Pool-seq Data from Tundra Vole Populations in Northern Norway and Eastern Poland
Tissue samples from wild tundra voles were obtained from Northern Norway representing the Northern population (n=12, 5 females, 7 males) and Poland, representing the Southern population (n=13, 5 males, 8 females). The northern population was sampled on September 1st, 2015, in the Troms & Finnmark county, Ifjordfjellet region between the towns Lakselv and Tana (70°24'N 27°16'E) at an altitude of about 400 m above sea level. Samples from the Southern population were kindly provided by Karol Zub (The Mammal Research Institute is located in Bialowieza, eastern Poland). These voles were caught in Bialowieza (52°42'N 23°51'E) at an altitude of 160 m over the period from June to October in the years from 2010 to 2014.    From the Norwegian population, a 25mg muscle sample was dissected directly from each individual. From the Poland population, a ~2cm tail sample was sent dry. Total genomic DNA was extracted using the DNeasy Blood & Tissue kit (Qiagen, Hilden, Germany) following the instructions of the manufacturer. Prior to DNA isolation, the samples were ruptured with a TissueLyser II (Qiagen, Hilden Germany) by placing a 5 mm stainless steel bead in standard 2ml Eppendorf tubes containing the samples. The machine was run at 25 Hz for five minutes. In the last step of the kit, the samples were eluded twice with 200µl AE buffer (10mM Tris-Cl 0.5mM EDTA; PH 9.0), to achieve a total volume of 400µl. The sample quality and concentration were measured with Nanodrop 2000 (Thermoscientific TM, Waltham, Massachusetts, United States). Sanger sequencing (by Eurofins Genomics, Ebersberg, Germany) of a 136 bp fragment of the Cytochrome B gene (position 666 – 801) was used to confirm the samples as Alexandromys oeoconomus by aligning the sequences against the NCBI database (Sayers et al. 2021) using BLAST (Altschul et al. 1990). Cytochrome B primers and PCR amplification conditions were taken from the paper by Galan, Pagès, and Cosson (2012):  L15411F 5'-GAY AAA RTY CCV TTY CAY CC-3' and  H15546R 5'-AAR TAY CAY TCD GGY TTR AT-3' and PCR instructions described there.   In preparation for Illumina sequencing, 1 µl Rnase A (10mg/ml stock; VWR E866-1ML) was added to 400µl of DNA samples and incubated at 37 degrees Celsius for 20 minutes. The samples were cleaned through ethanol precipitation, and purity was checked with Nanodrop followed by Qubit (Invitrogen Qubit 2.0) analysis for a more precise concentration estimation. DNA quality was checked on a 0.8% agarose gel run for 30 min on 100 volts. Genomic DNA of the individuals within a population was pooled with each individual contributing equally in amount of DNA. Truseq PCR free libraries were created for each population pool. Pools were sequenced on an Illumina Hiseq 3000 machine with 150 bp paired-end reads on 8 lanes in total, resulting in an average coverage of ~191 fold per site and ~15 fold per individual.