11.1 Gene Regulation

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11.1 Gene Regulation

• Only a fraction of the genes in a cell are
  expressed at any given time.
• Expressed genes are genes that were transcribed
  to the RNA.
• Certain DNA sequences act as binding sites for
  RNA polymerase, and start and stop signs for
  transcription.

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• Every cell can express different genes.
• Pancreas secretes many digestive enzymes,
  amylase, that help break down starches.
  Expression of this genes allows it to function.
  Our marrow cells would not need to have this
  protein produced.
• Morphogenesis (cell differentiation, cell
  specialization)

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• Expression in Prokaryotes
• Operon series of genes
• Pg 218
• E. Coli
• The lac genes are turned off by repressors and
  turned on be the presence of lactose.
• What happens if there is no lactose?

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• Regulator codes for a repressor
• Pg 218
• If lactose is not present repressor is located
  on the operator (preventing RNA polymerase to
  transcribe.

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In Eukaryotes

• TATA box a warning to the RNA Polymerase.
• Introns (bad) and Exons (good)
• Around 28-30 base pairs long
• Helps the Genome project

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Regulation and Development

• Homeotic Gene
• Control the organs and tissues, and determine the
  basic body plan of animals.
• Homeobox a certain sequence for hox genes
• Pg 224

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Cancer

• Read page 225

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12.1 Inheritance and Human Genetics

• Sex Chromosomes X or Y
• Male XY, Female XX
• Autosomes 1-22
• Germ Cell vs. Somatic Cell
• SRY on the Y chromosome (sex-determining region

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Sex linked genes and traits

• If on the X chromosome most females are
  carriers and males express the trait
• X Chromosome inactivation in females. Form barr
  bodies in females

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Linked genes

• Close together and on the same chromosome, called
  linkage groups

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Gene Map

• Rough
• estimation
• Of distances
• b/w genes.

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In your Notes

• Write
• TACAATGCTCAAACT
• 1. mRNA Strand to match
• And Decode
• Replace 3rd A with a C
• Now Transcribe and translate again.
• What happened?
• What type of mutation?

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Write same DNA sequence again

• Now insert a T after the 2nd T in the DNA strand
• What does that do to the amino acids produced?
• What type of mutation is this?

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Mutations

• Gene mutations single gene
• Point mutation is a mistake on just one
  nucleotide
• Nucleotides can be deleted or inserted (pg 307)
• Frameshift mutation

This is an example of sickle cell Substitution
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Chromosomal Mutations

• Changes in the number or structure of
  chromosomes. (locations of genes, number of
  copies of genes)
• Deletion
• Duplication
• Inversion
• Translocation
• Nondisjunction (too few or too many chromosomes

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Web

• http//learn.genetics.utah.edu/content/disorders/w
  hataregd/

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12.2

• Pedigree
• Map of generations phenotypic inheritance
• Male square, female circle

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• Complex characteristics not just genetic but
  also environmental.
• Height, personality, skin color, health in
  general
• Multiple alleles blood type, fur color
• Polygenic skin color, eye color
• Codominance both expressed AB blood, roan
  cow
• Incomplete dominance share
• X linked most recessive, on X

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• Look at Disorders
• http//learn.genetics.utah.edu/content/disorders/w
  hataregd/

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• Read Gene Therapy
• This will be our next chapter..