The chironomid midges Belgica antarctica,\ud Eretmoptera murphyi (subfamily Orthocladiinae) and\ud Parochlus steinenii (subfamily Podonominae), are the\ud only Diptera species currently found in Antarctica. The\ud relationships between these species and a range of further\ud taxa of Chironomidae were examined by sequencing\ud domains 1 and 3–5 of 28S ribosomal RNA. The resulting\ud molecular relationships between B. antarctica and\ud E. murphyi, within Orthocladiinae, were highly supported\ud by validation analyses, confirming their position\ud within Chironomidae, as generated by classical taxonomy.\ud Within Podonominae, P. steinenii from the Maritime\ud Antarctic was more closely related to material from\ud sub-Antarctic South Georgia than to material from\ud Patagonia. Taking advantage of the availability of a\ud molecular substitution rate calculated for this gene in\ud Diptera, a dating of divergence between our study taxa\ud was tentatively established. The divergence dates obtained\ud were 49 million years (Myr), between B. antarctica\ud and E. murphyi, and 68.5 Myr between these species\ud and the closest Orthocladiinae taxon tested from Patagonia,\ud suggesting that B. antarctica and E. murphyi were\ud representatives of an ancient lineage. As both are endemic\ud to their respective tectonic microplates, their\ud contemporary distribution is, therefore, likely to have\ud been shaped by vicariance rather than dispersal

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Parnassius apollo (Linnaeus, 1758) is probably the most renowned Eurasian montane butterfly. Its specialized ecology makes it very sensitive to habitat and climate changes, so that it is now experiencing range contraction and local extinction across most of its range. We sequenced 869 bp of the mitochondrial DNA (mtDNA) cytochrome oxidase I gene in 78 P. apollo populations (201 individuals) in order to: (1) assess the phylogeographic pattern of the species; (2) shed light on the historical biogeographic processes that shaped the distribution of the species; and (3) identify geographic population units of special value for the conservation of the species' genetic diversity. Our analyses revealed a very strong phylogeographic structure in P. apollo, which displays a number of distinctive mtDNA lineages populating geographically distinct areas. Overall sequence divergence is relatively shallow, and is consistent with a recent (late Pleistocene) colonization of most of the range. We propose that P. apollo is best viewed as an atypical glacial invader in southern and western Europe, the isolated, montane populations of which, threatened by climate warming, retain a large fraction of the species evolutionary heritage. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101, 169–183

Aim To investigate the molecular phylogenetic divergence and historical biogeography of cave crickets belonging to the genus Dolichopoda (Orthoptera, Rhaphidophoridae).Location Caves in continental and insular Greece.Methods We sequenced 1967 bp of mitochondrial DNA, corresponding to three fragments of the small and large subunit of the ribosomal RNA (16S and 12S rRNA, respectively) and to the subunit I of cytochrome oxidase (COI), to reconstruct phylogenetic relationships among all 30 known Greek species of Dolichopoda. Alternative hypotheses about the colonization of the Hellenic Peninsula by Dolichopoda species were tested by comparing the degree of discordance between species trees and gene trees under four plausible biogeographical scenarios. ResultsThe present study revealed a rather well resolved phylogeny at species level, identifying a number of clades that represent long-separated lineages and diverse evolutionary histories within the genus Dolichopoda. Two main clades were revealed within Hellenic-Aegean species, identifying a north-western and a south-eastern species group. Based on Bayesian analysis, we applied a relaxed molecular clock to estimate the divergence times between the lineages. The results revealed that the origins of eastern Mediterranean lineages are much older than those of previously studied western Mediterranean Dolichopoda. Tests of alternative biogeographical hypotheses showed that a double colonization of the Hellenic Peninsula, following separate continental and trans-Aegean routes during the Messinian stage, best accounts for the present distribution of Greek Dolichopoda species.Main conclusions Reconstruction and biogeographical hypothesis testing indicated that the colonization of Greece by Dolichopoda species comprised two episodes and two different routes. The southern lineage probably arose from a transAegean colonization during the Messinian salinity crisis (5.96-5.33 Ma). The northern lineage could be the result of dispersal from the north through the Balkan Peninsula. The opening of the Mid-Aegean Trench could have promoted an initial diversification within the uprising Anatolian Plateau, while the Messinian marine regression offered the conditions for a rapid dispersal through the whole AegeanHellenic region. In addition, climatic events during the Plio-Pleistocene may have been responsible for the speciation within each of the two different phylogeographical units, principally attributable to vicariance events.

Aim  Our study provides a description of the mitogenetic structure of alpine butterflies of the Parnassius phoebus complex throughout their Holarctic distribution. Our analyses extend and reassess population history models for alpine butterflies under an explicit calibration of their mitochondrial DNA (mtDNA) substitution rate. Location  Mountain ranges of the Holarctic region. Methods  A fragment (824 bp) of the mitochondrial cytochrome c oxidase subunit I (COI) gene was sequenced in 203 samples (72 locations), and combined with previously available COI sequences (499 samples), to obtain full coverage of the Holarctic distribution of the P. phoebus complex. A global species distribution model (SDM) was calculated by the maximum entropy (Maxent) approach, allowing assignment of samples into geographically consistent ‘operational’ units. Phylogenetic and coalescent methods were applied to describe the global mitogenetic structure and estimate population genetics parameters. Geological and palaeoecological evidence was used for internal calibration and validation of a COI substitution rate. Results  Eurasian (including Alaskan) and North American populations form two distinct mitochondrial clades. The mitochondrial time to most recent common ancestor (TMRCA) of the North American clade was estimated at less than 125 ka, and the TMRCA of the Eurasian–Alaskan clade at less than 80 ka, except for a single divergent sequence from Mongolia. Pairwise divergence times between all geographical units within each continent date well within the last 100 ka, and most likely, the last 50–10 ka. Main conclusions  In contrast with its currently scattered distribution within each of Eurasia and North America, the mitogenetic structure of the P. phoebus complex in both continents is shallow and weak, and shows no evidence of geographical structure dating back earlier than the last glacial cycle. We argue that mtDNA data are consistent with recent (Würm/Wisconsin) range expansion across each of the two continents and with persistent glacial long-range gene flow which ceased during the Holocene. We propose that P. phoebus may represent a model for Holarctic alpine invertebrates with moderate dispersal abilities in that its genetic structure at a continental scale reflects extensive connectivity during the most recent glacial phases

It has been shown recently that Selenium (Se), an essential trace element for humans, is involved in the regulation of thyroid function, since the enzyme that catalyzes the liver conversion of the thyroid hormone T4 to the more active form T3 is a selenoenzyme. In chronic uremic patients, low blood Se levels as well as thyroid function abnormalities are often found. The present study was carried out to verify whether any correlation exists between Se levels and thyroid function, and to evaluate possible changes in hormonal pattern during Se supplementation in 10 chronic uremic patients on hemodialysis (HD) treatment. Se was supplemented orally as sodium selenite over six consecutive months. Basic plasma Se levels were significantly lower in patients than in normal controls. Right from the start of Se supplementation, plasma Se concentration promptly normalized and leveled off in the normal range throughout the study. Significant increase of FT3 and reduction of TSH levels were detected during Se supplementation. In Se-supplemented patients, a significant direct correlation was also found between reverse T3 (rT3) and TSH, and a significant inverse correlation was found between Se and TSH. Our results suggest that Se deficiency in chronic uremic patients represents a factor influencing the thyroid function and that the Se status should be determined in the evaluation of thyroid metabolism in these patients.

Transforming growth factor (TGF)-beta1-decreased major histocompatibility complex (MHC) class I gene expression in thyrocytes is transcriptional; it involves trans factors and cis elements important for hormone- as well as iodide-regulated thyroid growth and function. Thus, in rat FRTL-5 thyrocytes, TGF-beta1 regulates two elements within -203 bp of the transcription start site of the MHC class I 5'-flanking region: Enhancer A, -180 to -170 bp, and a downstream regulatory element (DRE), -127 to -90 bp, that contains a cAMP response element (CRE)-like sequence. TGF-beta1 reduces the interaction of a NF-kappaB p50/fra-2 heterodimer (MOD-1) with Enhancer A while increasing its interaction with a NF-kappaB p50/p65 heterodimer. Both reduced MOD-1 and increased p50/p65 suppresses class I expression. Decreased MOD-1 and increased p50/p65 have been separately associated with the ability of autoregulatory (high) concentrations of iodide to suppress thyrocyte growth and function, as well as MHC class I expression. TGF-beta1 has two effects on the downstream regulatory element (DRE). It increases DRE binding of a ubiquitously expressed Y-box protein, termed TSEP-1 (TSHR suppressor element binding protein-1) in rat thyroid cells; TSEP-1 has been shown separately to be an important suppressor of the TSH receptor (TSHR) in addition to MHC class I and class II expression. It also decreases the binding of a thyroid-specific trans factor, thyroid transcription factor-1 (TTF-1), to the DRE, reflecting the ability of TGF-beta1 to decrease TTF-1 RNA levels. TGF-beta1-decreased TTF-1 expression accounts in part for TGF-beta1-decreased thyroid growth and function, since decreased TTF-1 has been shown to decrease thyroglobulin, thyroperoxidase, sodium iodide symporter, and TSHR gene expression, coincident with decreased MHC class I. Finally, we show that TGF-beta1 increases c-jun RNA levels and induces the formation of new complexes involving c-jun, fra-2, ATF-1, and c-fos, which react with Enhancer A and the DRE. TGF-beta1 effects on c-jun may be a pivotal fulcrum in the hitherto unrecognized coordinate regulation of Enhancer A and the DRE.

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