenta
Vitamin deficiency causing neural tube defects?
Folate
What do alar and basal plate give rise to?
Alar: sensory neurons (dorsal)
Basal: motor neurons (ventral)
When is embryo most susceptible to teratogens?
Embryonic period: weeks 3 - 8
When do heart and limb development begin?
Week 4: 4 chambers, 4 limbs
When does gender development begin?
Week ten
Derivatives of ectoderm and what do they become?
- Surface ectoderm: skin
- Neuroectoderm: Brain / spinal cord
- Neural crest: PNS
What are melanocytes derived from?
Neural crest
What does the mesoderm become?
- Muscle, bone, connective tissue, CV, lymphatics, blood, kidneys, spleen
What does endoderm become?
Gut, lungs, liver, pancreas, gallbladder, thyroid, parathyroid
What is agenesis?
Absent organ from absence of primordial tissue
What is aplasia?
Absent organ with present primordial tissue
Difference between deformation and malformation
Deform: extrinsic interruption after embryonic period
Malform: internal interruption during embryonic (3-8 weeks)
What do aminoglycosides cause?
Ototoxicity
What does cocaine cause?
Placental abruption
What does Li cause?
Ebstein anomaly: atrialization of right ventricle
Heparin or warfarin in pregnancy?
Heparin: does not cross placenta
Presentation of fetal alcohol syndrome?
- Small, widely spaced eyes
- Thin upper lip
- Smooth philtrum
* ***Caused by failure of cell migration
What does # chorions equal?
Number of placentas