Martinez et al. (2007)

From Haplowiki

Martinez et al. (2007)

Paleolithic Y-haplogroup heritage predominates in a Cretan highland plateau

Laisel Martinez1, Peter A Underhill2, Lev A Zhivotovsky3, Tenzin Gayden1, Nicholas K Moschonas4, Cheryl-Emiliane T Chow2, Simon Conti2, Elisabetta Mamolini5, L Luca Cavalli-Sforza2 and Rene J Herrera1

• 1. Department of Biological Sciences, Florida International University, Miami, FL, USA
• 2. Department of Genetics, Stanford University, Stanford, CA, USA
• 3. N.I. Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
• 4. Department of Biology, University of Crete, Crete, Greece
• 5. Department of Biology, University of Ferrara, Ferrara, Italy

Correspondence: Dr RJ Herrera, Department of Biological Sciences, Florida International University, University Park, Room OE304, Miami, FL 33199, USA, Tel: +1 305 348 1258; Fax: +1 305 348 1259; E-mail: herrerar@fiu.edu

European Journal of Human Genetics (2007) 15, 485–493. doi:10.1038/sj.ejhg.5201769; published online 31 January 2007

http://www.nature.com/ejhg/journal/v15/n4/full/5201769a.html

Received 13 July 2006; Revised 24 October 2006; Accepted 21 November 2006; Published online 31 January 2007.

Abstract

The island of Crete, credited by some historical scholars as a central crucible of western civilization, has been under continuous archeological investigation since the second half of the nineteenth century. In the present work, the geographic stratification of the contemporary Cretan Y-chromosome gene pool was assessed by high-resolution haplotyping to investigate the potential imprints of past colonization episodes and the population substructure. In addition to analyzing the possible geographic origins of Y-chromosome lineages in relatively accessible areas of the island, this study includes samples from the isolated interior of the Lasithi Plateau – a mountain plain located in eastern Crete. The potential significance of the results from the latter region is underscored by the possibility that this region was used as a Minoan refugium. Comparisons of Y-haplogroup frequencies among three Cretan populations as well as with published data from additional Mediterranean locations revealed significant differences in the frequency distributions of Y-chromosome haplogroups within the island. The most outstanding differences were observed in haplogroups J2 and R1, with the predominance of haplogroup R lineages in the Lasithi Plateau and of haplogroup J lineages in the more accessible regions of the island. Y-STR-based analyses demonstrated the close affinity that R1a1 chromosomes from the Lasithi Plateau shared with those from the Balkans, but not with those from lowland eastern Crete. In contrast, Cretan R1b microsatellite-defined haplotypes displayed more resemblance to those from Northeast Italy than to those from Turkey and the Balkans.

Data

CRETE	out of	E-M35(xM78,M123)	E-M78	E-M123*	E-M34
Heraklion Prefecture	104	2	7	0	2
Heraklion Prefecture	100%	1.90%	6.70%	0	1.90%
Lasithi Plateau	41	0	2	0	0
Lasithi Plateau	100%	0	4.90%	0	0
Lasithi Prefecture	23	0	2	0	1
Lasithi Prefecture	100%	0	8.70%	0	4.30%

This can be usefully compared to the data collected by Di Giacomo et al. (2003).

Quotes

E3b1-M78 samples were genotyped for Y-STR markers A7.1, DYS19, and DYS439 in order to classify them into E3b1-M78alpha, beta, italic gamma, and delta lineages, respectively.

From the section "Neolithic and postneolithic signals from eastern Crete":-

The clinal frequency pattern of haplogroup E in the Mediterranean region has been associated with several dispersal events during and after the Neolithic period.19, 25, 26 Originally emanating from East Africa, haplogroup E3b-M35 and particularly subhaplogroup E3b1-M78 are believed to be signatures of a demic diffusion of Neolithic farmers from the Middle East to Europe. This haplogroup has left its strongest imprint along the Southern Mediterranean.20, 26, 27

In the three Cretan populations studied in this work, the frequency of E3b-M35-derived chromosomes range from 4.9% in the Lasithi Plateau to 13% in the Lasithi Prefecture population. As expected, the most common subhaplogroup observed is E3b1-M78, which is the only one found in the Lasithi Plateau collection (Figure 2). Further genotyping of the M78-derived samples for the Y-STR markers A7.1, DYS19 and DYS439, allowed their classification into two of the four previously delineated E3b1-M78 lineages (ie, alpha, beta, italic gamma, and delta).19 One chromosome from the Lasithi Plateau population and two chromosomes from the Heraklion Prefecture belong to the lineage M78delta, whereas the remaining eight Cretan samples belong to the lineage M78alpha. The highest frequency of the M78alpha lineage was previously observed in the Balkans. This decreased in the western and northeastern directions in European populations.19 Cluster M78delta, on the other hand, was detected at low frequencies in Europe, the Near East, eastern and northern Africa,19 and it has been found to be associated with at least three M78 downstream mutations.28 Given the paraphyletic character of this cluster, it is not possible to relate, at this juncture, the Cretan M78delta chromosomes with those found in neighboring locations. Considering the relatively high frequency of E3b1-M78 chromosomes in Albania, Macedonia and Greece,16, 19, 26 and particularly the M78alpha lineage in the first two of these collections (data not available for Greece), it is possible that the presence of this lineage in Crete represents gene flow from mainland Greece during and/or after the Neolithic.

In the case of Cretan E3b3-M123 (M34) chromosomes, they most likely signal East African or Middle-Eastern gene flow rather than European, due to the scarcity of this lineage in the latter area.19, 26 Similarly, the presence of E3b-M35* individuals in the Heraklion Prefecture population could probably be attributed to an East-African or North-African contribution.