Genetics Lab Finals

• Stem cell


  A single cell that can replicate itself and differentiate into other cell types
• Stem cells


  • Do not have any tissue-specific structures that allow them to perform specialized functions
  • Divided into groups depending on their differentiation abilities (potency)
• Gene regulation


  Important in all organisms, both prokaryotic and eukaryotic, to turn on and off genes in response to internal and external environmental conditions
• Eukaryotic gene regulation


  Eukaryotic organisms rely on gene regulation to create different cell types despite having the same genome, in order to maintain the proper specialized functions of each cell
• Lentivirus


  A genus of retroviruses, example is human immunodeficiency virus (HIV)
• Lentivirus structure


  1. LTR sequences become the border of the gag, pol and env genes

  2. Lentivirus also encodes tat and rev
• Lentivirus genes


  • gag: structural protein
  • pol: nucleic acid polymerase/integrases
  • env: surface glycoprotein
  • tat: regulatory protein for gene expression
  • rev: regulatory protein accessory genes
• Retroviruses are desirable gene delivery vehicles or vectors
• Reverse Transcription PCR


  1. Conversion of RNA into cDNA using reverse transcriptase

  2. Amplification of cDNA using PCR
• Western blotting


  An important method in protein identification, can detect one specific protein in a solution that contains numerous other proteins
• Induced pluripotent stem cells (iPS) are better to avoid immunological reactions than embryonic stem cells (ES)
• Transcription factors and enhancer region


  Increase the gene expression rate in eukaryotes
• Every cell in our body uses its own set of unique transcription factors to regulate gene expression
• NANOG gene expression


  Unregulated in iPS cells but silenced in differentiated cells, suggesting it sustains stem cells self-renewal ability
• Analyzing RT-PCR results from embryonic stem cells and fibroblast cells is important as they are the experimental controls
• Analyzing NANOG protein levels is important to monitor post-transcriptional modifications
• Obtaining a protein sample from cells

  Lyse the cells
• Cells transduced with general transcription factors do not express NANOG protein
• Phosphorylation and degradation by proteasomes

  Post-translational regulation
• Gene therapy


  An experimental technique for treating disease by altering the patient's genetic material
• Adeno-Associated Virus (AAV)


  A small, single-stranded DNA virus that belongs to the family of Parvoviridae
• AAV structure and genome

  • Characterized by an icosahedral capsid and a genome size of 4.7 kb, containing two open reading frames encoding for rep and cap
• AAV in gene therapy

  The desired therapeutic gene cDNA is inserted between two inverted terminal repeats (ITRs) that aid the packaging of the viral genome into the virus capsid
• Cardiac cycle


  The period of time that begins with contraction of the atria and ends with ventricular relaxation
• Heart failure


  A condition in which the heart is not able to pump sufficient blood to cover the body's needs
• Recombinant adeno-associated virus (AAV) production

  The most common system is based on a 3 plasmid co-transfection of HEK293 cells as the packaging cell line
• Transmission Electron Microscopy


  Utilizes electrons instead of light to image samples
• Embryology


  The study of the development of the anatomy of an organism
• Hamburger-Hamilton series


  A series used to stage and characterize chick embryos
• Liebenberg syndrome


  Characterized by stiff elbow joints and the fusion of the wrist bones, caused by the misexpression of a homeotic gene
• Next Generation Sequencing


  An advanced sequencing technology where many short DNA molecules are sequenced at the same time
• The Liebenberg syndrome is a genetic defect caused by mutation, which is why his mother and grandfather have the same defect
• Chicken embryos are a good model organism to easily observe a developing embryo
• A 40-day old human embryo would be the best suited to visualize the development of four limbs and a living vertebrae
• Difference in warming a hind limb instead of a forelimb

  Gene expression
• Tbx5


  A gene that may play a role in patterning the forelimb
• Pitx1 and Tbx4


  Genes that are candidates for being responsible for the hindlimb patterning
• The mouse model system was used to identify candidate genes responsible for the Liebenberg syndrome because mice have limbs
• A 10.5 day chicken embryo is at stage 37 of development
• Microsatellites


  Short repeating DNA sequences of two to six base pairs, with varying numbers of repeats among individuals representing different alleles