Transcript Chapter 15 The Human Genome

Biology, Seventh Edition
Solomon • Berg • Martin
Chapter 15
The Human Genome
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 15 The Human Genome
• Studying Human Genetics
• Karyotyping
–Studies the number and kind of
chromosomes in the nucleus
–Enables researchers to identify chromosome
abnormalities
• Pedigree
–Family tree
–Transmission of genetic traits over
generations
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
Karyotyping
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
Pedigree
for albinism
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
• Human genetics
• Human genome and Human Genome
Project
• Bioinformatics
–Storage, retrieval, and comparison of DNA
• Pharmacogenetics
–Drugs customized to individual
• Proteomics
–Study of proteins encoded by human
genome
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 15 The Human Genome
• Mouse models to study disease
• Ethical issues in using humans as test
subjects
• Animal model is used instead
–Example is cystic fibrosis, a genetic
disease
–Gene targeting used to produce mice
homozygous or heterozygous for cystic
fibrosis
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
A DNA
microarray
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
• Abnormalities in chromosome
number and structure
• Aneuploidy: missing or extra copies of
certain chromosomes
–Trisomy: trisomy 21 common form of Down
syndrome
–Monosomy: Turner syndrome
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
• Meiotic nondisjunction
• Sister chromatids or homologous
chromosomes fail to move apart in
meiosis
• Cause of
–Trisomy
–Monosomy
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
Meiotic nondisjunction
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
• Structural abnormalities in
chromosomes
• Translocations
• Deletions
• Fragile sites
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
Reciprocal translocation
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
Fragile X
syndrome
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
• Genetic diseases caused by
single-gene mutations
• Autosomal recessive disorder
–PKU
–Sickle cell anemia
• Autosomal dominant disorder
–Huntington’s disease
• X-linked recessive
–Hemophilia
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
Sickle
cell
anemia
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
Age of onset of Huntington’s disease
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
• Gene therapy
• Normal allele is cloned
• DNA introduced into certain body cells
• One technical challenge is finding
appropriate vector
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
• Prenatal gene testing and
counseling
• Amniocentesis
• Chorionic villus sampling (CVS)
• Preimplantation genetic diagnosis
(PGD)
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
Amniocentesis
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
Chorionic
villus
sampling
(CVS)
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
• Genetic screening
• Identifies individuals who might carry a
serious genetic disease
• Newborn screening important in
preventive medicine
• Genetic counseling
• Medical and genetic information given
when there is a risk of abnormality
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Biology, Seventh Edition
CHAPTER 15 The Human Genome
• Genetic discrimination
• Discrimination because of differences
from the “normal” genome
• Controversy regarding whether
information should be given to
insurance companies and employers
• Issues of genetic privacy will become
increasingly important
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