L17 - Genome Evolution

Question 1

Within orgaisms most of the genes are ___________ what changes is the __________

Answer 1

The same

Expression of the genes

Question 2

What is phylogeny

Answer 2

Systematic classification of the animals into groups based upon their morphology

Question 3

When genome sequencing was first used what was seen

Answer 3

That most of the genes are the same

Question 4

From a phylogenic tree what needed to be estimated

Answer 4

The timing of the branch points

Question 5

Why do we share manyg many genes with other species

Answer 5

Many genes arose at the common single cell stage which were the requirements for life

Question 6

What is the traditional way of calibrating the clock

Answer 6

Using fossil records and carbon dating

Question 7

What is the change in the nucleotide sequence change between humans and organutans

Answer 7

1.5 bases per 100

Question 8

FOXP2 differs in mouse, chimp and humans at which three positions

Answer 8

80, 303, 325

Question 9

In FOXP2 at position 80 was is the AA in humans and in mice

Answer 9

D in humans and chimps

E in mouse

Question 10

So the common ancestor of human and chimp …

Answer 10

Had a D at psotion 80

Question 11

Parsimony means

Answer 11

Assuming the simplest model

Question 12

How is the parsimony decided

Answer 12

Programs related to blast consider all of the possible scenarios to come up with the most likely one

Question 13

If 80D had arrisen twice by chance - what would this have been an example of

Answer 13

Convergent evolution

Question 14

Molecular phylogeny is compared with ….. to give us a deeper understanding of evolution

Answer 14

Morphological phylogeny and fossil records to give us a deeper understanding of evolution

Question 15

How many vertebrate FGFs are there?

How many clusters?

Answer 15

22

4

Question 16

What is special regarding the composition of FGF in the ciona

What does this suggest

Answer 16

It has a single representative of each of the 4 clusters

Suggests common ancestory of Ci and vertebrates had 4 FGFs

Question 17

What are the two ways in which so many FGFs arise

Answer 17

Changes in ploidy of the cells and local duplications

Question 18

New copies of genes in the genome are known as …

Answer 18

Paralogues

Question 19

What is special about the large strawberry

Answer 19

It is octaploid

Question 20

After duplication it is likely that the duplicate genes will first be ….

Answer 20

REDUNDANT

Question 21

The extra copy of the gene would the be able to ….

Answer 21

Change in the following ways

Change pattern of expression OR change in strucutre of the protein

Question 22

What are thought to be the most common sort of change which drives morphological evolution of animals

Answer 22

Changes in expression patterns

Question 23

Does evolution involve the creation of new genes

Answer 23

No it is the modifcation of old ones

IT IS GENE EVOLUTION WHICH DRIVES MORPHOLOGICAL EVOLUTION

Question 24

Why are changes in expression patters thought to play a major role in morphological evolution

Answer 24

Because enhnacers can change easily

Question 25

Why are enhancers able to change easily

Answer 25

Due to the fact that the exact psoiton of an enhancer is unimportant and TF bidning site motifs are simple

Question 26

Why do changes that affect the STRUCTURE of a protein have to be more precise

Answer 26

So as not to introduce a stop codon, change the ORF, interfere with folding or disrupt splicing

Question 27

How does chick and mouse show evidence of change of expression playing a major role in evolution

Answer 27

Chick has a longer neck - more cervical vertebrae and less thoracic vertebrae

Question 28

What hox gene specifies the cervical vertebrae

Answer 28

Hox C5

Question 29

What hox gene specifies the thoracic vertebrae

Answer 29

Hox C6

Question 30

What can be said about the expression of HOX C6 in the chick compared to the mouse

Answer 30

Expression of C6 (specifies the thoracic vertebrae) starts more posteriorly in the chick

Question 31

Genes that a capable of the formation of organs are known as

Answer 31

Master regulatory genes

Question 32

What occurs when a master regulatory gene is ectopically expressed

Answer 32

Ectopic limb/organ development

Question 33

Are ectopic organs functional? What is this an example of?

Answer 33

Yes functional Evolutional robustness

Question 34

Which organism has legs on their abdomens Crrustaceans or insects?

Answer 34

Crustaceans have legs on their abdomens but insects dont

Question 35

What does Dlx specifiy

Answer 35

Leg precurrsor cells

Question 36

Describe the expression in fly embryos

Answer 36

Ubx expressed in abdomen where it represses Dlx ==> no legs in abdomen

Question 37

What does dlx stand for

Answer 37

Distal-less

Question 38

Explain the expression of Ubx in insects - what does this imply about the evolution of Ubx

Answer 38

Dlx and ubx BOTH expressed in the abdomen Crustacaen ubx has an antirepression motif which was lost in insects