Genetics 321

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Genetics 321

• From Mendel to Genomes

10 Weeks
2
Jeff Young, Botanistyoung_at_biol.wwu.edux3638Offi
ce BI412
Arabidopsis thaliana Genome-based study of plant
physiology and environmental responses.
Office Hours M,W,F 1230 - 130 pm by
appointment.
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Class Business

• Bulletin Board outside of BI463,
• Answer Keys,
• etc.
• Graded exams and quizzes,
• outside of BI412,
• Online Materials...
• http//fire.biol.wwu.edu/young/321g07.html

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Itinerary

• M W F, 10 - 1120, 5 minute break (1045).
• M F, Usually, questions and answers after
  break,
• W, (without exception) quiz 1105 - 1120,
• All midterms in class, 1000 - 1120,
• Final 1030 - 1230, Tuesday, December 11

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Genetics 321

• From Mendel to Genomes

10 Weeks
6

• Essential Genetics A Genomics Perspective by
  Hartl and Jones, 4th ed.
• ISBN 0-7637-3527-2
• Text Assignments
• Unless amended in class, all reading
  assignments listed on the syllabus are required,
• Additional reading assignments will be made,
• You will be responsible for in class
  additions and changes made to the syllabus.

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Grades

• Three hourly exams plus final exam (450 pts),
• You will have the full session time to
  complete each exam,
• You will be allowed one 11 x 8.5 crib sheet,
  one side, for each exam,
• Exams - 150 points each, Final Exam
  cumulative.
• Quizzes will be given every Wednesday (total
  100 pts),
• will cover the basics of the assigned reading
• (including that day's assignment),
• quizzes 12.5 points each, 15 minutes,
• quizzes may be taken in teams of two (except Q
  1 and 2),

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Extra Credit

• e-mail me a synopsis of a news story concerning
  Genetics, in the body of the email, 1 per email,
• 1 point each for up to 15 points,
• maximum, 2 per week,
• journal, date, byline, who, where, what and the
  significance,
• in English sentences,
• not an automatic point,
• must be well presented.

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Extra Credit Sources

• paper newspapers,
• online newspapers,
• do not just cut and paste,
• I reserve the right to be the final judge and
  arbiter of valid extra credit contributions,
• you will receive automatic notification(within 24
  hours) that your email got to me. This is not
  automatic approval.
• if I suspect that liberties are being taken, your
  extra credit account will be tallied to zero
  permanently,
• Ill let you know if I have a problem with your
  entry.
• no professional journals.

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Map
Young Pass
Unhappyham
You are here...
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Genetics ...the study of heredity and variation.

• The most powerful tool in the biologists toolbox.

• Not just for biologists,
• societal,
• personal.

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Classical Geneticseucaryotic

• ...the transmission of the primary hereditary
  material,

Chromosomes
DNA
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DNA NucleotidesBases
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ChromosomesLong Polymers
Phosphodiester Bonds Backbone
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Genomes
... haploid chromosome component of an organism,

• human (23), 3 Gb,
• fruit fly (4), 120 Mb,
• nematode (5), 100 Mb,
• mustard (5), 120 Mb,
• yeast (16), 12 Mb,
• bacteria, (1), 5-15 Mb.

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Units of HeredityClassical Genetics
chromosome DNA (Mb long) proteins
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Transmission of Hereditary Materials
(meiosis/sex)

• ...Meiosis the process of two consecutive cell
  divisions in the diploid progenitors of sex cells.

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Meiosis

• Cell Biology
• ...the mechanism, timing and steps of cell
  division,
• how a cell divides,
• growth and repair.

• Genetics
• a major result of cell division is the
  partitioning of DNA,
• transmission of genomes,
• via the transmission of chromosomes.

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Chromosomesself-replicating genetic structures.

• two copies of each chromosome are present at some
  stage of an eukaryotic organisms life cycle,
• haploid cells carrying one full set of
  chromosomes,
• diploid cells carrying two full sets of
  chromosomes,
• n number of haploid chromosomes.
• 2n number of chromosomes in a diploid organism.

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2n 4
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Homologous Chromosomes

• a pair of chromosomes containing the same linear
  gene sequence, each derived from one parent,
• homologous chromosomes carry the same complement
  of genes,
• the DNA sequence of the genes on homologous
  chromosomes may differ,
• alleles genes at the same location (locus) on
  homologous chromosomes, but that have different
  DNA sequences.

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Alleles
Alleles occur at the same locations (loci) on
homologous chromosomes.
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Meiosis
Haploid Cell
Diploid Cell
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Synthesis
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Chromosome Structure(cartoons)
M phase
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Meiosis
Haploid Cell
Diploid Cell
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Meiosis Prophase I

• Synapsis the highly specific parallel
  alignment of homologous chomosomes during the
  first division of meiosis,

tetrad the two homologous chromosomes become
attached along their length in a structure termed
a tetrad.
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Chiasmata
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Meiosis Prophase I cont.
A
a
A
a
a
A
B
B
b
b
Crossing Over rearranges the genes from each
parent.
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Meiosis Metaphase I -- Telophase I
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Meiosis Prophase II -- Telophase II
Aa
a
A
no DNA synthesis
bb
BB
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Meiosis is critical for sexual reproduction in
all diploid organisms

• ...meiosis leads to the formation of gametes,
• gametes (one from each parent) conjugate to form
  a zygote,
• ...meiosis is the basis for extensive variation
  among members of a population.

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Genetic Recombination I
Crossing over.
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Genetic Recombination II
2n combinations of chromosomes, n haploid
number of chromosomes.
Random Assortment of Chromosomes.
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2n combinations of chromosomes n number of
chromosomes

• n 1, 2n 2
• n 2, 2n 4
• n 3, 2n 8
• n 5, 2n 32 Arabidopsis
• n 23, 2n 8,388,608 H. sapiens
• n 39, 2n yip! dog

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Mendelian Genetics

• Gregor Mendel (1822-1884),
• Augustinian monk,
• Botanist,

• Pisum sativa,
• Garden pea,
• 1st Model System.

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Model Systems

• Modern Biology depends largely on the ability to
  study simple organisms, and then apply the
  resulting principles to more complex systems,
• i.e., ask simple questions about immensely
  complex processes,
• the answers are often simple, though not obvious.

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Model Organisms

• Ease of cultivation,
• Rapid Reproduction,
• Small size,
• Fecund (large brood size),
• Mutants are available and easy to identify,
• Broad literature and experimental background
  available.

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Model Organisms
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20,000- 25,000?
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(No Transcript)
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General Cell Function

• ECOCYC

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(No Transcript)
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Cell Cycle
400 of 6022 Saccharomyces cerevisiae genes are
active in conjunction with the cell cycle.
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Model Organisms
DNA bases
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Genome Sizes
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GenomicsDNA Reagent for the 21st Century
Biology is in the midst of an intellectual and
experimental sea change.... ...essentially the
discipline is moving from being largely a
data-poor science to becoming a data-rich
science.
Vukmirovic and Tilghman, Nature 405, 820-822
(2000)
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• gt 145 Gb (Aug, 2006)
• gt 165,000 organisms

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Complete Genomic SequencesDNA SequenceReagent
for the 21st Century
2007

• 2001
• 9 ARCHAEAL
• 36 BACTERIAL
• 6 EUKARYAL

• 2007 
• 345 Eukaryotic Genome Sequencing Projects
• Complete - 26,
• Assembly - 130,
• In Progress - 189
• 477 Complete Microbial Genomes

2007 1,793 Viral Genomes, gt547 Organelles,
others
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Genomics

• The systematic study of genomes that begins with
  large scale DNA sequencing (Structural Genomics),
• Functional genomics how particular DNA sequences
  facilitate biological functions,
• Comparative Genomics differences between
  individuals, differences between species, etc.
• Bioinformatics computational discipline that has
  evolved to handle modern biological data...

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Post Genomics Era
Genetic Testing
Drug Discovery
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More Genomics
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Online Mendelian Inheritance In Man OMIM
Bioinformatics
http//www.ncbi.nlm.nih.gov/entrez/query.fcgi?dbO
MIM
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Post-Genomics Biology
The new paradigm, now emerging, is that all
genes will be known (in the sense of being
resident in databases available electronically),
and that the starting point of a biological
investigation will be theoretical. -
Walter Gilbert Nobel Laureate,
Chemistry DNA Science
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"I guess there's cool stuff about science,"
Watanabe continued, "like space travel and bombs.
But that stuff is so hard, it's honestly not even
worth the effort."
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Friday

• Turn in take home quiz, beginning of class,
• Read Chapter 1, and review Chapter 3 if you are
  shaky with meiosis.