Clock gene PERIOD3 polymorphism is associated with susceptibility to Graves’ disease but not to Hashimoto’s thyroiditis

ABSTRACT

Circadian disruption has been linked with immune-related morbidities including autoimmune diseases. PERIOD3 (PER3) clock gene is a key player in the mammalian circadian system. This study evaluated the possible association of PER3 rs2797685 (G/A) polymorphism and susceptibility of autoimmune thyroid diseases (AITD) and assessed if this SNP contributes to disease characteristics and serum levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). The PER3 rs2797685 (G/A) polymorphism was assessed in 125 patients with AITD [Graves’ disease (GD), 69; Hashimoto’s thyroiditis (HT), 56] and 115 unrelated healthy controls. Subjects carrying at least one variant allele of PER3 rs2797685 (GA+AA) had increased risk for GD (OR 1.9, 95% CI 1–3.61, p= .05). There were no differences in the frequencies of genotypes and alleles of the PER3 rs2797685 polymorphism between HT patients and control subjects. No association was observed between genotypes of the studied SNP and any of the disease characteristics in GD and HT patients. The GA+AA genotype of PER3 rs2797685 was associated with lower levels of IL-6 in patients with Graves’ disease. There were no differences between genotypes of the studied SNP regarding TNF-α levels in GD, HT or control groups. In conclusion, this study provides the first evidence for a genetic association between GD and the PER3 gene, highlighting the possible relevance of polymorphisms in clock genes in the etiopathogenesis of AITD. However, functional studies to identify the underlying molecular mechanisms of this association are needed to translate these findings to clinical applications.     

Morphometric and genetic structure of the edible dormouse (Glis glis): a consequence of forest fragmentation in Turkey

Past climatic fluctuations influenced forest habitats and impacted heavily the distribution of forest species, such as the edible dormouse, by changing the distribution and composition of forests themselves. Such effects may be valid for ongoing climate change as well. To improve our understanding of the edible dormouse's history and how it responded to changes in its environment, we investigated its variation across the understudied zone of Northern Turkey using two complementary markers of differentiation: the mitochondrial cytochrome b gene for genetics, and size and shape of the first upper molar for phenotypic differences. Genetic and morphometric results were strongly discrepant. Genetic analyses evidenced an amazing homogeneity throughout the Eurasian range of the edible dormouse, whereas morphometrics pointed to a complex, step‐wise differentiation along the Black Sea coast, the main signal being an opposition between Easternmost and Westernmost Turkish dormice. The genetic homogeneity suggests that this phenotypic differentiation is not the inheritance of glacial refuges, but the consequence of a more recent post‐glacial isolation. The transition between the European and Asian groups is located eastwards from the Marmara straits, undermining its claimed role as an efficient barrier but stressing the importance of climatic and vegetational factors. A secondary differentiation between populations from the Central Black Sea coast and Easternmost regions was evidenced, attributed to a complex interplay of climatic, topographic, anthropogenic, and ecological factors. Turkey, at the crossroad of European and Asian species, heavily impacted by the current global change including climatic and anthropogenic factors, appears of importance for understanding the historical dynamics of differentiation and exchanges between populations that shaped the current distribution of Eurasian species and their future survival. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 107 , 611–623.     

Genetic structure,ecological versatility,and skull shape differentiation in Arvicola water voles (Rodentia,Cricetidae)

Water voles from the genus Arvicola display an amazing ecological versatility, with aquatic and fossorial populations. The Southern water vole (Arvicola sapidus) is largely accepted as a valid species, as well as the newly described Arvicola persicus. In contrast, the taxonomic status and evolutionary relationships within Arvicola amphibiussensu lato had caused a long-standing debate. The phylogenetic relationships among Arvicola were reconstructed using the mitochondrial cytochrome b gene. Four lineages within A. amphibiuss.l. were identified with good support: Western European, Eurasiatic, Italian, and Turkish lineages. Fossorial and aquatic forms were found together in all well-sampled lineages, evidencing that ecotypes do not correspond to distinct species. However, the Western European lineage mostly includes fossorial forms whereas the Eurasiatic lineage tends to include mostly aquatic forms. A morphometric analysis of skull shape evidenced a convergence of aquatic forms of the Eurasiatic lineage toward the typically aquatic shape of A. sapidus. The fossorial form of the Western European lineage, in contrast, displayed morphological adaptation to tooth-digging behavior, with expanded zygomatic arches and proodont incisors. Fossorial Eurasiatic forms displayed intermediate morphologies. This suggests a plastic component of skull shape variation, combined with a genetic component selected by the dominant ecology in each lineage. Integrating genetic distances and other biological data suggest that the Italian lineage may correspond to an incipient species (Arvicola italicus). The three other lineages most probably correspond to phylogeographic variations of a single species (A. amphibius), encompassing the former A. amphibius, Arvicola terrestris, Arvicola scherman, and Arvicola monticola.     

Genetic analysis and screening of pyrethroid resistance mutations in Varroa destructor populations from Turkey

Experimental and Applied Acarology - Varroa destructor is the most common ectoparasite of the Western honey bee (Apis mellifera L.) worldwide and poses a serious threat to bee health. Synthetic...     

Evaluation of in-house factors affecting the population distribution of Dermanyssus gallinae in cage and backyard rearing systems by using a modified monitoring method

Experimental and Applied Acarology - Dermanyssus gallinae (poultry red mite, PRM) is a main ectoparasite of poultry that represents a serious economic threat to all farming systems, including cages...     

Thermal tolerance of European Sea Bass (Dicentrarchus labrax) juveniles acclimated to three temperature levels

This study was carried out to determine upper (CTMax) and lower (CTMin) thermal tolerance, acclimation response ratio (ARR) and thermal tolerance polygon of the European sea bass inhabiting the Iskenderun Bay, the most southeasterly part of the Mediterranean Sea, at three acclimation temperatures (15, 20, 25 °C). Acclimation temperature significantly affected the CTMin and CTMax values of the fish. At 0.3 °C min⁻¹ cooling or heating rate, CTMin ranged from 4.10 to 6.77 °C and CTMax ranged from 33.23 to 35.95 °C in three acclimation temperatures from 15 to 25 °C. Thermal tolerance polygon for the juveniles at the tested acclimation temperatures was calculated to be 296.14 °C². In general, the current data show that our sea bass population possesses acclimation response ratio (ARR) values (0.25-0.27) similar to some tropical species. The cold tolerance values attained for this species ranged from 4.10 to 6.77 °C, suggesting that cold winter temperatures may not pose danger during the culture of European sea bass in deep ponds or high water exchange rate systems. Upper thermal tolerance is more of a problem in the southern part of the Mediterranean as maximum water temperature in ponds may sometimes exceed 33-34 °C, during which underground cool-water should be used to lower ambient water temperature in the mid-summer. For successful culture of sea bass in ponds, temperature should be maintained around 25 °C throughout the year and this can be managed under greenhousing systems using underground well-waters, commonly available in the region.