Introduction

The high copy number per cell, the stability against degradation and the maternal mode of inheritance make the mitochondrial (mt) genome particularly suitable for palaeo-, medical- and forensic-genetic investigations. Its increased evolutionary rate led to sequence variation that has been generated by sequential accumulation of new mutations along radiating maternal lineages during human dispersal into different parts of the world. Forensic molecular biology takes advantage of this variation for human identity testing by sequence analysis of hypervariable segments within the mtDNA control region. MtDNA analysis is a powerful tool to exclude samples as originating from the same individual/matriline. If two samples cannot be excluded the significance of the mtDNA match needs to be assessed by making reference to the frequency with which that particular mtDNA sequence (= mtDNA haplotype) has been observed in a relevant population.

Concept

The EMPOP Database aims at the collection, quality control and the searchable presentation of mtDNA control region haplotypes from all over the world. The EMPOP project is a scientific collaboration between the Institute of Legal Medicine (GMI), Innsbruck Medical University and laboratories performing mtDNA research.

The EMPOP Database has been carefully envisioned as high quality mtDNA database, where primary sequence lane data are permanently linked to the compiled sequences, and a variety of quality control analyses, phylogenetic and logical, are applied to the data to check for error.

Forensic data: Submission of sequences to EMPOP is in the form of raw database files, which are then assembled anew into consensus sequences, with any sequences not meeting forensic criteria excluded. The compiled consensus sequences are further checked by phylogenetic analysis and compared to the results obtained from the collaborating laboratory as an additional mutual check for correctness. The retention of primary sequence data will permit questionable positions checked at any time.

Literature data are compiled from the literature or were submitted to EMPOP as data tables. These data undergo critical a posteriori analysis using phylogenetic methods (e.g. Network, see below) and logistic checks prior to the upload onto the database.

In the first EMPOP release we concentrated on West Eurasian variation, adding only few examples of other major populations. With the generation of European etalon datasets we are able to quality-check and include literature data from West Eurasia and will continue to do so in the future. In a similar way, we will establish etalon datasets for other major populations to proceed in the same manner.

How to use the EMPOP

The QUERY site can be used to determine the occurrence of individual polymorphic sites and segments of the mtDNA control region. The HELP page guides you through the individual functions and settings in detail.

MyEMPOP

MyEMPOP is a personalized section of the webpage that offers the additional features.

• As REGISTERED member you get access to the mtDNA haplotypes stored in the database. The displayed differences to the query sequence are compiled for convenient analysis.
• MyEMPOP supports NETWORK, a software tool to visualize mtDNA data tables for phylogenetic analysis and quality control of mtDNA haplotypes.
• A HISTORY-function is included, which saves the database - and network queries for later inspection.
• A pdf-file can be build to document the query results

Technical requirements for best web-performance

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