Development and diversity

Question 1

Describe biochemistry

Answer 1

the study of material with some biological activity that has been extracted from a living tissue

Question 2

Describe some biochemical techniques

Answer 2

• fractionation
• repeated assay

Question 3

Describe Bmps

Answer 3

• Bone Morphogenetic Proteins
• intercellular signalling proteins

Question 4

Describe FGF’s

Answer 4

• Fibroblast Growth Factor
• intercellular signalling protein

Question 5

How are inbred mutation lines created?

Answer 5

• male eats food with mutagen
• developing sperm have different mutations
• cross with WT females
• offspring have different mutations
• outcross offspring separately

Question 6

What can inbred mutation lines be used for

Answer 6

examination of homozygous embryos for adults for developmental defects

Question 7

Most of the genes identified in the mutant screens were involved in two sorts of activity…

Answer 7

• Control of transcription (TFs)
• Intercellular communication (signaling)

Question 8

What is the developmental gene toolkit

Answer 8

• genes in an organism’s genome whose products control development
• evolved before the Cambrian
• ancestral trait of most animals

Question 9

Describe some conserved genes of the gene toolkit

Answer 9

• Hox
• MyoD
• FGF
• Wnt
• Bmp

Question 10

Describe sponge development

Answer 10

fewer genes in the toolkit

Question 11

Describe Wnt in AP axis development

Answer 11

signal localisation

Question 12

Wnt signalling works by

Answer 12

• controlling nuclear import β- catenin
• specification of endoderm and mesoderm
• early role in axis patterning

Question 13

DV axis specification by Bmp is ancestral to the

Answer 13

Bilateria

Question 14

Describe the Hox genes

Answer 14

• a conserved mechanism for AP cell identity
• cluster(s) of homologous genes
• encode TFs that bind DNA through the Homeodomain
• expressed in subdomains along the AP axis
• colinear

Question 15

Homeodomain

Answer 15

DNA binding domain

Question 16

Discuss colinearity

Answer 16

order of genes in cluster is same
as order of expression along axis

Question 17

Where can Hox genes be traced to?

Answer 17

common ancestor of the Cnidaria and Bilaterian animals

Question 18

Describe tandem duplication

Answer 18

• creates linked copies of a gene

Question 19

Describe the Hox cluster in early vertebrate evolution

Answer 19

• duplicated to give 4 clusters on different chromosomes
• whole genome duplication

Question 20

Describe the effects of sequence differences in the DNA binding domain

Answer 20

two proteins may bind to different DNA sequences

Question 21

Describe neofunctionalisation in Hox

Answer 21

• new developmental functions by changes in expression
• ancestral role in AP development
• new role in limb development

Question 22

How do changes in gene expression evolve?

Answer 22

new TF-enhancer interactions generate new expression domains

Question 23

Describe some possible TF-enhancer interactions

Answer 23

• new TF evolves to recognise new DNA sequence
• enhancer sequence evolves such that another TF can bind it
• enhancer sequence evolves so binding of TF lost