Genes and Evolution

Comparative Genome Structure and Evolution

Synteny- comparison of chromosome order in related species

C

B

A

D

Ricechromosome

4

SyntenyThe order of genes in closely related species is conserved

A

B

DC

Maizechromosome

2

Geneticdistance (cM)

0

100

Oats

Wheat, barley

Rice

Bamboo

Finger millet

Maize, sugarcane,sorghum

Pearl millet

Phylogeny of the grass family (Poaceae)

R12b

R8 R9 R11aR11b

R12b

R5bR6aR6b

R7

R3bR4aR4b

R5aR1aR1b

R2 R3a

R10

R3c

Rice has the simplest cereal genome

1 2 3 4 5 6 7 8 9 10 11 12

1/ It has the smallest genome (420 Mb)

2/ It has 12 chromosomes with little duplication

3/ These 12 chromosomes can be split up to produce linkage blocks that define the other cereals

R12b

R8

R9

R11aR11b

R12b

R5b

R6aR6b

R7

R3b

R4aR4b

R5a

R1aR1b

R2

R3a

R10

R3c

The Rice Genome

R6b

R12bR9

R2

R6aR8

R3c

R12aR11aR11b

R7

R1aR1b

R3b

R5aR10R5b

R4a

R3a

R4b

W1

W2

W3

W4

W5

W6

W7

The WheatGenome

R2

R4a

R9R7

R10R3bR3a

R11a

R6b

R5b

R3cR8

R12aR1aR1b

R6a

R4b

R5a

R9R7

R4bR12a

R10R3bR3a

R11a

R6a

R8?R3c

R2

R1aR5aR5bR1b

R4a

R6b

M3

M6

M1

M4

M2

M8

M9

M5

M7

M10

The Maize Genome

Making a circle displays the syntenic relationship between grass crops

The 22 autosomal and 2 sex chromosomes of human

The synteny between the human genome and the first 4 chromosomes of the mouse

Synteny between Human and Mouse

6

218

1

10921115

20

83431

4

8

9

1

Synteny- why is it important?

It is interesting

It demonstrates the role of chromosomal rearrangements in evolution

It can be used to deduce taxonomic relationships between organisms

It facilitates the exploitation of model species- rice for grasses, mice for humans