Genetics Lab

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Genetics Lab

• Dr. Jeff Young young_at_biol.wwu.edu
• Office Hours BI 412 MR 10 - 11 am or by
  appointment
• Lecture M 1 150 pm in BH104
• Lab TR 200 450 pm in BI454

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Course Goals

• Content goals
• You should understand and be able to apply
  classical genetic and molecular genetic
  principles in a laboratory setting. Specifically,
  you should obtain a reasonably sophisticated
  understanding of several major aspects of
  genetics, including Mendelian Genetics,
  prokaryotic genetics, and molecular genetics.
• You should acquire skills in handling model
  organisms, keeping detailed research records,
  analyzing data and writing scientific reports.
•  Process goals
• You should improve your critical thinking skills
  through the analysis of experimental data.
• You should improve your quantitative reasoning
  skills.
• You should improve your written communication
  skills.

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Lab Notebook

• Will be used to record your activities and
  observations during each laboratory period
• with numbered pages,
• with table of contents,
• organize your notebook by experiment and not by
  class period.
• Prepare and hand in an abstract of the days
  work.
• Work up and analyze your data as soon as you've
  completed the experiment and while it is still
  fresh in your mind.

4
Texts/Lab Manual/etc.

• None.
• Hand outs (also posted).
• Genetics texts on reserve.
• Attendance is mandatory.

5
Evaluation

• Notebooks 40 points total,
• 1 pt/lab, pre-lab hand in 
• Lab Behavior 30 points
• Formal Lab Write-ups 50 pts. 
• Mid Term and Final 50 pts. (each) 
• Pop quizzes and other assignments 30 pts. 
• Approximate Grading Scale
• 225-250 points A
• 200-224 points B
• 175-199 points C
• 150-174 points D
• Below 150 points F

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Schedule

• Subject to Change

7
Mendel Revisited

• C. elegans is a nematode, phyllum Nematoda.
  Nematodes can be free-living or parasitic and can
  be found in terrestrial or aquatic habitats.  
• Bacteriovorous in the lab, C. elegans is fed on
  E. coli. 
• Self-fertilizing adult C. elegans are usually
  self-fertilizing protandrous hermaphrodites. Thus
  it is easy to generate homozygous mutant stocks.
   
• The lifecycle takes about 2.5 days at 250 C 
• C. elegans is diploid and has five pairs of
  chromosomes (named I, II, III, IV and V) and sex
  chromosome(s) (X). 
• Gender is determined by an XX (hermaphrodite) -
  XO (male) chromosomal system .
• Males are found rarely (about 0.05 of normal lab
  populations).  
• The commonest lab strain, and the designated
  "wild type" strain, is called N2. 
• Hermaphrodites have exactly 959 cells, each cell
  derived in an exact and invariable manner. 
• Males have 1031 cells.

• Caenorhabditis elegans
• A small, free-living bacteriovorous soil nematode.

Parts
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Cell Fate
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C. elegans Genome

• The C. elegans genome is spread across six
  approximately equally sized chromosomes (5
  autosomes, one X). 
• The genome size is 97 Megabases (Mb) 
• The genomes of other nematodes are in the same
  range. Brugia malayi, a filarial parasite of
  humans, has a genome of 100 Mb.  
• The AT content is 60. 
• The genome is sequenced.

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C. elegans Nomenclature
Tower of Babel
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Making Crosses

• C. elegans is usually a self-fertilizing
  hermaphrodite. However, it is possible to set up
  genetic crosses
• C. elegans (0.05) males are found in natural, or
  wildtype populations 
• they develop after accidental non-disjunction of
  the X chromosomes in gametogenesis (males are XO 
• the rate of non-disjunction can be increased by
  exposing a population of hermaphrodites to heat
  shock (30 deg. C for gt6 hrs) 
• Male sperm out-competes hermaphrodite sperm,
• male lines" can be propagated indefinitely by
  picking individual males and hermaphrodites 
• him strains, mutant lines that yield high
  frequencies of males.

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Wt (N2) X unc-32 dpy-11

• Wt

• unc

dpy
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Lab Life Cycles

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Diagram Crossdue Friday, in Notebook

• P N2 X unc-32 dpy-11
• F1 Genotype(s), Ratio
• F2 Genotype(s), Ratio
• Save Room for the next assignment
• F3 generation, from wt phenotype F2s.

Tails
Movements Size
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Bioinformatics

• Tuesday, Introduction to Bioinformatics