A molecular phylogeny of the lizard genus Phymaturus (Squamata,Liolaemini): Implications for species diversity and historical biogeography of southern South America

The lizard genus Phymaturus is widely distributed in Argentina and along the eastern edge of Chile between 25° and 45° south. We sampled 27 of the 38 currently recognized species plus 22 candidate species using two mitochondrial genes (cytb and 12S), four protein coding nuclear genes and seven anonymous nuclear loci, and present the first comprehensive molecular phylogenetic hypothesis for the clade. We recovered two large clades (the palluma or northern group and patagonicus or southern group) previously recognized on the basis of morphological and mitochondrial sequence evidence, and compared results obtained from concatenated-gene analyses with results of a coalescent-based species-tree approach (BEST). With both methods we identified four main clades within the palluma group (mallimaccii, roigorum, verdugo, and vociferator) and five main clades within the patagonicus group (calcogaster, indistinctus, payuniae, somuncurensis, and spurcus). We found several instances of non-monophyly with cytb and cases of incongruence between mitochondrial vs nuclear data for which we discuss alternative hypotheses. Although with lower support values, combined BEST results are more congruent with concatenated nuclear data than with combined concatenated analyses, suggesting that BEST is less influenced by demographic processes than combined concatenated analyses. We discuss the taxonomic, biogeographic and conservation implications of these results and how the future integration of phylogeographic and morphological approaches will allow the further testing of demographic and biogeographic hypotheses.     

Bilateral impairments of shoulder abduction in chronic hemiparesis: Electromyographic patterns and isokinetic muscle performance

ObjectiveTo analyze electromyographic (EMG) patterns and isokinetic muscle performance of shoulder abduction movement in individuals who sustained a cerebrovascular accident (CVA).DesignTwenty-two individuals who sustained a CVA and 22 healthy subjects volunteered for EMG activity and isokinetic shoulder abduction assessments. EMG onset time, root mean square (RMS) for upper trapezius and deltoid muscles, as well as the isokinetic variables of peak torque, total work, average power and acceleration time were compared between limbs and groups.ResultsThe paretic side showed a different onset activation pattern in shoulder abduction, along with a lower RMS for both muscles (21.8 ± 13.4% of the maximal voluntary isometric contraction (MVIC) for the deltoid and 25.9 ± 15.3% MVIC for the upper trapezius, about 50% lower than the control group). The non-paretic side showed a delay in both muscles activation and a lower RMS for the deltoid (32.2 ± 13.7% MVIC, about 25% lower than the control group). Both sides of the group of individuals who sustained a CVA presented a significantly lower isokinetic performance compared to the control group (paretic side ～60% lower; non-paretic side ～35% lower).ConclusionsShoulder abduction muscle performance is impaired in both paretic and non-paretic limbs of individuals who sustained a CVA.     

Calcitriol downregulates TNF-α and IL-6 expression in cultured placental cells from preeclamptic women

Placenta is an important source and target of hormones that contribute to immunological tolerance and maintenance of pregnancy. In preeclampsia (PE), placental calcitriol synthesis is low; whereas pro-inflammatory cytokines levels are increased, threatening pregnancy outcome. Previously, we showed that calcitriol inhibits Th-1 cytokines under experimental inflammatory conditions in normal trophoblasts. However, a study of the regulation of inflammatory cytokines by calcitriol in trophoblasts from a natural inflammatory condition, such as PE, is still lacking. Therefore, the aim of the present study was to investigate calcitriol effects upon TNF-α, IFN-γ, IL-6 and IL-1β in cultured placental cells from preeclamptic women by using qPCR and ELISA. Placentas were collected after cesarean section from preeclamptic women and enriched trophoblastic preparations were cultured in the absence or presence of different calcitriol concentrations during 24 h. In these cell cultures, pro-inflammatory cytokines TNF-α and IL-6 secretion and mRNA expression were downregulated by calcitriol (P < 0.05). No significant effects of calcitriol upon IFN-γ and IL-1β were observed. In addition, basal expression of TNF-α, IL-6 and IL-1β decreased as the cells formed syncytia. Our study supports an important autocrine/paracrine role of placental calcitriol in controlling adverse immunological responses at the feto–maternal interface, particularly in gestational pathologies associated with exacerbated inflammatory responses such as preeclampsia.     

PIK3R1 Mutations Cause Syndromic Insulin Resistance with Lipoatrophy

Short stature, hyperextensibility of joints and/or inguinal hernia, ocular depression, Rieger anomaly, and teething delay (SHORT) syndrome is a developmental disorder with an unknown genetic cause and hallmarks that include insulin resistance and lack of subcutaneous fat. We ascertained two unrelated individuals with SHORT syndrome, hypothesized that the observed phenotype was most likely due to de novo mutations in the same gene, and performed whole-exome sequencing in the two probands and their unaffected parents. We then confirmed our initial observations in four other subjects with SHORT syndrome from three families, as well as 14 unrelated subjects presenting with syndromic insulin resistance and/or generalized lipoatrophy associated with dysmorphic features and growth retardation. Overall, we identified in nine affected individuals from eight families de novo or inherited PIK3R1 mutations, including a mutational hotspot (c.1945C>T [p.Arg649Trp]) present in four families. PIK3R1 encodes the p85α, p55α, and p50α regulatory subunits of class IA phosphatidylinositol 3 kinases (PI3Ks), which are known to play a key role in insulin signaling. Functional data from fibroblasts derived from individuals with PIK3R1 mutations showed severe insulin resistance for both proximal and distal PI3K-dependent signaling. Our findings extend the genetic causes of severe insulin-resistance syndromes and provide important information with respect to the function of PIK3R1 in normal development and its role in human diseases, including growth delay, Rieger anomaly and other ocular affections, insulin resistance, diabetes, paucity of fat, and ovarian cysts.     

川芎嗪对Aβ25-35诱导体外大鼠海马神经元细胞凋亡的影响

本文通过Aβ25-35诱导体外原代培养的SD乳大鼠海马神经元,建立Aβ毒性损伤细胞模型,结合AnnexinV-FITC/PI荧光双染法流式细胞术、MTT比色法、实时荧光定量PCR及Western blot方法检测川芎嗪(tetrameth-ylpyrazine,TMP)对原代培养的海马神经元细胞活性、早期凋亡率和Bax、Bcl-2基因表达的影响。结果显示川芎嗪高、中剂量可明显增强细胞活性,增加神经元细胞的存活率(P<0.01),可显著抑制海马神经元细胞早期凋亡(P<0.01),抑制凋亡蛋白Bax的表达(P<0.01),增强抗凋亡蛋白bcl-2的表达(P<0.01)。川芎嗪可通过调节Bax/Bcl-2平衡抵抗Aβ25-35诱导的海马神经元凋亡,降低Aβ的神经元毒性,对海马神经元损伤有明显的保护作用。     

Modelling expected trout ranges under current and future water temperature regimes in the Eastern Cape,South Africa

Different values have resulted in conflicts between anglers and conservation lobbies in the management of trout in South Africa. Key to the conflict is the demarcation of boundaries to areas in which brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss currently occur, or are likely to establish following stocking for angling. To provide a longer-term perspective on these areas, we developed models to link salmonid biological thermal thresholds to elevation. These, when applied spatially using a digital elevation model with a probability of occurrence model, provided the basis for estimating potentially available thermal habitat for these two cold water species. Here, we acknowledge that other variables (stocking history; river connectivity) also play a role in understanding trout distributions. Using a simple scenario of an increase in mean daily water temperatures of 2 °C, we demonstrated that both brown and rainbow trout are likely to exhibit considerable range reductions in the future. Because it is possible that these range restrictions will result in an increasing desire to introduce trout into areas above their current distribution limits for the maintenance of angling opportunities, conservation managers should prioritise these areas, with management interventions seeking to understand what will help to limit introductions.     

Lysosomal Signaling Licenses Embryonic Stem Cell Differentiation via Inactivation of Tfe3

1. Download high-res image (175KB)
2. Download full-size image