mtDNA Variation in the Altai-Kizhi Population of Southern Siberia: A Synthesis of Genetic Variation

Abstract

The native peoples of Gorno Altai in southern Siberia represent a genetically diverse population and have been of great interest to anthropological genetics. In particular, the southern Altaian population is argued to be the best candidate for the New World ancestral population. In this study we sampled Altai-Kizhi from the southern Altaian village of Mendur-Sokkon, analyzed mtDNA RFLP markers and HVS-I sequences, and compared the results to other published mtDNA data from Derenko et al. (2003) and Shields et al. (1993) encompassing the same region. Because each independent study uses different sampling techniques in characterizing gene pools, in this paper we explore the accuracy and reliability of evolutionary studies on human populations. All the major Native American haplogroups (A, B, C, and D) were identified in the Mendur-Sokkon sample, including a single individual belonging to haplogroup X. The most common mtDNA lineages are C (35.7%) and D (13.3%), which is consistent with the haplogroup profiles of neighboring Siberian groups. The Mendur-Sokkon sample exhibits depressed HVS-I diversity values and neutrality test scores, which starkly differs from the Derenko et al. (2003) data set and more closely resembles the results for neighboring south Siberian groups. Furthermore, the multidimensional scaling plot of D^sub A^ genetic distances does not cluster the Altai samples, showing different genetic affinities with various Asian groups. The findings underscore the importance of sampling strategy in the reconstruction of evolutionary history at the population level.

KEY WORDS: ALTAI, SIBERIA, RFLP, mtDNA, MOLECULAR ANALYSIS.

To identify differences among various samples from the same geographic area and to investigate the effect of independent sampling on the reconstruction of human evolutionary history, we examined multiple data sets from a key region of southern Siberia, the Gorno Altai of the Altai Republic. This semi-autonomous republic of Russia is situated in Eurasia, adjacent to China, Mongolia, Kazakhstan, and Russian Siberia. In language, culture, geographic distribution, and genetics, the Altaian tribes can be divided into two distinct groups: the Northern Altaians and the Southern Altaians (Levin and Potapov 1964). The Chelkans, Kumandins, Tubalars, and Maimalars represent the Northern Altaian ethnic groups. The Southern Altaian groups consist of the Altai-Kizhi, also referred to as "proper Altai," the Teleuts, and the Telenghits (Derenko et al. 2003). The focus of the present study, the village of Mendur-Sokkon, lies in the Southern Altaian region (Figure 1).

The rich history of the Gorno Altai contributes to its significant anthropological interest, especially regarding the peopling of the Americas across the Bering land bridge. For more than 50,000 years the region has experienced continuous Homo habitation, judging from several Middle Paleolithic Mousterian sites (Goebel 1999). The Altai was at the crossroads between Europe and Asia, with population movements and invasions from Mongolia, China, and Russia. Archeological evidence reveals that since the 5th and 6th centuries B.C., the Altai have had cultural contact with Mongolians in the form of both trade and invasion (Levin and Potapov 1964). In addition, historical texts document that the Altai have maintained trade connections with the Chinese. In 1756 the Altai established cultural and political contacts with the Russians, who were expanding into Siberia (Levin and Potapov 1964).

As the diverse ethnic history of the region would suggest, the Altaian mtDNA gene pool displays a complex mixture of East Asian and West Eurasian lineage (Derenko et al. 200la, 2003). This region is of particular importance with regard to the peopling of the New World because it is the only region outside the Americas where all five founding New World mtDNA haplogroups-A, B, C, D, and X-have been identified (Derenko et al. 2001b). For this reason the Altai region has been an area of intense interest to anthropological geneticists, and several field investigations have been conducted by various research teams.

Our goals in this paper are to genetically characterize the Southern Altaian population of Mendur-Sokkon village by using both mtDNA RFLP and HVS-I data and to compare these results with other published studies of the Altai (Shields et al. 1993; Derenko et al. 2003) and surrounding populations. In this paper we also address the reliability of sampling and genetic analysis of populations from the same geographic region by determining whether the multiple mtDNA data sets from the Altaian population yield similar diversity scores and phylogenetic results.

Materials and Methods

Population: The Altai-Kizhi of Gorno Altai. Approximately 60,000 native people live in the Gorno Altai region. The indigenous Altaian population is composed of various distinct Turkic-speaking groups to which the Altai-Kizhi belong (Levin and Potapov 1964). The Altaian valleys between the surrounding mountains of the Altai-Sayan range provide exceptional grazing grounds, and these pastures are used today by the Altai-Kizhi, a pastoral, seminomadic people who traditionally subsist by herding cattle (Crawford et al. 2002).