Genetic relationships of Asians and Northern Europeans, revealed by Y-chromosomal DNA analysis

Abstract

We have identified a new T-IC transition on the human Y chromosome. C-allele chromosomes have been found only in a subset of the populations from Asia and northern Europe and reach their highest frequencies in Yakut, Buryats, and Finns. Examination of the microsatellite haplotypes of the C-allele chromosomes suggests that the mutation occurred recently in Asia. The Y chromosome thus provides both information about population relationships in Asia and evidence for a substantial paternal genetic contribution of Asians to northern European populations such as the Finns. 1174 Zerjal et al.: Y Chromosome and Asian/European Origins 1994) and of mtDNA (Sajantila et al. 1995) confirms that the Saami are distinct from other European populations, but results for the Finns are less clear. Early studies provided evidence for some Asian admixture (Nevanlinna 1980), but more recent work has found that the Finns are indistinguishable from other European populations (Lahermo et al. 1996). It therefore has been suggested that the Finns are of European origin and originally spoke an Indo-European language but recently have adopted their present Uralic language (Sajantila and Paabo 1995). The new Y-chromosomal marker allows us to compare paternal lineages with the information provided by maternal lineages and language. It reveals that the European Uralic-speaking populations share with some central and northeastern Asians a Y-chromosome haplotype, providing genetic evidence for a substantial Asian paternal contribution to these northern European populations. 117S The primers Tatl (5 '-GACTCTGAGTGTAGACTTGTGA-3') and Tat3 (5'-GAAGGTGCCGTAAAAGTGTGAA-3') were designed to amplify a 112-bp fragment spanning the polymorphism. PCR conditions were as described above, except that the pH was 9.5 and the MgCI2 concentration was 2.5 mM. The cycling protocol was 94°C for 1 min, 60°C for 1 min, and 72°C for 30 s. Most population screening (table 1) was performed by use of the RSD and RSI primers and by digestion with either NlaIII (New England Biolabs) or its isoschizomer Hsp92II (Promega), since the additional sites within the 1.5-kb fragment provided internal controls for monitoring the digestion. Digests were analyzed by electrophoresis in a 2.8% NuSieve, 0.8% agarose gel containing ethidium bromide in 0.5 x Tris-acetate EDTA (TAE) buffer. Degraded DNA samples were amplified by use of the Tatl and Tat3 primers, and nested PCR with both sets of primers was used in some cases. The 112bp fragment was analyzed by Hsp92II digestion and electrophoresis in a 4% NuSieve, 1 % agarose gel containing ethidium bromide in 0.5 x TAE buffer. The sequence of most C-allele chromosomes was confirmed by digestion with MaeII (Boehringer).