Fruit Bats (Chiroptera: Pteropodidae) as Seed Dispersers and Pollinators in a Lowland Malaysian Rain Forest1

The aims of this study were to (1) characterize the food resources exploited by fruit bats (Pteropodidae) within an old‐growth Malaysian dipterocarp forest, (2) test the viability of the seeds they disperse, and (3) provide an estimate of the proportion of trees that are to some degree dependent upon bats for seed dispersal and/or pollination. Fruit species exploited by bats could be distinguished from those eaten by birds largely on the basis of color (as perceived by human beings). Bat‐dispersed fruits were typically inconspicuous shades of green–yellow or dull red–brown, whereas fruits eaten by birds were generally bright orange to red. Dietary overlap between bats and nonflying mammals was relatively high. In contrast to primates and squirrels, which were major seed predators for several of the plant species under investigation, fruit bats had no negative impact on seed viability. A botanical survey in 1 ha of old‐growth forest revealed that 13.7 percent of trees (?15 cm girth at breast height) were at least partially dependent upon fruit bats for pollination and/or seed dispersal.     

Identification of the replication-associated protein binding domain within the intergenic region of tomato leaf curl geminivirus.

The geminiviral replication-associated protein (Rep) is the only viral protein required for viral DNA replication. Tomato leaf curl virus (TLCV) Rep was expressed in Escherichia coli as a histidine-tagged fusion protein and purified to homogeneity in non-denaturing form. The fusion protein was used in in vitro binding experiments to identify the Rep-binding elements within the origin of replication of TLCV. Electrophoretic mobility shift assays demonstrated that the Rep binds specifically to a 120 bp fragment within the TLCV intergenic region. Fine resolution of the binding regions within the 120 bp fragment, using DNase I footprinting, demonstrated two footprints covering the sequences GCAATTGGTGTCTCTCAA and TGAATCGGTGTCTGGGG containing a direct repeat of the motif GGTGTCT (underlined). Our results suggest that the repeated motif is involved in virus-specific Rep-binding, but may not constitute the entire binding element. This is the first demonstration of geminivirus sequence elements involved in Rep-binding by direct protein-DNA interaction assays.     

De novo assembly of mitochondrial genomes provides insights into genetic diversity and molecular evolution in wild boars and domestic pigs

Up to date, the scarcity of publicly available complete mitochondrial sequences for European wild pigs hampers deeper understanding about the genetic changes following domestication. Here, we have assembled 26 de novo mtDNA sequences of European wild boars from next generation sequencing (NGS) data and downloaded 174 complete mtDNA sequences to assess the genetic relationship, nucleotide diversity, and selection. The Bayesian consensus tree reveals the clear divergence between the European and Asian clade and a very small portion (10 out of 200 samples) of maternal introgression. The overall nucleotides diversities of the mtDNA sequences have been reduced following domestication. Interestingly, the selection efficiencies in both European and Asian domestic pigs are reduced, probably caused by changes in both selection constraints and maternal population size following domestication. This study suggests that de novo assembled mitogenomes can be a great boon to uncover the genetic turnover following domestication. Further investigation is warranted to include more samples from the ever-increasing amounts of NGS data to help us to better understand the process of domestication.     

Synthesis,cytotoxicity assessment,and interaction and docking of novel palladium(II) complexes of imidazole derivatives with human serum albumin

Imidazole analogs are the agents that attract both bioinorganic chemist and drug designer. Numerous methods have been proposed for synthesis of imidazole derivatives. In this study, a series of heterocyclic system with p-conjugated system such as 2-aryl-imidazo[4,5-f][1,10]phenanthroline analogs were synthesized. Then, three new palladium(II) complexes containing 2-(Furan-2-yl)-1H-Imidazo[4,5-f][1,10]Phenanthroline (FIP) and 2-(thiophen-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (TIP) ligands were synthesized. The structures of the compounds, [Pd(Phen)(TIP)](NO₃)₂, [Pd(Phen)(FIP)](NO₃)₂, and [Pd(FIP)₂]Cl were determined by spectroscopic methods and elemental analysis. Biological activity of the complexes synthesized was assessed against chronic myelogenous leukemia cell line, K562. Also, the interactions of human serum albumin with complexes were investigated using isothermal titration in the Tris buffer, pH 7.4. According to the results obtained, it was found that there is a set of six binding sites for these complexes on HSA with positive cooperativity in the binding process. Docking technique was also applied to confirm the experimental results. The results showed that smaller complexes have higher interaction affinity.     

Probing the biological evaluations of a new designed Pt(II) complex using spectroscopic and theoretical approaches: human hemoglobin as a target

In recent years, using heavy metal compounds such as platinum as anticancer agent is one of the common ways in chemical therapy. In this study, a new anticancer compound of glycine derivatives of Pt(II) complex (amyl-glycine1, 10-phenanthroline Platinum nitrate) was designed, and the biological effects of this novel compound on the alterations in the function and structure of human hemoglobin (Hb) at different temperatures of 25 and 37°C were assessed by applying various spectroscopic (fluorescence and circular dichroism (CD)) and theoretical methods. Fluorescence data indicated the strong ability of Pt(II) complex to quench the intrinsic fluorescence of Hb. The binding constant, number of binding sites, and thermodynamic parameters at two temperatures were calculated, and the results indicated the major possibility of occurring van der Waals force or hydrogen bond interactions in the Pt(II) complex–Hb interaction. For evaluating the alteration of secondary structure of Hb upon interaction with various concentrations of complex, far-UV CD spectra were used and it was observed that in high dose of complex, significant changes were occurred which is indicative of some side effects in overdosing of this complex. On the other hand, the molecular docking results illustrate that are well in agreement in obtaining data with spectroscopy. Above results suggested that using Pt(II) complex as an anticancer agent, model drug in high-dose usage might cause some disordering in structure and function of Hb as well as improve understanding of the side effects of newly designed metal anticancer drugs undergoing.     

库车种子植物区系垂直分布格局分析

该研究通过野外植被调查及相关文献资料查阅,探讨了库车山区种子植物区系的垂直分布格局特征及其对海拔变化的响应。结果表明:该区种子植物约有78科376属960种。其中,裸子植物3科3属9种,被子植物75科373属951种。植物科、属、种总数随着海拔的升高呈现先增加后降低的单峰分布结构。其中科总数在海拔1 600~1 800 m处为最高峰,属总数在海拔1 800~1 900 m处呈现最高峰;物种总数在海拔1 900~2 000 m处呈现最高峰,有478种(隶属59科,230属)。种子植物区系地理成分分析中,库车山区植物区系垂直海拔梯度上不管是科级水平还是属级水平种类成分都以温带分布型占优势。在垂直分布梯度上,温带分布科最高点出现在海拔1 800~1 900 m(含20科),从海拔2 800~2 900 m开始,随着海拔梯度升高呈现下降趋势,到海拔3 600~3 700 m时为最低点(含6科);温带分布属峰值出现在海拔1 900~2 000 m,随着海拔的升高呈现下降趋势。该研究结果对该区植物种质资源和生态系统多样性,植物资源的引种驯化、栽培和合理利用具有重要意义。     

Differential regulation of nuclear and mitochondrial Bcl-2 in T cell apoptosis

Activated T cells require anti-apoptotic cytokines for their survival. The anti-apoptotic effects of these factors are mediated by their influence on the balance of expression and localisation of pro- and anti-apoptotic members of the Bcl-2 family. Among the anti-apoptotic Bcl-2 family members, the expression level of Bcl-2 itself and its interaction with the pro-apoptotic protein Bim are now regarded as crucial for the regulation of survival in activated T cells. We studied the changes in Bcl-2 levels and its subcellular distribution in relation to mitochondrial depolarisation and caspase activation in survival factor deprived T cells. Intriguingly, the total Bcl-2 level appeared to remain stable, even after caspase 3 activation indicated entry into the execution phase of apoptosis. However, cell fractionation experiments showed that while the dominant nuclear pool of Bcl-2 remained stable during apoptosis, the level of the smaller mitochondrial pool was rapidly downregulated. Signals induced by anti-apoptotic cytokines continuously replenish the mitochondrial pool, but nuclear Bcl-2 is independent of such signals. Mitochondrial Bcl-2 is lost rapidly by a caspase independent mechanism in the absence of survival factors, in contrast only a small proportion of the nuclear pool of Bcl-2 is lost during the execution phase and this loss is a caspase dependent process. We conclude that these two intracellular pools of Bcl-2 are regulated through different mechanisms and only the cytokine-mediated regulation of the mitochondrial pool is relevant to the control of the initiation of apoptosis. D. Scheel-Toellner and K. Raza have contributed equally to this study.