Signatures of de-domestication in autochthonous pig breeds and of domestication in wild boar populations from MC1R and NR6A1 allele distribution

Autochthonous pig breeds are usually reared in extensive or semi-extensive production systems that might facilitate contact with wild boars and, thus, reciprocal genetic exchanges. In this study, we analysed variants in the melanocortin 1 receptor (MC1R) gene (which cause different coat colour phenotypes) and in the nuclear receptor subfamily 6 group A member 1 (NR6A1) gene (associated with increased vertebral number) in 712 pigs of 12 local pig breeds raised in Italy (Apulo-Calabrese, Casertana, Cinta Senese, Mora Romagnola, Nero Siciliano and Sarda) and south-eastern European countries (Krškopolje from Slovenia, Black Slavonian and Turopolje from Croatia, Mangalitsa and Moravka from Serbia and East Balkan Swine from Bulgaria) and compared the data with the genetic variability at these loci investigated in 229 wild boars from populations spread in the same macro-geographic areas. None of the autochthonous pig breeds or wild boar populations were fixed for one allele at both loci. Domestic and wild-type alleles at these two genes were present in both domestic and wild populations. Findings of the distribution of MC1R alleles might be useful for tracing back the complex genetic history of autochthonous breeds. Altogether, these results indirectly demonstrate that bidirectional introgression of wild and domestic alleles is derived and affected by the human and naturally driven evolutionary forces that are shaping the Sus scrofa genome: autochthonous breeds are experiencing a sort of 'de-domestication' process, and wild resources are challenged by a 'domestication' drift. Both need to be further investigated and managed.

The LRP1 Gene Polymorphism is associated with Increased Risk of Metabolic Syndrome Prevalence in the Serbian Population

The determination of genetic background in metabolic syndrome (MetS) represents one of the necessary steps to prevent the disorder, thus reducing the cost of medical treatments and helping to design targeted therapy. The study explores the association between individual alleles of the LRP1 gene and the diagnosis of MetS to find correlation between the low-density lipoprotein receptor-related (LRP1) gene polymorphism and each individual anthropometric and biochemical parameter. The study included 93 males and females, aged from 19 to 65, divided into two groups. The genotype of each person was determined from the restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) profile. Results indicated the association of the T allele form of exon 3 LRP1 gene with development and progression of MetS that further pointed out its negative impact on tested anthropometric and biochemical parameters. The presence of the T allele in patients multiplies the chance of occurrence of deviations from the reference values of body mass index (BMI), (4.24-fold) and low-density lipoprotein (LDL) (20.26-fold) compared to C allele carriers. The results showed that T allele presence multiplies the chance (4.76 fold) for the occurrence of MetS in comparison to C allele carriers. Correlation found that the T allele of the LRP1 gene with MetS determinants is not negligible, therefore, the T allele may be considered as a risk factor for MetS development.

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.

Differentiation of meat from European wild boars and domestic pigs using polymorphisms in the MC1R and NR6A1 genes

Wild boar meat cannot be easily distinguished from domestic pig meat, especially in processed products, thus it can be fraudulently substituted with cheaper domestic pork. In this study we genotyped polymorphisms in two genes (MC1R, affecting coat color and NR6A1, associated with number of vertebrae) in 293 domestic pigs of five commercial breeds, 111 wild boars sampled in Italy, and 90 in Slovenia and other Western Balkan regions. Allele and genotype frequency data were used to set up a DNA-based method to distinguish meat of wild boars and domestic pigs. Genotyping results indicated that domesticated genes were introgressed into wild boar populations. This complicated the determination of the origin of the meat and would cause a high error rate if markers of only one gene were used. The combined use of polymorphisms in the two analyzed genes substantially reduced false negative results.

Low-dose dexamethasone treatment promotes the pro-survival signalling pathway in the adult rat prefrontal cortex

Synthetic glucocorticoid dexamethasone (DEX), a highly potent anti-inflammatory and immunosuppressive agent, is widely used in the treatment of brain cancer, as well as for inflammatory and autoimmune diseases. The present study aimed to determine whether low-dose subchronic DEX treatment (100 μg/kg for eight consecutive days) exerts long-term effects on apoptosis in the adult rat prefrontal cortex (PFC) by examining the expression of cell death-promoting molecules [poly(ADP-ribose) polymerase (PARP), p53, procaspase 3, cleaved caspase 3, Bax] and cell-survival molecules (AKT, Bcl-2). The results obtained revealed that body, thymus and adrenal gland weights, as well corticosterone levels, in the serum and PFC were reduced 1 day after the last DEX injection. In the PFC, DEX caused activation of AKT, augmentation of pro-survival Bcl-2 protein and an enhanced Bcl-2/Bax protein ratio, as well Bcl-2 translocation to the mitochondria. An unaltered profile with respect to the protein expression of apoptotic molecules PARP, procaspase 3 and Bax was detected, whereas p53 protein was decreased. Reverse transcriptase -polymerase chain reaction analysis showed a decrease of p53 mRNA levels and no significant difference in Bcl-2 and Bax mRNA expression in DEX-treated rats. Finally, a DNA fragmentation assay and Fluoro-Jade staining demonstrated no considerable changes in apoptosis in the rat PFC. Our findings support the concept that low-dose DEX creates a hypocorticoid state in the brain and also indicate that subchronic DEX treatment activates the pro-survival signalling pathway but does not change apoptotic markers in the rat PFC. This mechanism might be relevant for the DEX-induced apoptosis resistance observed during and after chemotherapy of patients with brain tumours.

Inhibition of mitochondrial Na+-dependent Ca²+ efflux by 17β-estradiol in the rat hippocampus

Our results, as well as those of others, have indicated that 17β-estradiol (E2) exerts its nongenomic effects in neuronal cells by affecting plasma membrane Ca(2+) flux. In neuronal cells mitochondria possess Ca(2+) buffering properties as they both sequester and release Ca(2+). The goal of this study was to examine the rapid non-genomic effect of E2 on mitochondrial Ca(2+) transport in hippocampal synaptosomes from ovariectomised rats. In addition, we aimed to determine if, and to what extent, E2 receptors participated in mitochondrial Ca(2+) transport modulation by E2 in vitro. E2-specific binding and Ca(2+) transport was monitored. At physiological E2 concentrations (0.1-1.5 nmol/L), specific E2 binding to mitochondria isolated from hippocampal synaptosomes was detected with a B(max.) and K(m) of 37.6±2.6 fmol/mg protein and 0.69±0.14 nmol/L of free E2, respectively. The main mitochondrial Ca(2+) influx mechanism is the Ruthenium Red-sensitive uniporter driven by mitochondrial membrane potential. Despite no effect of E2 on Ca(2+) influx, a physiological E2 concentration (0.5 nmol/L) protected mitochondrial membrane potential and consequently Ca(2+) influx from the uncoupling agent carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (1 μmol/L). In neuronal cells the predominant mitochondrial Ca(2+) efflux mechanism is the Na(+)/Ca(2+) exchanger. E2 caused Ca(2+) efflux inhibition (by 46%) coupled with increased affinity of the Na(+)/Ca(2+) exchanger for Na(+). Using E2 receptor (ERα and ERβ) antagonists and agonists, we confirmed ERβ's involvement in E2-induced mitochondrial membrane potential protection as well as Ca(2+) efflux inhibition. In summary, our results indicate that the non-genomic neuromodulatory role of E2 in rat hippocampus is achieved by affecting mitochondrial Ca(2+) transport via, in part, mitochondrial ERβ.