Diet and trophic position of two mackerel species in the archipelago of Madeira,Portugal

The Atlantic chub mackerel Scomber colias and the blue jack mackerel Trachurus picturatus are two abundant species in the Macaronesia region which includes the archipelago of Madeira, Portugal. Both are key species in the trophic web, being important prey for several local top predators, such as seabirds and marine mammals. Nonetheless, little is known about their feeding ecology in oceanic environments. In this study, the authors describe the seasonal variation in the diet of S. colias and T. picturatus in the oceanic region of Madeira throughout a year. Visual inspection of stomach contents revealed that S. colias fed on a broader range of prey groups than T. picturatus, but for both species, zooplankton (particularly calanoid copepods) and fish were the most important food items. The diet of S. colias included a higher proportion of fish, namely Atlantic saury Scomberesox saurus and S. colias, than that of T. picturatus, that included mostly the longspine snipefish Macroramphosus scolopax. T. picturatus consumed a higher proportion of decapods and other copepods. Seasonal variation was found in the diet of both species, with zooplanktonic species being more important in colder months (February to April) for S. colias and during warm months (May to October) for T. picturatus. Their diet in other seasons was dominated by fish. Although they consume similar prey, carbon and nitrogen stable isotope analysis of muscle of S. colias and T. picturatus showed little overlap in their diets, and T. picturatus showed higher δ¹⁵N and a narrower isotopic niche.     

不同坡位水曲柳木质部解剖特征及其与气候关系

随着气候变暖,东北地区暖干化加剧。为了解干旱胁迫对小兴安岭地区不同坡位水曲柳径向生长的影响,采用木材解剖学方法,分析了水曲柳木质部解剖特征对不同坡位水分变化的响应。结果表明: 上、下坡位水曲柳木质部解剖参数整体上变化趋势一致,导管数量呈线性分布,最大导管面积和总导管面积总体上呈对数分布,平均导管面积总体上呈偏正态分布。不同坡位多个解剖参数均存在显著差异,下坡位导管数量、导管面积总体上大于上坡位。大部分解剖参数与日积温呈显著正相关,但存在一定差异,上坡位水曲柳总导管面积与日均温呈正相关,导管数量、总导管面积与相对湿度呈正相关,相关性均大于下坡位。上坡位最小导管面积与日积温和相对湿度呈显著负相关;而下坡位,总导管面积与相对湿度呈显著正相关。气候暖干化会导致水曲柳导管面积和导管数量相对减少,但基本上不影响导管分布状况,上、下坡位导管分布基本一致。目前,气候暖干化未限制而是促进了水曲柳的径向生长。     

Single‐cell dynamics of chromatin activity during cell lineage differentiation in Caenorhabditis elegans embryos

Elucidating the chromatin dynamics that orchestrate embryogenesis is a fundamental question in developmental biology. Here, we exploit position effects on expression as an indicator of chromatin activity and infer the chromatin activity landscape in every lineaged cell during Caenorhabditis elegans early embryogenesis. Systems‐level analyses reveal that chromatin activity distinguishes cellular states and correlates with fate patterning in the early embryos. As cell lineage unfolds, chromatin activity diversifies in a lineage‐dependent manner, with switch‐like changes accompanying anterior–posterior fate asymmetry and characteristic landscapes being established in different cell lineages. Upon tissue differentiation, cellular chromatin from distinct lineages converges according to tissue types but retains stable memories of lineage history, contributing to intra‐tissue cell heterogeneity. However, the chromatin landscapes of cells organized in a left–right symmetric pattern are predetermined to be analogous in early progenitors so as to pre‐set equivalent states. Finally, genome‐wide analysis identifies many regions exhibiting concordant chromatin activity changes that mediate the co‐regulation of functionally related genes during differentiation. Collectively, our study reveals the developmental and genomic dynamics of chromatin activity at the single‐cell level.     

九州虫草-半枝莲发酵产物不同极性部位与其抗A549细胞增殖活性的相关性分析

建立九州虫草-半枝莲双向固体发酵产物不同极性部位的HPLC特征图谱,并考察与其抑制肺腺癌A549细胞增殖活性的相关性。采用双向固体发酵技术制备九州虫草-半枝莲发酵产物;溶剂萃取法获得发酵产物的不同极性部位,并运用HPLC法建立不同极性部位的特征图谱;MTT法考察不同极性部位对A549细胞的增殖抑制作用;偏最小二乘回归法分析不同极性部位HPLC色谱峰与其抗增殖作用的相关性。抗增殖试验结果表明,不同极性部位对A549细胞均具有增殖抑制作用并且呈浓度依赖性;标示的9个共有色谱峰与抗增殖活性均呈正相关,其中色谱峰8、4、1、2、9分别为木犀草素、黄芩苷、对香豆酸、野黄芩苷、黄芩素。本研究建立了不同极性部位的HPLC特征图谱,极性部位中以二氯甲烷部位对A549细胞的体外抗增殖作用最佳,并借助谱效相关初步探究了发酵产物抗A549细胞增殖的药效物质基础,为双向固体发酵技术应用于菌种与传统中药提供了参考。     

Identification of structural DNA variations in human cell cultures after long-term passage

Random amplified polymorphic DNA (RAPD) analysis was adapted for genomic identification of cell cultures and evaluation of DNA stability in cells of different origin at different culture passages. DNA stability was observed in cultures after no more than 5 passages. Adipose-derived stromal cells demonstrated increased DNA instability. RAPD fragments from different cell lines after different number of passages were cloned and sequenced. The chromosomal localization of these fragments was identified and single-nucleotide variations in RAPD fragments isolated from cell lines after 8–12 passages were revealed. Some of them had permanent localization, while most variations demonstrated random distribution and can be considered as de novo mutations.     

Behavioral remodeling of normal and cancerous epithelial cell lines with differing invasion potential induced by substrate elastic modulus

ABSTRACT

The micro-environment of cancer cells in the body is mechanically stiffer than that of normal cells. We cultured three breast cell lines of MCF10A-normal, MCF7-noninvasive, and MDA-MB-231-invasive on PDMS substrates with different elastic moduli and different cellular features were examined.Effects of substrate stiffness on cell behavior were evident among all cell lines. Cancerous cells were more sensitive to substrate stiffness for cell behaviors related to cell motility and migration which are necessary for invasion. The invasive cancerous cells were the most motile on substrates with moderate stiffness followed by non-invasive cancerous cells. Gene markers alterations were generally according to the analyzed cell movement parameters. Results suggest that alterations in matrix stiffness may be related to cancer disease and progression.     

Studies on the regioselectivity and kinetics of the action of trypsin on proinsulin and its derivatives using mass spectrometry

Human M-proinsulin was cleaved by trypsin at the R³¹R³²–E³³ and K⁶⁴R⁶⁵–G⁶⁶ bonds (B/C and C/A junctions), showing the same cleavage specificity as exhibited by prohormone convertases 1 and 2 respectively. Buffalo/bovine M-proinsulin was also cleaved by trypsin at the K⁵⁹R⁶⁰–G⁶¹ bond but at the B/C junction cleavage occurred at the R³¹R³²–E³³ as well as the R³¹–R³²E³³ bond. Thus, the human isoform in the native state, with a 31 residue connecting C-peptide, seems to have a unique structure around the B/C and C/A junctions and cleavage at these sites is predominantly governed by the structure of the proinsulin itself. In the case of both the proinsulin species the cleavage at the B/C junction was preferred (65%) over that at the C/A junction (35%) supporting the earlier suggestion of the presence of some form of secondary structure at the C/A junction. Proinsulin and its derivatives, as natural substrates for trypsin, were used and mass spectrometric analysis showed that the k_cat./K_m values for the cleavage were most favourable for the scission of the bonds at the two junctions (1.02 ± 0.08 × 10⁵ s^− 1 M^− 1) and the cleavage of the K²⁹–T³⁰ bond of M-insulin-RR (1.3 ± 0.07 × 10⁵ s^− 1 M^− 1). However, the K²⁹–T³⁰ bond in M-insulin, insulin as well as M-proinsulin was shielded from attack by trypsin (k_cat./K_m values around 1000 s^− 1 M^− 1). Hence, as the biosynthetic path follows the sequence; proinsulin → insulin-RR → insulin, the K²⁹–T³⁰ bond becomes shielded, exposed then shielded again respectively.     

黑果枸杞不同组织内生细菌群落多样性

【目的】黑果枸杞是我国荒漠区特有的药用盐生植物,本研究分析了黑果枸杞不同组织中内生细菌群落多样性特征及分布规律。【方法】应用Illumina MiSeq高通量测序技术对黑果枸杞内生细菌的16S rRNAV5-V7区域序列进行测定,并分析群落组成、多样性及功能等生物学信息。【结果】黑果枸杞不同组织内生细菌群落多样性及功能均有较大的差异。花、叶、果、茎和根产生的OTUs分别是182、173、119、187和254,群落多样性表现为根花果、茎叶。从门水平上看,变形菌门是优势菌门,在不同组织中均有分布,花、叶、果、茎和根中的相对丰度分别为87.66%、41.51%、81.76%、97.67%和61.85%。在属水平上显示内生细菌的分布表现出器官差异性。花部能够准确分类的优势菌属为沙雷氏菌属和不动杆菌属,相对丰度分别为11.57%和8.55%。叶部为红球菌属和慢生根瘤菌属,相对丰度分别为29.68%和5.53%。果实中为泛菌属、红球菌属和沙雷氏菌属,相对丰度分别为23.12%、5.52%和4.29%。茎部为沙雷氏菌属和假单胞菌属,相对丰度分别为12.03%和17.71%。根部为盐单胞菌属、Fodinicurvata和Lipingzhangella,相对丰度分别为24.18%、5.16%和4.86%。在不同组织中分布较广的盐单胞菌、沙雷氏菌、不动杆菌、红球菌、泛菌等菌属均具有较高耐盐性和促生、生防、降解有机污染物及抗氧化等功能。PICRUSt功能预测分析显示,黑果枸杞组织中内生细菌功能中涉及丰富的多糖、萜类和酮类、酶及维他命等次生代谢产物的生物合成。【结论】黑果枸杞内生细菌具有丰富的群落和功能多样性,拥有多种益生功能性状,也含有多个与人和植物体代谢相关的功能信息。不同组织优势菌属和功能信息各有不同,其中根部的内生细菌物种最丰富,花部和茎部参与各种代谢调控的细菌丰度最高。此外,不同组织中还含有大量未知种属的微生物类群,这些都为内生细菌功能利用和挖掘新的有益微生物资源提供广阔的发展空间。     

稀有鮈鲫(Gobiocypris rarus)的骨骼特征及系统发育地位

稀有鮈鲫(Gobiocypris rarus)已作为新型实验动物而逐渐成为生物学研究各领域的热门对象,但是,其系统分类位置仍存在争议。本研究制作了稀有鮈鲫的透明骨骼标本,对其骨骼特征进行描述;选取47个形态特征,与鲤科各亚科鱼类的典型特征进行比较,建立了分支分析特征矩阵,并使用PAUP4.0软件中的最大简约法(MP)构建系统发育树。结果显示,稀有鮈鲫和鮈亚科鱼类聚在一起,属于鮈亚科。