Lecture 5 - Lecture 5 Genetic Model Organisms/Pedigrees...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 5: Genetic Model Organisms/Pedigrees Aneuploidy September 9, 2013 Extensions of Mendelian Genetics (Chapter 5) • Continuous Characteristics • Genetic model organisms – Why and how we use them – Examples • Pedigrees: Recognizing different patterns – Autosomal Recessive Traits – Autosomal Dominant Traits
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Lecture 5: Genetic Model Organisms/Pedigrees Aneuploidy September 9, 2013 • Pedigrees: Recognizing different patterns - X-Linked Recessive Traits – X-Linked Dominant Traits – Y-Linked Traits Aneuploidy (Chapter 9) Trisomy 21 (Down Syndrome) Chromosome morphology Karyotype
Background image of page 2
Inheritance of Continuous Characteristics So far we have studied discontinuous characteristics: a few easily distinguished variations Continuous characteristics : a continuous distribution of phenotypes is observed examples: height, weight Also called quantitative characteristics .
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Inheritance of Continuous Characteristics When a single locus with two alleles encodes a characteristic, there are three genotypes possible: AA, Aa, and aa When there are two loci, each with two alleles, there are 3 2 = 9 genotypes The number of genotypes encoding a characteristic is 3 n n = number of loci with two alleles that inFuence the characteristic.
Background image of page 4
Polygenic Traits So, if there are 8 loci, 3 8 = 6561 different genotypes. Many different phenotypes with only slight differences. Add in the environment, and there’s even more variation We’ll return to quantitative traits later (assuming we have time)
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Chapter 6: Genetic Model Organisms • Genetic model organisms – Why and how we use them – Examples
Background image of page 6
Genetic model organisms: why? The vast majority of organisms Use the same genetic material (DNA or RNA) Use the same genetic code Use many of the same genes to accomplish the same tasks. Indicates that all life on earth evolved from the same primordial ancestor (3.5-4 billion years ago) Thus, the study of other organisms can provide insight into human biology, and ultimately the treatment of disease.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Genetic model organisms Organisms with characteristics that are particularly useful for genetic analysis: short generation time large number of progeny adaptable to lab environment housed and propagated relatively inexpensively genomes sequenced (recently)
Background image of page 8
Genetic model organisms 7 major genetic model organisms Escherichia coli - a bacterium in the human gut Saccharomyces cerevisiae - baker’s/brewer’s yeast Caenorhabditis elegans - a microscopic nematode (round worm) Drosophila melanogaster - fruit Fy Danio rerio - zebra±sh (newbie - sequencing ongoing) Mus musculus - house mouse Arabidopsis thaliana - the thale cress plant Also Neurospora crassa - bread mold, and Zea mays - corn
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Example: Zebrafsh and human skin color Zebrafsh small vertebrates many progeny easy to raise in labs golden mutants were discovered in a pet store in Oregon in the 1970’s.
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 62

Lecture 5 - Lecture 5 Genetic Model Organisms/Pedigrees...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online