Domestication-2

Question 1

Chicken domestication

Answer 1

TSHR gene
BCDO2 gene
NELL-1 
PDGFC
HNF4G

6000 years ago in China

Question 2

Selective sweep

Answer 2

Reduction or elimination of variation in neighbouring DNA due to a mutation or strong positive selection

Large population- lots of variation
Advantageous trait selected for= genetic bottleneck
Population grows, but less diverse

Question 3

TSHR

Answer 3

Thyroid stimulating hormone receptor
Responsible for photoperiod signalling between pituitary and hypothalamus
TSHRG558R mutation
Glycine, small uncharged to Arginine charged
Change in protein structure
Reduced sensitivity to light

Question 4

Nell-1

Answer 4

Responsible for the increase in skull and rib size of chickens, needed for broilers

Question 5

Bcdo2

Answer 5

Beta carotene dioxygenase enzyme
Breaks down beta carotene in chickens
Domesticated have mutation so less BCDO2 expression
Chicken skin remains yellow, more attractive

Question 6

PGGFC

Answer 6

Platelet derived growth factor c

Increases leg muscle and thigh size in broiler chickens

Question 7

HNF4G

Answer 7

Allows chickens to gain more weight by eating less food

Question 8

Brassica family

Answer 8

Buds, flowers, shoots, leaves

Brocolli, cauliflower, sprouts, kale

Question 9

Cauliflower

Answer 9

Profusion of arrested inflorescence meristems
Heading phenotype
Mutation in boCAL and BoAP1 gene needed for phenotype
Mediterranean origin, 1400’s

Question 10

Broccoli

Answer 10

Arrested floral meristems
BoCAL gene is truncated
1500’s

Question 11

BoCAL gene

Answer 11

Mutation in exon 5 which changes GAG to TAG, premature stop codon, so truncated gene

Question 12

Arabidopsis experiements

Answer 12

Mutations in AP1 and CAL together produced heading phenotype

AP1 and CAL are mads box transcription factors
Candidate genes, studied in domesticated species