The transmembrane domain of the SNARE protein VAMP2 is highly sensitive to its lipid environment

Neurotransmitter and hormone exocytosis depends on SNARE protein transmembrane domains and membrane lipids but their interplay is poorly understood. We investigated the interaction of the structure of VAMP2, a vesicular transmembrane SNARE protein, and membrane lipid composition by infrared spectroscopy using either the wild-type transmembrane domain (TMD), VAMP2_TM22, or a peptide mutated at the central residues G₁₀₀/C₁₀₃ (VAMP2_TM22VV) previously identified by us as being critical for exocytosis. Our data show that the structure of VAMP2_TM22, in terms of α-helices and β-sheets is strongly influenced by peptide/lipid ratios, by lipid species including cholesterol and by membrane surface charges. Differences observed in acyl chain alignments further underscore the role of the two central small amino acid residues G₁₀₀/C₁₀₃ within the transmembrane domain during lipid rearrangements in membrane fusion.     

A new genus of moths (Lepidoptera: Gracillarioidea: Douglasiidae) in Myanmar amber

A new genus and species of moths, Tanyglossus orectometopus n. gen. et sp. (Lepidoptera: Gracillarioidea), is described from mid-Cretaceous Myanmar amber. Autapomorphies for the new genus are small size (body length of only 0.9 mm), long proboscis greater than body length, presence of ocelli, 3-segmented porrect labial palps, 5-segmented curved maxillary palps, no eye cap, lanceolate wings with reduced venation and a body and wing covering of several types of scales. Based on the available characters, the fossil is placed in the small, aberrant family Douglasiidae and represents the first fossil member of this family. This study adds to our scant knowledge of the diversity of Mesozoic Glossata.     

A bizarre sternorrhynchan wing from the Lower Jurassic of Luxembourg (Hemiptera: Sternorrhyncha: Pincombeomorpha?)

Fossil wing of Hemiptera Sternorrhyncha with peculiar venation is described from the lower Toarcian (Lower Jurassic) of Bascharage (Grand-duchy of Luxembourg). It represents new family Xulsigiidae fam. nov., comprising a new genus and species Xulsigia karetsa gen. et sp. nov. It is placed preliminarily in extinct infraorder Pincombeomorpha for the presence of three branches of median vein. Key to families of Pincombeomorpha is given and the taxonomic position and venation features of the new fossil are discussed.

Family Xulsigiidae is registered in Zoobank under the http://www.zoobank.org/urn:lsid:zoobank.org:act:3A57B428-638A-439A-AEC4-D18B5959B5CA

Genus Xulsigia is registered in Zoobank under the http://www.zoobank.org/urn:lsid:zoobank.org:act:2B255A30-5A7C-4CF8-AE77-18ED6E8E03C2     

裸花紫珠治疗烧烫伤模型大鼠活性部位的筛选及其作用机制研究

为筛选裸花紫珠治疗烧烫伤的活性部位,并初步研究其作用机制。实验采用90°C热水造成大鼠烫伤模型。以伤口面积大小,伤口性状,如颜色、软硬程度等为指标,通过宏观和微观检测筛选裸花紫珠治疗烧烫伤的活性部位。采用ELISA和Western blot等方法初步研究其作用机制。进入组织增生重塑期后,石油醚组相较其它各组,伤口愈合最为显著;在组织增生最后的成熟期,石油醚组的表皮和真皮恢复得最好,伤疤最小。石油醚组的VEGF浓度在早期出现了明显的上调;在第21天时,TGF-β1的表达水平最低。裸花紫珠治疗烧烫伤的活性部位初步推测在石油醚层,其治疗烧烫伤作用机制可能是早期裸花紫珠使VEGF上调,在后期下调了TGF-β1以达到。本研究为裸花紫珠治疗烧烫伤的进一步研究和应用提供依据。     

青花椒水提物及精油对松材线虫的防治探究

探究了青花椒水提物及精油对松材线虫的防治作用。分别提取青花椒水提物及精油,倍比稀释法探究其对松材线虫寿命及运动行为的影响。实验结果表明2.5 mg/mL的青花椒水提物和0.1%的青花椒精油4小时均能完全杀灭松材线虫,青花椒水提物和精油均能降低松材线虫的运动行为能力,从而说明青花椒水提物及精油对松材线虫具有防治作用。     

Suspension Culture and Somatic Embryogenesis of Korean Pine

Korean pine is an important afforestation tree species in Northeast China, which has a high ecological and economic value. Although regeneration of somatic embryogenesis using immature zygotic embryos of Korean pine as explants has been successful, it cannot be applied to automation and large-scale production. Therefore, we urgently need a method that can increase the output of somatic embryos (SEs) to meet the needs of large-scale production. We used Korean pine 1–1 and 1–100 cell lines as research materials to evaluate the effects of inoculum-density, culture time, orbiting speed, vessel volume, plant growth regulator (PGR) concentration, and carbon source on the proliferation of embryogenic tissue (ET). The somatic embryogenesis ability of ET cultured in different liquid suspension media was also evaluated. We found that during liquid suspension culture of Korean pine ET, the sedimented cell volume (SCV), fresh weight (FW) and dry weight (DW) were affected by inoculum-density, culture time, orbiting speed, 2,4-D concentration, 6-BA concentration and carbon source type. Fourty mg ⋅ mL⁻¹ ET were transferred to a 200 mL Erlenmeyer flask containing 20 mL liquid medium, and cultured at 100 rpm/min for 14 days to obtain the maximum proliferation. In addition, we also found that SCV, FW and DW were higher when PGRs were reduced in the liquid suspension medium. The substitution of maltose for sucrose resulted in slow growth of cultures and limited SE yield (13 SEs g⁻¹ FW). Although culture proliferation was high at 50 rpm, SE yield was inhibited by 48% compared with 100 rpm (50 rpm = 33 SEs g⁻¹ FW; 100 rpm/min = 70 SEs g⁻¹ FW). Cultivation in low-concentration PGR(1.15 μM ⋅ L⁻¹ 2,4-D, 0.25 μM ⋅ L⁻¹ 6-BA) and sucrose liquid medium at 100 rpm/min (80 SEs g⁻¹ FW) could not only promote culture proliferation but also increase SE yield. The determination of the suspension culture scheme of Korean pine ET provides a reference for further expansion to bioreactor culture in the future and lays a foundation for the automation and scale of somatic embryogenesis of Korean pine.     

Cell shape regulates global histone acetylation in human mammary epithelial cells

Extracellular matrix (ECM) regulates cell morphology and gene expression in vivo; these relationships are maintained in three-dimensional (3D) cultures of mammary epithelial cells. In the presence of laminin-rich ECM (lrECM), mammary epithelial cells round up and undergo global histone deacetylation, a process critical for their functional differentiation. However, it remains unclear whether lrECM-dependent cell rounding and global histone deacetylation are indeed part of a common physical-biochemical pathway. Using 3D cultures as well as nonadhesive and micropatterned substrata, here we showed that the cell 'rounding' caused by lrECM was sufficient to induce deacetylation of histones H3 and H4 in the absence of biochemical cues. Microarray and confocal analysis demonstrated that this deacetylation in 3D culture is associated with a global increase in chromatin condensation and a reduction in gene expression. Whereas cells cultured on plastic substrata formed prominent stress fibers, cells grown in 3D lrECM or on micropatterns lacked these structures. Disruption of the actin cytoskeleton with cytochalasin D phenocopied the lrECM-induced cell rounding and histone deacetylation. These results reveal a novel link between ECM-controlled cell shape and chromatin structure and suggest that this link is mediated by changes in the actin cytoskeleton.     

Seed defensins from T. kiharae and related species: genome localization of defensin-encoding genes

Ten new defensins have been isolated from seeds of Triticum kiharae and related species of the Triticum and Aegilops genera by a combination of chromatographic procedures including affinity-, size-exclusion, and reversed-phase high-performance liquid chromatography. Nine were completely sequenced and shown to represent a family of closely related peptides with highly conserved amino acid sequences. Analysis of defensin compositions in diploid A-, B-, and D-genome donors to polyploid wheat allowed us for the first time to assign most defensin-encoding genes to particular hexaploid wheat genomes.     

Le gisement rupestre de Siega Verde, Salamanque: Une vision de synthèse

The Paleolithic shelter Art in the open air of Siega Verde, Salamanca, is the unitary group better endowed with paleolithic shelter manifestations in the bleakness of the whole Iberian Peninsula. Its study, consequence of more than 10 years of works on the land, has culminated with the recent publication of a complete monograph. In the following lines, we intend to synthesize the content of that, with special emphasis in the internal analysis of the representations and in their relationship with its cultural immediate environment, the Upper Paleolithic of the Castilian Plateau. The results of so long investigation process suppose a new interpretation way, not only of the own site, but also of the whole Paleolithic shelter phenomenon inside the Peninsula, and in a more general environment, of the graphic system of the European Upper Paleolithic.