犬传染性肝炎病毒在体外细胞质内的发生

通过对犬传染性肝炎病毒（ＩＣＨＶ）在犬肾传代细胞内形态发生及其抗原定位的电镜和免疫胶体金电镜研究,发现ＩＣＨＶ除了在宿主细胞核内发生外,还有一条细胞质内的发生途径。在细胞质内病毒核壳体的装配是以均质致密包涵体和副晶格包涵体为“基地”,这与人们熟知的细胞核内形态发生方式相似。免疫胶体金标记显示,细胞质包涵体中含有大量的ＩＣＨＶ抗原成分,显核壳体在细胞质内装配病毒的结构蛋白来源。此外,在感染的细胞质内还观察到与核内相同的病毒核心样结构。     

Cryopreservation of <Emphasis Type="Italic">Panax ginseng</Emphasis> Adventitious Roots

We tested desiccation and/or vitrification procedures to cryopreserve the adventitious roots of Panax ginseng, the source of commercially produced ginsenosides. When only desiccation was applied, the post-freeze survival of 3- to 4-mm root tips was <14% regardless of the composition of the preculture medium or the explant origin. Callus formation was frequently observed after cryopreservation. In contrast, 90% survival and 32.5% root formation efficiency were achieved after cryopreservation when a vitrification protocol was followed. Adventitious root cultures in flasks and bioreactors were reestablished from root tips cryopreserved by vitrification. A prolonged lag-phase and lower biomass production were recorded in post-freeze-regenerated cultures compared with control roots that were subcultured four times in flasks. However, biomass accumulations did not differ between control and regenerated roots at the end of the sixth subculturing period. After 40 days of culture in bioreactors, a mean value of 12.5 g dw L⁻¹ was recorded for post-freeze-regenerated cultures versus 9.1 g dw L⁻¹ for the control roots. Production of triol and diol ginsenosides in our bioreactor cultures also was enhanced after cryopreservation, by 41.0% and 89.8%, respectively. These results suggest that the vitrification method is successful for cryopreservation of P. ginseng adventitious roots.     

Queue Size Determines the Width of Tunnels in the Formosan Subterranean Termite (Isoptera: Rhinotermitidae)

We present a model of tunnel excavation by termites that requires no pheromone labeling of soil or work sites, but instead relies on tactile interactions and individuals who actively orient their movement. Potential termite excavators moved from the tunnel origin towards the distal end of the tunnel and formed a queue behind those termites at the digging face. Delayed termites excavated soil laterally from the tunnel wall at a position governed by their position in the queue of termites. By examining excavation under artificially induced conditions of longer and shorter queues of termites at the tunnel end, we showed that tunnel width increased with increased queue size and the rate of lateral excavation in a process we termed “digging pressure.”     

微乳体系中11β-羟基甲羟孕酮的C1,2生物脱氢

为改善过程传质,提高甾类药物中间体11β-羟基甲羟孕酮C1,2生物脱氢转化率,采用简单节杆菌Arthrobacter simplex UR016菌株在Tween-80/乙醇/食油/水构成的微乳体系中进行生物脱氢,并考察了微乳体系组成、转化温度、投料浓度对脱氢反应的影响。结果表明:以菌体培养液作为水相,食油作为油相构建微乳体系,食油最适加量为10g/L,表面活性剂Tween-80加量为4g/L;底物经醇溶后水析投料,乙醇最适加量为发酵液体积的7%(V/V);最适转化温度为33oC;当底物浓度为4g/L时,在构建的微乳体系中转化46h,脱氢转化率达88.6%,与水相转化工艺相比提高了66.2%。在该体系中疏水性11β-羟基甲羟孕酮底物得到了有效的增溶和扩散,生物脱氢转化率明显提高。     

The stimulatory effect of ROCK inhibitor on bovine corneal endothelial cells

Reagents which can promote the proliferation, adhesion and migration of cultured corneal endothelial cells (CECs) will be helpful for the treatment of reduced visual acuity due to CECs deficiency. The objectives of this study were to investigate the potential use of an inhibitor of Rho-associated protein kinase (ROCK), Y-27632, to cultured bovine corneal endothelial cells (B-CECs) and evaluated its effects on the proliferation, adhesion and migration of B-CECs. The proliferation of cultured B-CECs was moderately enhanced by 10 μM Y-27632. Y-27632 induced fibroblast-like morphological changes in the cultured B-CECs and normal cell morphology could recover after Y-27632 removal. In addition, Y-27632 was found to significantly enhance the adhesion and migration of B-CECs. Furthermore, the hanging drop aggregation assay showed that Y-27632 promoted B-CECs to form cellular networks and sheets, which proliferated along the liquid–air interface and migrated to the surface of the lid of dish. Our study demonstrated that Y-27632 is a potentially powerful reagent which can enhance the proliferation of cultured B-CECs. Y-27632 will be useful in CEC injection therapy and topical application for CEC deficiency.     

Evolution of resident bird breeding phenology in a landscape with heterogeneous resource phenology and carryover effects

It is generally expected that, in environments with pronounced seasonal resource peaks, birds’ reproductive success will be maximised when nestlings’ peak food demand coincides with the timing of high food availability. However in certain birds that stay resident over winter, earlier breeding leads juveniles to join the winter flock earlier, which by the prior residence effect increases their success in breeding territory competition. This trade-off between reproduction and competition may explain why, in certain species, breeding phenology is earlier and asynchronous with the resource. This study extends a previous model of the evolution of breeding phenology in a single habitat type to a landscape with two habitat types: ‘early’ and ‘late’ resource phenology. The offspring’s natal habitat type has a carryover effect upon their competitive ability regardless of which habitat type they settle in to potentially breed. We find that, when the difference in resource phenology between habitats is small (weak carryover effect), breeding phenology in the late habitat evolves to occur earlier and more asynchronously than in the early habitat, to compensate for the competitive disadvantage to juveniles raised there. However if the difference is large (strong carryover effect), then the reproductive cost of earlier breeding outweighs the benefit of the compensation, so instead breeding phenology in the late habitat evolves to become more synchronous with the resource. Recruitment is generally asymmetric, from early to late habitat type. However if the early habitat is less frequent in the landscape or produces fewer offspring, then the asymmetry is reduced, and if there is some natal habitat-type fidelity, then recruitment can have an insular pattern, i.e. most recruits to each habitat type come from that same habitat type. We detail the different scenarios in which the different recruitment patterns are predicted, and we propose that they have implications for local adaptation.     

陕南寒武系下部宽川铺组帽球状化石*

陕南寒武纪早期宽川铺组微体球状化石类型多样,如何正确辨别这些球状化石的生物属性是当前早期生命演化古生物学研究中的一个难点。我们在宽川铺组中发现了一类为数众多,具有一个或者多个不规则的帽状隆起结构以及翻边帽沿的帽状化石。研究表明这些帽状化石均为不完整的个体,其完整形态呈不规则的凹球形。根据帽球状化石帽身的数量和相对位置,这类化石可划分为"单帽型"、"双帽型"和"复帽型"三种类型。这些凹球状化石呈双层壳壁,内壁光滑,外壁粗糙。因为凹球状化石形态及其表面小孔与微体藻类、后生动物的胚胎以及壳体化石差异都非常显著,所以推测这类化石可能与带壳原生动物亲缘关系最为紧密。     

Photoacoustic microscopy of electronic acupuncture (EA) effect in small animals

Acupuncture has been an effective treatment for various pain in China for several thousand years. However, the mechanisms underlying this mysterious ancient healing are still largely unknown. Here we applied photoacoustic microscopy (PAM) to investigate brain hemodynamic changes in response to electronic acupuncture (EA) at ST36 (Zusanli). Due to the high optical absorption of blood at 532 nm, PAM could sensitively probe changes in hemoglobin concentration (HbT, i.e., cerebral blood volume [CBV]) of cortical regions in high resolution. Six healthy mice were stimulated at the acupoint and three healthy mice were stimulated at sham points. Remarkable CBV changes in sensorimotor and retrosplenial agranular cortex were observed. Results showed the potential of PAM as a visualization tool to study the acupuncture effect on brain hemodynamics in animal models.

( a ) Schematic showing the stimulation points. ( b ) B‐scan images overlaid with mouse atlas. ( c ) & ( d ) Statistical results of CBV changes from cortical regions.     

Edelfosine-induced metabolic changes in cancer cells that precede the overproduction of reactive oxygen species and apoptosis

Background  

Metabolic flux profiling based on the analysis of distribution of stable isotope tracer in metabolites is an important method widely used in cancer research to understand the regulation of cell metabolism and elaborate new therapeutic strategies. Recently, we developed software Isodyn, which extends the methodology of kinetic modeling to the analysis of isotopic isomer distribution for the evaluation of cellular metabolic flux profile under relevant conditions. This tool can be applied to reveal the metabolic effect of proapoptotic drug edelfosine in leukemia Jurkat cell line, uncovering the mechanisms of induction of apoptosis in cancer cells.     

甘蓝型油菜珠孔与胚囊的超微结构研究

甘蓝型油菜的外珠孔基本上为开放结构,内珠孔为闭合结构。胚囊成熟时反足细胞已退化,仅由二个助细胞、一个卵细胞、与一个中央细胞组成。助细胞极性不明显,二个助细胞在花粉管到达前均显示同等退化迹象。卵细胞极性明显。中央细胞中含结构独特的质体。受精前,卵与中央细胞的质膜之间含有特殊的电子致密物质。