Midterm 2 - Notes 3 (Part 4) Flashcards
Where are WG in eukaryotes most common?
In plants
What does WGD allow? (2)
- Allows rapid evolution for whole pathways
2. Allows rapid variation of lineage to take place
What is a driving force for speciation?
WGD
What are 2 advantages for WGD?
- Difficult to show changes in specific phenotype traits
2. WGD allows for stability of multiple copies better at inhibiting mutations
What is very unstable? And what is the exception?
Poly-ploid
- the except in body size
What does poly-ploid produce?
Larger fruit
- selective breeding also helps with this
What does WGD correlate with?
Major evolutionary
What is WGD always a part of? And what is its effect?
It is part of a combination, so it is hard to pinpoint where the advantages occur
Segmental duplications
Any type of duplication that is intermediate in size
What do segmental duplications do?
Block duplication of the genome
How does segmental duplication occur? (2)
- Through replication errors
2. Inexact DNA break repairs
What does segmental duplication involve?
Only a small portion of the genome
How do duplications arrange?
In tandem in the genome
Tandem
Right next to each other
What is an example of a segmental duplication experiment?
Comparing humans vs chimps genomes
What caused the most differences?
Duplication
- rather than single nucleotide changes
What does segmental duplication allow?
Allows evolution of new functions while old functions is maintained
What do Antarctic fish produce? And where?
They produce anti-freezing proteins
- in the pancreas
What are the anti-freezing proteins rich with? (2)
- Alanine
- Threonine
- consists of many repeats
What is the anti-freezing protein common in? (2)
- Cold blooded animals
2. Cold adaptive plants
How do anti-freezing proteins work?
By binding to ice crystals
What does it mean when they found different anti-freezing proteins in different lineages?
That they are not the same and that it had to evolve over time and in different animals
How did they find similarities in organisms?
Looked at flanking sequences
What did they discover after they looked at flanking sequences?
Discovered the tripsinogen gene and was able to identify gene similarities
What 2 proteins had no overall similarity with other genes?
- Anti-freezing protein
2. Trypsinogen
In the end what did they discover?
That they were nearly identical
- very few differenes
What marks the end of the last intron in trypsinogen?
ag
What does the ‘a’ missing in the AFP and positions of 3, 4 and 5 of exon 6 in trypsinogen become?
A TGA stop codon in AFP
What do incorrect fusions cause?
An early termination codon
What does an incorrect fusion of exon 6 to tandem repeats create? (2)
- A frameshift mutation
2. Premature stop codon
