Mihajla Djan

Different associations of apoE gene polymorphism with metabolic syndrome in the Vojvodina Province (Serbia)

The metabolic syndrome (MetS) is a polygenic multifactorial metabolic disorder with strong socioeconomic influence. MetS has became a worldwide epidemic, that directly increases the risk of cardiovascular diseases and type 2 diabetes mellitus. The human apoE gene, coding Apolipoprotein E, has three common polymorphisms in human population: e2, e3 and e4, which are proved to be associated with impaired lipid metabolism. The contribution of apoE polymorphism to MetS disorders has not been investigated previously in Vojvodina Province, region with the highest number of obese people in Serbia. The aim of this study was to evaluate apoE gene polymorphism in relation to MetS disorders. The healthy control group of 30 individuals and 63 MetS patients were examined for apoE variants in relation to biochemical and anthropometric parameters. The genotypes were determined by PCR–RFLP. Regarding all parameters, significantly higher values were detected in MetS group compared to control. The MetS group of patients had significantly higher frequency of e4 allele. In addition, positive relation was revealed between e4 allele presence and all measured parameters. It was found that the e4 allele was related with a significantly increased OR of MetS disorders according to the International Diabetes Federation definition. These results suggested that e4 allele may act as a one of determinants for development of metabolic syndrome.

Population genetic structure of wild boars in the West Balkan region

We investigated the population genetic structure of wild boars from Vojvodina (Serbia), Slavonija (Croatia) and Bosnia using four microsatellite markers. All loci presented a high degree of polymorphism and a total of 76 alleles (mean 19 alleles per locus) were detected. Average observed heterozygosity (Ho) value was 0.60. Deviation from Hardy-Weinberg equilibrium was found due to significant heterozygote deficiency detected for three of the four analyzed loci and for all populations. FIS value over all loci and all populations was 0.29, and the effective number of migrants based on private alleles was 1.64. Sufficient levels of gene flow were found between all populations and the spatial structure showed slightly closer nuclear gene pool affinity of Vojvodina and Slavonija populations in relation of Bosnia population.

Polymorphism of mtDNA regions in brown hare (Lepus europaeus) populations from Vojvodina (Serbia and Montenegro)

It is well known that there is heterogeneity of mitochondrial DNA (mtDNA) within and among natural populations of same species. The polymorphism level of particular regions of mtDNA gives valuable results in detection of population genetic structure. The aim of this paper was to detect polymorphism of three mtDNA regions: cytochrome oxidase I (COI), Control region, and 12S/16S rRNA, by the mtDNA RFLP-PCR method, in three Lepus europaeus populations from Vojvodina province (Serbia and Montenegro). Polymorphism was detected within the two regions, COI and Control region, while 12S/16S rRNA region was monomorphic in all 77 individuals. Eight haplotypes were detected in the brown hare population in Vojvodina, and three were unique for the Srem brown hare population.

Polymorphism Val103Ile of the melanocortin-4 receptor gene in the Serbian population

The melanocortin-4 receptor (MC4R) plays an important role in weight and energy homeostasis and it is associated with lower risk to develop obesity and lower body mass index. The contribution of MC4R mutation to obesity in Vojvodina (Northern Province of Serbia), known as a region with the largest number of overweight people, has not been previously investigated. The objective of this study was to examine the Val103Ile polymorphism of MC4R in a population of Vojvodina and its association with obesity. The study was carried out in a group of 96 persons: 62 obese and 34 normal weight men and women. Anthropometric measurements and cardiovascular risk factors assessment were done. The genotypes were determined by PCR-RFLP. In our on going study, three subjects were heterozygous for Val103Ile mutation (3.12%), and one was homozygous for 103Ile allele (1.04%). Among obese patients no isoleucine allele homozygous was found. The frequencies of the 103Ile allele in a group of obese and normal weight persons were found to be 1.61 and 4.41%, respectively. Val103Ile polymorphism of melanocortin-4 receptor is unlikely to be a major cause of overweight and obesity in Vojvodina, but further studies on larger groups of patients are needed.

Allozyme diversity in pheasants (Phasianus spp.) from breeding stations in Serbia

The pheasant breeds are widely used for restocking of natural populations depleted by hunting. The pheasant population number decline was detected during the 1970s in many hunting areas of Europe. One of its possible reasons might be the loss of adaptability in populations originating from breeding stations, which was caused by inbreeding depression. The aim of this paper was the analysis of genetic variability in pheasant populations from three breeding stations in Vojvodina province (Serbia) by means of allozyme diversity detection. The allozyme variability analysis of pheasants from all three breeding stations revealed polymorphisms at nine loci: Ldh-1, Mor-1, Mor-2, Es-1, Mod-2, Pgd, Gpi-2, Odh, and Sod. The analysis of individuals from three different breeding stations showed mean values of observed heterozygosity of Ho=0.137, polymorphism P95%=30%, and H/P ratio H/P=0.430, which indicate a normal level of genetic variability for bird populations. Comparative analysis of three pheasant populations showed a high level of interpopulation differentiation.

Potential uses of microsatellites in marker-assisted selection for improved bread-making quality in wheat

Implementation of marker assisted selection (MAS) in conventional breeding programs could allow assessment of the genetic potential of specific genotypes prior to their phenotypic evaluation. Furthermore, it could identify important trait alleles or marker-trait associations for further determination of a precise position for the loci of interest. Potential uses of microsatellite markers in molecular evaluation of bread-making quality was tested in a sample of 69 wheat genotypes that were genotyped with 3 microsatellites linked to previously mapped QTLs for loaf volume and Hagberg falling number on chromosome 3A. A total of 19 alleles were found, with an average of 6.33 alleles per loci, and average PIC value of 0.40. Specific SSR alleles were tested for association with bread-making related parameters. The association study approach, which uses statistical analysis of marker and phenotypic data, showed significant association of a specific allele at the GWM674 locus with Hagberg falling number in wheat.

Demographic history, current expansion and future management challenges of wild boar populations in the Balkans and Europe.

Wild boar (Sus scrofa), one of the most widespread wildlife species, has entered a stage of continuous growth in Europe, and could even be considered a pest species. We analysed microsatellite variability in 723 wild boars from across Europe, including the northern Dinaric Balkans. Our aims were: (1) to define the population structure of wild boars in the Balkans and its relation with other European populations; (2) to estimate effective populations sizes, levels of intra- and inter-population diversity, inbreeding migration and gene flow patterns; (3) to test subpopulations for bottlenecks; (4) to interpret these results in light of current knowledge about the demographic history of wild boars in Europe; and (5) to discuss the relevance of these findings for management and conservation. Strong population structuring was observed and 14 subpopulations were revealed. High genetic diversity was found, and besides the well-known identity of the Italian populations of Sardinia and Castelporziano, we bring new insights into other potential relevant, refugial populations such as Littoral Slovenia, South Portugal, North-western Iberia and an entire cluster in the Balkans. There was evidence of gene flow going from these refugial subpopulations towards less peripheral and more admixed subpopulations. Recent population bottlenecks and expansions were detected, mostly in the peninsular refuge subpopulations. The results are consistent with the fluctuations of wild boar numbers in Europe since the beginning of the twentieth century. These results should be taken into account in future conservation and management plans for wild boar populations in Europe.

Large-scale mitochondrial DNA analysis reveals new light on the phylogeography of Central and Eastern-European Brown hare (Lepus europaeus Pallas, 1778)

European brown hare, Lepus europaeus, from Central and Eastern European countries (Hungary, Poland, Serbia, Lithuania, Romania, Georgia and Italy) were sampled, and phylogenetic analyses were carried out on two datasets: 1.) 137 sequences (358 bp) of control region mtDNA; and 2.) 105 sequences of a concatenated fragment (916 bp), including the cytochrome b, tRNA-Thr, tRNA-Pro and control region mitochondrial DNA. Our sequences were aligned with additional brown hare sequences from GenBank. A total of 52 and 51 haplotypes were detected within the two datasets, respectively, and assigned to two previously described major lineages: Anatolian/Middle Eastern (AME) and European (EUR). Furthermore, the European lineage was divided into two subclades including South Eastern European (SEE) and Central European (CE). Sympatric distribution of the lineages of the brown hare in South-Eastern and Eastern Europe revealed contact zones there. BAPS analysis assigned sequences from L. europaeus to five genetic clusters, whereas CE individuals were assigned to only one cluster, and AME and SEE sequences were each assigned to two clusters. Our findings uncover numerous novel haplotypes of Anatolian/Middle Eastern brown hare outside their main range, as evidence for the combined influence of Late Pleistocene climatic fluctuations and anthropogenic activities in shaping the phylogeographic structure of the species. Our results support the hypothesis of a postglacial brown hare expansion from Anatolia and the Balkan Peninsula to Central and Eastern Europe, and suggest some slight introgression of individual haplotypes from L. timidus to L. europaeus.

Close relatives of Mediterranean endemo-relict hoverflies (Diptera, Syrphidae) in South Africa: Morphological and molecular evidence in the Merodon melanocerus subgroup

An ongoing study of the genus Merodon Meigen, 1803 in the Republic of South Africa (RSA) has revealed the existence of new species related to M. melanocerus Bezzi, 1915. The M. melanocerus subgroup belongs to the Afrotropical lineage of the M. desuturinus group. Revision of all available material from museums and detailed analyses of newly -collected specimens from our own expeditions to RSA resulted in delimitation of five species: M. capensis Hurkmans sp. n., M. commutabilis Radenković et Vujić sp. n., M. drakonis Vujić et Radenković sp. n., M. flavocerus Hurkmans sp. n. and M. melanocerus. In addition to classical morphological characters, sequences of the mitochondrial COI gene are provided for four related taxa. Results of molecular phylogenetic analyses supports monophyly of the M. desuturinus group and confirmed delimitation between species. Links between Palaearctic and Afrotropical faunas of this group, as well as possible evolutionary paths, are discussed. Based on phylogenetic analyses, four lineages (putative subgenera) have been recognized within the genus Merodon; besides the three previously established ones, albifrons+desuturinus, aureus (sensu lato) and avidus-nigritarsis, one new lineage named natans is distinguished.

An integrative approach in the assessment of species delimitation and structure of the Merodon nanus species group (Diptera: Syrphidae)

The Merodon nanus group (Diptera, Syrphidae) is a small group of closely related species with high morphological similarity. Until now, based on morphological characters, this group consisted of five species: M. nanus Sack, 1931; M. telmateia Hurkmans, 1987; M. kopensis Vujić et Hayat, 2015; M. neonanus Vujić et Taylor, 2015; and M. rasicus Vujić et Radenković, 2015. Here, using an integrative approach based on molecular characters (sequences of the D2–3 region of the nuclear 28S rRNA gene and the mitochondrial COI gene) and data obtained from geometric morphometry of wing shape, we distinguish all five previously morphologically defined species of the group. Additionally, we identify one species as being new to science, M. vladimiri Vujić et Kočiš Tubić sp. n. We emphasize the separation of this newly described species according to the sequences obtained from the slowly evolving 28S rRNA gene, which demonstrated four to five mutation positions between this species and morphologically the most similar M. neonanus species. Also, our results show a clear division of M. telmateia into at least three population groups that we designate as the subspecies: M. telmateia mediterraneus Ačanski et Kočiš Tubić subsp. n. and M. telmateia samosensis Ačanski et Kočiš Tubić subsp. n. exhibiting western distributions (western Anatolia and the Greek island of Samos, respectively) and the nominative subspecies M. telmateia telmateia with an eastern Anatolian distribution.