甘蓝型油菜ZF-HD基因家族的鉴定与系统进化分析

ZF-HD是一类植物特有的转录因子, 在植物生长发育及胁迫响应过程中发挥重要作用。利用生物信息学方法, 在甘蓝型油菜(Brassica napus)基因组中鉴定到62个ZF-HD基因, 其中83.9%的基因缺乏内含子, 93.5%的BnZF-HD等电点大于7, 预测定位于细胞核的蛋白大多由100个以上氨基酸组成。根据进化关系可将其分为6个亚群, 在每个亚群中, 甘蓝(B. oleracea)和白菜(B. rapa)的ZF-HD基因数量相等或近似相等, 而甘蓝型油菜的ZF-HD基因数量接近或等同于甘蓝和白菜的ZF-HD基因数量之和。同一亚群的motif数量和类型高度相似。共线性分析结果显示, 全基因组三倍体化使ZF-HD基因在二倍体祖先得到扩张, 而异源多倍体化又进一步使甘蓝型油菜ZF-HD基因家族扩张。K_a/K_s值说明大多数ZF-HD基因在进化过程中受到了纯化选择。所有BnZF-HD基因都具有光响应元件, 2/3的基因具有MeJA、ABA和厌氧诱导顺式作用元件, 推测这些基因可能参与相关生物学过程。研究结果为进一步挖掘该家族基因的生物学功能奠定基础, 同时为揭示多基因家族在异源多倍体中的进化式样提供借鉴。     

Temporal and spatial changes in macrozoobenthos diversity in Poyang Lake Basin,China

Poyang Lake plays a significant role in maintaining and replenishing the macrozoobenthos biodiversity in the middle Yangtze River. However, due to human activities and natural factors, the habitat of Poyang Lake has been seriously degraded, resulting in a decline in macrozoobenthos biodiversity. Here, we analyzed the effect of human activity and environmental elements change on the diversity of macrozoobenthos based on a systematic investigation of Poyang Lake Basin in 2016–2017. The current species richness, density, and biomass of macrozoobenthos were lower than those in the historical period. At the same time, the community structure of the macrozoobenthos assemblage exhibits significant temporal and spatial differences. In addition, the spatial turnover component was the main contribution to beta diversity, which indicated that a number of protected areas would be necessary to conserve the biodiversity of macrozoobenthos. Water depth, dissolved oxygen, water velocity, and chlorophyll‐a were significantly correlated with macrozoobenthos distributions and assemblage structure based on RDA. These results indicated that human activities have seriously destroyed the macrozoobenthos habitat and led to the decline in macrozoobenthos diversity. Therefore, habitat restoration and the conservation of macrozoobenthos have become urgent in Poyang Lake Basin, and an integrated management plan should be developed and effectively implemented.     

Trace elements removal ability and antioxidant activity of Phragmites australis (from Algeria)

Abstract

In this study, roots, stems and leaves of the worldwide distributed macrophyte Phragmites australis (common reed) were tested as potential removal and biomonitors of trace elements contamination in sediment. In particular, the concentrations (100, 200, and 500?mg/kg) of the following elements were analyzed: Zn, Cu, Pb, and Fe. Results showed that the amount of concentrations in plant tissues is significantly (p?≤?0.01) dependent on the kind of organ and element. Trace element concentrations decreased according to the pattern of Fe^a (Roots^a > Stems^b > Leaves^b) > Zn^b (Root^a > Leaves^b > Stems^c) > Cu^c (Roots^a > Leaves^b > Stems^c) > Pb^c (Roots^a > Stems^b > Leaves^c), as well as the roots acted as the main centers of bioaccumulation for all elements studied, and stems as the transit organs for translocation from roots to leaves. The major mechanisms employed by the plant were probably phytostabilization on the basis of the calculated Biological Concentration Factor (BCF – metal concentration ratio of plant root to soil); and Translocation Factor (TF – metal concentration ratio of plants roots to above ground part). Finally, due to the low scavenger effect of the radical DPPH, we excluded the hypothesis of the use of antioxidant mechanism in the tolerance of metals.     

Bioaccumulation and translocation of nine heavy metals by Eichhornia crassipes in Nile Delta,Egypt: perspectives for phytoremediation

Abstract

The current research was carried out to estimate the potential of water hyacinth (WH) for removal of nine heavy metals (HMs) from three irrigation canals in Nile Delta. Sampling was achieved in monospecific and homogeneous WH stands at three irrigation canals in the study area, and WH biomass was sampled at monthly intervals from April 2014 to November 2014 using five randomly distributed quadrats (each 0.5?×?0.5?m) at each canal. All HM concentrations were significantly higher in the roots compared with the other WH organs. The WH was recognized by a bioaccumulation factor >1.0 for all HMs. The WH was recognized by translocation factor <1.0 for all HMs (except Pb). In many cases, the concentrations of the HMs in the different organs of WH were correlated with the same HMs in the water. Such correlations indicate that WH reflects the cumulative influences of environmental pollution from the water, and thereby suggesting its potential use in the bio-monitoring of most examined HMs. In conclusion, WH is a promising macrophyte for remediation of irrigation canals polluted with Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn.     

Nutritional status and risks of potentially toxic elements in some paddy soils and rice tissues

This experiment was conducted to investigate the potential risk of toxic elements in paddy soils and rice straws, bran, and husked grains in Kuchesfahan, Gilan, Iran. The average content of total and DTPA-extractable of Cd, Cu, Fe, Mn, Ni, Pb, and Zn were 7.0, 26.3, 20728.8, 1516.7, 43.8, 16.6, and 211.8?mg kg^?1, and 0.32, 14.1, 97.3, 63.4, 1.7, 4.8, and 56.2?mg kg^?1, respectively. In addition, the average content of Cd, Cu, Fe, Mn, Ni, Pb, and Zn in rice grain was 0.16, 2.4, 135.5, 34.1, 2.0, 0.6, and 15.0?mg kg^?1, respectively. The average transfer factor for Cd, Cu, Fe, Mn, Ni, Pb, and Zn from soil to straw was 0.38, 0.16, 0.004, 0.13, 0.3, 0.04, and 0.09, respectively. The average values of estimated daily intake for Cd, Cu, Fe, Mn, Ni, Pb, and Zn through rice consumption for adult are respectively, estimated to be 0.0004, 0.005, 0.32, 0.08, 0.005, 0.0015, and 0.035?mg kg^?1 body weight per day. There was no health risk index (HRI) values for adult greater than 1 (except three samples for Fe, and one sample for Mn and Cd); indicated that intake of single metal through the consumption of rice was safe. The average of heath index (HI) value for rice consumption was 0.33 and 0.35 for adult and children, respectively. Therefore, combination of several potentially toxic elements may not cause risk to local residents. Spatial distributions of HRI were obtained for potentially toxic metals in husked grains.     

Epidermal Growth Factor Activates the Rho GTPase-activating Protein (GAP) Deleted in Liver Cancer 1 via Focal Adhesion Kinase and Protein Phosphatase 2A

Deleted in Liver Cancer 1 (DLC1) is a RHO GTPase-activating protein (GAP) that negatively regulates RHO. Through its GAP activity, it modulates the actin cytoskeleton network and focal adhesion dynamics, ultimately leading to suppression of cell invasion and metastasis. Despite its presence in various structural and signaling components, little is known about how the activity of DLC1 is regulated at focal adhesions. Here we show that EGF stimulation activates the GAP activity of DLC1 through a concerted mechanism involving DLC1 phosphorylation by MEK/ERK and its subsequent dephosphorylation by protein phosphatase 2A (PP2A) and inhibition of focal adhesion kinase by MEK/ERK to allow the binding between DLC1 and PP2A. Phosphoproteomics and mutation studies revealed that threonine 301 and serine 308 on DLC1, known previously to be mutated in certain cancers, are required for DLC1-PP2A interaction and the subsequent activation of DLC1 upon their dephosphorylation. The intricate interplay of this “MEK/ERK-focal adhesion kinase-DLC1-PP2A” quartet provides a novel checkpoint in the spatiotemporal control of cell spreading and cell motility.     

Biomolecular identification of ancient Mycobacterium tuberculosis complex DNA in human remains from Britain and continental Europe

Tuberculosis is known to have afflicted humans throughout history and re‐emerged towards the end of the 20th century, to an extent that it was declared a global emergency in 1993. The aim of this study was to apply a rigorous analytical regime to the detection of Mycobacterium tuberculosis complex (MTBC) DNA in 77 bone and tooth samples from 70 individuals from Britain and continental Europe, spanning the 1st–19th centuries AD. We performed the work in dedicated ancient DNA facilities designed to prevent all types of modern contamination, we checked the authenticity of all products obtained by the polymerase chain reaction, and we based our conclusions on up to four replicate experiments for each sample, some carried out in an independent laboratory. We identified 12 samples that, according to our strict criteria, gave definite evidence for the presence of MTBC DNA, and another 22 that we classified as “probable” or “possible.” None of the definite samples came from vertebrae displaying lesions associated with TB. Instead, eight were from ribs displaying visceral new bone formation, one was a tooth from a skeleton with rib lesions, one was taken from a skeleton with endocranial lesions, one from an individual with lesions to the sacrum and sacroiliac joint and the last was from an individual with no lesions indicative of TB or possible TB. Our results add to information on the past temporal and geographical distribution of TB and affirm the suitability of ribs for studying ancient TB. Am J Phys Anthropol 153:178–189, 2014. © 2013 Wiley Periodicals, Inc.