LeCHE  
Lactase persistence and the early Cultural History of Europe  
line decor
     HOME  :  PARTICIPANTS  :  
   
 
JOHANNES GUTENBERG UNIVERSITY

SkullsThe Paleogenetics Group’s interests lie in molecular genetics of prehistoric, historic and fossil remains, including the domestication of cattle (Biology Letters 2005, Proc Royal Soc B 2007) and horse, and species extinction of Pleistocene lions (MPE 2004). Within the framework of a broader project, including various national and international working groups, the early colonisation history of Europe by Neolithic farmers is investigated (Science 2005, 2006). Furthermore, various population genetic analyses of prehistoric populations (Merovingian, Sarmatian, Mesolithic) were carried out (PNAS 2007). Other work concentrates on DNA damage, bone chemistry and decomposition.

ESR4 Genetics of ancient humans
Prof. Joachim Burger
top

Analysis based on the conservation of lactase gene haplotypes indicates a recent origin and high selection coefficients for LP, although it has not been possible to say if early Neolithic European populations were lactase persistent at appreciable frequencies. So far, we have obtained high-confidence LP-associated genotypes from 8 Neolithic and 1 Mesolithic human remains (PNAS 2007, 104:3736 PNAS). We did not observe the 13.910*T allele indicating that LP was rare in early European farmers. While our data are consistent with strong selection for LP beginning with the introduction of cattle to Europe ca. 8,300 BP, it is unlikely that fresh milk consumption was widespread in Europe before frequencies of the 13.910*T allele had risen appreciably, during the millennia after the onset of farming.
Important questions remain regarding the origin, mode and direction of spread of the -13.910*T allele, and the precise nature of the selective advantage(s) conferred by LP. A number of approaches are available for inferring the geographic origin and direction of spread of an allele using modern population data (e.g. Geographic structuring, ESR3, Computer simulations ESR12), but all inference-based methods carry a degree of uncertainty. An aDNA approach is the most direct way of studying the evolution of LP in Europe. We therefore plan to combine mitochondrial haplotype typing of archaeological remains, (Scienc 2005, 310:1016), with the typing of -13.910*T alleles.
We plan (with ESR6 ) to optimize our technical protocols to improve this success rate, by i) improving existing aDNA extraction methods and analysis methods ii) make use of modern high-throughput sequencing technology (Solexa and 454) – see ESR6 . In addition we will use LeCHE to help optimise sampling. Using a database of biomolecular preservation (with Collins, GeneTime MCEST collaboration, further data from ESR6 ) and the diagenetic screening in (ESR13) we will obtain the first map of biomolecular preservation in Europe. This will help us identify well-preserved Neolithic skeletons with nuclear DNA, for examination of not only for LP associated genotypes but other markers related to the consumption of milk and the adoption to Northern European environment and climate, such as alleles correlated with skin and hair colour, NaCl re-absorption capacity, and others. We plan to screen 1.000 Neolithic skeletons.

Given that only a small fraction of genomic diversity may be addressed in any aDNA program, a key question for bovine aDNA is which Single Nucleotide Polymorphisms (SNPs) or sequences will give the maximally useful information when typed in early European remains? LeCHE is timely given the resources currently emerging from the bovine genome project. In particular, Bradley is a member of the consortium conducting the analysis of an emerging cattle ‘hapmap’ data set where population samples from 19 breeds have been genotyped for 33,000 SNPs. However, the breeds typed to date were chosen on economic rather than biogeographic or archaeogenetic criteria. Here we will type, using the existing and emerging bovine high-throughput SNP typing resources, a series of additional population samples chosen to inform the origins and dispersal of cattle; samples are already in place in TCD. We will identify panels of markers which are diagnostic for the major biogeographical divisions in European cattle - subsequent typing of these in ancient remains will inform on the time depth and origins of these divisions. Another output will be the identification of loci in genome regions which show a population genetic signature of selection. This will include genes linked to milk production and SNPs that are informative for dairy-associated biological change in cattle through time will be identified. This project will link with ESR6 , be guided by ER1 and ESR13 and report to ER2.

 
STAFF
top

Prof. Dr. Joachim Burger is the head of the Palaeogenetics Group in Mainz and a board member of the German Archaeometry Society (GNAA).

Dr. Ruth Bollongino is researcher and lab manager in the Palaeogenetics group. She has a strong international reputation for her work in the population genetics of domestication of cattle.

Dr. Barbara Bramanti is researcher at the Department of Anthropology. Her main research areas are the population genetics of ancient European population from the Neolithics onward.

 
FACILITIES
top

The group has both an acclaimed aDNA facility (pre-PCR), for all procedures of sample preparation, DNA extraction and the set-up of PCR, and a second post-PCR lab that is a standard molecular genetics lab for gel electrophoresis and DNA sequencing including a cloning facility.

 
REFERENCES
top

1. Edwards CJ, et al Genetic Mitochondrial DNA analysis shows a Near Eastern Neolithic origin for domestic cattle and no indication of domestication of European aurochs. (2007) Proceedings of the Royal Society B 274:1377-1385

2. Burger J, Kirchner M, Bramanti B, Haak W, Thomas MG, Absence of the Lactase-Persistence associated allele in early Neolithic Europeans. (2007) Proceedings of the National Academy of Sciences 104:3736-3741

3. Haak W, et al. Ancient DNA from the First European farmers in 7500-year-old Neolithic sites. (2005) Science 310:1016-1018