Phylogeography of the mottled spinefoot Siganus fuscescens: Pleistocene divergence and limited genetic connectivity across the Philippine archipelago

Historical isolation during Pleistocene low sea level periods is thought to have contributed to divergence among marine basin populations across the Coral Triangle. In the Philippine archipelago, populations in the South China Sea, Sulu Sea–inland seas, and Philippine Sea‐Celebes Sea basins might have been partially isolated. Meanwhile, present‐day broadscale oceanographic circulation patterns suggest connectivity between these basins. To evaluate hypotheses regarding the influence of historical and contemporary factors on genetic structure, phylogeographic patterns based on mitochondrial control region sequences for a reef‐associated fish, Siganus fuscescens, were analysed. Three distinct lineages were recovered. One lineage was identified as the morphologically similar species Siganus canaliculatus, while two lineages are monophyletic with S. fuscescens. Clade divergence and demographic expansion in S. fuscescens occurred during the Pleistocene. A strong signal of latitudinal structure was detected (Φ_CT = 0.188), driven by marked differences in clade distribution: one clade is widely distributed (clade A), while a second clade (clade B) has a restricted northern distribution. Regional structure of clade A is consistent with the basin isolation hypothesis (Φ_CT = 0.040) and suggests isolation of the South China Sea (Φ_CT = 0.091). Fine‐scale structure was observed in the South China Sea and south Philippine Sea, while Sulu Sea and inland seas were unstructured. Genetic structure across multiple spatial scales (archipelagic, regional, and fine‐scale within basins) suggests the influence of vicariant barriers and contemporary limits to gene flow in S. fuscescens that may be influenced by oceanographic circulation, geographical distance between available habitats, and latitudinal temperature differences.     

<Emphasis Type="Italic">In vitro</Emphasis> and <Emphasis Type="Italic">ex vivo</Emphasis> effect of hyaluronic acid on erythrocyte flow properties

Background  

Hyaluronic acid (HA) is present in many tissues; its presence in serum may be related to certain inflammatory conditions, tissue damage, sepsis, liver malfunction and some malignancies. In the present work, our goal was to investigate the significance of hyaluronic acid effect on erythrocyte flow properties. Therefore we performed in vitro experiments incubating red blood cells (RBCs) with several HA concentrations. Afterwards, in order to corroborate the pathophysiological significance of the results obtained, we replicated the in vitro experiment with ex vivo RBCs from diagnosed rheumatoid arthritis (RA) patients, a serum HA-increasing pathology.     

1590名农村中老年人生存质量调查分析(英文)

目的:采用SF-36量表中文版评价农村中老年人生存质量,并为提高农村中老年人的生存质量和健康水平提供科学依据和建议。方法:采用随机抽样的方法,采用面对面访谈的形式,记分方法参照国际生存质量评价计划(IQOLA)的制定标准,评价其生理和心理健康状况。结果:1590名农村中老年人男性生存质量得分高于女性。经济水平对农村中老年人的生理健康的影响大于对其心理健康的影响。配偶健在的农村中老年人的各维度得分均高于无配偶者。农村中老年人的各维度得分随教育水平的升高呈升高趋势。结论:农村中老年人的生存质量与年龄成负相关,同时也受文化程度和经济水平等多个因素的影响。因而,对农村中老年人这一弱势群体应该给予更多关注。     

Staphylococcal peptidoglycan co-localizes with Nod2 and TLR2 and activates innate immune response via both receptors in primary murine keratinocytes

In mammalian host cells staphylococcal peptidoglycan (PGN) is recognized by Nod2. Whether PGN is also recognized by TLR2 is disputed. Here we carried out PGN co-localization and stimulation studies with TLR2 and Nod2 in wild type and mutant host cells. To exclude contamination with lipoproteins, polymeric staphylococcal PGN (PGN(pol)) was isolated from Staphylococcus aureus Δlgt (lacking lipidated prelipoproteins). PGN(pol) was biotinylated (PGN-Bio) for fluorescence monitoring with specific antibodies. Keratinocytes from murine oral epithelium (MK) readily internalized PGN-Bio in an endocytosis-like process. In wt MK, PGN(pol) induced intracellular accumulation of Nod2 and TLR2 and co-localized with Nod2 and TLR2, but not with TLR4. In TLR2-deficient MK Nod2 and in Nod2-deficient MK TLR2 was induced, indicating that PGN(pol) recognition by Nod2 is independent of TLR2 and vice versa. In both mutants IL-6 and IL-1B release was decreased by approximately 50% compared to wt MK, suggesting that the immune responses induced by Nod2 and TLR2 are comparable and that the two receptors act additively in MK. In TLR2-transfected HEK293 cells PGN(pol) induced NFkB-promoter fused luciferase expression. To support the data, co-localization and signaling studies were carried out with SHL-PGN, a lipase protein covalently tethered to PGN-fragments of varying sizes at its C-terminus. SHL-PGN also co-localized with Nod2 or TLR2 and induced their accumulation, while SHL without PGN did not. The results show that staphylococcal PGN not only co-localizes with Nod2 but also with TLR2. PGN is able to stimulate the immune system via both receptors.     

Actin and phosphoinositide binding by the ActA protein of the bacterial pathogen Listeria monocytogenes

The surface protein ActA of the pathogenic bacterium Listeria monocytogenes induces actin-driven movement of bacteria in the cytoplasm of infected host cells and serves as a model for actin-based motility in general. We generated and purified soluble recombinant fragments of ActA and assessed their ability to interact with the acidic phospholipids phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 3,4,5-trisphosphate, both implicated in the regulation of actin polymerization. Purified ActA consisted of biologically active, elongated molecules with an alpha-helix and beta-sheet content of 11 and 32%, respectively. In the presence of either phosphatidylinositol 4,5-bisphosphate or phosphatidylinositol 3,4,5-trisphosphate, but not phosphatidylcholine, ActA molecules underwent a structural change that raised the alpha-helix content to 19% and lowered the beta-sheet content to 27%. Co-sedimentation experiments with phosphatidylcholine vesicles containing different acidic phospholipids demonstrated that ActA binds preferentially to D-3 phosphoinositides. The D-3 phosphoinositide binding activity was mapped to a small subregion in the N-terminal domain of ActA. This subregion comprised 19 amino acids and showed homology to cecropins. In addition, we found that amino acids 33 to 74 of ActA mediated actin binding by the whole, folded ActA molecule. These findings shed new light on ActA function.     

Testicular mitosis, meiosis and apoptosis in mink (Mustela vison) during breeding and non-breeding seasons

Testes of mink were compared between the breeding (March) and non-breeding seasons with the start (November) and cessation (May) of spermatogenic activity. Testicular mass and spermatozoa per gram testis were assessed. Percentages of haploid (1C), diploid (2C) and tetraploid (4C) cells were monitored using DNA flow cytometry and the proportions of somatic and spermatogenetic cells were determined after selective labelling of somatic cells with a vimentin antibody. Apoptosis was examined by cell death detection ELISA, and testosterone concentrations were measured with an enzyme-immunoassay. The significantly higher testis mass during the breeding period coincided with higher numbers of testicular spermatozoa per gram testis and peak of testicular testosterone concentration in comparison with non-breeding periods. The proportions of 1C, 2C and 4C cells showed corresponding strong differences between these periods with the maximum of 1C cells during breeding. The proportions of testicular cells in G2-M phase of mitosis were very low during the period of peak spermatogenesis; they were markedly increased in the time of autumnal resumption in November but were even higher during testis involution in May. However. the meiotic transformation (1C:4C ratio) is maximal in March. The total as well as the relative proportions of spermatogenic and somatic cells differed significantly not only between breeding and non-breeding periods but also between the periods at the start and at the end of active spermatogenesis. The intensity of apoptosis was also seasonally dependent. The highest level in March indicates a stimulated apoptosis even during the breeding period. In conclusion, the production of spermatozoa in mink is intensified by enlargement of gonads as well as enhanced efficiency of spermatogenesis during breeding. In this time, the testosterone concentration and the meiotic transformation show high levels, but the mitotic activity of spermatogenic cells is already significantly diminished and an intensified apoptosis seems to precede the forthcoming testis involution after breeding. The results suggest that the regulation of seasonal testicular activity is characterised by co-ordinated shifts in the relationships between mitosis, meiosis, apoptosis and testosterone production.     

Interactions between the cartilage oligomeric matrix protein and matrilins. Implications for matrix assembly and the pathogenesis of chondrodysplasias

The cartilage oligomeric matrix protein (COMP) and matrilins are abundant non-collagenous proteins in the cartilage extracellular matrix. In the presence of calcium, COMP and matrilin-1 elute together in the gel filtration of cartilage extracts and can be co-immunoprecipitated. In a screen for ligands of matrilin-1, -3, and -4 using an ELISA-style binding assay, COMP was identified as a prominent binding partner for all three, indicating a conservation of the COMP interaction among matrilins. The interaction of COMP and matrilin-4 is saturable, and an apparent K(D) of 1 nm was determined. However, only the full-length COMP and the full-length matrilin-4 proteins showed a strong interaction, indicating that the oligomeric structures markedly increase the affinity. Mutations in COMP or matrilin-3 cause related forms of human chondrodysplasia, and the COMP mutation D469Delta, which is found in patients with pseudoachondroplasia, has been shown to cause a reduced calcium binding. Despite this, the mutation causes only a slight decrease in matrilin-4 binding. This indicates that impaired binding of COMP to matrilins does not cause the pseudoachondroplasia phenotype but rather that matrilins may be coretained in the rough endoplasmatic reticulum where COMP accumulates in the chondrocytes of patients.     

Selective retrograde transsynaptic transfer of a protein, tetanus toxin, subsequent to its retrograde axonal transport

The fate of tetanus toxin (mol wt 150,000) subsequent to its retrograde axonal transport in peripheral sympathetic neurons of the rat was studied by both electron microscope autoradiography and cytochemistry using toxin-horseradish peroxidase (HRP) coupling products, and compared to that of nerve growth factor (NGF), cholera toxin, and the lectins wheat germ agglutinin (WGA), phytohaemagglutinin (PHA), and ricin. All these macromolecules are taken up by adrenergic nerve terminals and transported retrogradely in a selective, highly efficient manner. This selective uptake and transport is a consequence of the binding of these macromolecules to specific receptive sites on the nerve terminal membrane. All these ligands are transported in the axons within smooth vesicles, cisternae, and tubules. In the cell bodies these membrane compartments fuse and most of the transported macromolecules are finally incorporated into lysosomes. The cell nuclei, the parallel golgi cisternae, and the extracellular space always remain unlabeled. In case the tetanus toxin, however, a substantial fraction of the labeled material appears in presynaptic cholinergic nerve terminals which innervate the labeled ganglion cells. In these terminals tetanus toxin-HRP is localized in 500-1,000 A diam vesicles. In contrast, such a retrograde transsynaptic transfer is not at all or only very rarely detectable after retrograde transport of cholera toxin, NGF, WGA, PHA, or ricin. An atoxic fragment of the tetanus toxin, which contains the ganglioside-binding site, behaves like intact toxin. With all these macromolecules, the extracellular space and the glial cells in the ganglion remain unlabeled. We conclude that the selectivity of this transsynaptic transfer of tetanus toxin is due to a selective release of the toxin from the postsynaptic dendrites. This release is immediately followed by an uptake into the presynaptic terminals.