Lecture 7: Cleavage II Flashcards Preview

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Flashcards in Lecture 7: Cleavage II Deck (20):
1

Genomic imprinting

Differential gene expression depending on whether chromosome is inherited from male or female parent (due to DNA methylation)

2

Prader-Willi Syndrome

Mutation inherited from father (deletion in long arm of chromosome 15); small hands/feet, short stature, MR, obesity

3

Angelman Syndrome

Mutation inherited from mother (deletion in long arm of chromosome 15); frequent laughter, seizures, uncontrolled muscle movement

4

X-inactivation

Dosage compensation by inactivating one X chromosome in order to have an equal amount of genetic material between males and females

5

Xist gene

Produces RNA molecule that coats the X chromosome and induces X inactivation by methylation

6

Barr body

Inactive X chromosome - only seen in females

7

Regulation

Ability of embryo to compensate for removal of structures or addition of structures

8

Chimeras/mosaics

Single cell in early cleavage injected into blastocoel of genetically different host

9

Fate mapping

Follows cell differentiation and shows totipotency of blastomeres

10

Production of tetra/hexaparental embryos

Combines material of 2-3 embryos; chimeras can be produced this way

11

Deletion/ablation experiments

Removing part of embryo and observing changes

12

Addition experiments

Adding to the embryo and observing changes

13

Transgenic embryos

Injection of foreign DNA into pronuclei

14

Knock-out experiments

Inactivation of specific genes/gene products

15

Fraternal/Dizygotic twinning

Product of the fertilization of 2 eggs

16

Identical/Monozygotic twinning

Product of fertilization of a single egg

17

Most common form of monozygotic twinning

Splitting of ICM in blastocyst forms 2 embryos with a common trophoblast

18

Conjoined twinning

ICM fails to split or rejoins at some point in development

19

Parasitic twinning

Smaller, but complete body portion attached to host twin

20

Bateson's Rule

When duplicated structures are joined during critical developmental stages, one structure is the mirror image of the other