Lecture 7: Cleavage II Flashcards
Genomic imprinting
Differential gene expression depending on whether chromosome is inherited from male or female parent (due to DNA methylation)
Prader-Willi Syndrome
Mutation inherited from father (deletion in long arm of chromosome 15); small hands/feet, short stature, MR, obesity
Angelman Syndrome
Mutation inherited from mother (deletion in long arm of chromosome 15); frequent laughter, seizures, uncontrolled muscle movement
X-inactivation
Dosage compensation by inactivating one X chromosome in order to have an equal amount of genetic material between males and females
Xist gene
Produces RNA molecule that coats the X chromosome and induces X inactivation by methylation
Barr body
Inactive X chromosome - only seen in females
Regulation
Ability of embryo to compensate for removal of structures or addition of structures
Chimeras/mosaics
Single cell in early cleavage injected into blastocoel of genetically different host
Fate mapping
Follows cell differentiation and shows totipotency of blastomeres
Production of tetra/hexaparental embryos
Combines material of 2-3 embryos; chimeras can be produced this way
Deletion/ablation experiments
Removing part of embryo and observing changes
Addition experiments
Adding to the embryo and observing changes
Transgenic embryos
Injection of foreign DNA into pronuclei
Knock-out experiments
Inactivation of specific genes/gene products
Fraternal/Dizygotic twinning
Product of the fertilization of 2 eggs
