MBG 3050 Final Study Guide

What triggers egg activation in fertilization

Fusion of sperm and egg gametes

What does cleavage of the zygote production

Blastomeres —> blastocysts

What are the components of the blasocyst

Trophoblast, inner cell mass (ICM), blastocoel

What does the trophoblast form

The chorion (placenta)

What does the ICM give rise to

Epiblast (embryo) and hypoblast (yolk sac)

What do epiblast cells form through gastrulation

The three germ layers: endoderm, mesoderm, ectoderm

How do monozygotic twins form

One embryo splits into two identical embryos

What are RTKs

Receptor tyrosine kinases - surface receptors involved in cell signaling

What causes Achondroplasia

Gain of function mutations in FGFR3

What causes craniosynostosis

FGFR2 mutations

What causes Piebaldism/Waardenburg

Mutations in c-Kit or MITF

What fusion proteins causes CML

Bcr-Abl

What is the main role of transcription factors

Bind DNA to regulate gene expression

What do Hox genes do

Pattern the embryo along the anterior-posterior axis

What is MITF’s role

Pigmentation via neural crest cell derivations

What is Gli involved in

Shh signaling for embryo and limb patterning

What does p53 regulate

Cell cycle arrest, apoptosis, DNA repair

What gene determines male sex development

SRY on Y chromosome

What does SRY encode

TDF (Testis-determining factor)

What causes 46, XY female (pseudohermaphroditism)

SRY deletion, androgen insensitivity or AMF mutation

What causes 46, XX male (female pseudophermaphroditism)

Gain of SRY, congenital adrenal hyperplasia

What are totipotent stem cells

Can form all cells including placenta

What are pluripotent stem cells

Can form all body cells and germ cells

What are multipotent stem cells

Can form limited cell types (e.g. blood, skin)

What is SCNT

Somatic nucleus transferred into enucleated egg

How are iPS cells creasted

Introducing TFs (Oct4, Sox2, etc) to reprogram somatic cells

What is transdifferentiation

Switching one cell type directly to another

What is gene augmentation

Adding a normal copy of a gene

How are mutations fixed

Genome editiing (CRISPR, ZFNs, TALENs)

What is gene silencing

Blocking gene expression (RNAI, antisense)

What is CAR-T therapy an example of

Indirect killing of diseased cells

What virus infects dividing/non-dividing cells and integrates

Lentivirus

What viral vector is mostly episomal and low-immunogenic

AAV

Which vector is safest but least efficient

Liposomes

What are oncogenes

Genes that promote cell division when activated (e.g. Ras, Myc, Src)

What are tumour suppressor genes (TSGs)

Genes that inhibit division, both copies must be lost (e.g. p53, Rb)

What are 3 hallmarks of cancer

Evade death, grow uncontrollably, invade tissues

What is LOH

Loss of the normal allele in a heterozygous cell —> loss of function

What theory explains LOH in cancer

Knudson's two-hit theory

What is knockdown

Reduce gene expression (RNAi)

What is knockout

Complete gene deletion (e.g. via CRISPR)

What is a dominant negative mutation

Mutant protein disrupts wild-type protein function

What does RNAseq study

Entire transcriptome

What is aminocentesis

16-20 wk test to analyze fetal DNA in amniotic fluid

What is CVS

10-14 wk test using placental tissue

What does NIPT analyze

Cell-free fetal DNA in maternal blood

What is c-Kit

RTK involved in pigmentation

What is FGFR3 associated with

Achondroplasia (dwarfism)

What activates Ras in RTK pathway

GEF (Sos)

What inactivates Ras

GEF (Sos)

What is the Shh pathway sequences

Shh—> Patched —> Smoothened —> Gli

What happens in the Wnt pathway

Wnt—> Frizzled —> Disheveled —> Inhibit GSK-3 —> Stabilize B-catenin —> Activate TCF/LEF

What does APC do

Tumour suppressor that degrades B-catenin

What is the order of RTK signalling components

Ligand —> RTK —> Grb2 —> Sos —> Ras —> Raf —> MEK —> ERK —> TFs (e.g. MITF)

What does proteomics study

All proteins, their abundance and interactions