Molecular systematics of the Sicista tianschanica species complex: a contribution from historical DNA analysis

Abstract

The Tianshan birch mouse Sicista tianschanica is an endemic of the Central Asian mountains and has previously been shown to include several karyomorphs (“Terskey”, “Talgar”, “Dzungar”); however, the taxonomic status of these forms has remained uncertain. We examined the genetic variation in S. tianschanica based on historical DNA samples from museum collections, including the type series. Mitochondrial and nuclear data indicated that the species complex includes two major clades: Northern (N) and Southern (S) (cytb distance 13%). The N clade corresponds to the “Dzungar” karyomorph (Dzungar Alatau, Tarbagatay). The S clade is comprised of four lineages (S1–S4) divergent at 6–8%; the relationships among which are resolved incompletely. The S1 lineage is found in eastern Tianshan and corresponds to the nominal taxon. The S2 is distributed in central and northern Tianshan and corresponds to the “Terskey” karyomorph. The S3 is restricted to Trans-Ili Alatau and belongs to the “Talgar” karyomorph. The S4 is represented by a single specimen from southeastern Dzungar Alatau with "Talgar" karyotype. No interlineage gene flow was revealed. The validity of S. zhetysuica (equivalent to the N clade) is supported. Based on genetic and karyotypic evidence, lineages S2 and S3 are described as distinct species. The status of the S4 requires further investigation.

Integrative Taxonomy within Eremias multiocellata Complex (Sauria, Lacertidae) from the Western Part of Range: Evidence from Historical DNA

“…DNA degrade in historical specimens, but modern methods and special facilities allow us to obtain data from such difficult material, including successful attempts to extract DNA from formalin-fixed museum specimens [ 15 , 16 , 17 , 18 ]. As the historical DNA, we consider DNA isolated from old museum samples (or historical samples) following the understanding of this term in the zoological literature [ 19 , 20 , 21 , 22 ]. The Laboratory of Historical DNA at the Zoological Museum of the Lomonosov Moscow State University focuses on the genotyping of museum collections, especially type specimens and the specimens from the type localities, which is of crucial importance in clarifying challenging taxonomic and nomenclature issues.…”