Genetic differentiation of the Meriones tristrami (Mammalia: Rodentia) subpopulations in Turkey - inferring allozyme variations

Turkish Journal of Zoology Turk J Zool (2016) 40: 894-899 © TÜBİTAK doi:10.3906/zoo-1507-28 http://journals.tubitak.gov.tr/zoology/ Research Article Genetic differentiation of the Meriones tristrami (Mammalia: Rodentia) subpopulations in Turkey – inferring allozyme variations 1 2, 1 1 1 Nuri YİĞİT , Fulya SAYGILI YİĞİT *, Ercüment ÇOLAK , Reyhan ÇOLAK , Derya ÇETİNTÜRK 1 Department of Biology, Faculty of Science, Ankara University, Ankara, Turkey 2 Department of Biology, Faculty of Arts and Science, Niğde University, Niğde, Turkey Received: 22.07.2015 Accepted/Published Online: 09.05.2016 Final Version: 06.12.2016 Abstract: Allozyme variations of Tristram’s jird Meriones tristrami, which is distributed in the steppe and semiarid areas of Turkey, were studied using 24 loci of 83 specimens from ten locations in Turkey. Seven loci were found to be polymorphic. According to the patterns of allozyme variation, the percentage of polymorphic loci was 12.5. FST was found to be 0.44, indicating high genetic variations among M. tristrami; accordingly the Nm value (0.3157) appeared quite low. The UPGMA dendrogram, based on genetic distance, showed that the populations established two very close subclusters, and supported the idea that the westernmost population connected to the northern part of the central Anatolian population. As expected, the eastern population appeared to be more divergent due to geographic distance. Our findings supported that genetic isolation among these subpopulations might be caused by geographic isolation. Key words: Meriones tristrami, Anatolian steppe, geographic distance, genetic diversity, Turkey 1. Introduction Five species of the genus Meriones are distributed in the Asiatic part of Turkey (Yiğit et al., 1997, 1998a, 1998b, Yiğit and Çolak, 1999). These species have adapted to the semiarid steppe in the Palearctic region (Harrison and Bates, 1991; Yiğit et al., 1997; Musser and Carleton, 2005). Unlike the other species, M. tristrami has the widest range in Asiatic Turkey, extending from the Iranian border to the westernmost border around İzmir. This species is distributed in steppe and semidesert habitats and also occurs at the edges of cereal fields, and feeds on grain, seeds, and green plant parts (Yiğit et al., 1995, 1997). Several subspecies of M. tristrami were identified and recorded in Turkey as follows: M. t. lycaon, M. t. blackleri, M. t. intraponticus, and M. t. kilisensis, which have type locations in Turkey, and M. t. bodenheimeri and M. t. bogdanovi, which were recorded in Turkey (Yiğit and Çolak, 1998; Yiğit et al., 1998b). Studies on the Turkish Meriones species mainly focused on morphology and karyology, and were performed by Yiğit et al. (1997, 1998a, 1998b), Yiğit and Çolak (1998, 1999), Aşan et al. (2010), and Kaya and Coşkun (2012). There are very few studies regarding genetic variability in this genus. Benazzou et al. (1984) first performed an allozyme analysis of the genus Meriones using nine enzyme systems. Bulut and Yiğit (2011) investigated allozyme variations of three subspecies * Correspondence: 894 of M. tristrami from western Anatolia. Yiğit et al. (2013) used 24 enzyme systems to determine allozyme variations of five Meriones species. Hence, the aim of the present study was to reveal the genetic diversity among the M. tristrami subpopulations, which have a wider range than do the other Meriones species in Turkey. 2. Materials and methods Specimens of the M. tristrami were caught from ten localities in Turkey and a total of 83 specimens were studied (Figure 1). These subspecies of M. tristrami were described with slightly morphological and biometrical characteristics, except for M. tristrami blackleri, which has a very marked white tip on the tail and occupies the westernmost part of Anatolia. Moreover, these subspecies (codes are Mt1, Mt4, Mt5, Mt6, Mt7, and Mt8 in this study) from the easternmost to the westernmost areas have a different number of chromosome arms (Yiğit et al., 1998a; Yiğit and Çolak, 1998; Coşkun, 1999). Specimen numbers are as follows; Mt1 (Gaziantep, Adana) = 8, Mt2 (Central Anatolia; Cihanbeyli/Konya, Sivrihisar/Eskişehir) = 13, Mt3 (Denizli) = 8, Mt4 (Şanlıurfa) = 17, Mt5 (Iğdır) = 2, Mt6 (Tosya/Kastamonu) = 13, Mt7 (Karadağ/Karaman) = 10, and Mt8 (Turgutlu/Manisa) = 12. Voucher specimens and tissues of these specimens were deposited at Prof Dr N Yiğit and Prof Dr E Çolak’s collection (Ankara University YİĞİT et al. / Turk J Zool Figure 1. Map of the locations of the M. tristrami specimens in Turkey (Gaziantep, Adana: Mt1; Central Anatolia (Cihanbeyli/Konya, Sivrihisar/Eskişehir): Mt2; Denizli: Mt3; Şanlıurfa: Mt4; Iğdır: Mt5; Tosya/Kastamonu: Mt6; Karadağ/Karaman: Mt7; Turgutlu/ Manisa: Mt8). Mammalian Research Collection; AUMAC). Muscle tissues were preserved at –80 °C until the beginning of the allozyme studies. Homogenates obtained from these tissues were freshly prepared and used for each experiment. The horizontal gel electrophoresis method, which was modified from Shaw and Prasad (1970) and Harris and Hopkinson (1976), was used to reveal genetic variation. Allozyme variability was screened using 20 enzyme systems by 24 encoded loci: ACON (4.2.1.3 Aconitase hydratase; Aco), G6PDH (E.C. 1.1.1.49 Glucose-6phosphate dehydrogenase; G6pdh), GPI (5.3.1.9 Glucose6-phosphate isomerase; Gpi), α-GPDH (E.C. 1.1.1.8 α-Glycerophosphate dehydrogenase α-Gpdh), IDH (1.1.1.42 Isocitrate dehydrogenase; Idh), MDH (1.1.1.37 Malate dehydrogenase; Mdh), ME (1.1.1.40 Malic enzyme; Me), PGM (5.4.2.2 Phosphoglucomutase; Pgm), SOD (1.15.1.1 Superoxide dismutase; Sod), FUM (4.2.1.2 Fumarase; Fum), PGD (1.1.1.44 Phosphogluconate dehydrogenase; Pgd), ADA (3.5.4.4 Adenosine deaminase; Ada), HK (Hk, E.C. 2.7.1.1 Hexokinase; Hk), LDH (1.1.1.27 Lactate dehydrogenase; Ldh), ALD (4.1.2.13 Aldolase; Ald), CA (4.2.1.1 Carbonic anhydrase; Ca), G3PDH (E.C.1.2.1.12 Glyceraldehyde-3-phosphate dehydrogenase; G3pdh), GOT (E.C.2.6.1.1 Glutamic oxaloacetic transaminase; Got), MPI (E.C.5.3.1.8 Mannosephosphate isomerase; Mpi), and AK (E.C.2.7.4.3 Adenylate kinase; Ak). The electrophoretic bands, which were presumptive alleles, were designated alphabetically by their relative mobility according to Harris and Hopkinson’s (1976) method. The allozymic data were evaluated with BIOSYS-2 (Black, 1997, the original version BIOSYS-1 v.1.7 program of Swofford and Selander, 1981). Allele frequencies (f), the mean number of alleles per locus (A), the proportion of polymorphic loci (P, 95% criterion; a locus was considered polymorphic if the frequency of the most common allele was ≤0.95), and the mean heterozygosity (H; Ho = observed and He = expected frequencies of heterozygotes under Hardy–Weinberg equilibrium) were calculated for estimating genetic variation between subpopulations. The amount of genetic divergence between subpopulations was estimated using the indices of standard genetic identity (I, the unbiased genetic id (...truncated)