Msaken, Tunisia: A Common Paternal Ancestor Confirmed by Y Chromosome DNA Analysis

Abstract

Msaken City (Tunisia) is believed to have been founded around 1360 AD by five related men who migrated from West Asia. The population would have grown with the descendants of these founders and with the arrival of other populations from different regions of Tunisia. In order to elucidate the TMRCA of the founder population and to reveal their geographic origin, 23 males from different families of Msaken were examined, using the services of commercial companies, for 12 to 440 Y chromosome Short Tandem Repeats (STR) and Single Nucleotide Polymorphisms (SNP) markers using NG testing technology. Eight samples were genotyped for SNPs to determine their Haplogroups. In order to refine the phylogeny, traditional Sanger testing was performed on one sample for 300,000 bp in Y Chr (in Walk Through the Y chromosome project). Seven samples were also tested using Next Generation Testing (BigY) covering 20 million bp of Y chromosome overlapping 85% of Gold standard region (chromosome Y positions placed on the phylogenetic tree by the YCC) using NGS instruments, HiSeq 2000 and 2500. A comparison of STR results with data from different sources and databases was made, using SQL scripts and data mining tools, to find matching haplotypes. All the STR results were found to have no more than three mismatches per 12 markers and not more than six mismatches per 67 markers and the SNP results showed that all tested samples belonged to Haplogroup J-M172 inside its subgroup J-L24. Relying on the common STR marker values, we define a Msaken-Haplotype. NG tests for our samples as well as those added to the yfull.com tree allowed us to refine the phylogeny of J-L24 and the samples were all found to belong to J-L271 Haplogroup and share 54 exclusive SNPs. The calculated Time to Most Recent Common Ancestor (TMRCA) based on NG testing, ranges between1500 and 6200 YBP showing a strong bottleneck around 5400 YBP. The variation of the collected results shows a geographic root of J-L192 in East Anatolia, present day Armenia, Azerbaijan, and West Iran. 20 to 30% of random Tunisian STR haplotypes belonging to J-M172 (J2) Haplogroup exhibit the Msaken-Haplotype.