genes, peoples, and languages across the western mediterranean david comas unitat de biologia...

Genes, peoples, and languagesacross the Western Mediterranean

David ComasUnitat de Biologia EvolutivaUniversitat Pompeu Fabra

[email protected]

Sahara Desert

Objectives

Elucidate the genetic structure ofNW African and SW European populations

Compare the genetic compositionof both Mediterranean shores

Detect possible sub-SaharanAfrica admixture in NW Africa

Compare the genetic composition ofBerber and Arab populations in NW Africa

Genetic markers

Classical polymorphisms: proteins

Autosomal markers: STRs, Alu insertions

Uniparental markers: Y-chromosome and mtDNA

DNA markers

Cavalli-Sforza LL, Menozzi P, Piazza A (1994). The history and geography of human genes

Classical genetic markers in Europe

First Principal Component (28.1%)

Classical genetic markers in North Africa

First Principal Component (36.5%)

Bosch E, Calafell F, Pérez-Lezaun A, Comas D, Mateu E, Bertranpetit J (1997)Population history of North Africa: evidence from classical genetic markersHum Biol 69: 295-311

Simoni L, Gueresi P, Pettener D, Barbujani G (1999)Patterns of gene flow inferred from genetic distances in the Mediterranean regionHum Biol 71:399-415

Classical genetic markers in the Mediterranean

Sharpest genetic boundaries

From Arnaiz-Villena and Martínez-Laso (1997) Origen de ibéricos, vascos y argelinosInvestigación y Ciencia

A30-B18-DR3A1-B8-DR3A29-B44-DR7A1-B57-DQ2A11-B27-DR1

A30-B18-DR3A1-B8-DR3A29-B44-DR7A33-B14-DR1

A30-B18-DR3A33-B14-DR1A1-B57-DQ2A2-B35-DR11

Classical genetic markers: HLA evidence

91 41

7880

9066

35

Neighbor-joining tree based on 7 HLA loci

Comas D, Mateu E, Calafell F, Pérez-Lezaun A, Bosch E, Martínez-Arias R, Bertranpetit J (1998)HLA class I and class II DNA typing and the origin of Basques. Tissue Antigens 51: 30-40

Classical genetic markers: HLA evidence

PORTUGUESE

BASQUESCATALANS

ANDALUSIANS

MOZABITES

NCBERBERS

ARABS

SO BERBERS

SAHARAWI

Autosomal STRs (Short Tandem Repeats)D3S1358 (TCTA)n

vWA* (TCTA)n

FGA (CTTT)n

D8S1179 (TCTA/G)n

D21S11 (TCTG/TA)n

D18S51 (AGAA)n

D5S818*(AGAT)n

D13S317 (GATA)n

D7S820*(GATA)n

TH01 (CATT)n

TPOX (AATG)n

CSF1PO (AGAT)n

(GATA)n

(GATA)n (GATA)n

(GATA)n

(GATA)n

(AGAT)n

(AAAG)n

(ATTT)n

(GATA)n

D11S2010D13S767D14S306D18S848D2S1328D4S243F13A1FES / FPSD9S926

21STRs

AACTTGCTAAGATAGATAGATAGATAGATAGCGCGCC

AACTTGCTAAGATAGATAGATAGATAGCGCGCC

-30

-20

-10

0

10

20

30

40

-60 -40 -20 0 20 40 60

75%

AFRICANAMERICANS

MOZABITES

SAHARAWI

ARABS

NCBERBERS

SOBERBERS

ANDALUSIANS

PORTUGUESE

ITALIANS

EUROPEANAMERICANS

CATALANS

BASQUES

Bosch E, Calafell F, Pérez-Lezaun A, Clarimón J, Comas D, Mateu E, Martínez-Arias R,Morera B, Brakez Z, Akhayat O, Sefiani A, Hariti G, Cambon-Thomsen A, Bertranpetit J (2000)Genetic structure of north-west Africa revealed by STR analysis. Eur J Hum Genet 8: 360-366

Autosomal STRs (Short Tandem Repeats)

Alu insertion polymorphisms

BASQUESCATALANS

ANDALUSIANS

ALGERIANSN. MOROCCANSW. MOROCCANS

SE. MOROCCANS

SAHARAWI

TUNISIANS

Alu elementAlu element

Alu element

A25 ACE APO B65 D1 FXIIIB PV92 TPA25 HS243 HS323 HS465

11 Alu insertion polymorphisms

-/- +/- +/+

0

10

20

30

40

50

60

70

80

90

100A

25

ACE

APO

B65

D1

FX

IIIB

PV92

TPA

25

HS

243

HS

323

HS

465

Basque

Catalan

Andalusian

Saharawi

E.Moroccan

W.Moroccan

N.Moroccan

Algerian

Tunisian

Comas D, Calafell F, Benchemsi N, Helal A, Lefranc G, Stoneking M, Batzer MA, Bertranpetit J,Sajantila A (2000). Alu insertion polymorphisms in NW Africa and the Iberian Peninsula:evidence for a strong genetic boundary through the Gibraltar Straits. Hum Genet 107:312-319


Basque

AndalusianCatalan

NorthernMoroccan

WesternMoroccan S. Eastern

Moroccan

SaharawiTunisian

Algerian

98.7

60.4

60.4

85.728.9

46.3

Neighbor-joining treeof populations

11 Alu insertion loci

1,000 bootstrap iterations

NW AfricansIberians


S.EasternMoroccan

Saharawi

WesternMoroccan

Catalan

Andalusian

Basque

NorthernMoroccan

Tunisian

Algerian

First PC (48.0%)

Sec

ond

PC

(20

.8%

)

Principal component analysis of the Alu insertion frequencies


!Kung

Nguni

Bantu

SEMoroccansSaharawi

Algerians

Tuni

sian

s

WM

oroc

cans

NMor

occa

nsCat

alan

s

Sw

issB

reto

ns

French

BasquesAnd

alus

ians

85.882.9

96.9

1,000 bootstrap iterations

Sub-SaharansNW AfricansEuropeans


Neighbor-joining treeof populations

11 Alu insertion loci

First PC (44.9%)

Sec

ond

PC

(24

.2%

)

Principal component analysis of the Alu insertion frequencies


Sub-SaharansNW AfricansEuropeans

??3 individuals: 2 Basques and 1 Northern Moroccan


Larger Alu insertion in PV92 locus

Alu element

Alu elementAlu element

Alu element



Comas D, Plaza S, Calafell F, Sajantila A, Bertranpetit J. (2001)Recent insertion of an Alu element within a polymorphic human-specific Alu insertion.Mol Biol Evol 18:85-88



3 individuals: 2 Basques and 1 Northern Moroccan


mtDNA

autosomes

Y chromosome


Five generations

MALE

FEMALE

16 Great-greatgrandparents

Son

FatherMother

4 Grand-parents

8 Great-grand-Parents 32 Great

great-great grandparents


Y Adam and mtDNA Eve

2

3

4

5

6

7

8

1genera

tions

MRCA

Uniparental markers: Y-chromosome and mtDNA mtDNA phylogenyY-chromosome phylogeny


Phylogeography: ex. Y-chromosome


Gender specific behaviours

Patrilocality: females are more likely to move from their birthplace upon marriage than males

Polygyny: certain men father a disproportionately large number of children compared to other men

Y-chromosome lineages

BASQUESCATALANS

ANDALUSIANS

NCBERBERS

ARABS

SO BERBERS

SAHARAWI

DYS388 DYS19 DYS390 DYS391 DYS392 DYS393 DYS389I DYS389II

+ 8 STRs44 binary

Bosch E, Calafell F, Comas D,Oefner PJ, Underhill P, Bertranpetit J (2001)High-resolution analysis of human Y-chromosome variation shows a sharp discontinuityand limited gene flow between Northwestern Africa and the Iberian PeninsulaAm J Hum Genet 68: 1019-1029

E3a*


E3b2


F*


R1*


Iberian Peninsula

NW Africa

North African Paleolithic substrate 75%

Sub-Saharangenetic flow 8%

North African genetic flow 5.2%

Neolithic contribution 16.4%

Neolithiccontribution 13.6%

European Paleolithicsubstrate78.4%

Iberian geneticflow 2.8%


Mauritanians

Saharawis

SBerbers

MArabsNBerbers

Mozabites

Algerians

Tunisians

SItalians

CItalians

Tuscans

Sardinians

CatalansBasquesGalicians

ValenciansAndalusians

Central SpainNPortugueseCPortuguese

SPortuguese

Portuguese

Sicilians

Mitochondrial lineages

Plaza S, Calafell F, Helal A, Bouzerna, Lefranc G, Bertranpetit J, Comas D (2003)Joining the Pillars of Hercules: mtDNA sequences show multidirectional gene flow in the Western MediterraneanAnn Hum Genet 67: 312-328

HVS I Control Region+ 4 SNPs Coding Region 10400

12308

12705

10873

mtDNA haplogroups defined bycontrol region sequencesand coding polymorphisms



First principal co-ordinate (55.4%)

.8.6.4.20-.2-.4

Sec

ond

prin

cipa

l co-

ordi

nate

(12

.7%

).8

.6

.4

.2

-.0

-.2

-.4

-.6

ValenciansValencians

CSCSCICI SPortSPort

Central PortugueseCentral Portuguese

NorthNorthPortuguesePortuguese

PortuguesePortuguese

GaliciansGalicians

BasquesBasques

CatalansCatalans

AndAndTusTus

SouthSouthItaliansItalians

SicSicSardSard

MauritaniansMauritanians

SaharawiSaharawi

SBerbersSBerbers M ArabsM Arabs

M BerbersM Berbers

MozabitesMozabites

AlgeriansAlgerians

TunisiansTunisians

Plot of the two principal co-ordinate scores based on genetic distances

L1L1L2L2L3L3

Haplogroup L


U/KU/KU6U6


Haplogroup U/K

180

278

311 290

311

278

261174

188

163

164

129

271

222

239

311

172

297

111

293180

189

359182

192

235

355145

311

051

ItaliansIberians

North Africans

U6b

HH

VV

HVHV


Haplogroup H and V

153

189

075

240

259

183

189254216140291

249

362298

256

304

235

153093

259037264086

172 344311

129

242

124

319

039240

261

169

339

265129

218

239

ItaliansIberians

North Africans

M1M1


Haplogroup M

MM55


Sened

Matmata

Chenini-Douiret


-3,0

-2,0

-1,0

0,0

1,0

2,0

3,0

-2,0 -1,0 0,0 1,0 2,0

W

U6V

L2

L1L3

UH

M1X

J

Other

N K

I

T

HV

J/T

Mozabites C.Moroccan2

Mauritanians

Tuareg

Saharawi

MoroccanS.Moroccan

MatmataAlgerian

Sened Tunisian

C.Moroccan1

Egyptians Chenini-Douiret

mtDNA haplogroupArabBerber

Fadhlaoui-Zid K, Plaza S, Calafell F, Ben Amor M, Comas D, Bennamar El Gaaied A (2004)Mitochondrial heterogeneity in Tunisian Berbers. Ann Hum Genet 68: 222-233

Correspondence analysis based on haplogroup frequencies


Arabs 1.54** 98.46

Berbers 6.24** 93.76

Analysis of the molecular variance (AMOVA)

ns not significat** p < 0.01

Fadhlaoui-Zid K, Plaza S, Calafell F, Ben Amor M, Comas D, Bennamar El Gaaied A (2004)Mitochondrial heterogeneity in Tunisian Berbers. Ann Hum Genet 68: 222-233

All populations 4.14** 95.86

Arabs-Berbers -0.21 ns 4.25** 95.95

Groups Among groups Among populations Within populations

1) Clear genetic difference between NW Africa and SW Europe

The Palaeolithic and Neolithic may have run in parallel along the two shores

Gibraltar Straits may have acted as a geographical barrier

Little genetic impact in Iberia of Arab occupation

Western Mediterranean populations: Conclusions

2) Sub-Saharan flow detected in some NW African samples

Continuous gene flow through the Sahara desert

South-north gradient of sub-Saharan admixture


3) No differences between Berber and Arab samples

Arabisation in the Maghreb (7th and 11th C A.D.):

Cultural replacement with little demographic impact



4) Greater heterogeneity in NW Africa

Genetic drift in isolated populations

Differential genetic admixture

Population sampling bias ?

Genes, peoples, and languagesacross the Western Mediterranean

David ComasUnitat de Biologia EvolutivaUniversitat Pompeu Fabra

[email protected]

genes, peoples, and languages across the western mediterranean david comas unitat de biologia...

Documents

benchemsi n

agat n d13s317gata n

dr11 classical genetic

nw africa slide

genetic distances

genetic composition

bertranpetit j

sahara desert slide